Upload
others
View
3
Download
0
Embed Size (px)
Citation preview
Hydrochemistry and carbonate sediment characterisationof Bacalar Lagoon Mexican Caribbean
Nidia I Tobon VelazquezA Mario Rebolledo VieyraAC Adina PaytanBKyle H BroachB and Laura M Hernandez TerronesADE
ACentro de Investigacion Cientıfica de Yucatan Unidad Quintana Roo Unidad de Ciencias del
AguaCalle 839 Lote-1Manzana29 SuperManzana64 77524CancunQuintanaRooMexicoBInstitute of Marine Sciences Earth and Marine Science Building University of California Santa
Cruz 1156 High Street Santa Cruz CA 95064 USACPresent address Chipre 5 Residencial Isla Azul Cancun Quintana Roo 77500 MexicoDPresent address Universidad del Caribe Lote-1 Manzana 1 Esquina Fraccionamiento
Tabachines Super Manzana 78 CP 77528 Cancun Quintana Roo MexicoECorresponding author Email lmhernandezucaribeedumx
Abstract The aim of the study is to determine the distribution of trace and major elements in the water and in thesediments of the south part of the Bacalar Lagoon and to identify the sources of the trace elements and their changes overtime The western part of the lagoon water column is characterised by high concentrations of Ca2thorn HCO3
and Sr2thornderived from groundwater input In contrast the eastern part of the lagoon is characterised by high concentrations ofMg2thornNathorn and Cl The lagoon is not affected by present-day seawater intrusion Water column and sediment geochemicalanalyses performed in Bacalar Lagoon show clear spatial distribution of different parameters The saturation index of the
water column indicates three main groups (1) a zone oversaturated with regard to aragonite calcite and dolomite (2) anundersaturated area where all three minerals are dissolving and (3) an area with calcite equilibrium and undersaturationwith regard to the otherminerals Hereinwe present the first measurements of trace element (Ba2thornMn2thorn Kthorn Ni2thorn Zn2thorn)concentrations in carbonates obtained from sediments in Bacalar Lagoon In order to evaluate whether the trace elements
are derived from natural or anthropogenic sources four pollution indices were calculated The results confirmed thatBacalar Lagoon sediments are not contaminated with Ni2thorn Kthorn Mn2thorn and Ba2thorn and that the Zn2thorn seems to have apredominantly anthropogenic origin
Additional keywords carbonate mineral solubility groundwater sediment geochemistry
Received 15 February 2018 accepted 31 July 2018 published online 23 October 2018
Introduction
Surface and groundwater systems in the Mexican Caribbean arebeing affected by contaminants particularly heavy metals dueto poor or a lack of proper waste water treatment and an increasein activities related to growth in population tourism agriculture
and livestock (Dıaz 2005 Medina et al 2014 Ochoa et al
2016) The economy of Quintana Roo is based on tourism andits population has increased 17-fold over the past 40 years
(Dixon et al 2001 Bauer-Gottwein et al 2011 InstitutoNacional de Estadıstica y Geografıa 2016) This representssubstantial infrastructure needed for clean water supply and
waste water treatment and improperly functioning or non-existent infrastructure results in the discharge of waste waterinto surface waterbodies such as the coastal ocean and lagoons
(Hernandez-Terrones et al 2011) Moreover the karst nature ofthe area promotes waste water infiltration and mixing withgroundwater (Beddows 2002)
Bacalar Lagoon (south Quintana Roo) is a very popular place
for tourism Bacalar Lagoon is unique in the region due to thepresence of carbonate structures called stromatolites Thelagoonrsquos stromatolites are one of the largest freshwater micro-bialite occurrences in the world (10 km Gischler et al 2008
Centeno et al 2012) and preserve past information aboutclimatic and microbial life conditions and processes at the timeof sedimentation so it is important to ensure that these forma-
tions are not affected by water pollution The growth ofstromatolites depends on the physicochemical conditions ofthe water they are sensitive to changes in the environment
and any change in water quality could affect their development(Dupraz et al 2011) The main activities around the lagoon aretourism agriculture (sugarcane pineapple rice and maize)
livestock (cattle swine sheep) and aquaculture (InstitutoNacio-nal de Estadıstica y Geografıa 2002 Dıaz 2005) Bacalar townbecame a municipality in 2014 and is planning regulation to
CSIRO PUBLISHING
Marine and Freshwater Research
httpsdoiorg101071MF18035
Journal compilation CSIRO 2018 wwwpublishcsiroaujournalsmfr
ensure tourism activities will not stress the lagoonrsquos ecosystemhowever the lagoon has not been declared a protected area The
current lack of regulation for infrastructure and tourism mayresult in degradation of the water quality of the lagoon ecosys-tem structure and possibly the integrity of stromatolites (Dıaz
2005) Previous studies in Bacalar Lagoon provided physicalinformation about the lagoon but none focused on water qualityand sources of pollution (Dıaz 2005 Gischler et al 2008 2011
Perez et al 2011 Siqueiros-Beltrones et al 2013 Castro-Contreras et al 2014 Gonzalez et al 2014 Sanchez et al
2015 Oliva et al 2016)Pollution from trace elements may be of particular concern
Trace metals can occur as dissolved or colloidal phases or theymay be present in association with suspended particles in thewater column andwithin sedimentary phases (Katip et al 2011)
Many trace metals are present at higher concentrations insedimentary phases than in the water column (Nriagu andPacyna 1988 Pradit et al 2010) Trace metal concentrations
in the water are controlled by inputs from land through weath-ering processes groundwater discharge and atmospheric depo-sition (Salomons and Forstner 1980) as well as fromanthropogenic activities and each input can change over time
Therefore sediments (including stromatolite beds) can serve asarchives of environmental changes through time and changes inthe chemical composition of the sediments may be informative
of changes in natural and anthropogenic sources and fluxes oftrace metals (Boyle 2001) The chemical composition of sedi-ments and water can also be used to identify the rockndashwater
interaction and mineralogical composition of aquifer rocks(Elango and Kannan 2007)
Herein we report for the first time the distribution of trace
and major elements in the water column (along with hydrogra-phy) and in the sediments of the south part of the lagoon (near thelocation of the stromatolites) Through these analyses weidentify the sources of the trace elements and their changes over
time in Bacalar Lagoon
Materials and methods
Study area
Bacalar Lagoon is located in the south-eastern part of QuintanaRooMexico (from18856026500N 8889028600Wto18832038600N88827048600W) 15 m above sea level Fig 1) This area ischaracterised by a humid tropical climate with a mean annual airtemperature of 2608C Three meteorological seasons dominatethe region (1) the lsquonortesrsquo season between October and April
characterised by cold fronts (2) the dry season betweenApril andMay and (3) the wet season from June to October when tropicalstorms and hurricanes result in high rainfall The average annual
rainfall in the region ranges between 100 and 1500 mm year1with mean temperatures during winter and summer being280and2908C respectively (Comision Nacional del Agua 2015)
The lagoon has a surface area of 420 km2 (length 400 kmwidth10ndash20 km Comision Nacional del Agua 2002 Castro-Contreras et al 2014) It is an oligotrophic freshwater system
(electrical conductivity (EC) 23 mS cm1) and has a pHbetween 76 and 83 (Beltran 2010) The maximum water depthof the lagoon is 15 m but the water level of the lagoon canincrease by up to 300 cm during the wet season (Junendash
October Gischler et al 2011)
Bacalar Lagoon is situated in Hydrological Region number 33(RH33ComisionNacional del Agua 2012) Five sinkholes (locally
called cenotes) are located inside andnear the lagoon (Gischler et al2008) The cenotes Cocalitos Esmeralda and Negro are locatedinside the lagoon whereas cenote Azul (with a maximum water
depth of 900 m) is located outside the lagoon but has an under-ground connection to the lagoonCenoteXul-Ha is connected to thelagoon through a surface channel in the south-west area (Perry et al2009 Beltran 2010 Gischler et al 2011 Perez et al 2011)
The lagoon is located along the Bacalar fault system andsurrounding rocks are mostly from the Bacalar Formation thathave been assigned aNeogene age To the north the outcrops are
ofmarine Pliocene to Holocene age whereasMiocene age rocksare observed to the south Upper Cretaceous outcrops have alsobeen identified particularly along the west side of the lagoon
(Kenkmann and Schonian 2006) Based on Sr isotopes Perryet al (2009) suggest that in this region the slow-movinggroundwater derives its ion chemistry from relatively soluble
aquifer rocks including gypsum calcite dolomite and accessoryminerals such as celestite (SrSO4) Perry et al (2009) alsoobserved that water Sr isotope analyses of Bacalar Lagoonand cenote Azul suggest that these waterbodies derive their Sr
from dissolution of minerals of CretaceousndashEocene age
Field sampling
Seven sampling sites were selected along the southernmost
100 km of Bacalar Lagoon with five sites located on the
88270W
0 1 2 3 4 km05183
30
N18
36
0N
183
90
N18
42
0N
183
30
N18
36
0N
183
90
N18
42
0N
88240W 88210W
88270W 88240W 88210W
N
S
W E
Fig 1 Location of Bacalar Lagoon showing sampling sites Site details are
given in Table 1 BAC1 Bacalar 1 BAC2 Bacalar 2 BAC3 Bacalar 3 Caz
cenote Azul Ccoc cenote Cocalitos COC Cocalitos RAP Los Rapidos
B Marine and Freshwater Research N I Tobon ndashVelazquez et al
western side of the lagoon and two located on the eastern side(Fig 1) Two sampling campaigns were performed The loca-
tions of the sites were determined using a global positioningsystem (GPS (NOMAD Trimble Sunnyvale CA USA) withtheWorld Geodetic System (WGS) 84 datum Temperature pH
depth total dissolved solids (TDS) EC and dissolved oxygen(DO) were measured in the field (during both samplingcampaigns) using a multiparameter sonde (Model 6600 YSI
Control Tecnico y Representaciones Mexico City Mexico)Temperature profile data were collected using a CastAway-CTD (SonTek Xylem San Diego CA USA) The field para-meters were measured as close to sediment core and water
sample collection points as possibleThe first sampling campaign was conducted in November
2016 Five sediment cores of variable length (between 11 and
41 cm) were collected using a steel push core with 50-cmdiameter plastic liners Three sediment cores were taken at thewestern side of the lagoon (COCRAPandBAC3) and two cores
were taken at the eastern side (BAC1 and BAC2 Fig 1) Thesamples were kept at 408C The sediment cores were sectionedinto 40-cm intervals for a total of 27 samples Samples weredried at 508C in an oven and powdered using an agate mortar and
pestle In addition surface water samples were collected at eachof the seven study sites (Fig 1) Allwater samples were collectedin acid-washed polyethylene bottles (Nalgene SigmandashAldrich
Mexico Toluca Mexico) rinsed with sample at the time ofcollection Samples were filtered using 045-mm syringe filtersand analysed for alkalinity nutrients cations and anions
The second sampling campaign was conducted in June 2017During this campaign water samples were taken from sites atcenote Azul (Caz) and cenote Cocalitos (Ccoc Fig 1) At each
site two water samples (surface and at a depth of 150 m) werecollected by divers All samples collected during both campaignswere kept at 408C and transported to the Hydrogeochemistryand Water Quality Laboratory of the Water Sciences Unit
Centro de Investigacion Cientıfica de Yucatan
Laboratory analysis
Alkalinity was measured by the titration method using 02 Nsulfuric acid (H2SO4) Nutrients (NO3
NO2 PO4
3) cations(Ca2thorn Nathorn Mg2thorn Kthorn Sr2thorn) and anions (Cl SO4
2) weredetermined using ion chromatography with an 882 CompactPlus ICMetrohm (MetrohmMexico Mexico City Mexico) andcertified standards (TraceCERT SigmandashAldrich Mexico) forcalibration For determination of NH4
thorn a spectrophotometer
(LaMotte Analisis y Soluciones Ambientales Mexico CityMexico) was used Water analyses were performed at theHydrogeochemistry andWater Quality Laboratory of theWater
Sciences Unit Centro de Investigacion Cientıfica de YucatanAC The concentrations of major elements (Al Fe Ca Mg TiSr and K) and trace elements (Mn Ba Ni Zn andU) in sediment
samples were determined after sample dissolution using induc-tively coupled plasmandashmass spectrometry (ICP-MS XRThermoScientific San Diego CA USA) at the Institute of Marine Sci-
ences at the University of California ndash Santa Cruz (UCSC) Priorto these analyses 100 mg of homogenised sediment was dis-persed in 15 mL ofMilliQwater and digested using 155 N nitricacid (HNO3
) A 100-mL subsample was diluted 200-fold using
1HNO3 for analysis Instrumental drift was corrected with Sc
and Rh standards Rhwas used as the internal standard correctionfor Sr Ba and U whereas Sc was used as the internal standard
correction for all other elements Counts per second values wereconverted to concentrations using a standard curve prepared froma homemade rendition of the NIST1D (National Institute of
Standards and Technology NIST) standard reference material(argillaceous limestone) An average of three procedural blankswas subtracted from final concentration values
To determine the sediment mineralogy sediment samples(20 g) were analysed using a Panalytical XrsquoPert Pro X-RayDiffraction (XRD) Spectrometer (Royston UK) with a 1-hrotating platter in the Marine Sciences Laboratory UCSC
Sample 2-theta peaks were identified using the PanalyticalSpectrometer mineral spectrum database as a reference Themost prominent peaks for all samples occurred near 2958with a
pair of peaks near 46 and 478
Results and discussion
Physicochemical parameters
The main physicochemical features of shallow water in BacalarLagoon are presented in Table 1 The low EC values (265ndash319 mS cm1) indicate a freshwater system with pH ranging
from 66 to 73 at the sampling sites (mean pHfrac14 705) Watertemperature was relatively stable in the study area during oursampling campaigns (275ndash2978C) The EC temperature andpH ranges measured in this study are consistent with measure-
mentsmade byGischler et al (2008) Beltran (2010) Perez et al(2011) Castro-Contreras et al (2014) and Sanchez et al (2015)in this system
Fig 2 shows the temperature profiles along the southern sideof Bacalar Lagoon The relatively small temperature variabilityamong lagoon sites (285ndash2888C) suggests a near-homoge-
neous temperature with depth for both seasons (Fig 2b) Thisindicates awell-mixedwater column consistentwith the shallowdepth of the lagoon where the samples were collected
In contrast the water column profiles of the cenotes show
slight variability between sampling campaigns in June thetemperature of cenotes Azul and Cocalitos was higher (310and 3048C respectively) compared with November tempera-
tures (3008C) During both sampling campaigns the cenotes
clearly show stratification with two thermoclines During Junethe cenote Azul thermoclines are at depths of 05 and 120 m
whereas in November they are at 23 and 290 m (Fig 2c) Atcenote Cocalitos the June thermoclines are at 38 and 290 mwhereas in November they are at 20 and 240 m (Fig 2d) For
both cenotes the first thermocline is related to diurnal changesin solar radiation (heating of surfacewaters) whereas the secondis derived from distinct mixing that varies seasonally andbetween years During winter (November) water column mix-
ing extends deeper due to wind action whereas during summer(June) the changes in thermocline depth are due to an increase intemperature over the warm months allowing for water column
stratification and shallowing of the thermoclineNO3
concentrations ranged from 01 to 27 mg L1whereas NO2
and PO43concentrations were below the limits
of detection of the method used in the present study (001 and01 mg L1 respectively) These results are consistent with theoligotrophic designation of Bacalar Lagoon It has been
Hydrochemistry of Bacalar Lagoon Marine and Freshwater Research C
suggested (Beltran 2010) that the low concentrations of bio-
available nitrogen (NH4thorn NO2
and NO3) promote N2 fixa-
tion in the lagoon The lower nutrient concentrations also favourthe growth of stromatolites (Beltran 2010)
Cation abundance in Bacalar Lagoon water follows the order
Ca2thornMg2thornNathorn Sr2thornKthorn anion abundance is in theorder SO4
2HCO3ClNO3
(see Table 1) In orderto determine the main hydrochemical features of the lagoon a
88200W882240W882520W88280W
88200W882240W882520W88280W
0 095 19 285 38 km
284 285 286 287 2880
5
10
15
20
25
30
285 295 305 315 26 27 28 29 30 31
Temperature (degC)
Dep
th (
m)
(b) (c) (d )
184
120
N18
38
40N
183
60
N18
33
20N
184
120
N18
38
40N
183
60
N18
33
20N
(a)
N
S
EW
Fig 2 Temperature profiles in the lagoon and cenotes (a) Sampling locations Each symbol corresponds to the traces shown in the graphs on the right (b)
Temperature profiles at the different study sites in Bacalar Lagoon (c d) Temperature profiles of cenote Azul (c) and cenote Cocalitos (d) Grey (dots and
diamonds) correspond to the November 2016 sampling campaign dashed lines correspond to the June 2017 sampling campaign
Table 1 Main physical and chemical parameters of water samples in Bacalar Lagoon
Standard deviation for the elements is as followsNathorn 097Kthorn 013Mg2thorn 298Ca2thorn 1429 Sr2thorn 034Cl 211 SO42 90 SiO2
26NO3
019 andNH4thorn 004BLD below the limit of detectionNA data not available Ionic balance10 The locations of each of the sample sites are shown in
Fig 1
COC RAP BAC1 BAC2 BAC3 Ccoc Caz
Site Cocalitos Los Rapidos Bacalar 1 Bacalar 2 Bacalar 3 Cenote Cocalitos Cenote Azul
Depth (m) 05 05 05 05 05 05 150 05 150
pH 658 697 731 734 NA 654 NA 685 NA
Temperature (8C) 2926 2891 2747 2967 2920 293 2850 3084 2960
EC (mS cm1) 293 265 315 319 250 268 NA 267 NA
TDS (mgL1) 176 160 195 190 NA 157 NA 156 NA
Chemical composition (mgL1)
Nathorn 630 3247 13357 10811 3273 4740 3410 3130 3360
Kthorn 075 041 180 174 025 358 297 282 305
Mg2thorn 7120 7320 890 8365 7560 7340 7750 7680 7810
Ca2thorn 3930 3760 3860 3860 4220 2080 3540 3420 3650
Sr2thorn 546 631 715 439 270 476 592 545 552
Cl 10074 4166 28317 22640 4165 910 470 410 420
SO42 9620 10150 10910 9620 11740 9130 12370 11070 12840
SiO2 1625 220 2225 2350 1575 320 300 360 310
HCO3 15670 27090 8650 6190 22530 1550 2440 2140 2410
NO3 140 174 268 010 267 20 128 255 283
NO2 BLD BLD BLD BLD BLD BLD BLD BLD BLD
NH4thorn 018 013 028 019 014 020 026 021 023
PO43 BLD BLD BLD BLD BLD BLD BLD BLD BLD
D Marine and Freshwater Research N I Tobon ndashVelazquez et al
Piper diagram was made in Aquachem (ver 37 WaterlooHydrogeologic Kitchener ON Canada) using the proportionsofmajor cations and anions (Fig 3) All samples cluster together
in a group corresponding to a sulfatendashcalcium (CandashSO4) watertype Studies performed by Sanchez et al (2015) reported a CandashHCO3 water type in the northern part of the lagoon and Oliva
et al (2016) showed that the north side of Bacalar Lagoon ischaracterised by muddy sediments with murky water all yearlong In contrast the south of the lagoon is associatedwith sandy
sediments and high water transparency We attribute theobserved differences in water chemistry in the lagoon to theeffects of sulfate-rich groundwater inputs in the south compared
with the north where lower groundwater input and sulfateconcentrations were measured by Sanchez et al (2015) Thewater chemistry in the south can have a direct effect on theformation of stromatolites which are more abundant in the
southern part of theBacalar Lagoon Pacton et al (2015) showedthat stromatolites appear to prefer fresh water rather than turbidand brackish lake waters and turbidity is one of the most
important factors restraining stromatolite developmentAccording to the Piper diagram (Fig 3) the water type of
Bacalar Lagoon is dominated by sulfates (9620ndash
11740 mg L1) The SO4 Cl ratio may be indicative of waterorigin and the ratio at the western side ranged between 696 and2055 higher than at the eastern side (281ndash310) All theSO4 Cl ratios in Bacalar Lagoon are between 27- and 197-fold
greater than those of seawater (0103 Perry et al 2002)indicating that the sulfate source in the lagoon is not seawaterintrusion Therefore we interpret the findings to indicate high
sulfate originating from dissolution of evaporitesAlthough all the lagoonwater samples cluster into one group
spatial differences are present within the lagoon and may
suggest differences in input sources or fluxes as well as inprocesses affecting solute concentrations within the lagoon The
western side of the lagoon is characterised by higher alkalinityand calcium concentrations (1570ndash2700 mg CaCO3 L
1 and3760ndash4220 mg L1 respectively) compared with the eastern
side (620ndash860 mg CaCO3 L1 and 860 mg L1 respectively)
The alkalinity of the western side is similar to the alkalinitymeasured at Caz and Ccoc (2440 and 2410 mg CaCO3 L1
respectively at a depth of 150 m) A gradient of increasingalkalinity is seen from north to south Because high alkalinity isassociated with groundwater input and the waters are undersat-urated with regard to carbonate minerals this alkalinity gradient
indicates a diminishing effect of groundwater towards the northof the lagoon Schmitter-Soto et al (2002) reported other factorsthat can affect alkalinity in the Yucatan Peninsula including the
contribution of meteoric water (rich in carbonate and bicarbon-ate) and precipitation which promotes the dissolution of carbo-nates and therefore affects alkalinity
The concentrations of Ca2thorn and SO42 are lower on the
eastern than western side of the lagoon potentially explainingthe formation of stromatolites in the western part of the lagoonwhere external sources of Ca2thorn and SO4
2 are present To reach
the saturation necessary for precipitation of microbialites Ca2thorn
and SO42 are needed which has been reported in other systems
(Chagas et al 2016) The EC (315ndash319 mS cm1) and Nathorn
(47ndash58 mg L1) and Cl (410ndash2830 mg L1) concentrationson the eastern side of the lagoon are higher than on the westernside (265ndash293 mS cm1) These differences most likely occur
because the eastern part of Bacalar Lagoon is shallower (04ndash06 m) than the western part (10ndash22 m) promoting higherevaporation on the eastern side Marfia et al (2004) identified
high-calcium high-sulfate water in the south-eastern area ofQuintana Roo including north-eastern Belize likely fromgypsum dissolution when the groundwater is mixed withseawater the mixture forms a caliche barrier preventing seawa-
ter intrusion characteristic of the north-east coastThe (Ca2thornthornMg2thornthornHCO3
) to (NathornthornClthorn SO42) ratio
has been used to determine the effect of carbonate and evaporite
solute sources in groundwater and surface waters (Appelo andPostma 2005 Khedidja and Boudoukha 2016) When plottingthis ratio against EC (Fig 4) it is clear that dissolution of
evaporitic substratum is the dominant source of cations in thissystem The lower EC (fresh water) and a carbonate to sulfateion ratio 10 also indicate that evaporite dissolution and notseawater intrusion controls ion composition in Bacalar Lagoon
The saturation indices (SI) for the different mineral speciesconsidered in our system (calcite dolomite aragonite gypsumand celestite) were calculated based on field pH and temperature
measurements using PHREEQC (ver 37 US Geological Sur-vey Denver CO USA) (Fig 5) Our calculations allowed us todetermine the SI of Bacalar Lagoon water (note SIfrac14 0 signifies
equilibrium SI 0 signifies oversaturation and thus mineralprecipitation and SI 0 signifies undersaturation and thusmineral dissolution (Appelo and Postma 2005)
According to the SI calculations three trends were identified(Fig 5) The first corresponds to four sites (RAP BAC3 Cazand Ccoc 15 m deep) and shows oversaturated conditions withregard to aragonite calcite and dolomite In the second group
(Coc and Ccoc surface sample) all the minerals are
C a t i o n s A n i o n s mEq L1
NaK HCO3CO3 Cl
Mg SO4
CaCalcium (Ca) Chloride (Cl)
(SO 4
) (C
l)
(Ca)
(Mg)
(CO 3
)(H
CO 3
)
(Na)
(K)
Sulfate (SO4 )
Mag
nesi
um (M
g)
80 60 40 20 20 40 60 80
8060
4020
20
40
60
80
2040
6080
80
60
40
20
2040
6080
20
40
60
80
80
60
4020
8060
4020
COCRAPBAC1BAC2BAC3CcocCaz
Fig 3 Piper diagram and groundwater composition Each symbol corre-
spond to lagoon sites white square and white triangle points correspond to
cenotes samples which represent the groundwater in the region BAC1
Bacalar 1 BAC2 Bacalar 2 BAC3 Bacalar 3 Caz cenote Azul Ccoc
cenote Cocalitos COC Cocalitos RAP Los Rapidos
Hydrochemistry of Bacalar Lagoon Marine and Freshwater Research E
experiencing dissolution (undersaturation) Finally the thirdgroup (BAC1 and BAC2) is associated with calcite equilibrium
and undersaturation of the other minerals Bacalar Lagoon islocated in a region whereMiocene rocks containing gypsum andanhydrite are common and waterndashrock interaction results in the
dissolution of evaporites (Perry et al 2002 2009) The highconcentrations of Ca2thorn SO4
2 and Sr2thorn could be derived fromthe dissolution of these minerals The water samples in Bacalar
Lagoon are all undersaturated with regard to gypsum andanhydrite indicating that these minerals would not precipitatewithin the lagoon Ceballos Martınez (2002) indicated that
gypsum and limestone in the Bacalar formation tend to beconcentrated in the surface due to weathering forming lamellarcaliche
The Sr2thorn concentrations in samples from the western side are
quite similar to concentrations measured at the cenotes indicat-ing an input of this element from groundwater The same wassuggested by Perry et al (2002 2009) when they compared
concentrations of Sr2thorn and SO42 and Sr isotopes in the lagoon
to those of cenote AzulStandardised principal component analysis (PCA) was per-
formed using R (ver 340 R Foundation for Statistical Com-puting Vienna Austria) to identify the dominant limnologicalgradients in the dataset Fig 6 shows the results of a PCAappliedto the 15 hydrochemical variables measured here (water tem-
perature pH EC TDS SiO2 HCO3
Cl SO42 NO3
NH4
thorn Ca2thorn Kthorn Mg2thorn Nathorn and Sr2thorn) We present only thefirst two components (PC1 and PC2) because these explained 47
and 22 of the total variance respectively (Table 2) PCArepresents standard deviations and when the distance among
COC RAP BAC3 BAC1 BAC2 Ccoc Ccoclowast Caz Cazlowast
Sat
urat
ion
inde
x
15
10
05
0
05
10
Anhydrite (CaSO4)Aragonite (CaCO3)
Calcite (CaCO3)
Celestite (SrSO4)Gypsum (CaSO42H2O)
Dolomite (Ca Mg(CO3))
Fig 5 Saturation index (SI) calculated for each sample site for all relevant
minerals Note SIfrac14 0 indicates the mineral equilibrium (grey line) SI 0
indicates oversaturation and SI 0 indicates undersaturation Asterisks
indicate cenote water samples at a depth of 15 m BAC1 Bacalar 1
BAC2 Bacalar 2 BAC3 Bacalar 3 Caz cenote Azul Ccoc cenote
Cocalitos COC Cocalitos RAP Los Rapidos
24
2
4
0
2
4
0
PC1
2 4
PC
2
Ca
pHSO4
HCO3
NO3
Temp
TDS
Mg
ECNaCl
Sr
NH4
Caz
Ccoc
BAC2 BAC1
RAP
BAC3
COC
SiO2SiO2
K
Fig 6 Principal component analysis based on 15 chemical variables (grey
arrows) at different sampling sites (lagoon and cenotes) PC1 principal
component 1 PC2 principal component 2 EC electrical conductivity
TDS total dissolved solids Temp temperature BAC1 Bacalar 1 BAC2
Bacalar 2 BAC3 Bacalar 3 Caz cenote Azul Ccoc cenote Cocalitos
COC Cocalitos RAP Los Rapidos
Table 2 Eigenvalues of principal component analysis components and
variance explained
Principal component Eigenvalue Variance explained ()
1 706 4712
2 338 2258
3 210 1402
4 127 851
0 05 10 15 20 25 30 3502
04
06
10
12
14
Effect ofevaporates
BAC3
RAP
COCCaz
CcocBAC2
BAC1
Ca
Mg
HC
O3
Na
Cl
SO
4
Conductivity (mS cm1)
Effect ofcarbonates
Fig 4 Mineralisation effect on water chemistry Dark grey points repre-
sent the sampling sites dashed circular areas indicate the range in which the
electrical conductivity and major element ratios are interpreted as resulting
from mineralisation of evaporites or carbonates according to Khedidja and
Boudoukha (2016) BAC1 Bacalar 1 BAC2 Bacalar 2 BAC3 Bacalar 3
Caz cenote Azul Ccoc cenote Cocalitos COC Cocalitos RAP Los
Rapidos
F Marine and Freshwater Research N I Tobon ndashVelazquez et al
samples is greater than 2 units this indicates that the physico-chemical conditions are distinct (Massaferro et al 2018) hence
variations could be interpreted as significant differencesbetween sites
Samples along PCA Axis 1 show two distinctive patterns
within the lagoon which are separated by pH EC TDS Nathorn
and HCO3 distribution The spread of samples within PC1 is
relatively large suggesting significant differences among sites
This spread reflects the distinct distributions of physicochemicalfeatures at the different sides of the lagoon the western side(Axis 1 from 4 to 0 units) is characterised by a high HCO3
content (COC RAP BAC3 Ccoc and Caz) whereas the eastern
side (Axis 1 from 0 to 4 units) is characterised by high EC NathornpH and TDS and corresponds to the BAC1 and BAC2 sites
PC2 is associated with SiO2 and Kthorn concentrations PC2
shows two groups with the first group corresponding to sampleswith low SiO2
and Kthorn concentrations (COC RAP BAC1BAC2 and BAC3) and positive values of Axis 2 (from 4 to 0)
The second group is characterised by high SiO2 and Kthorn
concentrations (Ccoc and Caz samples) and corresponds tonegative axis values (from 0 to 4) PC2 is associated withsilica content due to higher silica concentrations in the cenotes
compared with the rest of the lagoon samples This can beexplained by more rapid Si uptake in the sun-lit lagoon wherediatoms are abundant
Changes in pH and transparency by sediment disturbance canhave an effect on stromatolites Sulfate-reducing bacteria par-ticipate in the formation of stromatolites and appear to always be
associated with Mg calcite and low-salinity and low-turbiditywaters Although stromatolites were not analysed in the presentstudy we recommend that a water monitoring program be
established to survey nutrients and measure other variablessuch as transparency tourist and boat activity weatheringdisturbance of sediments and trace elements at least twice ayear to ensure that the stromatolites are not negatively affected
Sediment characterisation
X-Ray diffraction
The results from the XRD analyses indicate that the mainmineralogical composition for all sediment samples was calcite(CaCO3) dolomite (CaMg(CO3)2) and SiO2 (quartz and possi-
bly minor amounts of coesite) In general calcite was in highestabundance in all cores Dolomite was present in all samples atlower proportions
These results are in accordance with the SI where calcite is
oversaturated in the western part of the lagoon and Ca2thorn andHCO3
concentrations are elevated throughout the lagoonCoesite forms under conditions of high pressure (3ndash10 GPa
Hemley et al 1994) and the presence of this mineral could berelated to the impact of the Chicxulub meteorite (Lounejevaet al 2002) Fouke et al (2002) with an estimated diameter of
its effect 360 km The presence of coesite in Bacalar Lagooncould be associated with this event Fouke et al (2002) andKenkmann and Schonian (2006) reported Chicxulub ejecta
deposited in Belize and in some regions of the Rio Hondo (nearBacalar Lagoon) However identifying the origin of this min-eral in Bacalar Lagoon requires additional detailed studies withlonger scan times to confirm the presence of coesite Other
minerals that we found in lower proportions are barite (BaSO4)
and a few samples with sphalerite (ZnS) with higher propor-tions of barite in the western than eastern side of the lagoon
Geochemistry
Elemental concentrations in the sediment samples are shown
in Fig 7 All sediment cores had high concentrations of Ca2thornMg2thorn and Sr2thorn which were one to three orders of magnitudehigher than concentrations for the rest of the elements consis-
tent with carbonate minerals (calcite) dominating the sedimentElement abundance was similar in cores of sites located in
the western part of the lagoon (COC RAP and BAC3) in the
order Ca2thornMg2thornSr2thorn Si4thornAl3thorn Fe3thornZn2thorn
KthornBa2thornTi4thornNi2thornMn2thornU6thorn The order of ele-ment abundance for the eastern cores (BAC1 and BAC2) was
similar except that Mg was more abundant than Ca (Mg2thorn
Ca2thorn Sr2thorn Si4thornAl3thorn Fe3thornZn2thornKthornNi2thorn
Ba2thornTi4thornMn2thornU6thorn) These relative abundances sug-gest that cores from the western side are dominated by Ca2thorn
carbonate minerals (likely calcite) whereas those from the eastside contain more dolomite The BAC1 core had the highestconcentrations of Al3thorn Si4thorn Kthorn Ti4thorn Mn2thorn and Fe3thorn likelyrepresenting some silicates and ironndashmanganese oxides fromterrigenous sources The highest Ni2thorn and Zn2thornconcentrationswere measured in the core from BAC2 and may represent
anthropogenic pollutant inputs The other elements analysedhad similar distributions in all cores
In general concentrations of Ba2thorn U6thorn and Zn2thorn werehigher in deeper sections of the cores and this may suggest
temporal changes in the input of these elements The rest of theelements (Ca2thorn and Mg2thorn) did not show variations with depthdown the core (r2 05)
The concentrations of elements span orders of magnitudetherefore the data do not satisfy the assumption of normality ASpearman correlation was performed using STATISTICA
(ver 133 Palo Alto CA USA) to test the relationship betweenthe trace elements in each core with significance level atP 005
Except for BAC3 the most significant correlation was forAlndash(FendashTi) (r2 090) In the BAC2 core significant correla-tions were found for SrndashMg AlndashTi KndashNi and SindashTi (r2frac14 090090 088 and 086 respectively) For BAC1 the highest
correlations were found for SrndashCa Alndash(Fe Ni) Kndash(Fe Ni)and BandashMg (r2frac14 095 098 098 and 081 respectively) Nega-tive correlationswere found at theCOC site (r2frac14090) forAlndash
(Zn Sr) Fendash(Ca U) Mnndash(U Ca) UndashSi and BandashZn but apositive correlation was found for Tindash(Mn Fe) with r2frac14 090In the BAC3 core relationships were found for only four
elements UndashSr and CandashMg (r2frac14 099)The relationship for Alndash(Ti Fe) in almost all cores is derived
from the fact that these elements represent silicates and otherrefractory minerals and hence aeolian or fluvial input of
particulate matter from land (Drever 2005) The correlationfor Candash(SrndashMg) in most cores is consistent with the maincarbonate minerology of these sediments Other correlations
are not universal and in general no pattern in spatial distribu-tion was found in the correlation between elements among allcores suggesting that these elements are not controlled by the
same parameters at each site
Hydrochemistry of Bacalar Lagoon Marine and Freshwater Research G
Sediment pollution
Some trace elements in Bacalar Lagoon sediments mayreflect anthropogenic pollution Here we used four indices
followingManoj and Padhy (2014 see Table 3)We normalisedconcentrations to Al because it is a conservative lithogenic
element and is resistant to chemical weathering hence it does
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
8000 9000 10 000 11 000
Sr (ppm) Ba (ppm) U (ppm) Mg (ppm)
8 10 12 14 16 18 0 01 02 03 04 05 06 300 000 400 000
Dep
th (
cm)
0 1000 5000
Al (ppm) Si (ppm) Ti (ppm) Ca (ppm)
Mn (ppm) Fe (ppm) Ni (ppm) Zn (ppm)
10 000 2020 000 2001000 0 200 000 400 000
0 1 2 3 4 0 400 1000 2000 0 20 40 60 500 100 150 25020080
COC BAC3 BAC1 BAC2
Fig 7 Concentrations of trace andmajor elements in sediment cores BAC1 Bacalar 1 BAC2 Bacalar 2 BAC3 Bacalar 3
COC Cocalitos
H Marine and Freshwater Research N I Tobon ndashVelazquez et al
not actively participate in the dominant geochemical cycles and
does not have a significant anthropogenic source (Boes et al2011 Dautovic et al 2014)
For normalisation to Al values for the Earthrsquos crust were
taken from Turekian and Wedepohl (1961) in which the valuesare mean concentrations in carbonates rocks of the upper crustKfrac14 27000 ppm Mnfrac14 11000 ppm Nifrac14 200 ppm
Znfrac14 200 ppm and Bafrac14 100 ppmTo determine whether the elements are from lithological or
anthropogenic sources the trace element concentrations were
compared with the crustal composition (Hernandez et al 2003)
frac12M lithogenic frac14 frac12Als ethfrac12M =frac12AlcTHORN eth1THORN
frac12M anthropogenic frac14 frac12M T frac12M lithogenic eth2THORN
where the lithogenic input ([M]lithogenic) is estimated throughthe concentration of Al in the sample ([Al]s) and the ratio of the
average of the Earthrsquos crust ([M][Al]c) The anthropogenic input([M]anthropogenic) was calculated based on the total concentration([M]T) and the lithogenic input
The results of these calculations are summarised in Table 4For all cores U6thorn Mn2thorn and Kthorn show negative values for theindex of geoaccumulation (Igeo) whereas the values of CF(contamination factor) and CD (contamination degree) are
lower than 20 All factors indicate that the sediment is notpolluted with these elements which are likely of lithogenicorigin For Ni2thorn the Igeo (0) CF (1) and CD (6) indices
also indicate low pollution except for the upper samples (depthsof 0ndash6 and 6ndash11 cm) of theBAC2 core where theCF is30 andIgeo is 10 suggesting unpolluted to moderately polluted
conditions In contrast the values of these indices for Zn2thorn
and Ba2thorn show some spatial variabilityThe CD of Zn2thorn at all sites is 15 The eastern samples
(BAC1 and BAC2) show higher CD values (822 and 1805
respectively) suggesting moderate to considerable contamina-
tion of the sediment The Ba2thorn concentration exhibits a spatialdistribution the western sites (COC RAP and BAC3) havehigher Ba2thorn concentrations compared than the eastern sites and
the calculated indices were correspondingly higher for thewestern side of the lagoon However overall the indicesindicated that the sediments on both sides of the lagoon are
unpollutedwith regard to Ba and the differences are likely due tohigher barite content on thewestern side Based on these indicesno influence of human activities was detected in eastern core
samples (BAC1 and BAC2)The higher Zn2thorn and Ba2thorn concentrations may be due to a
higher input of these elements into the area close to these sitesHowever water column distributions have to be assessed to
confirm this Zn2thorn and Ba2thorn in Bacalar Lagoon sediments couldbe derived from two sources (1) authigenic minerals found inthe sediment which on thewestern side contain barite (BaSO4)
and some sphalerite (ZnS) and (2) anthropogenic sources suchas agricultural fertiliser or cattle feed Commercial fertiliserscontain micronutrients such as Zn2thorn Mn2thorn Fe3thorn Cu2thorn Mo6thorn
and Ba2thorn in concentrations ranging from trace to several ppmwhich could infiltrate and cause pollution in the soil andgroundwater (Adriano 1986) Baize (1997) indicated that Znis found in animal feed used for pigs that are raised domestically
and commercially in the region The waste water generated bythis industry has been poorly handled resulting in adverseeffects on the environment (Drucker et al 2003) Near the town
of Bacalar fertilisers and agrochemicals are used regularly(Alvarez-Legorreta 2009) The agriculture practices in themunicipality include maize sugarcane and pepper and more
than 40 products are spread annually on these crops (fertilisersherbicides and pesticides Euan-Avila et al 2002) Garcıa-Rıosand Gold-Bouchot (2002) identified Fe V Ni Pb Zn Cu and
Cd in sediments of nearby Chetumal Bay Indeed Bacalar andOthon P Blanco municipalities have the highest fertilised area
Table 3 Indices as indicators of sediment quality based on Manoj and Padhy (2014) and Javan et al (2015)
Ms sample element concentration Mb background concentration of the element
Index Equation Sediment quality
Index of geoacumulation Igeofrac14 ln(Ms15Mb) 0frac14 unpolluted
0ndash1frac14 unpolluted to moderately polluted
1ndash2frac14moderately polluted
2ndash3frac14moderately polluted to highly polluted
3ndash4frac14 highly polluted
4ndash5frac14 highly polluted to very highly polluted
5frac14 very highly polluted
Contamination factor CF5MsMb 1frac14 low CF
1 CF 3frac14moderate CF
3 CF 6frac14 considerable CF
$6frac14 very high CF
Contamination degree CD frac14Pnifrac141
CF 6frac14 low CD
6 CD 12frac14moderate CD
12 CD 24frac14 considerable CD
$24frac14 high CD (anthropogenic contamination)
Pollution load index PLI5 (CF1CFsyCFn)1n 0frac14 unpolluted
1frac14 baseline levels of pollutants present
1frac14 progressive deterioration of site
Hydrochemistry of Bacalar Lagoon Marine and Freshwater Research I
Table4
Index
ofgeoacummulation(Igeo)anthropogenic(A
)inputcontaminationfactor(C
F)andcontaminationdegree(C
D)forBaUKMnNiandZnin
thesedim
entary
record
ofthe
BacalarLagoon
NAdatanoavailablePLIpollutionload
indexBAC1Bacalar
1BAC2Bacalar
2BAC3Bacalar
3COCCocalitosRAPLosRapidos
Site
Depth
(cm)
Ba
UK
Mn
Ni
Zn
PLI
I geo
Ainput
CF
CD
I geo
Ainput
CF
CD
I geo
Ainput
CF
CD
I geo
Ainput
CF
CD
I geo
Ainput
CF
CD
I geo
Ainput
CF
CD
COC
0ndash6
016
1236
134
701
503
013
005
065
688
24629
001
003
1119
11361
0001
0002
371
021
011
053
203
529
037
479
005
6ndash12
015
1314
135
469
005
006
675
5569
001
1160
3753
0000
409
107
009
004
2846
146
006
12ndash17
004
1421
146
336
024
015
NA
10001
000
1147
4016
0001
405
107
009
037
2254
116
000
17ndash22
014
1627
165
304
035
018
1158
6288
000
1257
2588
0000
362
196
012
010
3174
161
004
22ndash27
031
1156
121
282
035
021
NA
14125
000
1338
5739
0000
367
132
012
301
267
019
000
RAP
0ndash6
039
1074
115
264
538
008
004
009
889
18818
000
002
1067
7912
0001
0001
508
057
004
014
156
870
051
284
004
6ndash11
001
1360
149
475
017
006
651
31721
002
1189
14691
0000
391
069
010
063
4390
233
007
BAC1
0ndash5
024
267
127
956
402
201
009
069
230
189364
031
161
896
110398
0003
0023
300
1639
019
115
174
1118
045
822
014
5ndash10
035
302
118
416
174
008
276
176636
022
907
96021
0003
311
1404
017
066
2982
237
017
10ndash15
048
382
108
437
137
007
307
139830
018
913
76341
0003
327
1083
016
119
074
066
013
15ndash20
031
444
121
423
150
008
295
153179
019
896
83486
0003
330
1220
015
013
1225
137
015
20ndash25
031
488
121
420
142
008
301
145741
019
883
79449
0003
351
1189
013
424
1293
008
009
25ndash30
039
504
114
408
121
009
320
128917
016
925
70152
0002
363
1037
012
061
689
098
013
30ndash35
016
581
134
385
145
010
299
154625
019
904
83454
0003
353
1264
013
069
337
093
014
35ndash40
041
467
113
419
127
008
313
131772
017
917
72183
0003
392
1120
010
012
1446
138
013
BAC2
0ndash6
035
1141
117
734
515
002
004
086
743
6689
001
006
1094
3596
0001
0006
374
157
011
444
051
4203
214
1805
007
6ndash11
052
1005
105
462
004
006
834
10694
000
949
4638
0002
119
6764
343
012
2666
138
012
11ndash16
055
984
103
442
006
007
750
9268
001
1126
4617
0001
420
078
008
144
1018
055
005
16ndash21
055
985
102
400
013
009
597
3426
002
1119
3962
0001
421
089
008
001
2953
151
008
21ndash26
043
1093
111
296
038
019
828
3839
000
1178
2046
0000
412
135
009
293
22785
1141
009
26ndash31
068
925
094
254
054
026
832
2578
000
1194
1524
0000
273
424
023
104
1434
073
006
36ndash41
056
1001
102
337
028
014
875
3556
000
1113
1759
0001
182
819
043
219
626
033
006
BAC3
0ndash6
016
1283
134
407
607
009
002
007
682
12943
001
002
1266
6706
0000
0001
553
057
003
008
211
572
035
152
003
6ndash12
020
1270
131
607
003
002
989
9545
000
1308
4043
0000
580
020
003
081
1639
086
002
12ndash18
008
1389
142
613
003
002
891
8695
000
1341
3872
0000
593
021
002
223
567
032
002
J Marine and Freshwater Research N I Tobon ndashVelazquez et al
in Quintana Roo state (Instituto Nacional de Estadıstica yGeografıa 2016) Owing to the karstic nature of the area these
products can immediately infiltrate the aquifer and thereforecould be affecting the lagoon Because the concentration of ZnSminerals was low in the cores it is suggested that the source of
Zn2thorn could be derived from human activities Although theresults from the pollution load index (PLI) (1) for all samplesindicate that the sites are not highly polluted the excess Zn2thorn in
the sediment suggests some local pollution with regard to thiselement Conversely the concentrations of Ba2thorn can beexplained by the variable occurrence of barite in the cores
Minimal trace metal pollution is consistent with previous
metal work in the lagoon Castro-Contreras et al (2014)reported heavy metal concentrations in Bacalar Lagoon waterbelow the maximum limits of the Mexican legislation (NOM-
127-SSA1-1994) and ecological water quality criteria (CE-CCA-00189) that establish the limits of heavy metals fordrinking water irrigation and recreational activities
Nevertheless organochloride compounds (pesticides andpolychlorinated biphenyls) and hydrocarbons in sediments havebeen identified by Norena-Barroso et al (1998) in the ChetumalBay area near Bacalar Lagoon Organochlorine pesticides
(OCPs) are used in agriculture in the region (Alvarez-Legorreta2009) Furthermore heavymetals and OCPs have been detectedin crocodilian eggs near Chichorro Atoll (Charruau et al 2013
Buenfil-Rojas et al 2015)
Conclusions
Bacalar Lagoon is a shallow and oligotrophic system (low-
nutrient waters) with a mineralogical composition dominatedby calcite dolomite and evaporites dissolution Water geo-chemical analyses show a clear spatial distribution of different
parameters The western part of the study area is characterisedby high alkalinity and calcium and sulfate concentrations theratios of these constituents indicate groundwater sources and noseawater intrusion The decreases in these parameters towards
the north indicate a gradient in groundwater influencethroughout the lagoon The eastern part of the study area ischaracterised by a shallower water column resulting in high
evaporation and high electrical conductivity compared with thewestern side
We present the first measurements of trace elements in
carbonate sediments in Bacalar Lagoon The sediment exhibitsonly moderate contamination with Zn2thorn on the western side ofthe lagoon The high Ba concentration in the sediment corre-
sponds to barite but further work is necessary to identify thesource of Ba2thorn and Zn2thorn This study can be useful for Bacalarmunicipality to make decisions and define actions regarding themanagement and development of Bacalar Lagoon
Conflicts of interest
The authors declare that they have no conflicts of interest
Declaration of funding
This investigation was financed by the lsquoWater Security Project inthe South-eastMexico in the face of twoclimate change scenariosrsquoproject (CONACYT 247565) and lsquoProject networks CONACYTrsquo
(282240) The authors acknowledge a grant from CONACYT
towards a Masters of Water Sciences degree (awarded to NidiaTobon Velazquez)
Acknowledgements
The authors thank technical staff Daniela Ortega (Water Sciences Unit
Centro de Investigacion Cientıfica de Yucatan) and Kimberly Bitterwolf
(University of CaliforniamdashSanta Cruz)
References
Adriano D C (1986) lsquoTrace Elements in the Terrestrial Environmentrsquo
(Springer-Verlag Berlin Germany)
Alvarez-Legorreta T (2009) Contaminacion acuatica In lsquoEl sistema ecolo-
gico de la Bahıa de Chetumal Corozal costa occidental del Mar Caribersquo
(Eds J Espinoza Avalos G A Islebe and H A Hernandez Arana)
pp 205ndash217 (El Colegio de la Frontera Sur Chetumal Mexico)
Appelo C A and Postma D (2005) lsquoGeochemistry Groundwater and
Pollutionrsquo 2nd edn (A A Balkema Rotterdam Netherlands)
Baize D (1997) lsquoTeneurs totales en elements trace metalliques dans les sols
(France) References et strategies drsquointerpretationrsquo (INRA Paris France)
Bauer-Gottwein P Gondwe B Charvet G Marin L Rebolledo V M
andMerediz A G (2011) Review the Yucatan Peninsula karst aquifer
Mexico Hydrogeology Journal 19 507ndash524 doi101007S10040-010-
0699-5
Beddows P A (2002) lsquoWhere Does the Sewage Go The Karst
Groundwater System of the Municipalidad de Solidaridad Quintana
Roo Mexicorsquo (Association for Mexican Cave Studies Houston
TX USA)
Beltran D Y (2010) Estimacion de los patrones de fijacion de nitrogeno y
diversidad asociada (nifH) en tapices microbianos y estromatolitos
MSc Thesis Universidad Nacional Autonoma de Mexico Ciudad de
Mexico Mexico
Boes X Rydberg J Martinez C A Bindler R and Renberg I (2011)
Evaluation of conservative lithogenic elements (Ti Zr Al and Rb) to
study anthropogenic element enrichments in lake sediments Journal of
Paleolimnology 46 75ndash87 doi101007S10933-011-9515-Z
Boyle J F (2001) Inorganic geochemical methods in paleolimnology In
lsquoTracking Environmental Change Using Lake Sediments Vol 2 Physi-
cal andGeochemicalMethodsrsquo (EdsMW Last and P J Smol) pp 83ndash
143 (Kluwer Academic Publishers Dordrecht Netherlands)
Buenfil-Rojas A M Alvarez- Legorreta T and Cedeno-Vazquez J R
(2015) Metals and metallothioneins in Moreletrsquos Crocodile (Crocodile
moreletii) from a Transboundary River between Mexico and Belize
Archives of Environmental Contamination and Toxicology 68(2) 265ndash
273 doi101007S00244-014-0088-5
Castro-Contreras C Murray K G Pecoits E Aubet N R Petrash D
Castro C S Gregory D Planavsky N and Konhauser K O (2014)
Textural and geochemical features of freshwater microbialites from
LagunaBacalarQuintanaRooMexicoPalaios 29(5) 192ndash209 doi10
2110PALO2013063
Ceballos Martınez R R (2002) Geografıa y medio ambiente en el sistema
lagunar San FelipendashBacalarndashGuerrero In lsquoContribuciones de la ciencia al
manejo costero integrado de laBahıa deChetumal y su area de influenciarsquo
(Eds F J Rosado-May RRomeroMayo andADe Jesus Navarrete) pp
17ndash22 (Universidad de Quintana Roo Chetumal Mexico)
Centeno M C Legendre P Beltran Y Alcantara H R Lidstrom E U
Ashby N M and Falcon I L (2012) Microbialite genetic diversity
and composition relate to environmental variables FEMSMicrobiology
Ecology 82 724ndash735 doi101111J1574-6941201201447X
Chagas A P Webb E G Burne V R and Southam G (2016) Modern
lacustrine microbialites towards a synthesis of aqueous and carbonate
geochemistry and mineralogy Earth-Science Reviews 162 338ndash363
doi101016JEARSCIREV201609012
Charruau P Henaut Y and Alvarez-Legorreta T (2013) Organo-
chlorine pesticides in nest substratum and infertile eggs of American
Hydrochemistry of Bacalar Lagoon Marine and Freshwater Research K
crocodiles (Reptilia Crocodylidae) in a Mexican Caribbean atoll
Caribbean Journal of Science 47 1ndash12 doi1018475CJOSV47I1A2
Comision Nacional del Agua (2002) lsquoDeterminacion de la disponibilidad de
agua en el acuıfero Penınsula de Yucatan estado de Yucatanrsquo (CON-
AGUA Gerencia de Aguas Subterraneas Ciudad de Mexico Mexico)
Comision Nacional del Agua (2012) lsquoPrograma Hıdrico Regional Vision
2030 Region Hidrologico-Administrativa XII Penınsula de Yucatanrsquo
1st edn (Secretarıa de Medio Ambiente y Recursos Naturales Mexico
City Mexico)
Comision Nacional del Agua (2015) lsquoActualizacion de la disponibilidad
media anual de agua en el acuıfero Cerros y Valles (2301) Estado de
QuintanaRoorsquo (CONAGUADiarioOficial de la Federacion Ciudad de
Mexico Mexico)
Dautovic J Fiket Z Baresic J Ahel M and Mikac N (2014) Sources
distribution and behavior of major and trace elements in a complex karst
lake system Aquatic Geochemistry 20 19ndash38 doi101007S10498-
013-9204-9
Dıaz J E (2005) lsquoDecreto por el cual se establece el programa de
ordenamiento ecologico territorial de la region de Laguna Bacalar
Quintana Roo Mexicorsquo (Periodico Oficial Chetumal Mexico)
Dixon J Hamilton K Pagiola S and Segnestam L (2001) Tourism and
environment in the Caribbean an economic framework (The World
Bank Washington DC USA) Available at httpdocumentsworldbank
orgcurateden672281468770397455pdfmulti0pagepdf [Verified 18
October 2018]
Drever J I (2005) lsquoSurface and Ground Water Weathering and Soilsrsquo
(Elsevier Oxford UK)
Drucker A Escalante R Gomez V and Magana S (2003) La industria
porcina en Yucatan un analisis de la generacion de aguas residuales
Problemas del Desarrollo Revista Latinoamericana de Economıa 34
(135) 105ndash120
Dupraz C Reid R P andVisscher P T (2011)MicrobialitesModern In
lsquoEncyclopedia of Geobiology Encyclopedia of Earth Science Seriesrsquo
(Eds J Reitner and V Thiel) pp 617ndash635 (Springer Heidelberg
Germany)
Elango L andKannan R (2007) Rockndashwater interaction and its control on
chemical composition of groundwater In lsquoDevelopments in Environ-
mental Sciencersquo Vol 5 (Eds D Sarkar R Datta and R Hannigan) pp
229ndash243 (Elsevier Oxford UK)
Euan-Avila J I Liceaga-CorreaM A and Rodrıguez Sanchez H (2002)
Caracterizacion de fuentes no puntuales de contaminacion agrıcola en el
municipio deOthon P Blanco enQuintanaRoo y su potencial influencia
en la Bahıa de Chetumal In lsquoContribuciones de la ciencia al manejo
costero integrado de la Bahıa de Chetumal y su area de influenciarsquo (Eds
F J Rosado-May R Romero Mayo and A De Jesus Navarrete) pp
197ndash204 (Universidad de Quintana Roo Chetumal Mexico)
Fouke W B Zerkle L A Alvarez W Pope O K Ocampos A C
Wachtman J R Grajales J M Claeys P and Fischer G A (2002)
Cathodoluminescence petrography and isotope geochemistry of KT
impact ejecta deposited 360 km from the Chicxulub crater at Albion
Island Belize Sedimentology 49 117ndash138 doi101046J1365-3091
200200435X
Garcıa-Rıos V Y and Gold-Bouchot G (2002) Especiacion de metales
pesados en sedimentos de la Bahıa de Chetumal Quintana Roo y la
acumulacion en el tejido muscular de bagres (Ariopsis assimilis) In
lsquoContribuciones de la ciencia al manejo costero integrado de la Bahıa de
Chetumal y su area de influenciarsquo (Eds F J Rosado-May R Romero
Mayo and A De Jesus Navarrete) pp 143ndash148 (Universidad de
Quintana Roo Chetumal Mexico)
Gischler E Gibson M A and Oschmann W (2008) Giant Holocene
freshwater microbialites Laguna de Bacalar Quintana Roo Mexico
Sedimentology 55 1293ndash1309 doi101111J1365-3091200700946X
Gischler E Golubic S Gibson M Oschamann W and Hudson J H
(2011) Microbial mats and microbialites in the freshwater Laguna
Bacalar Yucatan Peninsula Mexico In lsquoAdvances in Stromatolite
Geobiologyrsquo (Eds J Reitner M H Trauth K Stuwe and D Yuen)
pp 187ndash205 (Springer Berlin Germany)
Gonzalez B J L Carrion J J Cuevas D J Flores M F Yam G J O
Moreno C J Perez V J and Calva C G (2014) Acumulacion de Hg
Pb Cd y Zn por Pomacea flagellata en tres balnearios ubicados en la
region urbana de la Laguna de Bacalar TecnoCultura 35 14ndash23
Hemley R J Prewitt C T and Kingma K (1994) High-pressure
behavior of silica In lsquoSilica ndash Physical Behavior Geochemistry and
Materials Applications Reviews in Mineralogy Vol 29rsquo (Eds P J
Heaney C T Prewitt and G V Gibbs) pp 41ndash82 (Mineralogical
Society of America Washington DC USA)
Hernandez L Probst A Probst L J and Ulrich E (2003) Heavy metal
distribution in some French forest soils evidence for atmospheric
contamination The Science of the Total Environment 312(1ndash3)
195ndash219 doi101016S0048-9697(03)00223-7
Hernandez-Terrones L Rebolledo-Vieyra M Merino-Ibarra M Soto
M Le-Cossec A and Monroy-Rıos E (2011) Groundwater pollution
in a karstic region (NE Yucatan) baseline nutrient content and flux to
coastal ecosystems Water Air and Soil Pollution 218(1ndash4) 517ndash528
doi101007S11270-010-0664-X
InstitutoNacional de Estadıstica yGeografıa (2002) EstudioHidrologico del
Estado de Quintana Roo (INEGI Aguascalientes Mexico) Available at
httpinternetcontenidosinegiorgmxcontenidosproductosprod_serv
contenidosespanolbvinegiproductoshistoricos2104702825224196
702825224196_1pdf [Verified 5 September 2018]
Instituto Nacional de Estadıstica y Geografıa (2016) Anuario Estadıstico y
Geografico de Quintana Roo (INEGI Aguascalientes Mexico) Avail-
able at httpinternetcontenidosinegiorgmxcontenidosProductos
prod_servcontenidosespanolbvinegiproductosnueva_estrucanuarios_
2016702825084370pdf [Verified 5 September 2018]
Javan S Hessam H A Gholamalizadeh A A and Soltani J (2015)
Fractionation of heavy metals in bottom sediments in Chahnimeh 1
Zabol Iran Environmental Monitoring and Assessment 187(6) 340
doi101007S10661-015-4510-X
Katip A Karaer F Ileri S Sarmasik S Aydogan N and Zenginay S
(2011) Analysis and assessment of trace elements pollution in sediments
of Lake Ulubat Turkey Journal of Environmental Biology 33 961ndash968
Kenkmann T and Schonian F (2006) Ries and Chicxulub impact craters
on Earth provide insights for Martian ejecta blankets Meteoritics amp
Planetary Science 41(10) 1587ndash1603 doi101111J1945-51002006
TB00437X
Khedidja A and Boudoukha A (2016) Lrsquoaquifere Superficiel de
Tadjnanet-Chelghoum laid (Nord-Est Algerien) Larhyss Journal 28
181ndash197
Lounejeva E Ostroumov M and Sanchez R G (2002) Polimorfos de
alta presion de sılice en las impactitas de ChicxulubMexico ndash resultados
de espectrometrıa de Raman Revista Mexicana de Ciencias Geologicas
17(2) 137ndash141
Manoj K and Padhy P K (2014) Distribution enrichment and ecological
risk assessment of six elements in bed sediments of a tropical river
Chottanagpur Plateau a spatial and temporal appraisal Journal of
Environmental Protection 5 1419ndash1434 doi104236JEP2014514136
Marfia A M Krishnamurthya R V Atekwanab E A and Panton W F
(2004) Isotopic and geochemical evolution of ground and surfacewaters
in a karst dominated geological setting a case study fromBelize Central
America Applied Geochemistry 19 937ndash946 doi101016JAPGEO
CHEM200310013
Massaferro J Correa M A Montes de Oca F and Mauad M (2018)
Contrasting responses of lake ecosystems to environmental disturbance
a paleoecological perspective from northern Patagonia (Argentina)
Hydrobiologia 816(1) 79ndash89 doi101007S10750-016-3081-3
Medina M S Jimenez G A Gutierrez R M and Lizardi J M (2014)
Hydrocarbon pollution studies of underwater sinkholes along Quintana
L Marine and Freshwater Research N I Tobon ndashVelazquez et al
Roo as function of tourism development in the Mexican Caribbean
Revista Mexicana de Ingenierıa Quımica 13(2) 509ndash516
Norena-Barroso E Zapata-Perez O Ceja-Moreno V and Gold-Bouchot
G (1998) Hydrocarbon and organochloride residue concentrations in
sediments from Bay of Chetumal Mexico Bulletin of Environmental
Contamination and Toxicology 61 80ndash87 doi101007S001289900732
Nriagu J and Pacyna J (1988) Quantitative assessment of worldwide
contamination of air water and soils by trace metals Nature 333 134ndash
139 doi101038333134A0
Ochoa J C Gonzalez B J and Jimenez C J (2016) Metales pesados
(Cd Cr Pb Hg) en Rhizophora mangle en rıo y bahıa de Chetumal
Revista Mexicana de Agroecosistemas 3(2) 263ndash271
Oliva R J Ocana F A de Jesus N A de Jesus C R and Vargas E A
(2016) Reproduccion dePomacea flagellata (Mollusca Ampullariidae)
en la laguna de Bacalar Quintana Roo Mexico Revista de Biologıa
Tropical 64(4) 1643ndash1650
Pacton M Hunger G Martinuzzi V Cusminsky G Burdin B
Barmettler K Vasconcelos C and Ariztegui D (2015) Organomi-
neralization processes in freshwater stromatolites a living example from
eastern Patagonia International Association of Sedimentologists Jour-
nal 1(2) 130ndash146
Perez L Bugja R Lorenschat J Brenner M Curtis J Hoelzmann P
Islebe G Scharf B and SchwalbA (2011) Aquatic ecosystems of the
Yucatan Peninsula (Mexico) Belize and Guatemala Hydrobiologia
661 407ndash433 doi101007S10750-010-0552-9
Perry E C Velazquez O G and Marin L (2002) The hydrogeochem-
istry of the karst aquifer system of the northern Yucatan Peninsula
Mexico International Geology Review 44 191ndash221 doi102747
0020-6814443191
Perry E Paytan A Pedersen B and Velazquez O G (2009) Ground-
water geochemistry of the Yucatan Peninsula Mexico constraints on
stratigraphy and hydrogeology Journal of Hydrology 367 27ndash40
doi101016JJHYDROL200812026
Pradit S Wattayarkorn G Angsupanich S Baeyens W and Leer-
makers M (2010) Distribution of trace elements in sediments and biota
of Songkhla Lake Southern Thailand Water Air and Soil Pollution
206 155ndash174 doi101007S11270-009-0093-X
Salomons W and Forstner U (1980) Trace metal analysis on polluted
sediments II evaluation of environmental impact Environmental
Technology Letters 1 506ndash517 doi10108009593338009384007
Sanchez S J Alvarez L T Pacheco A J Gonzalez H R and Carrillo
B L (2015) Caracterizacion hidrogeoquımica de las aguas subterraneas
del sur del Estado de Quintana Roo Mexico Revista Mexicana de
Ciencias Geologicas 32(1) 62ndash76
Schmitter-Soto J J Comın F A Escobar B E Herrera S J Alcocer J
Suarez M E Elıas G M Dıaz A V Marın L E and Steinich B
(2002) Hydrogeochemical and biological characteristics of cenotes in
the Yucatan Peninsula (SE Mexico) Hydrobiologia 467 215ndash228
doi101023A1014923217206
Siqueiros-Beltrones D Hernandez A U and Hernandez A O (2013)
Diagnosis prospectiva sobre la diversidad de diatomeas epilıticas en la
laguna Bacalar Quintana Roo Mexico Revista Mexicana de Biodiver-
sidad 84 865ndash875 doi107550RMB33960
Turekian K K andWedepohl K H (1961) Distribution of the elements in
some major units of the Earthrsquos crust Bulletin of the Geological Society
of America 72 175ndash192 doi1011300016-7606(1961)72[175
DOTEIS]20CO2
Handling Editor Russell Frew
wwwpublishcsiroaujournalsmfr
Hydrochemistry of Bacalar Lagoon Marine and Freshwater Research M
ensure tourism activities will not stress the lagoonrsquos ecosystemhowever the lagoon has not been declared a protected area The
current lack of regulation for infrastructure and tourism mayresult in degradation of the water quality of the lagoon ecosys-tem structure and possibly the integrity of stromatolites (Dıaz
2005) Previous studies in Bacalar Lagoon provided physicalinformation about the lagoon but none focused on water qualityand sources of pollution (Dıaz 2005 Gischler et al 2008 2011
Perez et al 2011 Siqueiros-Beltrones et al 2013 Castro-Contreras et al 2014 Gonzalez et al 2014 Sanchez et al
2015 Oliva et al 2016)Pollution from trace elements may be of particular concern
Trace metals can occur as dissolved or colloidal phases or theymay be present in association with suspended particles in thewater column andwithin sedimentary phases (Katip et al 2011)
Many trace metals are present at higher concentrations insedimentary phases than in the water column (Nriagu andPacyna 1988 Pradit et al 2010) Trace metal concentrations
in the water are controlled by inputs from land through weath-ering processes groundwater discharge and atmospheric depo-sition (Salomons and Forstner 1980) as well as fromanthropogenic activities and each input can change over time
Therefore sediments (including stromatolite beds) can serve asarchives of environmental changes through time and changes inthe chemical composition of the sediments may be informative
of changes in natural and anthropogenic sources and fluxes oftrace metals (Boyle 2001) The chemical composition of sedi-ments and water can also be used to identify the rockndashwater
interaction and mineralogical composition of aquifer rocks(Elango and Kannan 2007)
Herein we report for the first time the distribution of trace
and major elements in the water column (along with hydrogra-phy) and in the sediments of the south part of the lagoon (near thelocation of the stromatolites) Through these analyses weidentify the sources of the trace elements and their changes over
time in Bacalar Lagoon
Materials and methods
Study area
Bacalar Lagoon is located in the south-eastern part of QuintanaRooMexico (from18856026500N 8889028600Wto18832038600N88827048600W) 15 m above sea level Fig 1) This area ischaracterised by a humid tropical climate with a mean annual airtemperature of 2608C Three meteorological seasons dominatethe region (1) the lsquonortesrsquo season between October and April
characterised by cold fronts (2) the dry season betweenApril andMay and (3) the wet season from June to October when tropicalstorms and hurricanes result in high rainfall The average annual
rainfall in the region ranges between 100 and 1500 mm year1with mean temperatures during winter and summer being280and2908C respectively (Comision Nacional del Agua 2015)
The lagoon has a surface area of 420 km2 (length 400 kmwidth10ndash20 km Comision Nacional del Agua 2002 Castro-Contreras et al 2014) It is an oligotrophic freshwater system
(electrical conductivity (EC) 23 mS cm1) and has a pHbetween 76 and 83 (Beltran 2010) The maximum water depthof the lagoon is 15 m but the water level of the lagoon canincrease by up to 300 cm during the wet season (Junendash
October Gischler et al 2011)
Bacalar Lagoon is situated in Hydrological Region number 33(RH33ComisionNacional del Agua 2012) Five sinkholes (locally
called cenotes) are located inside andnear the lagoon (Gischler et al2008) The cenotes Cocalitos Esmeralda and Negro are locatedinside the lagoon whereas cenote Azul (with a maximum water
depth of 900 m) is located outside the lagoon but has an under-ground connection to the lagoonCenoteXul-Ha is connected to thelagoon through a surface channel in the south-west area (Perry et al2009 Beltran 2010 Gischler et al 2011 Perez et al 2011)
The lagoon is located along the Bacalar fault system andsurrounding rocks are mostly from the Bacalar Formation thathave been assigned aNeogene age To the north the outcrops are
ofmarine Pliocene to Holocene age whereasMiocene age rocksare observed to the south Upper Cretaceous outcrops have alsobeen identified particularly along the west side of the lagoon
(Kenkmann and Schonian 2006) Based on Sr isotopes Perryet al (2009) suggest that in this region the slow-movinggroundwater derives its ion chemistry from relatively soluble
aquifer rocks including gypsum calcite dolomite and accessoryminerals such as celestite (SrSO4) Perry et al (2009) alsoobserved that water Sr isotope analyses of Bacalar Lagoonand cenote Azul suggest that these waterbodies derive their Sr
from dissolution of minerals of CretaceousndashEocene age
Field sampling
Seven sampling sites were selected along the southernmost
100 km of Bacalar Lagoon with five sites located on the
88270W
0 1 2 3 4 km05183
30
N18
36
0N
183
90
N18
42
0N
183
30
N18
36
0N
183
90
N18
42
0N
88240W 88210W
88270W 88240W 88210W
N
S
W E
Fig 1 Location of Bacalar Lagoon showing sampling sites Site details are
given in Table 1 BAC1 Bacalar 1 BAC2 Bacalar 2 BAC3 Bacalar 3 Caz
cenote Azul Ccoc cenote Cocalitos COC Cocalitos RAP Los Rapidos
B Marine and Freshwater Research N I Tobon ndashVelazquez et al
western side of the lagoon and two located on the eastern side(Fig 1) Two sampling campaigns were performed The loca-
tions of the sites were determined using a global positioningsystem (GPS (NOMAD Trimble Sunnyvale CA USA) withtheWorld Geodetic System (WGS) 84 datum Temperature pH
depth total dissolved solids (TDS) EC and dissolved oxygen(DO) were measured in the field (during both samplingcampaigns) using a multiparameter sonde (Model 6600 YSI
Control Tecnico y Representaciones Mexico City Mexico)Temperature profile data were collected using a CastAway-CTD (SonTek Xylem San Diego CA USA) The field para-meters were measured as close to sediment core and water
sample collection points as possibleThe first sampling campaign was conducted in November
2016 Five sediment cores of variable length (between 11 and
41 cm) were collected using a steel push core with 50-cmdiameter plastic liners Three sediment cores were taken at thewestern side of the lagoon (COCRAPandBAC3) and two cores
were taken at the eastern side (BAC1 and BAC2 Fig 1) Thesamples were kept at 408C The sediment cores were sectionedinto 40-cm intervals for a total of 27 samples Samples weredried at 508C in an oven and powdered using an agate mortar and
pestle In addition surface water samples were collected at eachof the seven study sites (Fig 1) Allwater samples were collectedin acid-washed polyethylene bottles (Nalgene SigmandashAldrich
Mexico Toluca Mexico) rinsed with sample at the time ofcollection Samples were filtered using 045-mm syringe filtersand analysed for alkalinity nutrients cations and anions
The second sampling campaign was conducted in June 2017During this campaign water samples were taken from sites atcenote Azul (Caz) and cenote Cocalitos (Ccoc Fig 1) At each
site two water samples (surface and at a depth of 150 m) werecollected by divers All samples collected during both campaignswere kept at 408C and transported to the Hydrogeochemistryand Water Quality Laboratory of the Water Sciences Unit
Centro de Investigacion Cientıfica de Yucatan
Laboratory analysis
Alkalinity was measured by the titration method using 02 Nsulfuric acid (H2SO4) Nutrients (NO3
NO2 PO4
3) cations(Ca2thorn Nathorn Mg2thorn Kthorn Sr2thorn) and anions (Cl SO4
2) weredetermined using ion chromatography with an 882 CompactPlus ICMetrohm (MetrohmMexico Mexico City Mexico) andcertified standards (TraceCERT SigmandashAldrich Mexico) forcalibration For determination of NH4
thorn a spectrophotometer
(LaMotte Analisis y Soluciones Ambientales Mexico CityMexico) was used Water analyses were performed at theHydrogeochemistry andWater Quality Laboratory of theWater
Sciences Unit Centro de Investigacion Cientıfica de YucatanAC The concentrations of major elements (Al Fe Ca Mg TiSr and K) and trace elements (Mn Ba Ni Zn andU) in sediment
samples were determined after sample dissolution using induc-tively coupled plasmandashmass spectrometry (ICP-MS XRThermoScientific San Diego CA USA) at the Institute of Marine Sci-
ences at the University of California ndash Santa Cruz (UCSC) Priorto these analyses 100 mg of homogenised sediment was dis-persed in 15 mL ofMilliQwater and digested using 155 N nitricacid (HNO3
) A 100-mL subsample was diluted 200-fold using
1HNO3 for analysis Instrumental drift was corrected with Sc
and Rh standards Rhwas used as the internal standard correctionfor Sr Ba and U whereas Sc was used as the internal standard
correction for all other elements Counts per second values wereconverted to concentrations using a standard curve prepared froma homemade rendition of the NIST1D (National Institute of
Standards and Technology NIST) standard reference material(argillaceous limestone) An average of three procedural blankswas subtracted from final concentration values
To determine the sediment mineralogy sediment samples(20 g) were analysed using a Panalytical XrsquoPert Pro X-RayDiffraction (XRD) Spectrometer (Royston UK) with a 1-hrotating platter in the Marine Sciences Laboratory UCSC
Sample 2-theta peaks were identified using the PanalyticalSpectrometer mineral spectrum database as a reference Themost prominent peaks for all samples occurred near 2958with a
pair of peaks near 46 and 478
Results and discussion
Physicochemical parameters
The main physicochemical features of shallow water in BacalarLagoon are presented in Table 1 The low EC values (265ndash319 mS cm1) indicate a freshwater system with pH ranging
from 66 to 73 at the sampling sites (mean pHfrac14 705) Watertemperature was relatively stable in the study area during oursampling campaigns (275ndash2978C) The EC temperature andpH ranges measured in this study are consistent with measure-
mentsmade byGischler et al (2008) Beltran (2010) Perez et al(2011) Castro-Contreras et al (2014) and Sanchez et al (2015)in this system
Fig 2 shows the temperature profiles along the southern sideof Bacalar Lagoon The relatively small temperature variabilityamong lagoon sites (285ndash2888C) suggests a near-homoge-
neous temperature with depth for both seasons (Fig 2b) Thisindicates awell-mixedwater column consistentwith the shallowdepth of the lagoon where the samples were collected
In contrast the water column profiles of the cenotes show
slight variability between sampling campaigns in June thetemperature of cenotes Azul and Cocalitos was higher (310and 3048C respectively) compared with November tempera-
tures (3008C) During both sampling campaigns the cenotes
clearly show stratification with two thermoclines During Junethe cenote Azul thermoclines are at depths of 05 and 120 m
whereas in November they are at 23 and 290 m (Fig 2c) Atcenote Cocalitos the June thermoclines are at 38 and 290 mwhereas in November they are at 20 and 240 m (Fig 2d) For
both cenotes the first thermocline is related to diurnal changesin solar radiation (heating of surfacewaters) whereas the secondis derived from distinct mixing that varies seasonally andbetween years During winter (November) water column mix-
ing extends deeper due to wind action whereas during summer(June) the changes in thermocline depth are due to an increase intemperature over the warm months allowing for water column
stratification and shallowing of the thermoclineNO3
concentrations ranged from 01 to 27 mg L1whereas NO2
and PO43concentrations were below the limits
of detection of the method used in the present study (001 and01 mg L1 respectively) These results are consistent with theoligotrophic designation of Bacalar Lagoon It has been
Hydrochemistry of Bacalar Lagoon Marine and Freshwater Research C
suggested (Beltran 2010) that the low concentrations of bio-
available nitrogen (NH4thorn NO2
and NO3) promote N2 fixa-
tion in the lagoon The lower nutrient concentrations also favourthe growth of stromatolites (Beltran 2010)
Cation abundance in Bacalar Lagoon water follows the order
Ca2thornMg2thornNathorn Sr2thornKthorn anion abundance is in theorder SO4
2HCO3ClNO3
(see Table 1) In orderto determine the main hydrochemical features of the lagoon a
88200W882240W882520W88280W
88200W882240W882520W88280W
0 095 19 285 38 km
284 285 286 287 2880
5
10
15
20
25
30
285 295 305 315 26 27 28 29 30 31
Temperature (degC)
Dep
th (
m)
(b) (c) (d )
184
120
N18
38
40N
183
60
N18
33
20N
184
120
N18
38
40N
183
60
N18
33
20N
(a)
N
S
EW
Fig 2 Temperature profiles in the lagoon and cenotes (a) Sampling locations Each symbol corresponds to the traces shown in the graphs on the right (b)
Temperature profiles at the different study sites in Bacalar Lagoon (c d) Temperature profiles of cenote Azul (c) and cenote Cocalitos (d) Grey (dots and
diamonds) correspond to the November 2016 sampling campaign dashed lines correspond to the June 2017 sampling campaign
Table 1 Main physical and chemical parameters of water samples in Bacalar Lagoon
Standard deviation for the elements is as followsNathorn 097Kthorn 013Mg2thorn 298Ca2thorn 1429 Sr2thorn 034Cl 211 SO42 90 SiO2
26NO3
019 andNH4thorn 004BLD below the limit of detectionNA data not available Ionic balance10 The locations of each of the sample sites are shown in
Fig 1
COC RAP BAC1 BAC2 BAC3 Ccoc Caz
Site Cocalitos Los Rapidos Bacalar 1 Bacalar 2 Bacalar 3 Cenote Cocalitos Cenote Azul
Depth (m) 05 05 05 05 05 05 150 05 150
pH 658 697 731 734 NA 654 NA 685 NA
Temperature (8C) 2926 2891 2747 2967 2920 293 2850 3084 2960
EC (mS cm1) 293 265 315 319 250 268 NA 267 NA
TDS (mgL1) 176 160 195 190 NA 157 NA 156 NA
Chemical composition (mgL1)
Nathorn 630 3247 13357 10811 3273 4740 3410 3130 3360
Kthorn 075 041 180 174 025 358 297 282 305
Mg2thorn 7120 7320 890 8365 7560 7340 7750 7680 7810
Ca2thorn 3930 3760 3860 3860 4220 2080 3540 3420 3650
Sr2thorn 546 631 715 439 270 476 592 545 552
Cl 10074 4166 28317 22640 4165 910 470 410 420
SO42 9620 10150 10910 9620 11740 9130 12370 11070 12840
SiO2 1625 220 2225 2350 1575 320 300 360 310
HCO3 15670 27090 8650 6190 22530 1550 2440 2140 2410
NO3 140 174 268 010 267 20 128 255 283
NO2 BLD BLD BLD BLD BLD BLD BLD BLD BLD
NH4thorn 018 013 028 019 014 020 026 021 023
PO43 BLD BLD BLD BLD BLD BLD BLD BLD BLD
D Marine and Freshwater Research N I Tobon ndashVelazquez et al
Piper diagram was made in Aquachem (ver 37 WaterlooHydrogeologic Kitchener ON Canada) using the proportionsofmajor cations and anions (Fig 3) All samples cluster together
in a group corresponding to a sulfatendashcalcium (CandashSO4) watertype Studies performed by Sanchez et al (2015) reported a CandashHCO3 water type in the northern part of the lagoon and Oliva
et al (2016) showed that the north side of Bacalar Lagoon ischaracterised by muddy sediments with murky water all yearlong In contrast the south of the lagoon is associatedwith sandy
sediments and high water transparency We attribute theobserved differences in water chemistry in the lagoon to theeffects of sulfate-rich groundwater inputs in the south compared
with the north where lower groundwater input and sulfateconcentrations were measured by Sanchez et al (2015) Thewater chemistry in the south can have a direct effect on theformation of stromatolites which are more abundant in the
southern part of theBacalar Lagoon Pacton et al (2015) showedthat stromatolites appear to prefer fresh water rather than turbidand brackish lake waters and turbidity is one of the most
important factors restraining stromatolite developmentAccording to the Piper diagram (Fig 3) the water type of
Bacalar Lagoon is dominated by sulfates (9620ndash
11740 mg L1) The SO4 Cl ratio may be indicative of waterorigin and the ratio at the western side ranged between 696 and2055 higher than at the eastern side (281ndash310) All theSO4 Cl ratios in Bacalar Lagoon are between 27- and 197-fold
greater than those of seawater (0103 Perry et al 2002)indicating that the sulfate source in the lagoon is not seawaterintrusion Therefore we interpret the findings to indicate high
sulfate originating from dissolution of evaporitesAlthough all the lagoonwater samples cluster into one group
spatial differences are present within the lagoon and may
suggest differences in input sources or fluxes as well as inprocesses affecting solute concentrations within the lagoon The
western side of the lagoon is characterised by higher alkalinityand calcium concentrations (1570ndash2700 mg CaCO3 L
1 and3760ndash4220 mg L1 respectively) compared with the eastern
side (620ndash860 mg CaCO3 L1 and 860 mg L1 respectively)
The alkalinity of the western side is similar to the alkalinitymeasured at Caz and Ccoc (2440 and 2410 mg CaCO3 L1
respectively at a depth of 150 m) A gradient of increasingalkalinity is seen from north to south Because high alkalinity isassociated with groundwater input and the waters are undersat-urated with regard to carbonate minerals this alkalinity gradient
indicates a diminishing effect of groundwater towards the northof the lagoon Schmitter-Soto et al (2002) reported other factorsthat can affect alkalinity in the Yucatan Peninsula including the
contribution of meteoric water (rich in carbonate and bicarbon-ate) and precipitation which promotes the dissolution of carbo-nates and therefore affects alkalinity
The concentrations of Ca2thorn and SO42 are lower on the
eastern than western side of the lagoon potentially explainingthe formation of stromatolites in the western part of the lagoonwhere external sources of Ca2thorn and SO4
2 are present To reach
the saturation necessary for precipitation of microbialites Ca2thorn
and SO42 are needed which has been reported in other systems
(Chagas et al 2016) The EC (315ndash319 mS cm1) and Nathorn
(47ndash58 mg L1) and Cl (410ndash2830 mg L1) concentrationson the eastern side of the lagoon are higher than on the westernside (265ndash293 mS cm1) These differences most likely occur
because the eastern part of Bacalar Lagoon is shallower (04ndash06 m) than the western part (10ndash22 m) promoting higherevaporation on the eastern side Marfia et al (2004) identified
high-calcium high-sulfate water in the south-eastern area ofQuintana Roo including north-eastern Belize likely fromgypsum dissolution when the groundwater is mixed withseawater the mixture forms a caliche barrier preventing seawa-
ter intrusion characteristic of the north-east coastThe (Ca2thornthornMg2thornthornHCO3
) to (NathornthornClthorn SO42) ratio
has been used to determine the effect of carbonate and evaporite
solute sources in groundwater and surface waters (Appelo andPostma 2005 Khedidja and Boudoukha 2016) When plottingthis ratio against EC (Fig 4) it is clear that dissolution of
evaporitic substratum is the dominant source of cations in thissystem The lower EC (fresh water) and a carbonate to sulfateion ratio 10 also indicate that evaporite dissolution and notseawater intrusion controls ion composition in Bacalar Lagoon
The saturation indices (SI) for the different mineral speciesconsidered in our system (calcite dolomite aragonite gypsumand celestite) were calculated based on field pH and temperature
measurements using PHREEQC (ver 37 US Geological Sur-vey Denver CO USA) (Fig 5) Our calculations allowed us todetermine the SI of Bacalar Lagoon water (note SIfrac14 0 signifies
equilibrium SI 0 signifies oversaturation and thus mineralprecipitation and SI 0 signifies undersaturation and thusmineral dissolution (Appelo and Postma 2005)
According to the SI calculations three trends were identified(Fig 5) The first corresponds to four sites (RAP BAC3 Cazand Ccoc 15 m deep) and shows oversaturated conditions withregard to aragonite calcite and dolomite In the second group
(Coc and Ccoc surface sample) all the minerals are
C a t i o n s A n i o n s mEq L1
NaK HCO3CO3 Cl
Mg SO4
CaCalcium (Ca) Chloride (Cl)
(SO 4
) (C
l)
(Ca)
(Mg)
(CO 3
)(H
CO 3
)
(Na)
(K)
Sulfate (SO4 )
Mag
nesi
um (M
g)
80 60 40 20 20 40 60 80
8060
4020
20
40
60
80
2040
6080
80
60
40
20
2040
6080
20
40
60
80
80
60
4020
8060
4020
COCRAPBAC1BAC2BAC3CcocCaz
Fig 3 Piper diagram and groundwater composition Each symbol corre-
spond to lagoon sites white square and white triangle points correspond to
cenotes samples which represent the groundwater in the region BAC1
Bacalar 1 BAC2 Bacalar 2 BAC3 Bacalar 3 Caz cenote Azul Ccoc
cenote Cocalitos COC Cocalitos RAP Los Rapidos
Hydrochemistry of Bacalar Lagoon Marine and Freshwater Research E
experiencing dissolution (undersaturation) Finally the thirdgroup (BAC1 and BAC2) is associated with calcite equilibrium
and undersaturation of the other minerals Bacalar Lagoon islocated in a region whereMiocene rocks containing gypsum andanhydrite are common and waterndashrock interaction results in the
dissolution of evaporites (Perry et al 2002 2009) The highconcentrations of Ca2thorn SO4
2 and Sr2thorn could be derived fromthe dissolution of these minerals The water samples in Bacalar
Lagoon are all undersaturated with regard to gypsum andanhydrite indicating that these minerals would not precipitatewithin the lagoon Ceballos Martınez (2002) indicated that
gypsum and limestone in the Bacalar formation tend to beconcentrated in the surface due to weathering forming lamellarcaliche
The Sr2thorn concentrations in samples from the western side are
quite similar to concentrations measured at the cenotes indicat-ing an input of this element from groundwater The same wassuggested by Perry et al (2002 2009) when they compared
concentrations of Sr2thorn and SO42 and Sr isotopes in the lagoon
to those of cenote AzulStandardised principal component analysis (PCA) was per-
formed using R (ver 340 R Foundation for Statistical Com-puting Vienna Austria) to identify the dominant limnologicalgradients in the dataset Fig 6 shows the results of a PCAappliedto the 15 hydrochemical variables measured here (water tem-
perature pH EC TDS SiO2 HCO3
Cl SO42 NO3
NH4
thorn Ca2thorn Kthorn Mg2thorn Nathorn and Sr2thorn) We present only thefirst two components (PC1 and PC2) because these explained 47
and 22 of the total variance respectively (Table 2) PCArepresents standard deviations and when the distance among
COC RAP BAC3 BAC1 BAC2 Ccoc Ccoclowast Caz Cazlowast
Sat
urat
ion
inde
x
15
10
05
0
05
10
Anhydrite (CaSO4)Aragonite (CaCO3)
Calcite (CaCO3)
Celestite (SrSO4)Gypsum (CaSO42H2O)
Dolomite (Ca Mg(CO3))
Fig 5 Saturation index (SI) calculated for each sample site for all relevant
minerals Note SIfrac14 0 indicates the mineral equilibrium (grey line) SI 0
indicates oversaturation and SI 0 indicates undersaturation Asterisks
indicate cenote water samples at a depth of 15 m BAC1 Bacalar 1
BAC2 Bacalar 2 BAC3 Bacalar 3 Caz cenote Azul Ccoc cenote
Cocalitos COC Cocalitos RAP Los Rapidos
24
2
4
0
2
4
0
PC1
2 4
PC
2
Ca
pHSO4
HCO3
NO3
Temp
TDS
Mg
ECNaCl
Sr
NH4
Caz
Ccoc
BAC2 BAC1
RAP
BAC3
COC
SiO2SiO2
K
Fig 6 Principal component analysis based on 15 chemical variables (grey
arrows) at different sampling sites (lagoon and cenotes) PC1 principal
component 1 PC2 principal component 2 EC electrical conductivity
TDS total dissolved solids Temp temperature BAC1 Bacalar 1 BAC2
Bacalar 2 BAC3 Bacalar 3 Caz cenote Azul Ccoc cenote Cocalitos
COC Cocalitos RAP Los Rapidos
Table 2 Eigenvalues of principal component analysis components and
variance explained
Principal component Eigenvalue Variance explained ()
1 706 4712
2 338 2258
3 210 1402
4 127 851
0 05 10 15 20 25 30 3502
04
06
10
12
14
Effect ofevaporates
BAC3
RAP
COCCaz
CcocBAC2
BAC1
Ca
Mg
HC
O3
Na
Cl
SO
4
Conductivity (mS cm1)
Effect ofcarbonates
Fig 4 Mineralisation effect on water chemistry Dark grey points repre-
sent the sampling sites dashed circular areas indicate the range in which the
electrical conductivity and major element ratios are interpreted as resulting
from mineralisation of evaporites or carbonates according to Khedidja and
Boudoukha (2016) BAC1 Bacalar 1 BAC2 Bacalar 2 BAC3 Bacalar 3
Caz cenote Azul Ccoc cenote Cocalitos COC Cocalitos RAP Los
Rapidos
F Marine and Freshwater Research N I Tobon ndashVelazquez et al
samples is greater than 2 units this indicates that the physico-chemical conditions are distinct (Massaferro et al 2018) hence
variations could be interpreted as significant differencesbetween sites
Samples along PCA Axis 1 show two distinctive patterns
within the lagoon which are separated by pH EC TDS Nathorn
and HCO3 distribution The spread of samples within PC1 is
relatively large suggesting significant differences among sites
This spread reflects the distinct distributions of physicochemicalfeatures at the different sides of the lagoon the western side(Axis 1 from 4 to 0 units) is characterised by a high HCO3
content (COC RAP BAC3 Ccoc and Caz) whereas the eastern
side (Axis 1 from 0 to 4 units) is characterised by high EC NathornpH and TDS and corresponds to the BAC1 and BAC2 sites
PC2 is associated with SiO2 and Kthorn concentrations PC2
shows two groups with the first group corresponding to sampleswith low SiO2
and Kthorn concentrations (COC RAP BAC1BAC2 and BAC3) and positive values of Axis 2 (from 4 to 0)
The second group is characterised by high SiO2 and Kthorn
concentrations (Ccoc and Caz samples) and corresponds tonegative axis values (from 0 to 4) PC2 is associated withsilica content due to higher silica concentrations in the cenotes
compared with the rest of the lagoon samples This can beexplained by more rapid Si uptake in the sun-lit lagoon wherediatoms are abundant
Changes in pH and transparency by sediment disturbance canhave an effect on stromatolites Sulfate-reducing bacteria par-ticipate in the formation of stromatolites and appear to always be
associated with Mg calcite and low-salinity and low-turbiditywaters Although stromatolites were not analysed in the presentstudy we recommend that a water monitoring program be
established to survey nutrients and measure other variablessuch as transparency tourist and boat activity weatheringdisturbance of sediments and trace elements at least twice ayear to ensure that the stromatolites are not negatively affected
Sediment characterisation
X-Ray diffraction
The results from the XRD analyses indicate that the mainmineralogical composition for all sediment samples was calcite(CaCO3) dolomite (CaMg(CO3)2) and SiO2 (quartz and possi-
bly minor amounts of coesite) In general calcite was in highestabundance in all cores Dolomite was present in all samples atlower proportions
These results are in accordance with the SI where calcite is
oversaturated in the western part of the lagoon and Ca2thorn andHCO3
concentrations are elevated throughout the lagoonCoesite forms under conditions of high pressure (3ndash10 GPa
Hemley et al 1994) and the presence of this mineral could berelated to the impact of the Chicxulub meteorite (Lounejevaet al 2002) Fouke et al (2002) with an estimated diameter of
its effect 360 km The presence of coesite in Bacalar Lagooncould be associated with this event Fouke et al (2002) andKenkmann and Schonian (2006) reported Chicxulub ejecta
deposited in Belize and in some regions of the Rio Hondo (nearBacalar Lagoon) However identifying the origin of this min-eral in Bacalar Lagoon requires additional detailed studies withlonger scan times to confirm the presence of coesite Other
minerals that we found in lower proportions are barite (BaSO4)
and a few samples with sphalerite (ZnS) with higher propor-tions of barite in the western than eastern side of the lagoon
Geochemistry
Elemental concentrations in the sediment samples are shown
in Fig 7 All sediment cores had high concentrations of Ca2thornMg2thorn and Sr2thorn which were one to three orders of magnitudehigher than concentrations for the rest of the elements consis-
tent with carbonate minerals (calcite) dominating the sedimentElement abundance was similar in cores of sites located in
the western part of the lagoon (COC RAP and BAC3) in the
order Ca2thornMg2thornSr2thorn Si4thornAl3thorn Fe3thornZn2thorn
KthornBa2thornTi4thornNi2thornMn2thornU6thorn The order of ele-ment abundance for the eastern cores (BAC1 and BAC2) was
similar except that Mg was more abundant than Ca (Mg2thorn
Ca2thorn Sr2thorn Si4thornAl3thorn Fe3thornZn2thornKthornNi2thorn
Ba2thornTi4thornMn2thornU6thorn) These relative abundances sug-gest that cores from the western side are dominated by Ca2thorn
carbonate minerals (likely calcite) whereas those from the eastside contain more dolomite The BAC1 core had the highestconcentrations of Al3thorn Si4thorn Kthorn Ti4thorn Mn2thorn and Fe3thorn likelyrepresenting some silicates and ironndashmanganese oxides fromterrigenous sources The highest Ni2thorn and Zn2thornconcentrationswere measured in the core from BAC2 and may represent
anthropogenic pollutant inputs The other elements analysedhad similar distributions in all cores
In general concentrations of Ba2thorn U6thorn and Zn2thorn werehigher in deeper sections of the cores and this may suggest
temporal changes in the input of these elements The rest of theelements (Ca2thorn and Mg2thorn) did not show variations with depthdown the core (r2 05)
The concentrations of elements span orders of magnitudetherefore the data do not satisfy the assumption of normality ASpearman correlation was performed using STATISTICA
(ver 133 Palo Alto CA USA) to test the relationship betweenthe trace elements in each core with significance level atP 005
Except for BAC3 the most significant correlation was forAlndash(FendashTi) (r2 090) In the BAC2 core significant correla-tions were found for SrndashMg AlndashTi KndashNi and SindashTi (r2frac14 090090 088 and 086 respectively) For BAC1 the highest
correlations were found for SrndashCa Alndash(Fe Ni) Kndash(Fe Ni)and BandashMg (r2frac14 095 098 098 and 081 respectively) Nega-tive correlationswere found at theCOC site (r2frac14090) forAlndash
(Zn Sr) Fendash(Ca U) Mnndash(U Ca) UndashSi and BandashZn but apositive correlation was found for Tindash(Mn Fe) with r2frac14 090In the BAC3 core relationships were found for only four
elements UndashSr and CandashMg (r2frac14 099)The relationship for Alndash(Ti Fe) in almost all cores is derived
from the fact that these elements represent silicates and otherrefractory minerals and hence aeolian or fluvial input of
particulate matter from land (Drever 2005) The correlationfor Candash(SrndashMg) in most cores is consistent with the maincarbonate minerology of these sediments Other correlations
are not universal and in general no pattern in spatial distribu-tion was found in the correlation between elements among allcores suggesting that these elements are not controlled by the
same parameters at each site
Hydrochemistry of Bacalar Lagoon Marine and Freshwater Research G
Sediment pollution
Some trace elements in Bacalar Lagoon sediments mayreflect anthropogenic pollution Here we used four indices
followingManoj and Padhy (2014 see Table 3)We normalisedconcentrations to Al because it is a conservative lithogenic
element and is resistant to chemical weathering hence it does
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
8000 9000 10 000 11 000
Sr (ppm) Ba (ppm) U (ppm) Mg (ppm)
8 10 12 14 16 18 0 01 02 03 04 05 06 300 000 400 000
Dep
th (
cm)
0 1000 5000
Al (ppm) Si (ppm) Ti (ppm) Ca (ppm)
Mn (ppm) Fe (ppm) Ni (ppm) Zn (ppm)
10 000 2020 000 2001000 0 200 000 400 000
0 1 2 3 4 0 400 1000 2000 0 20 40 60 500 100 150 25020080
COC BAC3 BAC1 BAC2
Fig 7 Concentrations of trace andmajor elements in sediment cores BAC1 Bacalar 1 BAC2 Bacalar 2 BAC3 Bacalar 3
COC Cocalitos
H Marine and Freshwater Research N I Tobon ndashVelazquez et al
not actively participate in the dominant geochemical cycles and
does not have a significant anthropogenic source (Boes et al2011 Dautovic et al 2014)
For normalisation to Al values for the Earthrsquos crust were
taken from Turekian and Wedepohl (1961) in which the valuesare mean concentrations in carbonates rocks of the upper crustKfrac14 27000 ppm Mnfrac14 11000 ppm Nifrac14 200 ppm
Znfrac14 200 ppm and Bafrac14 100 ppmTo determine whether the elements are from lithological or
anthropogenic sources the trace element concentrations were
compared with the crustal composition (Hernandez et al 2003)
frac12M lithogenic frac14 frac12Als ethfrac12M =frac12AlcTHORN eth1THORN
frac12M anthropogenic frac14 frac12M T frac12M lithogenic eth2THORN
where the lithogenic input ([M]lithogenic) is estimated throughthe concentration of Al in the sample ([Al]s) and the ratio of the
average of the Earthrsquos crust ([M][Al]c) The anthropogenic input([M]anthropogenic) was calculated based on the total concentration([M]T) and the lithogenic input
The results of these calculations are summarised in Table 4For all cores U6thorn Mn2thorn and Kthorn show negative values for theindex of geoaccumulation (Igeo) whereas the values of CF(contamination factor) and CD (contamination degree) are
lower than 20 All factors indicate that the sediment is notpolluted with these elements which are likely of lithogenicorigin For Ni2thorn the Igeo (0) CF (1) and CD (6) indices
also indicate low pollution except for the upper samples (depthsof 0ndash6 and 6ndash11 cm) of theBAC2 core where theCF is30 andIgeo is 10 suggesting unpolluted to moderately polluted
conditions In contrast the values of these indices for Zn2thorn
and Ba2thorn show some spatial variabilityThe CD of Zn2thorn at all sites is 15 The eastern samples
(BAC1 and BAC2) show higher CD values (822 and 1805
respectively) suggesting moderate to considerable contamina-
tion of the sediment The Ba2thorn concentration exhibits a spatialdistribution the western sites (COC RAP and BAC3) havehigher Ba2thorn concentrations compared than the eastern sites and
the calculated indices were correspondingly higher for thewestern side of the lagoon However overall the indicesindicated that the sediments on both sides of the lagoon are
unpollutedwith regard to Ba and the differences are likely due tohigher barite content on thewestern side Based on these indicesno influence of human activities was detected in eastern core
samples (BAC1 and BAC2)The higher Zn2thorn and Ba2thorn concentrations may be due to a
higher input of these elements into the area close to these sitesHowever water column distributions have to be assessed to
confirm this Zn2thorn and Ba2thorn in Bacalar Lagoon sediments couldbe derived from two sources (1) authigenic minerals found inthe sediment which on thewestern side contain barite (BaSO4)
and some sphalerite (ZnS) and (2) anthropogenic sources suchas agricultural fertiliser or cattle feed Commercial fertiliserscontain micronutrients such as Zn2thorn Mn2thorn Fe3thorn Cu2thorn Mo6thorn
and Ba2thorn in concentrations ranging from trace to several ppmwhich could infiltrate and cause pollution in the soil andgroundwater (Adriano 1986) Baize (1997) indicated that Znis found in animal feed used for pigs that are raised domestically
and commercially in the region The waste water generated bythis industry has been poorly handled resulting in adverseeffects on the environment (Drucker et al 2003) Near the town
of Bacalar fertilisers and agrochemicals are used regularly(Alvarez-Legorreta 2009) The agriculture practices in themunicipality include maize sugarcane and pepper and more
than 40 products are spread annually on these crops (fertilisersherbicides and pesticides Euan-Avila et al 2002) Garcıa-Rıosand Gold-Bouchot (2002) identified Fe V Ni Pb Zn Cu and
Cd in sediments of nearby Chetumal Bay Indeed Bacalar andOthon P Blanco municipalities have the highest fertilised area
Table 3 Indices as indicators of sediment quality based on Manoj and Padhy (2014) and Javan et al (2015)
Ms sample element concentration Mb background concentration of the element
Index Equation Sediment quality
Index of geoacumulation Igeofrac14 ln(Ms15Mb) 0frac14 unpolluted
0ndash1frac14 unpolluted to moderately polluted
1ndash2frac14moderately polluted
2ndash3frac14moderately polluted to highly polluted
3ndash4frac14 highly polluted
4ndash5frac14 highly polluted to very highly polluted
5frac14 very highly polluted
Contamination factor CF5MsMb 1frac14 low CF
1 CF 3frac14moderate CF
3 CF 6frac14 considerable CF
$6frac14 very high CF
Contamination degree CD frac14Pnifrac141
CF 6frac14 low CD
6 CD 12frac14moderate CD
12 CD 24frac14 considerable CD
$24frac14 high CD (anthropogenic contamination)
Pollution load index PLI5 (CF1CFsyCFn)1n 0frac14 unpolluted
1frac14 baseline levels of pollutants present
1frac14 progressive deterioration of site
Hydrochemistry of Bacalar Lagoon Marine and Freshwater Research I
Table4
Index
ofgeoacummulation(Igeo)anthropogenic(A
)inputcontaminationfactor(C
F)andcontaminationdegree(C
D)forBaUKMnNiandZnin
thesedim
entary
record
ofthe
BacalarLagoon
NAdatanoavailablePLIpollutionload
indexBAC1Bacalar
1BAC2Bacalar
2BAC3Bacalar
3COCCocalitosRAPLosRapidos
Site
Depth
(cm)
Ba
UK
Mn
Ni
Zn
PLI
I geo
Ainput
CF
CD
I geo
Ainput
CF
CD
I geo
Ainput
CF
CD
I geo
Ainput
CF
CD
I geo
Ainput
CF
CD
I geo
Ainput
CF
CD
COC
0ndash6
016
1236
134
701
503
013
005
065
688
24629
001
003
1119
11361
0001
0002
371
021
011
053
203
529
037
479
005
6ndash12
015
1314
135
469
005
006
675
5569
001
1160
3753
0000
409
107
009
004
2846
146
006
12ndash17
004
1421
146
336
024
015
NA
10001
000
1147
4016
0001
405
107
009
037
2254
116
000
17ndash22
014
1627
165
304
035
018
1158
6288
000
1257
2588
0000
362
196
012
010
3174
161
004
22ndash27
031
1156
121
282
035
021
NA
14125
000
1338
5739
0000
367
132
012
301
267
019
000
RAP
0ndash6
039
1074
115
264
538
008
004
009
889
18818
000
002
1067
7912
0001
0001
508
057
004
014
156
870
051
284
004
6ndash11
001
1360
149
475
017
006
651
31721
002
1189
14691
0000
391
069
010
063
4390
233
007
BAC1
0ndash5
024
267
127
956
402
201
009
069
230
189364
031
161
896
110398
0003
0023
300
1639
019
115
174
1118
045
822
014
5ndash10
035
302
118
416
174
008
276
176636
022
907
96021
0003
311
1404
017
066
2982
237
017
10ndash15
048
382
108
437
137
007
307
139830
018
913
76341
0003
327
1083
016
119
074
066
013
15ndash20
031
444
121
423
150
008
295
153179
019
896
83486
0003
330
1220
015
013
1225
137
015
20ndash25
031
488
121
420
142
008
301
145741
019
883
79449
0003
351
1189
013
424
1293
008
009
25ndash30
039
504
114
408
121
009
320
128917
016
925
70152
0002
363
1037
012
061
689
098
013
30ndash35
016
581
134
385
145
010
299
154625
019
904
83454
0003
353
1264
013
069
337
093
014
35ndash40
041
467
113
419
127
008
313
131772
017
917
72183
0003
392
1120
010
012
1446
138
013
BAC2
0ndash6
035
1141
117
734
515
002
004
086
743
6689
001
006
1094
3596
0001
0006
374
157
011
444
051
4203
214
1805
007
6ndash11
052
1005
105
462
004
006
834
10694
000
949
4638
0002
119
6764
343
012
2666
138
012
11ndash16
055
984
103
442
006
007
750
9268
001
1126
4617
0001
420
078
008
144
1018
055
005
16ndash21
055
985
102
400
013
009
597
3426
002
1119
3962
0001
421
089
008
001
2953
151
008
21ndash26
043
1093
111
296
038
019
828
3839
000
1178
2046
0000
412
135
009
293
22785
1141
009
26ndash31
068
925
094
254
054
026
832
2578
000
1194
1524
0000
273
424
023
104
1434
073
006
36ndash41
056
1001
102
337
028
014
875
3556
000
1113
1759
0001
182
819
043
219
626
033
006
BAC3
0ndash6
016
1283
134
407
607
009
002
007
682
12943
001
002
1266
6706
0000
0001
553
057
003
008
211
572
035
152
003
6ndash12
020
1270
131
607
003
002
989
9545
000
1308
4043
0000
580
020
003
081
1639
086
002
12ndash18
008
1389
142
613
003
002
891
8695
000
1341
3872
0000
593
021
002
223
567
032
002
J Marine and Freshwater Research N I Tobon ndashVelazquez et al
in Quintana Roo state (Instituto Nacional de Estadıstica yGeografıa 2016) Owing to the karstic nature of the area these
products can immediately infiltrate the aquifer and thereforecould be affecting the lagoon Because the concentration of ZnSminerals was low in the cores it is suggested that the source of
Zn2thorn could be derived from human activities Although theresults from the pollution load index (PLI) (1) for all samplesindicate that the sites are not highly polluted the excess Zn2thorn in
the sediment suggests some local pollution with regard to thiselement Conversely the concentrations of Ba2thorn can beexplained by the variable occurrence of barite in the cores
Minimal trace metal pollution is consistent with previous
metal work in the lagoon Castro-Contreras et al (2014)reported heavy metal concentrations in Bacalar Lagoon waterbelow the maximum limits of the Mexican legislation (NOM-
127-SSA1-1994) and ecological water quality criteria (CE-CCA-00189) that establish the limits of heavy metals fordrinking water irrigation and recreational activities
Nevertheless organochloride compounds (pesticides andpolychlorinated biphenyls) and hydrocarbons in sediments havebeen identified by Norena-Barroso et al (1998) in the ChetumalBay area near Bacalar Lagoon Organochlorine pesticides
(OCPs) are used in agriculture in the region (Alvarez-Legorreta2009) Furthermore heavymetals and OCPs have been detectedin crocodilian eggs near Chichorro Atoll (Charruau et al 2013
Buenfil-Rojas et al 2015)
Conclusions
Bacalar Lagoon is a shallow and oligotrophic system (low-
nutrient waters) with a mineralogical composition dominatedby calcite dolomite and evaporites dissolution Water geo-chemical analyses show a clear spatial distribution of different
parameters The western part of the study area is characterisedby high alkalinity and calcium and sulfate concentrations theratios of these constituents indicate groundwater sources and noseawater intrusion The decreases in these parameters towards
the north indicate a gradient in groundwater influencethroughout the lagoon The eastern part of the study area ischaracterised by a shallower water column resulting in high
evaporation and high electrical conductivity compared with thewestern side
We present the first measurements of trace elements in
carbonate sediments in Bacalar Lagoon The sediment exhibitsonly moderate contamination with Zn2thorn on the western side ofthe lagoon The high Ba concentration in the sediment corre-
sponds to barite but further work is necessary to identify thesource of Ba2thorn and Zn2thorn This study can be useful for Bacalarmunicipality to make decisions and define actions regarding themanagement and development of Bacalar Lagoon
Conflicts of interest
The authors declare that they have no conflicts of interest
Declaration of funding
This investigation was financed by the lsquoWater Security Project inthe South-eastMexico in the face of twoclimate change scenariosrsquoproject (CONACYT 247565) and lsquoProject networks CONACYTrsquo
(282240) The authors acknowledge a grant from CONACYT
towards a Masters of Water Sciences degree (awarded to NidiaTobon Velazquez)
Acknowledgements
The authors thank technical staff Daniela Ortega (Water Sciences Unit
Centro de Investigacion Cientıfica de Yucatan) and Kimberly Bitterwolf
(University of CaliforniamdashSanta Cruz)
References
Adriano D C (1986) lsquoTrace Elements in the Terrestrial Environmentrsquo
(Springer-Verlag Berlin Germany)
Alvarez-Legorreta T (2009) Contaminacion acuatica In lsquoEl sistema ecolo-
gico de la Bahıa de Chetumal Corozal costa occidental del Mar Caribersquo
(Eds J Espinoza Avalos G A Islebe and H A Hernandez Arana)
pp 205ndash217 (El Colegio de la Frontera Sur Chetumal Mexico)
Appelo C A and Postma D (2005) lsquoGeochemistry Groundwater and
Pollutionrsquo 2nd edn (A A Balkema Rotterdam Netherlands)
Baize D (1997) lsquoTeneurs totales en elements trace metalliques dans les sols
(France) References et strategies drsquointerpretationrsquo (INRA Paris France)
Bauer-Gottwein P Gondwe B Charvet G Marin L Rebolledo V M
andMerediz A G (2011) Review the Yucatan Peninsula karst aquifer
Mexico Hydrogeology Journal 19 507ndash524 doi101007S10040-010-
0699-5
Beddows P A (2002) lsquoWhere Does the Sewage Go The Karst
Groundwater System of the Municipalidad de Solidaridad Quintana
Roo Mexicorsquo (Association for Mexican Cave Studies Houston
TX USA)
Beltran D Y (2010) Estimacion de los patrones de fijacion de nitrogeno y
diversidad asociada (nifH) en tapices microbianos y estromatolitos
MSc Thesis Universidad Nacional Autonoma de Mexico Ciudad de
Mexico Mexico
Boes X Rydberg J Martinez C A Bindler R and Renberg I (2011)
Evaluation of conservative lithogenic elements (Ti Zr Al and Rb) to
study anthropogenic element enrichments in lake sediments Journal of
Paleolimnology 46 75ndash87 doi101007S10933-011-9515-Z
Boyle J F (2001) Inorganic geochemical methods in paleolimnology In
lsquoTracking Environmental Change Using Lake Sediments Vol 2 Physi-
cal andGeochemicalMethodsrsquo (EdsMW Last and P J Smol) pp 83ndash
143 (Kluwer Academic Publishers Dordrecht Netherlands)
Buenfil-Rojas A M Alvarez- Legorreta T and Cedeno-Vazquez J R
(2015) Metals and metallothioneins in Moreletrsquos Crocodile (Crocodile
moreletii) from a Transboundary River between Mexico and Belize
Archives of Environmental Contamination and Toxicology 68(2) 265ndash
273 doi101007S00244-014-0088-5
Castro-Contreras C Murray K G Pecoits E Aubet N R Petrash D
Castro C S Gregory D Planavsky N and Konhauser K O (2014)
Textural and geochemical features of freshwater microbialites from
LagunaBacalarQuintanaRooMexicoPalaios 29(5) 192ndash209 doi10
2110PALO2013063
Ceballos Martınez R R (2002) Geografıa y medio ambiente en el sistema
lagunar San FelipendashBacalarndashGuerrero In lsquoContribuciones de la ciencia al
manejo costero integrado de laBahıa deChetumal y su area de influenciarsquo
(Eds F J Rosado-May RRomeroMayo andADe Jesus Navarrete) pp
17ndash22 (Universidad de Quintana Roo Chetumal Mexico)
Centeno M C Legendre P Beltran Y Alcantara H R Lidstrom E U
Ashby N M and Falcon I L (2012) Microbialite genetic diversity
and composition relate to environmental variables FEMSMicrobiology
Ecology 82 724ndash735 doi101111J1574-6941201201447X
Chagas A P Webb E G Burne V R and Southam G (2016) Modern
lacustrine microbialites towards a synthesis of aqueous and carbonate
geochemistry and mineralogy Earth-Science Reviews 162 338ndash363
doi101016JEARSCIREV201609012
Charruau P Henaut Y and Alvarez-Legorreta T (2013) Organo-
chlorine pesticides in nest substratum and infertile eggs of American
Hydrochemistry of Bacalar Lagoon Marine and Freshwater Research K
crocodiles (Reptilia Crocodylidae) in a Mexican Caribbean atoll
Caribbean Journal of Science 47 1ndash12 doi1018475CJOSV47I1A2
Comision Nacional del Agua (2002) lsquoDeterminacion de la disponibilidad de
agua en el acuıfero Penınsula de Yucatan estado de Yucatanrsquo (CON-
AGUA Gerencia de Aguas Subterraneas Ciudad de Mexico Mexico)
Comision Nacional del Agua (2012) lsquoPrograma Hıdrico Regional Vision
2030 Region Hidrologico-Administrativa XII Penınsula de Yucatanrsquo
1st edn (Secretarıa de Medio Ambiente y Recursos Naturales Mexico
City Mexico)
Comision Nacional del Agua (2015) lsquoActualizacion de la disponibilidad
media anual de agua en el acuıfero Cerros y Valles (2301) Estado de
QuintanaRoorsquo (CONAGUADiarioOficial de la Federacion Ciudad de
Mexico Mexico)
Dautovic J Fiket Z Baresic J Ahel M and Mikac N (2014) Sources
distribution and behavior of major and trace elements in a complex karst
lake system Aquatic Geochemistry 20 19ndash38 doi101007S10498-
013-9204-9
Dıaz J E (2005) lsquoDecreto por el cual se establece el programa de
ordenamiento ecologico territorial de la region de Laguna Bacalar
Quintana Roo Mexicorsquo (Periodico Oficial Chetumal Mexico)
Dixon J Hamilton K Pagiola S and Segnestam L (2001) Tourism and
environment in the Caribbean an economic framework (The World
Bank Washington DC USA) Available at httpdocumentsworldbank
orgcurateden672281468770397455pdfmulti0pagepdf [Verified 18
October 2018]
Drever J I (2005) lsquoSurface and Ground Water Weathering and Soilsrsquo
(Elsevier Oxford UK)
Drucker A Escalante R Gomez V and Magana S (2003) La industria
porcina en Yucatan un analisis de la generacion de aguas residuales
Problemas del Desarrollo Revista Latinoamericana de Economıa 34
(135) 105ndash120
Dupraz C Reid R P andVisscher P T (2011)MicrobialitesModern In
lsquoEncyclopedia of Geobiology Encyclopedia of Earth Science Seriesrsquo
(Eds J Reitner and V Thiel) pp 617ndash635 (Springer Heidelberg
Germany)
Elango L andKannan R (2007) Rockndashwater interaction and its control on
chemical composition of groundwater In lsquoDevelopments in Environ-
mental Sciencersquo Vol 5 (Eds D Sarkar R Datta and R Hannigan) pp
229ndash243 (Elsevier Oxford UK)
Euan-Avila J I Liceaga-CorreaM A and Rodrıguez Sanchez H (2002)
Caracterizacion de fuentes no puntuales de contaminacion agrıcola en el
municipio deOthon P Blanco enQuintanaRoo y su potencial influencia
en la Bahıa de Chetumal In lsquoContribuciones de la ciencia al manejo
costero integrado de la Bahıa de Chetumal y su area de influenciarsquo (Eds
F J Rosado-May R Romero Mayo and A De Jesus Navarrete) pp
197ndash204 (Universidad de Quintana Roo Chetumal Mexico)
Fouke W B Zerkle L A Alvarez W Pope O K Ocampos A C
Wachtman J R Grajales J M Claeys P and Fischer G A (2002)
Cathodoluminescence petrography and isotope geochemistry of KT
impact ejecta deposited 360 km from the Chicxulub crater at Albion
Island Belize Sedimentology 49 117ndash138 doi101046J1365-3091
200200435X
Garcıa-Rıos V Y and Gold-Bouchot G (2002) Especiacion de metales
pesados en sedimentos de la Bahıa de Chetumal Quintana Roo y la
acumulacion en el tejido muscular de bagres (Ariopsis assimilis) In
lsquoContribuciones de la ciencia al manejo costero integrado de la Bahıa de
Chetumal y su area de influenciarsquo (Eds F J Rosado-May R Romero
Mayo and A De Jesus Navarrete) pp 143ndash148 (Universidad de
Quintana Roo Chetumal Mexico)
Gischler E Gibson M A and Oschmann W (2008) Giant Holocene
freshwater microbialites Laguna de Bacalar Quintana Roo Mexico
Sedimentology 55 1293ndash1309 doi101111J1365-3091200700946X
Gischler E Golubic S Gibson M Oschamann W and Hudson J H
(2011) Microbial mats and microbialites in the freshwater Laguna
Bacalar Yucatan Peninsula Mexico In lsquoAdvances in Stromatolite
Geobiologyrsquo (Eds J Reitner M H Trauth K Stuwe and D Yuen)
pp 187ndash205 (Springer Berlin Germany)
Gonzalez B J L Carrion J J Cuevas D J Flores M F Yam G J O
Moreno C J Perez V J and Calva C G (2014) Acumulacion de Hg
Pb Cd y Zn por Pomacea flagellata en tres balnearios ubicados en la
region urbana de la Laguna de Bacalar TecnoCultura 35 14ndash23
Hemley R J Prewitt C T and Kingma K (1994) High-pressure
behavior of silica In lsquoSilica ndash Physical Behavior Geochemistry and
Materials Applications Reviews in Mineralogy Vol 29rsquo (Eds P J
Heaney C T Prewitt and G V Gibbs) pp 41ndash82 (Mineralogical
Society of America Washington DC USA)
Hernandez L Probst A Probst L J and Ulrich E (2003) Heavy metal
distribution in some French forest soils evidence for atmospheric
contamination The Science of the Total Environment 312(1ndash3)
195ndash219 doi101016S0048-9697(03)00223-7
Hernandez-Terrones L Rebolledo-Vieyra M Merino-Ibarra M Soto
M Le-Cossec A and Monroy-Rıos E (2011) Groundwater pollution
in a karstic region (NE Yucatan) baseline nutrient content and flux to
coastal ecosystems Water Air and Soil Pollution 218(1ndash4) 517ndash528
doi101007S11270-010-0664-X
InstitutoNacional de Estadıstica yGeografıa (2002) EstudioHidrologico del
Estado de Quintana Roo (INEGI Aguascalientes Mexico) Available at
httpinternetcontenidosinegiorgmxcontenidosproductosprod_serv
contenidosespanolbvinegiproductoshistoricos2104702825224196
702825224196_1pdf [Verified 5 September 2018]
Instituto Nacional de Estadıstica y Geografıa (2016) Anuario Estadıstico y
Geografico de Quintana Roo (INEGI Aguascalientes Mexico) Avail-
able at httpinternetcontenidosinegiorgmxcontenidosProductos
prod_servcontenidosespanolbvinegiproductosnueva_estrucanuarios_
2016702825084370pdf [Verified 5 September 2018]
Javan S Hessam H A Gholamalizadeh A A and Soltani J (2015)
Fractionation of heavy metals in bottom sediments in Chahnimeh 1
Zabol Iran Environmental Monitoring and Assessment 187(6) 340
doi101007S10661-015-4510-X
Katip A Karaer F Ileri S Sarmasik S Aydogan N and Zenginay S
(2011) Analysis and assessment of trace elements pollution in sediments
of Lake Ulubat Turkey Journal of Environmental Biology 33 961ndash968
Kenkmann T and Schonian F (2006) Ries and Chicxulub impact craters
on Earth provide insights for Martian ejecta blankets Meteoritics amp
Planetary Science 41(10) 1587ndash1603 doi101111J1945-51002006
TB00437X
Khedidja A and Boudoukha A (2016) Lrsquoaquifere Superficiel de
Tadjnanet-Chelghoum laid (Nord-Est Algerien) Larhyss Journal 28
181ndash197
Lounejeva E Ostroumov M and Sanchez R G (2002) Polimorfos de
alta presion de sılice en las impactitas de ChicxulubMexico ndash resultados
de espectrometrıa de Raman Revista Mexicana de Ciencias Geologicas
17(2) 137ndash141
Manoj K and Padhy P K (2014) Distribution enrichment and ecological
risk assessment of six elements in bed sediments of a tropical river
Chottanagpur Plateau a spatial and temporal appraisal Journal of
Environmental Protection 5 1419ndash1434 doi104236JEP2014514136
Marfia A M Krishnamurthya R V Atekwanab E A and Panton W F
(2004) Isotopic and geochemical evolution of ground and surfacewaters
in a karst dominated geological setting a case study fromBelize Central
America Applied Geochemistry 19 937ndash946 doi101016JAPGEO
CHEM200310013
Massaferro J Correa M A Montes de Oca F and Mauad M (2018)
Contrasting responses of lake ecosystems to environmental disturbance
a paleoecological perspective from northern Patagonia (Argentina)
Hydrobiologia 816(1) 79ndash89 doi101007S10750-016-3081-3
Medina M S Jimenez G A Gutierrez R M and Lizardi J M (2014)
Hydrocarbon pollution studies of underwater sinkholes along Quintana
L Marine and Freshwater Research N I Tobon ndashVelazquez et al
Roo as function of tourism development in the Mexican Caribbean
Revista Mexicana de Ingenierıa Quımica 13(2) 509ndash516
Norena-Barroso E Zapata-Perez O Ceja-Moreno V and Gold-Bouchot
G (1998) Hydrocarbon and organochloride residue concentrations in
sediments from Bay of Chetumal Mexico Bulletin of Environmental
Contamination and Toxicology 61 80ndash87 doi101007S001289900732
Nriagu J and Pacyna J (1988) Quantitative assessment of worldwide
contamination of air water and soils by trace metals Nature 333 134ndash
139 doi101038333134A0
Ochoa J C Gonzalez B J and Jimenez C J (2016) Metales pesados
(Cd Cr Pb Hg) en Rhizophora mangle en rıo y bahıa de Chetumal
Revista Mexicana de Agroecosistemas 3(2) 263ndash271
Oliva R J Ocana F A de Jesus N A de Jesus C R and Vargas E A
(2016) Reproduccion dePomacea flagellata (Mollusca Ampullariidae)
en la laguna de Bacalar Quintana Roo Mexico Revista de Biologıa
Tropical 64(4) 1643ndash1650
Pacton M Hunger G Martinuzzi V Cusminsky G Burdin B
Barmettler K Vasconcelos C and Ariztegui D (2015) Organomi-
neralization processes in freshwater stromatolites a living example from
eastern Patagonia International Association of Sedimentologists Jour-
nal 1(2) 130ndash146
Perez L Bugja R Lorenschat J Brenner M Curtis J Hoelzmann P
Islebe G Scharf B and SchwalbA (2011) Aquatic ecosystems of the
Yucatan Peninsula (Mexico) Belize and Guatemala Hydrobiologia
661 407ndash433 doi101007S10750-010-0552-9
Perry E C Velazquez O G and Marin L (2002) The hydrogeochem-
istry of the karst aquifer system of the northern Yucatan Peninsula
Mexico International Geology Review 44 191ndash221 doi102747
0020-6814443191
Perry E Paytan A Pedersen B and Velazquez O G (2009) Ground-
water geochemistry of the Yucatan Peninsula Mexico constraints on
stratigraphy and hydrogeology Journal of Hydrology 367 27ndash40
doi101016JJHYDROL200812026
Pradit S Wattayarkorn G Angsupanich S Baeyens W and Leer-
makers M (2010) Distribution of trace elements in sediments and biota
of Songkhla Lake Southern Thailand Water Air and Soil Pollution
206 155ndash174 doi101007S11270-009-0093-X
Salomons W and Forstner U (1980) Trace metal analysis on polluted
sediments II evaluation of environmental impact Environmental
Technology Letters 1 506ndash517 doi10108009593338009384007
Sanchez S J Alvarez L T Pacheco A J Gonzalez H R and Carrillo
B L (2015) Caracterizacion hidrogeoquımica de las aguas subterraneas
del sur del Estado de Quintana Roo Mexico Revista Mexicana de
Ciencias Geologicas 32(1) 62ndash76
Schmitter-Soto J J Comın F A Escobar B E Herrera S J Alcocer J
Suarez M E Elıas G M Dıaz A V Marın L E and Steinich B
(2002) Hydrogeochemical and biological characteristics of cenotes in
the Yucatan Peninsula (SE Mexico) Hydrobiologia 467 215ndash228
doi101023A1014923217206
Siqueiros-Beltrones D Hernandez A U and Hernandez A O (2013)
Diagnosis prospectiva sobre la diversidad de diatomeas epilıticas en la
laguna Bacalar Quintana Roo Mexico Revista Mexicana de Biodiver-
sidad 84 865ndash875 doi107550RMB33960
Turekian K K andWedepohl K H (1961) Distribution of the elements in
some major units of the Earthrsquos crust Bulletin of the Geological Society
of America 72 175ndash192 doi1011300016-7606(1961)72[175
DOTEIS]20CO2
Handling Editor Russell Frew
wwwpublishcsiroaujournalsmfr
Hydrochemistry of Bacalar Lagoon Marine and Freshwater Research M
western side of the lagoon and two located on the eastern side(Fig 1) Two sampling campaigns were performed The loca-
tions of the sites were determined using a global positioningsystem (GPS (NOMAD Trimble Sunnyvale CA USA) withtheWorld Geodetic System (WGS) 84 datum Temperature pH
depth total dissolved solids (TDS) EC and dissolved oxygen(DO) were measured in the field (during both samplingcampaigns) using a multiparameter sonde (Model 6600 YSI
Control Tecnico y Representaciones Mexico City Mexico)Temperature profile data were collected using a CastAway-CTD (SonTek Xylem San Diego CA USA) The field para-meters were measured as close to sediment core and water
sample collection points as possibleThe first sampling campaign was conducted in November
2016 Five sediment cores of variable length (between 11 and
41 cm) were collected using a steel push core with 50-cmdiameter plastic liners Three sediment cores were taken at thewestern side of the lagoon (COCRAPandBAC3) and two cores
were taken at the eastern side (BAC1 and BAC2 Fig 1) Thesamples were kept at 408C The sediment cores were sectionedinto 40-cm intervals for a total of 27 samples Samples weredried at 508C in an oven and powdered using an agate mortar and
pestle In addition surface water samples were collected at eachof the seven study sites (Fig 1) Allwater samples were collectedin acid-washed polyethylene bottles (Nalgene SigmandashAldrich
Mexico Toluca Mexico) rinsed with sample at the time ofcollection Samples were filtered using 045-mm syringe filtersand analysed for alkalinity nutrients cations and anions
The second sampling campaign was conducted in June 2017During this campaign water samples were taken from sites atcenote Azul (Caz) and cenote Cocalitos (Ccoc Fig 1) At each
site two water samples (surface and at a depth of 150 m) werecollected by divers All samples collected during both campaignswere kept at 408C and transported to the Hydrogeochemistryand Water Quality Laboratory of the Water Sciences Unit
Centro de Investigacion Cientıfica de Yucatan
Laboratory analysis
Alkalinity was measured by the titration method using 02 Nsulfuric acid (H2SO4) Nutrients (NO3
NO2 PO4
3) cations(Ca2thorn Nathorn Mg2thorn Kthorn Sr2thorn) and anions (Cl SO4
2) weredetermined using ion chromatography with an 882 CompactPlus ICMetrohm (MetrohmMexico Mexico City Mexico) andcertified standards (TraceCERT SigmandashAldrich Mexico) forcalibration For determination of NH4
thorn a spectrophotometer
(LaMotte Analisis y Soluciones Ambientales Mexico CityMexico) was used Water analyses were performed at theHydrogeochemistry andWater Quality Laboratory of theWater
Sciences Unit Centro de Investigacion Cientıfica de YucatanAC The concentrations of major elements (Al Fe Ca Mg TiSr and K) and trace elements (Mn Ba Ni Zn andU) in sediment
samples were determined after sample dissolution using induc-tively coupled plasmandashmass spectrometry (ICP-MS XRThermoScientific San Diego CA USA) at the Institute of Marine Sci-
ences at the University of California ndash Santa Cruz (UCSC) Priorto these analyses 100 mg of homogenised sediment was dis-persed in 15 mL ofMilliQwater and digested using 155 N nitricacid (HNO3
) A 100-mL subsample was diluted 200-fold using
1HNO3 for analysis Instrumental drift was corrected with Sc
and Rh standards Rhwas used as the internal standard correctionfor Sr Ba and U whereas Sc was used as the internal standard
correction for all other elements Counts per second values wereconverted to concentrations using a standard curve prepared froma homemade rendition of the NIST1D (National Institute of
Standards and Technology NIST) standard reference material(argillaceous limestone) An average of three procedural blankswas subtracted from final concentration values
To determine the sediment mineralogy sediment samples(20 g) were analysed using a Panalytical XrsquoPert Pro X-RayDiffraction (XRD) Spectrometer (Royston UK) with a 1-hrotating platter in the Marine Sciences Laboratory UCSC
Sample 2-theta peaks were identified using the PanalyticalSpectrometer mineral spectrum database as a reference Themost prominent peaks for all samples occurred near 2958with a
pair of peaks near 46 and 478
Results and discussion
Physicochemical parameters
The main physicochemical features of shallow water in BacalarLagoon are presented in Table 1 The low EC values (265ndash319 mS cm1) indicate a freshwater system with pH ranging
from 66 to 73 at the sampling sites (mean pHfrac14 705) Watertemperature was relatively stable in the study area during oursampling campaigns (275ndash2978C) The EC temperature andpH ranges measured in this study are consistent with measure-
mentsmade byGischler et al (2008) Beltran (2010) Perez et al(2011) Castro-Contreras et al (2014) and Sanchez et al (2015)in this system
Fig 2 shows the temperature profiles along the southern sideof Bacalar Lagoon The relatively small temperature variabilityamong lagoon sites (285ndash2888C) suggests a near-homoge-
neous temperature with depth for both seasons (Fig 2b) Thisindicates awell-mixedwater column consistentwith the shallowdepth of the lagoon where the samples were collected
In contrast the water column profiles of the cenotes show
slight variability between sampling campaigns in June thetemperature of cenotes Azul and Cocalitos was higher (310and 3048C respectively) compared with November tempera-
tures (3008C) During both sampling campaigns the cenotes
clearly show stratification with two thermoclines During Junethe cenote Azul thermoclines are at depths of 05 and 120 m
whereas in November they are at 23 and 290 m (Fig 2c) Atcenote Cocalitos the June thermoclines are at 38 and 290 mwhereas in November they are at 20 and 240 m (Fig 2d) For
both cenotes the first thermocline is related to diurnal changesin solar radiation (heating of surfacewaters) whereas the secondis derived from distinct mixing that varies seasonally andbetween years During winter (November) water column mix-
ing extends deeper due to wind action whereas during summer(June) the changes in thermocline depth are due to an increase intemperature over the warm months allowing for water column
stratification and shallowing of the thermoclineNO3
concentrations ranged from 01 to 27 mg L1whereas NO2
and PO43concentrations were below the limits
of detection of the method used in the present study (001 and01 mg L1 respectively) These results are consistent with theoligotrophic designation of Bacalar Lagoon It has been
Hydrochemistry of Bacalar Lagoon Marine and Freshwater Research C
suggested (Beltran 2010) that the low concentrations of bio-
available nitrogen (NH4thorn NO2
and NO3) promote N2 fixa-
tion in the lagoon The lower nutrient concentrations also favourthe growth of stromatolites (Beltran 2010)
Cation abundance in Bacalar Lagoon water follows the order
Ca2thornMg2thornNathorn Sr2thornKthorn anion abundance is in theorder SO4
2HCO3ClNO3
(see Table 1) In orderto determine the main hydrochemical features of the lagoon a
88200W882240W882520W88280W
88200W882240W882520W88280W
0 095 19 285 38 km
284 285 286 287 2880
5
10
15
20
25
30
285 295 305 315 26 27 28 29 30 31
Temperature (degC)
Dep
th (
m)
(b) (c) (d )
184
120
N18
38
40N
183
60
N18
33
20N
184
120
N18
38
40N
183
60
N18
33
20N
(a)
N
S
EW
Fig 2 Temperature profiles in the lagoon and cenotes (a) Sampling locations Each symbol corresponds to the traces shown in the graphs on the right (b)
Temperature profiles at the different study sites in Bacalar Lagoon (c d) Temperature profiles of cenote Azul (c) and cenote Cocalitos (d) Grey (dots and
diamonds) correspond to the November 2016 sampling campaign dashed lines correspond to the June 2017 sampling campaign
Table 1 Main physical and chemical parameters of water samples in Bacalar Lagoon
Standard deviation for the elements is as followsNathorn 097Kthorn 013Mg2thorn 298Ca2thorn 1429 Sr2thorn 034Cl 211 SO42 90 SiO2
26NO3
019 andNH4thorn 004BLD below the limit of detectionNA data not available Ionic balance10 The locations of each of the sample sites are shown in
Fig 1
COC RAP BAC1 BAC2 BAC3 Ccoc Caz
Site Cocalitos Los Rapidos Bacalar 1 Bacalar 2 Bacalar 3 Cenote Cocalitos Cenote Azul
Depth (m) 05 05 05 05 05 05 150 05 150
pH 658 697 731 734 NA 654 NA 685 NA
Temperature (8C) 2926 2891 2747 2967 2920 293 2850 3084 2960
EC (mS cm1) 293 265 315 319 250 268 NA 267 NA
TDS (mgL1) 176 160 195 190 NA 157 NA 156 NA
Chemical composition (mgL1)
Nathorn 630 3247 13357 10811 3273 4740 3410 3130 3360
Kthorn 075 041 180 174 025 358 297 282 305
Mg2thorn 7120 7320 890 8365 7560 7340 7750 7680 7810
Ca2thorn 3930 3760 3860 3860 4220 2080 3540 3420 3650
Sr2thorn 546 631 715 439 270 476 592 545 552
Cl 10074 4166 28317 22640 4165 910 470 410 420
SO42 9620 10150 10910 9620 11740 9130 12370 11070 12840
SiO2 1625 220 2225 2350 1575 320 300 360 310
HCO3 15670 27090 8650 6190 22530 1550 2440 2140 2410
NO3 140 174 268 010 267 20 128 255 283
NO2 BLD BLD BLD BLD BLD BLD BLD BLD BLD
NH4thorn 018 013 028 019 014 020 026 021 023
PO43 BLD BLD BLD BLD BLD BLD BLD BLD BLD
D Marine and Freshwater Research N I Tobon ndashVelazquez et al
Piper diagram was made in Aquachem (ver 37 WaterlooHydrogeologic Kitchener ON Canada) using the proportionsofmajor cations and anions (Fig 3) All samples cluster together
in a group corresponding to a sulfatendashcalcium (CandashSO4) watertype Studies performed by Sanchez et al (2015) reported a CandashHCO3 water type in the northern part of the lagoon and Oliva
et al (2016) showed that the north side of Bacalar Lagoon ischaracterised by muddy sediments with murky water all yearlong In contrast the south of the lagoon is associatedwith sandy
sediments and high water transparency We attribute theobserved differences in water chemistry in the lagoon to theeffects of sulfate-rich groundwater inputs in the south compared
with the north where lower groundwater input and sulfateconcentrations were measured by Sanchez et al (2015) Thewater chemistry in the south can have a direct effect on theformation of stromatolites which are more abundant in the
southern part of theBacalar Lagoon Pacton et al (2015) showedthat stromatolites appear to prefer fresh water rather than turbidand brackish lake waters and turbidity is one of the most
important factors restraining stromatolite developmentAccording to the Piper diagram (Fig 3) the water type of
Bacalar Lagoon is dominated by sulfates (9620ndash
11740 mg L1) The SO4 Cl ratio may be indicative of waterorigin and the ratio at the western side ranged between 696 and2055 higher than at the eastern side (281ndash310) All theSO4 Cl ratios in Bacalar Lagoon are between 27- and 197-fold
greater than those of seawater (0103 Perry et al 2002)indicating that the sulfate source in the lagoon is not seawaterintrusion Therefore we interpret the findings to indicate high
sulfate originating from dissolution of evaporitesAlthough all the lagoonwater samples cluster into one group
spatial differences are present within the lagoon and may
suggest differences in input sources or fluxes as well as inprocesses affecting solute concentrations within the lagoon The
western side of the lagoon is characterised by higher alkalinityand calcium concentrations (1570ndash2700 mg CaCO3 L
1 and3760ndash4220 mg L1 respectively) compared with the eastern
side (620ndash860 mg CaCO3 L1 and 860 mg L1 respectively)
The alkalinity of the western side is similar to the alkalinitymeasured at Caz and Ccoc (2440 and 2410 mg CaCO3 L1
respectively at a depth of 150 m) A gradient of increasingalkalinity is seen from north to south Because high alkalinity isassociated with groundwater input and the waters are undersat-urated with regard to carbonate minerals this alkalinity gradient
indicates a diminishing effect of groundwater towards the northof the lagoon Schmitter-Soto et al (2002) reported other factorsthat can affect alkalinity in the Yucatan Peninsula including the
contribution of meteoric water (rich in carbonate and bicarbon-ate) and precipitation which promotes the dissolution of carbo-nates and therefore affects alkalinity
The concentrations of Ca2thorn and SO42 are lower on the
eastern than western side of the lagoon potentially explainingthe formation of stromatolites in the western part of the lagoonwhere external sources of Ca2thorn and SO4
2 are present To reach
the saturation necessary for precipitation of microbialites Ca2thorn
and SO42 are needed which has been reported in other systems
(Chagas et al 2016) The EC (315ndash319 mS cm1) and Nathorn
(47ndash58 mg L1) and Cl (410ndash2830 mg L1) concentrationson the eastern side of the lagoon are higher than on the westernside (265ndash293 mS cm1) These differences most likely occur
because the eastern part of Bacalar Lagoon is shallower (04ndash06 m) than the western part (10ndash22 m) promoting higherevaporation on the eastern side Marfia et al (2004) identified
high-calcium high-sulfate water in the south-eastern area ofQuintana Roo including north-eastern Belize likely fromgypsum dissolution when the groundwater is mixed withseawater the mixture forms a caliche barrier preventing seawa-
ter intrusion characteristic of the north-east coastThe (Ca2thornthornMg2thornthornHCO3
) to (NathornthornClthorn SO42) ratio
has been used to determine the effect of carbonate and evaporite
solute sources in groundwater and surface waters (Appelo andPostma 2005 Khedidja and Boudoukha 2016) When plottingthis ratio against EC (Fig 4) it is clear that dissolution of
evaporitic substratum is the dominant source of cations in thissystem The lower EC (fresh water) and a carbonate to sulfateion ratio 10 also indicate that evaporite dissolution and notseawater intrusion controls ion composition in Bacalar Lagoon
The saturation indices (SI) for the different mineral speciesconsidered in our system (calcite dolomite aragonite gypsumand celestite) were calculated based on field pH and temperature
measurements using PHREEQC (ver 37 US Geological Sur-vey Denver CO USA) (Fig 5) Our calculations allowed us todetermine the SI of Bacalar Lagoon water (note SIfrac14 0 signifies
equilibrium SI 0 signifies oversaturation and thus mineralprecipitation and SI 0 signifies undersaturation and thusmineral dissolution (Appelo and Postma 2005)
According to the SI calculations three trends were identified(Fig 5) The first corresponds to four sites (RAP BAC3 Cazand Ccoc 15 m deep) and shows oversaturated conditions withregard to aragonite calcite and dolomite In the second group
(Coc and Ccoc surface sample) all the minerals are
C a t i o n s A n i o n s mEq L1
NaK HCO3CO3 Cl
Mg SO4
CaCalcium (Ca) Chloride (Cl)
(SO 4
) (C
l)
(Ca)
(Mg)
(CO 3
)(H
CO 3
)
(Na)
(K)
Sulfate (SO4 )
Mag
nesi
um (M
g)
80 60 40 20 20 40 60 80
8060
4020
20
40
60
80
2040
6080
80
60
40
20
2040
6080
20
40
60
80
80
60
4020
8060
4020
COCRAPBAC1BAC2BAC3CcocCaz
Fig 3 Piper diagram and groundwater composition Each symbol corre-
spond to lagoon sites white square and white triangle points correspond to
cenotes samples which represent the groundwater in the region BAC1
Bacalar 1 BAC2 Bacalar 2 BAC3 Bacalar 3 Caz cenote Azul Ccoc
cenote Cocalitos COC Cocalitos RAP Los Rapidos
Hydrochemistry of Bacalar Lagoon Marine and Freshwater Research E
experiencing dissolution (undersaturation) Finally the thirdgroup (BAC1 and BAC2) is associated with calcite equilibrium
and undersaturation of the other minerals Bacalar Lagoon islocated in a region whereMiocene rocks containing gypsum andanhydrite are common and waterndashrock interaction results in the
dissolution of evaporites (Perry et al 2002 2009) The highconcentrations of Ca2thorn SO4
2 and Sr2thorn could be derived fromthe dissolution of these minerals The water samples in Bacalar
Lagoon are all undersaturated with regard to gypsum andanhydrite indicating that these minerals would not precipitatewithin the lagoon Ceballos Martınez (2002) indicated that
gypsum and limestone in the Bacalar formation tend to beconcentrated in the surface due to weathering forming lamellarcaliche
The Sr2thorn concentrations in samples from the western side are
quite similar to concentrations measured at the cenotes indicat-ing an input of this element from groundwater The same wassuggested by Perry et al (2002 2009) when they compared
concentrations of Sr2thorn and SO42 and Sr isotopes in the lagoon
to those of cenote AzulStandardised principal component analysis (PCA) was per-
formed using R (ver 340 R Foundation for Statistical Com-puting Vienna Austria) to identify the dominant limnologicalgradients in the dataset Fig 6 shows the results of a PCAappliedto the 15 hydrochemical variables measured here (water tem-
perature pH EC TDS SiO2 HCO3
Cl SO42 NO3
NH4
thorn Ca2thorn Kthorn Mg2thorn Nathorn and Sr2thorn) We present only thefirst two components (PC1 and PC2) because these explained 47
and 22 of the total variance respectively (Table 2) PCArepresents standard deviations and when the distance among
COC RAP BAC3 BAC1 BAC2 Ccoc Ccoclowast Caz Cazlowast
Sat
urat
ion
inde
x
15
10
05
0
05
10
Anhydrite (CaSO4)Aragonite (CaCO3)
Calcite (CaCO3)
Celestite (SrSO4)Gypsum (CaSO42H2O)
Dolomite (Ca Mg(CO3))
Fig 5 Saturation index (SI) calculated for each sample site for all relevant
minerals Note SIfrac14 0 indicates the mineral equilibrium (grey line) SI 0
indicates oversaturation and SI 0 indicates undersaturation Asterisks
indicate cenote water samples at a depth of 15 m BAC1 Bacalar 1
BAC2 Bacalar 2 BAC3 Bacalar 3 Caz cenote Azul Ccoc cenote
Cocalitos COC Cocalitos RAP Los Rapidos
24
2
4
0
2
4
0
PC1
2 4
PC
2
Ca
pHSO4
HCO3
NO3
Temp
TDS
Mg
ECNaCl
Sr
NH4
Caz
Ccoc
BAC2 BAC1
RAP
BAC3
COC
SiO2SiO2
K
Fig 6 Principal component analysis based on 15 chemical variables (grey
arrows) at different sampling sites (lagoon and cenotes) PC1 principal
component 1 PC2 principal component 2 EC electrical conductivity
TDS total dissolved solids Temp temperature BAC1 Bacalar 1 BAC2
Bacalar 2 BAC3 Bacalar 3 Caz cenote Azul Ccoc cenote Cocalitos
COC Cocalitos RAP Los Rapidos
Table 2 Eigenvalues of principal component analysis components and
variance explained
Principal component Eigenvalue Variance explained ()
1 706 4712
2 338 2258
3 210 1402
4 127 851
0 05 10 15 20 25 30 3502
04
06
10
12
14
Effect ofevaporates
BAC3
RAP
COCCaz
CcocBAC2
BAC1
Ca
Mg
HC
O3
Na
Cl
SO
4
Conductivity (mS cm1)
Effect ofcarbonates
Fig 4 Mineralisation effect on water chemistry Dark grey points repre-
sent the sampling sites dashed circular areas indicate the range in which the
electrical conductivity and major element ratios are interpreted as resulting
from mineralisation of evaporites or carbonates according to Khedidja and
Boudoukha (2016) BAC1 Bacalar 1 BAC2 Bacalar 2 BAC3 Bacalar 3
Caz cenote Azul Ccoc cenote Cocalitos COC Cocalitos RAP Los
Rapidos
F Marine and Freshwater Research N I Tobon ndashVelazquez et al
samples is greater than 2 units this indicates that the physico-chemical conditions are distinct (Massaferro et al 2018) hence
variations could be interpreted as significant differencesbetween sites
Samples along PCA Axis 1 show two distinctive patterns
within the lagoon which are separated by pH EC TDS Nathorn
and HCO3 distribution The spread of samples within PC1 is
relatively large suggesting significant differences among sites
This spread reflects the distinct distributions of physicochemicalfeatures at the different sides of the lagoon the western side(Axis 1 from 4 to 0 units) is characterised by a high HCO3
content (COC RAP BAC3 Ccoc and Caz) whereas the eastern
side (Axis 1 from 0 to 4 units) is characterised by high EC NathornpH and TDS and corresponds to the BAC1 and BAC2 sites
PC2 is associated with SiO2 and Kthorn concentrations PC2
shows two groups with the first group corresponding to sampleswith low SiO2
and Kthorn concentrations (COC RAP BAC1BAC2 and BAC3) and positive values of Axis 2 (from 4 to 0)
The second group is characterised by high SiO2 and Kthorn
concentrations (Ccoc and Caz samples) and corresponds tonegative axis values (from 0 to 4) PC2 is associated withsilica content due to higher silica concentrations in the cenotes
compared with the rest of the lagoon samples This can beexplained by more rapid Si uptake in the sun-lit lagoon wherediatoms are abundant
Changes in pH and transparency by sediment disturbance canhave an effect on stromatolites Sulfate-reducing bacteria par-ticipate in the formation of stromatolites and appear to always be
associated with Mg calcite and low-salinity and low-turbiditywaters Although stromatolites were not analysed in the presentstudy we recommend that a water monitoring program be
established to survey nutrients and measure other variablessuch as transparency tourist and boat activity weatheringdisturbance of sediments and trace elements at least twice ayear to ensure that the stromatolites are not negatively affected
Sediment characterisation
X-Ray diffraction
The results from the XRD analyses indicate that the mainmineralogical composition for all sediment samples was calcite(CaCO3) dolomite (CaMg(CO3)2) and SiO2 (quartz and possi-
bly minor amounts of coesite) In general calcite was in highestabundance in all cores Dolomite was present in all samples atlower proportions
These results are in accordance with the SI where calcite is
oversaturated in the western part of the lagoon and Ca2thorn andHCO3
concentrations are elevated throughout the lagoonCoesite forms under conditions of high pressure (3ndash10 GPa
Hemley et al 1994) and the presence of this mineral could berelated to the impact of the Chicxulub meteorite (Lounejevaet al 2002) Fouke et al (2002) with an estimated diameter of
its effect 360 km The presence of coesite in Bacalar Lagooncould be associated with this event Fouke et al (2002) andKenkmann and Schonian (2006) reported Chicxulub ejecta
deposited in Belize and in some regions of the Rio Hondo (nearBacalar Lagoon) However identifying the origin of this min-eral in Bacalar Lagoon requires additional detailed studies withlonger scan times to confirm the presence of coesite Other
minerals that we found in lower proportions are barite (BaSO4)
and a few samples with sphalerite (ZnS) with higher propor-tions of barite in the western than eastern side of the lagoon
Geochemistry
Elemental concentrations in the sediment samples are shown
in Fig 7 All sediment cores had high concentrations of Ca2thornMg2thorn and Sr2thorn which were one to three orders of magnitudehigher than concentrations for the rest of the elements consis-
tent with carbonate minerals (calcite) dominating the sedimentElement abundance was similar in cores of sites located in
the western part of the lagoon (COC RAP and BAC3) in the
order Ca2thornMg2thornSr2thorn Si4thornAl3thorn Fe3thornZn2thorn
KthornBa2thornTi4thornNi2thornMn2thornU6thorn The order of ele-ment abundance for the eastern cores (BAC1 and BAC2) was
similar except that Mg was more abundant than Ca (Mg2thorn
Ca2thorn Sr2thorn Si4thornAl3thorn Fe3thornZn2thornKthornNi2thorn
Ba2thornTi4thornMn2thornU6thorn) These relative abundances sug-gest that cores from the western side are dominated by Ca2thorn
carbonate minerals (likely calcite) whereas those from the eastside contain more dolomite The BAC1 core had the highestconcentrations of Al3thorn Si4thorn Kthorn Ti4thorn Mn2thorn and Fe3thorn likelyrepresenting some silicates and ironndashmanganese oxides fromterrigenous sources The highest Ni2thorn and Zn2thornconcentrationswere measured in the core from BAC2 and may represent
anthropogenic pollutant inputs The other elements analysedhad similar distributions in all cores
In general concentrations of Ba2thorn U6thorn and Zn2thorn werehigher in deeper sections of the cores and this may suggest
temporal changes in the input of these elements The rest of theelements (Ca2thorn and Mg2thorn) did not show variations with depthdown the core (r2 05)
The concentrations of elements span orders of magnitudetherefore the data do not satisfy the assumption of normality ASpearman correlation was performed using STATISTICA
(ver 133 Palo Alto CA USA) to test the relationship betweenthe trace elements in each core with significance level atP 005
Except for BAC3 the most significant correlation was forAlndash(FendashTi) (r2 090) In the BAC2 core significant correla-tions were found for SrndashMg AlndashTi KndashNi and SindashTi (r2frac14 090090 088 and 086 respectively) For BAC1 the highest
correlations were found for SrndashCa Alndash(Fe Ni) Kndash(Fe Ni)and BandashMg (r2frac14 095 098 098 and 081 respectively) Nega-tive correlationswere found at theCOC site (r2frac14090) forAlndash
(Zn Sr) Fendash(Ca U) Mnndash(U Ca) UndashSi and BandashZn but apositive correlation was found for Tindash(Mn Fe) with r2frac14 090In the BAC3 core relationships were found for only four
elements UndashSr and CandashMg (r2frac14 099)The relationship for Alndash(Ti Fe) in almost all cores is derived
from the fact that these elements represent silicates and otherrefractory minerals and hence aeolian or fluvial input of
particulate matter from land (Drever 2005) The correlationfor Candash(SrndashMg) in most cores is consistent with the maincarbonate minerology of these sediments Other correlations
are not universal and in general no pattern in spatial distribu-tion was found in the correlation between elements among allcores suggesting that these elements are not controlled by the
same parameters at each site
Hydrochemistry of Bacalar Lagoon Marine and Freshwater Research G
Sediment pollution
Some trace elements in Bacalar Lagoon sediments mayreflect anthropogenic pollution Here we used four indices
followingManoj and Padhy (2014 see Table 3)We normalisedconcentrations to Al because it is a conservative lithogenic
element and is resistant to chemical weathering hence it does
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
8000 9000 10 000 11 000
Sr (ppm) Ba (ppm) U (ppm) Mg (ppm)
8 10 12 14 16 18 0 01 02 03 04 05 06 300 000 400 000
Dep
th (
cm)
0 1000 5000
Al (ppm) Si (ppm) Ti (ppm) Ca (ppm)
Mn (ppm) Fe (ppm) Ni (ppm) Zn (ppm)
10 000 2020 000 2001000 0 200 000 400 000
0 1 2 3 4 0 400 1000 2000 0 20 40 60 500 100 150 25020080
COC BAC3 BAC1 BAC2
Fig 7 Concentrations of trace andmajor elements in sediment cores BAC1 Bacalar 1 BAC2 Bacalar 2 BAC3 Bacalar 3
COC Cocalitos
H Marine and Freshwater Research N I Tobon ndashVelazquez et al
not actively participate in the dominant geochemical cycles and
does not have a significant anthropogenic source (Boes et al2011 Dautovic et al 2014)
For normalisation to Al values for the Earthrsquos crust were
taken from Turekian and Wedepohl (1961) in which the valuesare mean concentrations in carbonates rocks of the upper crustKfrac14 27000 ppm Mnfrac14 11000 ppm Nifrac14 200 ppm
Znfrac14 200 ppm and Bafrac14 100 ppmTo determine whether the elements are from lithological or
anthropogenic sources the trace element concentrations were
compared with the crustal composition (Hernandez et al 2003)
frac12M lithogenic frac14 frac12Als ethfrac12M =frac12AlcTHORN eth1THORN
frac12M anthropogenic frac14 frac12M T frac12M lithogenic eth2THORN
where the lithogenic input ([M]lithogenic) is estimated throughthe concentration of Al in the sample ([Al]s) and the ratio of the
average of the Earthrsquos crust ([M][Al]c) The anthropogenic input([M]anthropogenic) was calculated based on the total concentration([M]T) and the lithogenic input
The results of these calculations are summarised in Table 4For all cores U6thorn Mn2thorn and Kthorn show negative values for theindex of geoaccumulation (Igeo) whereas the values of CF(contamination factor) and CD (contamination degree) are
lower than 20 All factors indicate that the sediment is notpolluted with these elements which are likely of lithogenicorigin For Ni2thorn the Igeo (0) CF (1) and CD (6) indices
also indicate low pollution except for the upper samples (depthsof 0ndash6 and 6ndash11 cm) of theBAC2 core where theCF is30 andIgeo is 10 suggesting unpolluted to moderately polluted
conditions In contrast the values of these indices for Zn2thorn
and Ba2thorn show some spatial variabilityThe CD of Zn2thorn at all sites is 15 The eastern samples
(BAC1 and BAC2) show higher CD values (822 and 1805
respectively) suggesting moderate to considerable contamina-
tion of the sediment The Ba2thorn concentration exhibits a spatialdistribution the western sites (COC RAP and BAC3) havehigher Ba2thorn concentrations compared than the eastern sites and
the calculated indices were correspondingly higher for thewestern side of the lagoon However overall the indicesindicated that the sediments on both sides of the lagoon are
unpollutedwith regard to Ba and the differences are likely due tohigher barite content on thewestern side Based on these indicesno influence of human activities was detected in eastern core
samples (BAC1 and BAC2)The higher Zn2thorn and Ba2thorn concentrations may be due to a
higher input of these elements into the area close to these sitesHowever water column distributions have to be assessed to
confirm this Zn2thorn and Ba2thorn in Bacalar Lagoon sediments couldbe derived from two sources (1) authigenic minerals found inthe sediment which on thewestern side contain barite (BaSO4)
and some sphalerite (ZnS) and (2) anthropogenic sources suchas agricultural fertiliser or cattle feed Commercial fertiliserscontain micronutrients such as Zn2thorn Mn2thorn Fe3thorn Cu2thorn Mo6thorn
and Ba2thorn in concentrations ranging from trace to several ppmwhich could infiltrate and cause pollution in the soil andgroundwater (Adriano 1986) Baize (1997) indicated that Znis found in animal feed used for pigs that are raised domestically
and commercially in the region The waste water generated bythis industry has been poorly handled resulting in adverseeffects on the environment (Drucker et al 2003) Near the town
of Bacalar fertilisers and agrochemicals are used regularly(Alvarez-Legorreta 2009) The agriculture practices in themunicipality include maize sugarcane and pepper and more
than 40 products are spread annually on these crops (fertilisersherbicides and pesticides Euan-Avila et al 2002) Garcıa-Rıosand Gold-Bouchot (2002) identified Fe V Ni Pb Zn Cu and
Cd in sediments of nearby Chetumal Bay Indeed Bacalar andOthon P Blanco municipalities have the highest fertilised area
Table 3 Indices as indicators of sediment quality based on Manoj and Padhy (2014) and Javan et al (2015)
Ms sample element concentration Mb background concentration of the element
Index Equation Sediment quality
Index of geoacumulation Igeofrac14 ln(Ms15Mb) 0frac14 unpolluted
0ndash1frac14 unpolluted to moderately polluted
1ndash2frac14moderately polluted
2ndash3frac14moderately polluted to highly polluted
3ndash4frac14 highly polluted
4ndash5frac14 highly polluted to very highly polluted
5frac14 very highly polluted
Contamination factor CF5MsMb 1frac14 low CF
1 CF 3frac14moderate CF
3 CF 6frac14 considerable CF
$6frac14 very high CF
Contamination degree CD frac14Pnifrac141
CF 6frac14 low CD
6 CD 12frac14moderate CD
12 CD 24frac14 considerable CD
$24frac14 high CD (anthropogenic contamination)
Pollution load index PLI5 (CF1CFsyCFn)1n 0frac14 unpolluted
1frac14 baseline levels of pollutants present
1frac14 progressive deterioration of site
Hydrochemistry of Bacalar Lagoon Marine and Freshwater Research I
Table4
Index
ofgeoacummulation(Igeo)anthropogenic(A
)inputcontaminationfactor(C
F)andcontaminationdegree(C
D)forBaUKMnNiandZnin
thesedim
entary
record
ofthe
BacalarLagoon
NAdatanoavailablePLIpollutionload
indexBAC1Bacalar
1BAC2Bacalar
2BAC3Bacalar
3COCCocalitosRAPLosRapidos
Site
Depth
(cm)
Ba
UK
Mn
Ni
Zn
PLI
I geo
Ainput
CF
CD
I geo
Ainput
CF
CD
I geo
Ainput
CF
CD
I geo
Ainput
CF
CD
I geo
Ainput
CF
CD
I geo
Ainput
CF
CD
COC
0ndash6
016
1236
134
701
503
013
005
065
688
24629
001
003
1119
11361
0001
0002
371
021
011
053
203
529
037
479
005
6ndash12
015
1314
135
469
005
006
675
5569
001
1160
3753
0000
409
107
009
004
2846
146
006
12ndash17
004
1421
146
336
024
015
NA
10001
000
1147
4016
0001
405
107
009
037
2254
116
000
17ndash22
014
1627
165
304
035
018
1158
6288
000
1257
2588
0000
362
196
012
010
3174
161
004
22ndash27
031
1156
121
282
035
021
NA
14125
000
1338
5739
0000
367
132
012
301
267
019
000
RAP
0ndash6
039
1074
115
264
538
008
004
009
889
18818
000
002
1067
7912
0001
0001
508
057
004
014
156
870
051
284
004
6ndash11
001
1360
149
475
017
006
651
31721
002
1189
14691
0000
391
069
010
063
4390
233
007
BAC1
0ndash5
024
267
127
956
402
201
009
069
230
189364
031
161
896
110398
0003
0023
300
1639
019
115
174
1118
045
822
014
5ndash10
035
302
118
416
174
008
276
176636
022
907
96021
0003
311
1404
017
066
2982
237
017
10ndash15
048
382
108
437
137
007
307
139830
018
913
76341
0003
327
1083
016
119
074
066
013
15ndash20
031
444
121
423
150
008
295
153179
019
896
83486
0003
330
1220
015
013
1225
137
015
20ndash25
031
488
121
420
142
008
301
145741
019
883
79449
0003
351
1189
013
424
1293
008
009
25ndash30
039
504
114
408
121
009
320
128917
016
925
70152
0002
363
1037
012
061
689
098
013
30ndash35
016
581
134
385
145
010
299
154625
019
904
83454
0003
353
1264
013
069
337
093
014
35ndash40
041
467
113
419
127
008
313
131772
017
917
72183
0003
392
1120
010
012
1446
138
013
BAC2
0ndash6
035
1141
117
734
515
002
004
086
743
6689
001
006
1094
3596
0001
0006
374
157
011
444
051
4203
214
1805
007
6ndash11
052
1005
105
462
004
006
834
10694
000
949
4638
0002
119
6764
343
012
2666
138
012
11ndash16
055
984
103
442
006
007
750
9268
001
1126
4617
0001
420
078
008
144
1018
055
005
16ndash21
055
985
102
400
013
009
597
3426
002
1119
3962
0001
421
089
008
001
2953
151
008
21ndash26
043
1093
111
296
038
019
828
3839
000
1178
2046
0000
412
135
009
293
22785
1141
009
26ndash31
068
925
094
254
054
026
832
2578
000
1194
1524
0000
273
424
023
104
1434
073
006
36ndash41
056
1001
102
337
028
014
875
3556
000
1113
1759
0001
182
819
043
219
626
033
006
BAC3
0ndash6
016
1283
134
407
607
009
002
007
682
12943
001
002
1266
6706
0000
0001
553
057
003
008
211
572
035
152
003
6ndash12
020
1270
131
607
003
002
989
9545
000
1308
4043
0000
580
020
003
081
1639
086
002
12ndash18
008
1389
142
613
003
002
891
8695
000
1341
3872
0000
593
021
002
223
567
032
002
J Marine and Freshwater Research N I Tobon ndashVelazquez et al
in Quintana Roo state (Instituto Nacional de Estadıstica yGeografıa 2016) Owing to the karstic nature of the area these
products can immediately infiltrate the aquifer and thereforecould be affecting the lagoon Because the concentration of ZnSminerals was low in the cores it is suggested that the source of
Zn2thorn could be derived from human activities Although theresults from the pollution load index (PLI) (1) for all samplesindicate that the sites are not highly polluted the excess Zn2thorn in
the sediment suggests some local pollution with regard to thiselement Conversely the concentrations of Ba2thorn can beexplained by the variable occurrence of barite in the cores
Minimal trace metal pollution is consistent with previous
metal work in the lagoon Castro-Contreras et al (2014)reported heavy metal concentrations in Bacalar Lagoon waterbelow the maximum limits of the Mexican legislation (NOM-
127-SSA1-1994) and ecological water quality criteria (CE-CCA-00189) that establish the limits of heavy metals fordrinking water irrigation and recreational activities
Nevertheless organochloride compounds (pesticides andpolychlorinated biphenyls) and hydrocarbons in sediments havebeen identified by Norena-Barroso et al (1998) in the ChetumalBay area near Bacalar Lagoon Organochlorine pesticides
(OCPs) are used in agriculture in the region (Alvarez-Legorreta2009) Furthermore heavymetals and OCPs have been detectedin crocodilian eggs near Chichorro Atoll (Charruau et al 2013
Buenfil-Rojas et al 2015)
Conclusions
Bacalar Lagoon is a shallow and oligotrophic system (low-
nutrient waters) with a mineralogical composition dominatedby calcite dolomite and evaporites dissolution Water geo-chemical analyses show a clear spatial distribution of different
parameters The western part of the study area is characterisedby high alkalinity and calcium and sulfate concentrations theratios of these constituents indicate groundwater sources and noseawater intrusion The decreases in these parameters towards
the north indicate a gradient in groundwater influencethroughout the lagoon The eastern part of the study area ischaracterised by a shallower water column resulting in high
evaporation and high electrical conductivity compared with thewestern side
We present the first measurements of trace elements in
carbonate sediments in Bacalar Lagoon The sediment exhibitsonly moderate contamination with Zn2thorn on the western side ofthe lagoon The high Ba concentration in the sediment corre-
sponds to barite but further work is necessary to identify thesource of Ba2thorn and Zn2thorn This study can be useful for Bacalarmunicipality to make decisions and define actions regarding themanagement and development of Bacalar Lagoon
Conflicts of interest
The authors declare that they have no conflicts of interest
Declaration of funding
This investigation was financed by the lsquoWater Security Project inthe South-eastMexico in the face of twoclimate change scenariosrsquoproject (CONACYT 247565) and lsquoProject networks CONACYTrsquo
(282240) The authors acknowledge a grant from CONACYT
towards a Masters of Water Sciences degree (awarded to NidiaTobon Velazquez)
Acknowledgements
The authors thank technical staff Daniela Ortega (Water Sciences Unit
Centro de Investigacion Cientıfica de Yucatan) and Kimberly Bitterwolf
(University of CaliforniamdashSanta Cruz)
References
Adriano D C (1986) lsquoTrace Elements in the Terrestrial Environmentrsquo
(Springer-Verlag Berlin Germany)
Alvarez-Legorreta T (2009) Contaminacion acuatica In lsquoEl sistema ecolo-
gico de la Bahıa de Chetumal Corozal costa occidental del Mar Caribersquo
(Eds J Espinoza Avalos G A Islebe and H A Hernandez Arana)
pp 205ndash217 (El Colegio de la Frontera Sur Chetumal Mexico)
Appelo C A and Postma D (2005) lsquoGeochemistry Groundwater and
Pollutionrsquo 2nd edn (A A Balkema Rotterdam Netherlands)
Baize D (1997) lsquoTeneurs totales en elements trace metalliques dans les sols
(France) References et strategies drsquointerpretationrsquo (INRA Paris France)
Bauer-Gottwein P Gondwe B Charvet G Marin L Rebolledo V M
andMerediz A G (2011) Review the Yucatan Peninsula karst aquifer
Mexico Hydrogeology Journal 19 507ndash524 doi101007S10040-010-
0699-5
Beddows P A (2002) lsquoWhere Does the Sewage Go The Karst
Groundwater System of the Municipalidad de Solidaridad Quintana
Roo Mexicorsquo (Association for Mexican Cave Studies Houston
TX USA)
Beltran D Y (2010) Estimacion de los patrones de fijacion de nitrogeno y
diversidad asociada (nifH) en tapices microbianos y estromatolitos
MSc Thesis Universidad Nacional Autonoma de Mexico Ciudad de
Mexico Mexico
Boes X Rydberg J Martinez C A Bindler R and Renberg I (2011)
Evaluation of conservative lithogenic elements (Ti Zr Al and Rb) to
study anthropogenic element enrichments in lake sediments Journal of
Paleolimnology 46 75ndash87 doi101007S10933-011-9515-Z
Boyle J F (2001) Inorganic geochemical methods in paleolimnology In
lsquoTracking Environmental Change Using Lake Sediments Vol 2 Physi-
cal andGeochemicalMethodsrsquo (EdsMW Last and P J Smol) pp 83ndash
143 (Kluwer Academic Publishers Dordrecht Netherlands)
Buenfil-Rojas A M Alvarez- Legorreta T and Cedeno-Vazquez J R
(2015) Metals and metallothioneins in Moreletrsquos Crocodile (Crocodile
moreletii) from a Transboundary River between Mexico and Belize
Archives of Environmental Contamination and Toxicology 68(2) 265ndash
273 doi101007S00244-014-0088-5
Castro-Contreras C Murray K G Pecoits E Aubet N R Petrash D
Castro C S Gregory D Planavsky N and Konhauser K O (2014)
Textural and geochemical features of freshwater microbialites from
LagunaBacalarQuintanaRooMexicoPalaios 29(5) 192ndash209 doi10
2110PALO2013063
Ceballos Martınez R R (2002) Geografıa y medio ambiente en el sistema
lagunar San FelipendashBacalarndashGuerrero In lsquoContribuciones de la ciencia al
manejo costero integrado de laBahıa deChetumal y su area de influenciarsquo
(Eds F J Rosado-May RRomeroMayo andADe Jesus Navarrete) pp
17ndash22 (Universidad de Quintana Roo Chetumal Mexico)
Centeno M C Legendre P Beltran Y Alcantara H R Lidstrom E U
Ashby N M and Falcon I L (2012) Microbialite genetic diversity
and composition relate to environmental variables FEMSMicrobiology
Ecology 82 724ndash735 doi101111J1574-6941201201447X
Chagas A P Webb E G Burne V R and Southam G (2016) Modern
lacustrine microbialites towards a synthesis of aqueous and carbonate
geochemistry and mineralogy Earth-Science Reviews 162 338ndash363
doi101016JEARSCIREV201609012
Charruau P Henaut Y and Alvarez-Legorreta T (2013) Organo-
chlorine pesticides in nest substratum and infertile eggs of American
Hydrochemistry of Bacalar Lagoon Marine and Freshwater Research K
crocodiles (Reptilia Crocodylidae) in a Mexican Caribbean atoll
Caribbean Journal of Science 47 1ndash12 doi1018475CJOSV47I1A2
Comision Nacional del Agua (2002) lsquoDeterminacion de la disponibilidad de
agua en el acuıfero Penınsula de Yucatan estado de Yucatanrsquo (CON-
AGUA Gerencia de Aguas Subterraneas Ciudad de Mexico Mexico)
Comision Nacional del Agua (2012) lsquoPrograma Hıdrico Regional Vision
2030 Region Hidrologico-Administrativa XII Penınsula de Yucatanrsquo
1st edn (Secretarıa de Medio Ambiente y Recursos Naturales Mexico
City Mexico)
Comision Nacional del Agua (2015) lsquoActualizacion de la disponibilidad
media anual de agua en el acuıfero Cerros y Valles (2301) Estado de
QuintanaRoorsquo (CONAGUADiarioOficial de la Federacion Ciudad de
Mexico Mexico)
Dautovic J Fiket Z Baresic J Ahel M and Mikac N (2014) Sources
distribution and behavior of major and trace elements in a complex karst
lake system Aquatic Geochemistry 20 19ndash38 doi101007S10498-
013-9204-9
Dıaz J E (2005) lsquoDecreto por el cual se establece el programa de
ordenamiento ecologico territorial de la region de Laguna Bacalar
Quintana Roo Mexicorsquo (Periodico Oficial Chetumal Mexico)
Dixon J Hamilton K Pagiola S and Segnestam L (2001) Tourism and
environment in the Caribbean an economic framework (The World
Bank Washington DC USA) Available at httpdocumentsworldbank
orgcurateden672281468770397455pdfmulti0pagepdf [Verified 18
October 2018]
Drever J I (2005) lsquoSurface and Ground Water Weathering and Soilsrsquo
(Elsevier Oxford UK)
Drucker A Escalante R Gomez V and Magana S (2003) La industria
porcina en Yucatan un analisis de la generacion de aguas residuales
Problemas del Desarrollo Revista Latinoamericana de Economıa 34
(135) 105ndash120
Dupraz C Reid R P andVisscher P T (2011)MicrobialitesModern In
lsquoEncyclopedia of Geobiology Encyclopedia of Earth Science Seriesrsquo
(Eds J Reitner and V Thiel) pp 617ndash635 (Springer Heidelberg
Germany)
Elango L andKannan R (2007) Rockndashwater interaction and its control on
chemical composition of groundwater In lsquoDevelopments in Environ-
mental Sciencersquo Vol 5 (Eds D Sarkar R Datta and R Hannigan) pp
229ndash243 (Elsevier Oxford UK)
Euan-Avila J I Liceaga-CorreaM A and Rodrıguez Sanchez H (2002)
Caracterizacion de fuentes no puntuales de contaminacion agrıcola en el
municipio deOthon P Blanco enQuintanaRoo y su potencial influencia
en la Bahıa de Chetumal In lsquoContribuciones de la ciencia al manejo
costero integrado de la Bahıa de Chetumal y su area de influenciarsquo (Eds
F J Rosado-May R Romero Mayo and A De Jesus Navarrete) pp
197ndash204 (Universidad de Quintana Roo Chetumal Mexico)
Fouke W B Zerkle L A Alvarez W Pope O K Ocampos A C
Wachtman J R Grajales J M Claeys P and Fischer G A (2002)
Cathodoluminescence petrography and isotope geochemistry of KT
impact ejecta deposited 360 km from the Chicxulub crater at Albion
Island Belize Sedimentology 49 117ndash138 doi101046J1365-3091
200200435X
Garcıa-Rıos V Y and Gold-Bouchot G (2002) Especiacion de metales
pesados en sedimentos de la Bahıa de Chetumal Quintana Roo y la
acumulacion en el tejido muscular de bagres (Ariopsis assimilis) In
lsquoContribuciones de la ciencia al manejo costero integrado de la Bahıa de
Chetumal y su area de influenciarsquo (Eds F J Rosado-May R Romero
Mayo and A De Jesus Navarrete) pp 143ndash148 (Universidad de
Quintana Roo Chetumal Mexico)
Gischler E Gibson M A and Oschmann W (2008) Giant Holocene
freshwater microbialites Laguna de Bacalar Quintana Roo Mexico
Sedimentology 55 1293ndash1309 doi101111J1365-3091200700946X
Gischler E Golubic S Gibson M Oschamann W and Hudson J H
(2011) Microbial mats and microbialites in the freshwater Laguna
Bacalar Yucatan Peninsula Mexico In lsquoAdvances in Stromatolite
Geobiologyrsquo (Eds J Reitner M H Trauth K Stuwe and D Yuen)
pp 187ndash205 (Springer Berlin Germany)
Gonzalez B J L Carrion J J Cuevas D J Flores M F Yam G J O
Moreno C J Perez V J and Calva C G (2014) Acumulacion de Hg
Pb Cd y Zn por Pomacea flagellata en tres balnearios ubicados en la
region urbana de la Laguna de Bacalar TecnoCultura 35 14ndash23
Hemley R J Prewitt C T and Kingma K (1994) High-pressure
behavior of silica In lsquoSilica ndash Physical Behavior Geochemistry and
Materials Applications Reviews in Mineralogy Vol 29rsquo (Eds P J
Heaney C T Prewitt and G V Gibbs) pp 41ndash82 (Mineralogical
Society of America Washington DC USA)
Hernandez L Probst A Probst L J and Ulrich E (2003) Heavy metal
distribution in some French forest soils evidence for atmospheric
contamination The Science of the Total Environment 312(1ndash3)
195ndash219 doi101016S0048-9697(03)00223-7
Hernandez-Terrones L Rebolledo-Vieyra M Merino-Ibarra M Soto
M Le-Cossec A and Monroy-Rıos E (2011) Groundwater pollution
in a karstic region (NE Yucatan) baseline nutrient content and flux to
coastal ecosystems Water Air and Soil Pollution 218(1ndash4) 517ndash528
doi101007S11270-010-0664-X
InstitutoNacional de Estadıstica yGeografıa (2002) EstudioHidrologico del
Estado de Quintana Roo (INEGI Aguascalientes Mexico) Available at
httpinternetcontenidosinegiorgmxcontenidosproductosprod_serv
contenidosespanolbvinegiproductoshistoricos2104702825224196
702825224196_1pdf [Verified 5 September 2018]
Instituto Nacional de Estadıstica y Geografıa (2016) Anuario Estadıstico y
Geografico de Quintana Roo (INEGI Aguascalientes Mexico) Avail-
able at httpinternetcontenidosinegiorgmxcontenidosProductos
prod_servcontenidosespanolbvinegiproductosnueva_estrucanuarios_
2016702825084370pdf [Verified 5 September 2018]
Javan S Hessam H A Gholamalizadeh A A and Soltani J (2015)
Fractionation of heavy metals in bottom sediments in Chahnimeh 1
Zabol Iran Environmental Monitoring and Assessment 187(6) 340
doi101007S10661-015-4510-X
Katip A Karaer F Ileri S Sarmasik S Aydogan N and Zenginay S
(2011) Analysis and assessment of trace elements pollution in sediments
of Lake Ulubat Turkey Journal of Environmental Biology 33 961ndash968
Kenkmann T and Schonian F (2006) Ries and Chicxulub impact craters
on Earth provide insights for Martian ejecta blankets Meteoritics amp
Planetary Science 41(10) 1587ndash1603 doi101111J1945-51002006
TB00437X
Khedidja A and Boudoukha A (2016) Lrsquoaquifere Superficiel de
Tadjnanet-Chelghoum laid (Nord-Est Algerien) Larhyss Journal 28
181ndash197
Lounejeva E Ostroumov M and Sanchez R G (2002) Polimorfos de
alta presion de sılice en las impactitas de ChicxulubMexico ndash resultados
de espectrometrıa de Raman Revista Mexicana de Ciencias Geologicas
17(2) 137ndash141
Manoj K and Padhy P K (2014) Distribution enrichment and ecological
risk assessment of six elements in bed sediments of a tropical river
Chottanagpur Plateau a spatial and temporal appraisal Journal of
Environmental Protection 5 1419ndash1434 doi104236JEP2014514136
Marfia A M Krishnamurthya R V Atekwanab E A and Panton W F
(2004) Isotopic and geochemical evolution of ground and surfacewaters
in a karst dominated geological setting a case study fromBelize Central
America Applied Geochemistry 19 937ndash946 doi101016JAPGEO
CHEM200310013
Massaferro J Correa M A Montes de Oca F and Mauad M (2018)
Contrasting responses of lake ecosystems to environmental disturbance
a paleoecological perspective from northern Patagonia (Argentina)
Hydrobiologia 816(1) 79ndash89 doi101007S10750-016-3081-3
Medina M S Jimenez G A Gutierrez R M and Lizardi J M (2014)
Hydrocarbon pollution studies of underwater sinkholes along Quintana
L Marine and Freshwater Research N I Tobon ndashVelazquez et al
Roo as function of tourism development in the Mexican Caribbean
Revista Mexicana de Ingenierıa Quımica 13(2) 509ndash516
Norena-Barroso E Zapata-Perez O Ceja-Moreno V and Gold-Bouchot
G (1998) Hydrocarbon and organochloride residue concentrations in
sediments from Bay of Chetumal Mexico Bulletin of Environmental
Contamination and Toxicology 61 80ndash87 doi101007S001289900732
Nriagu J and Pacyna J (1988) Quantitative assessment of worldwide
contamination of air water and soils by trace metals Nature 333 134ndash
139 doi101038333134A0
Ochoa J C Gonzalez B J and Jimenez C J (2016) Metales pesados
(Cd Cr Pb Hg) en Rhizophora mangle en rıo y bahıa de Chetumal
Revista Mexicana de Agroecosistemas 3(2) 263ndash271
Oliva R J Ocana F A de Jesus N A de Jesus C R and Vargas E A
(2016) Reproduccion dePomacea flagellata (Mollusca Ampullariidae)
en la laguna de Bacalar Quintana Roo Mexico Revista de Biologıa
Tropical 64(4) 1643ndash1650
Pacton M Hunger G Martinuzzi V Cusminsky G Burdin B
Barmettler K Vasconcelos C and Ariztegui D (2015) Organomi-
neralization processes in freshwater stromatolites a living example from
eastern Patagonia International Association of Sedimentologists Jour-
nal 1(2) 130ndash146
Perez L Bugja R Lorenschat J Brenner M Curtis J Hoelzmann P
Islebe G Scharf B and SchwalbA (2011) Aquatic ecosystems of the
Yucatan Peninsula (Mexico) Belize and Guatemala Hydrobiologia
661 407ndash433 doi101007S10750-010-0552-9
Perry E C Velazquez O G and Marin L (2002) The hydrogeochem-
istry of the karst aquifer system of the northern Yucatan Peninsula
Mexico International Geology Review 44 191ndash221 doi102747
0020-6814443191
Perry E Paytan A Pedersen B and Velazquez O G (2009) Ground-
water geochemistry of the Yucatan Peninsula Mexico constraints on
stratigraphy and hydrogeology Journal of Hydrology 367 27ndash40
doi101016JJHYDROL200812026
Pradit S Wattayarkorn G Angsupanich S Baeyens W and Leer-
makers M (2010) Distribution of trace elements in sediments and biota
of Songkhla Lake Southern Thailand Water Air and Soil Pollution
206 155ndash174 doi101007S11270-009-0093-X
Salomons W and Forstner U (1980) Trace metal analysis on polluted
sediments II evaluation of environmental impact Environmental
Technology Letters 1 506ndash517 doi10108009593338009384007
Sanchez S J Alvarez L T Pacheco A J Gonzalez H R and Carrillo
B L (2015) Caracterizacion hidrogeoquımica de las aguas subterraneas
del sur del Estado de Quintana Roo Mexico Revista Mexicana de
Ciencias Geologicas 32(1) 62ndash76
Schmitter-Soto J J Comın F A Escobar B E Herrera S J Alcocer J
Suarez M E Elıas G M Dıaz A V Marın L E and Steinich B
(2002) Hydrogeochemical and biological characteristics of cenotes in
the Yucatan Peninsula (SE Mexico) Hydrobiologia 467 215ndash228
doi101023A1014923217206
Siqueiros-Beltrones D Hernandez A U and Hernandez A O (2013)
Diagnosis prospectiva sobre la diversidad de diatomeas epilıticas en la
laguna Bacalar Quintana Roo Mexico Revista Mexicana de Biodiver-
sidad 84 865ndash875 doi107550RMB33960
Turekian K K andWedepohl K H (1961) Distribution of the elements in
some major units of the Earthrsquos crust Bulletin of the Geological Society
of America 72 175ndash192 doi1011300016-7606(1961)72[175
DOTEIS]20CO2
Handling Editor Russell Frew
wwwpublishcsiroaujournalsmfr
Hydrochemistry of Bacalar Lagoon Marine and Freshwater Research M
suggested (Beltran 2010) that the low concentrations of bio-
available nitrogen (NH4thorn NO2
and NO3) promote N2 fixa-
tion in the lagoon The lower nutrient concentrations also favourthe growth of stromatolites (Beltran 2010)
Cation abundance in Bacalar Lagoon water follows the order
Ca2thornMg2thornNathorn Sr2thornKthorn anion abundance is in theorder SO4
2HCO3ClNO3
(see Table 1) In orderto determine the main hydrochemical features of the lagoon a
88200W882240W882520W88280W
88200W882240W882520W88280W
0 095 19 285 38 km
284 285 286 287 2880
5
10
15
20
25
30
285 295 305 315 26 27 28 29 30 31
Temperature (degC)
Dep
th (
m)
(b) (c) (d )
184
120
N18
38
40N
183
60
N18
33
20N
184
120
N18
38
40N
183
60
N18
33
20N
(a)
N
S
EW
Fig 2 Temperature profiles in the lagoon and cenotes (a) Sampling locations Each symbol corresponds to the traces shown in the graphs on the right (b)
Temperature profiles at the different study sites in Bacalar Lagoon (c d) Temperature profiles of cenote Azul (c) and cenote Cocalitos (d) Grey (dots and
diamonds) correspond to the November 2016 sampling campaign dashed lines correspond to the June 2017 sampling campaign
Table 1 Main physical and chemical parameters of water samples in Bacalar Lagoon
Standard deviation for the elements is as followsNathorn 097Kthorn 013Mg2thorn 298Ca2thorn 1429 Sr2thorn 034Cl 211 SO42 90 SiO2
26NO3
019 andNH4thorn 004BLD below the limit of detectionNA data not available Ionic balance10 The locations of each of the sample sites are shown in
Fig 1
COC RAP BAC1 BAC2 BAC3 Ccoc Caz
Site Cocalitos Los Rapidos Bacalar 1 Bacalar 2 Bacalar 3 Cenote Cocalitos Cenote Azul
Depth (m) 05 05 05 05 05 05 150 05 150
pH 658 697 731 734 NA 654 NA 685 NA
Temperature (8C) 2926 2891 2747 2967 2920 293 2850 3084 2960
EC (mS cm1) 293 265 315 319 250 268 NA 267 NA
TDS (mgL1) 176 160 195 190 NA 157 NA 156 NA
Chemical composition (mgL1)
Nathorn 630 3247 13357 10811 3273 4740 3410 3130 3360
Kthorn 075 041 180 174 025 358 297 282 305
Mg2thorn 7120 7320 890 8365 7560 7340 7750 7680 7810
Ca2thorn 3930 3760 3860 3860 4220 2080 3540 3420 3650
Sr2thorn 546 631 715 439 270 476 592 545 552
Cl 10074 4166 28317 22640 4165 910 470 410 420
SO42 9620 10150 10910 9620 11740 9130 12370 11070 12840
SiO2 1625 220 2225 2350 1575 320 300 360 310
HCO3 15670 27090 8650 6190 22530 1550 2440 2140 2410
NO3 140 174 268 010 267 20 128 255 283
NO2 BLD BLD BLD BLD BLD BLD BLD BLD BLD
NH4thorn 018 013 028 019 014 020 026 021 023
PO43 BLD BLD BLD BLD BLD BLD BLD BLD BLD
D Marine and Freshwater Research N I Tobon ndashVelazquez et al
Piper diagram was made in Aquachem (ver 37 WaterlooHydrogeologic Kitchener ON Canada) using the proportionsofmajor cations and anions (Fig 3) All samples cluster together
in a group corresponding to a sulfatendashcalcium (CandashSO4) watertype Studies performed by Sanchez et al (2015) reported a CandashHCO3 water type in the northern part of the lagoon and Oliva
et al (2016) showed that the north side of Bacalar Lagoon ischaracterised by muddy sediments with murky water all yearlong In contrast the south of the lagoon is associatedwith sandy
sediments and high water transparency We attribute theobserved differences in water chemistry in the lagoon to theeffects of sulfate-rich groundwater inputs in the south compared
with the north where lower groundwater input and sulfateconcentrations were measured by Sanchez et al (2015) Thewater chemistry in the south can have a direct effect on theformation of stromatolites which are more abundant in the
southern part of theBacalar Lagoon Pacton et al (2015) showedthat stromatolites appear to prefer fresh water rather than turbidand brackish lake waters and turbidity is one of the most
important factors restraining stromatolite developmentAccording to the Piper diagram (Fig 3) the water type of
Bacalar Lagoon is dominated by sulfates (9620ndash
11740 mg L1) The SO4 Cl ratio may be indicative of waterorigin and the ratio at the western side ranged between 696 and2055 higher than at the eastern side (281ndash310) All theSO4 Cl ratios in Bacalar Lagoon are between 27- and 197-fold
greater than those of seawater (0103 Perry et al 2002)indicating that the sulfate source in the lagoon is not seawaterintrusion Therefore we interpret the findings to indicate high
sulfate originating from dissolution of evaporitesAlthough all the lagoonwater samples cluster into one group
spatial differences are present within the lagoon and may
suggest differences in input sources or fluxes as well as inprocesses affecting solute concentrations within the lagoon The
western side of the lagoon is characterised by higher alkalinityand calcium concentrations (1570ndash2700 mg CaCO3 L
1 and3760ndash4220 mg L1 respectively) compared with the eastern
side (620ndash860 mg CaCO3 L1 and 860 mg L1 respectively)
The alkalinity of the western side is similar to the alkalinitymeasured at Caz and Ccoc (2440 and 2410 mg CaCO3 L1
respectively at a depth of 150 m) A gradient of increasingalkalinity is seen from north to south Because high alkalinity isassociated with groundwater input and the waters are undersat-urated with regard to carbonate minerals this alkalinity gradient
indicates a diminishing effect of groundwater towards the northof the lagoon Schmitter-Soto et al (2002) reported other factorsthat can affect alkalinity in the Yucatan Peninsula including the
contribution of meteoric water (rich in carbonate and bicarbon-ate) and precipitation which promotes the dissolution of carbo-nates and therefore affects alkalinity
The concentrations of Ca2thorn and SO42 are lower on the
eastern than western side of the lagoon potentially explainingthe formation of stromatolites in the western part of the lagoonwhere external sources of Ca2thorn and SO4
2 are present To reach
the saturation necessary for precipitation of microbialites Ca2thorn
and SO42 are needed which has been reported in other systems
(Chagas et al 2016) The EC (315ndash319 mS cm1) and Nathorn
(47ndash58 mg L1) and Cl (410ndash2830 mg L1) concentrationson the eastern side of the lagoon are higher than on the westernside (265ndash293 mS cm1) These differences most likely occur
because the eastern part of Bacalar Lagoon is shallower (04ndash06 m) than the western part (10ndash22 m) promoting higherevaporation on the eastern side Marfia et al (2004) identified
high-calcium high-sulfate water in the south-eastern area ofQuintana Roo including north-eastern Belize likely fromgypsum dissolution when the groundwater is mixed withseawater the mixture forms a caliche barrier preventing seawa-
ter intrusion characteristic of the north-east coastThe (Ca2thornthornMg2thornthornHCO3
) to (NathornthornClthorn SO42) ratio
has been used to determine the effect of carbonate and evaporite
solute sources in groundwater and surface waters (Appelo andPostma 2005 Khedidja and Boudoukha 2016) When plottingthis ratio against EC (Fig 4) it is clear that dissolution of
evaporitic substratum is the dominant source of cations in thissystem The lower EC (fresh water) and a carbonate to sulfateion ratio 10 also indicate that evaporite dissolution and notseawater intrusion controls ion composition in Bacalar Lagoon
The saturation indices (SI) for the different mineral speciesconsidered in our system (calcite dolomite aragonite gypsumand celestite) were calculated based on field pH and temperature
measurements using PHREEQC (ver 37 US Geological Sur-vey Denver CO USA) (Fig 5) Our calculations allowed us todetermine the SI of Bacalar Lagoon water (note SIfrac14 0 signifies
equilibrium SI 0 signifies oversaturation and thus mineralprecipitation and SI 0 signifies undersaturation and thusmineral dissolution (Appelo and Postma 2005)
According to the SI calculations three trends were identified(Fig 5) The first corresponds to four sites (RAP BAC3 Cazand Ccoc 15 m deep) and shows oversaturated conditions withregard to aragonite calcite and dolomite In the second group
(Coc and Ccoc surface sample) all the minerals are
C a t i o n s A n i o n s mEq L1
NaK HCO3CO3 Cl
Mg SO4
CaCalcium (Ca) Chloride (Cl)
(SO 4
) (C
l)
(Ca)
(Mg)
(CO 3
)(H
CO 3
)
(Na)
(K)
Sulfate (SO4 )
Mag
nesi
um (M
g)
80 60 40 20 20 40 60 80
8060
4020
20
40
60
80
2040
6080
80
60
40
20
2040
6080
20
40
60
80
80
60
4020
8060
4020
COCRAPBAC1BAC2BAC3CcocCaz
Fig 3 Piper diagram and groundwater composition Each symbol corre-
spond to lagoon sites white square and white triangle points correspond to
cenotes samples which represent the groundwater in the region BAC1
Bacalar 1 BAC2 Bacalar 2 BAC3 Bacalar 3 Caz cenote Azul Ccoc
cenote Cocalitos COC Cocalitos RAP Los Rapidos
Hydrochemistry of Bacalar Lagoon Marine and Freshwater Research E
experiencing dissolution (undersaturation) Finally the thirdgroup (BAC1 and BAC2) is associated with calcite equilibrium
and undersaturation of the other minerals Bacalar Lagoon islocated in a region whereMiocene rocks containing gypsum andanhydrite are common and waterndashrock interaction results in the
dissolution of evaporites (Perry et al 2002 2009) The highconcentrations of Ca2thorn SO4
2 and Sr2thorn could be derived fromthe dissolution of these minerals The water samples in Bacalar
Lagoon are all undersaturated with regard to gypsum andanhydrite indicating that these minerals would not precipitatewithin the lagoon Ceballos Martınez (2002) indicated that
gypsum and limestone in the Bacalar formation tend to beconcentrated in the surface due to weathering forming lamellarcaliche
The Sr2thorn concentrations in samples from the western side are
quite similar to concentrations measured at the cenotes indicat-ing an input of this element from groundwater The same wassuggested by Perry et al (2002 2009) when they compared
concentrations of Sr2thorn and SO42 and Sr isotopes in the lagoon
to those of cenote AzulStandardised principal component analysis (PCA) was per-
formed using R (ver 340 R Foundation for Statistical Com-puting Vienna Austria) to identify the dominant limnologicalgradients in the dataset Fig 6 shows the results of a PCAappliedto the 15 hydrochemical variables measured here (water tem-
perature pH EC TDS SiO2 HCO3
Cl SO42 NO3
NH4
thorn Ca2thorn Kthorn Mg2thorn Nathorn and Sr2thorn) We present only thefirst two components (PC1 and PC2) because these explained 47
and 22 of the total variance respectively (Table 2) PCArepresents standard deviations and when the distance among
COC RAP BAC3 BAC1 BAC2 Ccoc Ccoclowast Caz Cazlowast
Sat
urat
ion
inde
x
15
10
05
0
05
10
Anhydrite (CaSO4)Aragonite (CaCO3)
Calcite (CaCO3)
Celestite (SrSO4)Gypsum (CaSO42H2O)
Dolomite (Ca Mg(CO3))
Fig 5 Saturation index (SI) calculated for each sample site for all relevant
minerals Note SIfrac14 0 indicates the mineral equilibrium (grey line) SI 0
indicates oversaturation and SI 0 indicates undersaturation Asterisks
indicate cenote water samples at a depth of 15 m BAC1 Bacalar 1
BAC2 Bacalar 2 BAC3 Bacalar 3 Caz cenote Azul Ccoc cenote
Cocalitos COC Cocalitos RAP Los Rapidos
24
2
4
0
2
4
0
PC1
2 4
PC
2
Ca
pHSO4
HCO3
NO3
Temp
TDS
Mg
ECNaCl
Sr
NH4
Caz
Ccoc
BAC2 BAC1
RAP
BAC3
COC
SiO2SiO2
K
Fig 6 Principal component analysis based on 15 chemical variables (grey
arrows) at different sampling sites (lagoon and cenotes) PC1 principal
component 1 PC2 principal component 2 EC electrical conductivity
TDS total dissolved solids Temp temperature BAC1 Bacalar 1 BAC2
Bacalar 2 BAC3 Bacalar 3 Caz cenote Azul Ccoc cenote Cocalitos
COC Cocalitos RAP Los Rapidos
Table 2 Eigenvalues of principal component analysis components and
variance explained
Principal component Eigenvalue Variance explained ()
1 706 4712
2 338 2258
3 210 1402
4 127 851
0 05 10 15 20 25 30 3502
04
06
10
12
14
Effect ofevaporates
BAC3
RAP
COCCaz
CcocBAC2
BAC1
Ca
Mg
HC
O3
Na
Cl
SO
4
Conductivity (mS cm1)
Effect ofcarbonates
Fig 4 Mineralisation effect on water chemistry Dark grey points repre-
sent the sampling sites dashed circular areas indicate the range in which the
electrical conductivity and major element ratios are interpreted as resulting
from mineralisation of evaporites or carbonates according to Khedidja and
Boudoukha (2016) BAC1 Bacalar 1 BAC2 Bacalar 2 BAC3 Bacalar 3
Caz cenote Azul Ccoc cenote Cocalitos COC Cocalitos RAP Los
Rapidos
F Marine and Freshwater Research N I Tobon ndashVelazquez et al
samples is greater than 2 units this indicates that the physico-chemical conditions are distinct (Massaferro et al 2018) hence
variations could be interpreted as significant differencesbetween sites
Samples along PCA Axis 1 show two distinctive patterns
within the lagoon which are separated by pH EC TDS Nathorn
and HCO3 distribution The spread of samples within PC1 is
relatively large suggesting significant differences among sites
This spread reflects the distinct distributions of physicochemicalfeatures at the different sides of the lagoon the western side(Axis 1 from 4 to 0 units) is characterised by a high HCO3
content (COC RAP BAC3 Ccoc and Caz) whereas the eastern
side (Axis 1 from 0 to 4 units) is characterised by high EC NathornpH and TDS and corresponds to the BAC1 and BAC2 sites
PC2 is associated with SiO2 and Kthorn concentrations PC2
shows two groups with the first group corresponding to sampleswith low SiO2
and Kthorn concentrations (COC RAP BAC1BAC2 and BAC3) and positive values of Axis 2 (from 4 to 0)
The second group is characterised by high SiO2 and Kthorn
concentrations (Ccoc and Caz samples) and corresponds tonegative axis values (from 0 to 4) PC2 is associated withsilica content due to higher silica concentrations in the cenotes
compared with the rest of the lagoon samples This can beexplained by more rapid Si uptake in the sun-lit lagoon wherediatoms are abundant
Changes in pH and transparency by sediment disturbance canhave an effect on stromatolites Sulfate-reducing bacteria par-ticipate in the formation of stromatolites and appear to always be
associated with Mg calcite and low-salinity and low-turbiditywaters Although stromatolites were not analysed in the presentstudy we recommend that a water monitoring program be
established to survey nutrients and measure other variablessuch as transparency tourist and boat activity weatheringdisturbance of sediments and trace elements at least twice ayear to ensure that the stromatolites are not negatively affected
Sediment characterisation
X-Ray diffraction
The results from the XRD analyses indicate that the mainmineralogical composition for all sediment samples was calcite(CaCO3) dolomite (CaMg(CO3)2) and SiO2 (quartz and possi-
bly minor amounts of coesite) In general calcite was in highestabundance in all cores Dolomite was present in all samples atlower proportions
These results are in accordance with the SI where calcite is
oversaturated in the western part of the lagoon and Ca2thorn andHCO3
concentrations are elevated throughout the lagoonCoesite forms under conditions of high pressure (3ndash10 GPa
Hemley et al 1994) and the presence of this mineral could berelated to the impact of the Chicxulub meteorite (Lounejevaet al 2002) Fouke et al (2002) with an estimated diameter of
its effect 360 km The presence of coesite in Bacalar Lagooncould be associated with this event Fouke et al (2002) andKenkmann and Schonian (2006) reported Chicxulub ejecta
deposited in Belize and in some regions of the Rio Hondo (nearBacalar Lagoon) However identifying the origin of this min-eral in Bacalar Lagoon requires additional detailed studies withlonger scan times to confirm the presence of coesite Other
minerals that we found in lower proportions are barite (BaSO4)
and a few samples with sphalerite (ZnS) with higher propor-tions of barite in the western than eastern side of the lagoon
Geochemistry
Elemental concentrations in the sediment samples are shown
in Fig 7 All sediment cores had high concentrations of Ca2thornMg2thorn and Sr2thorn which were one to three orders of magnitudehigher than concentrations for the rest of the elements consis-
tent with carbonate minerals (calcite) dominating the sedimentElement abundance was similar in cores of sites located in
the western part of the lagoon (COC RAP and BAC3) in the
order Ca2thornMg2thornSr2thorn Si4thornAl3thorn Fe3thornZn2thorn
KthornBa2thornTi4thornNi2thornMn2thornU6thorn The order of ele-ment abundance for the eastern cores (BAC1 and BAC2) was
similar except that Mg was more abundant than Ca (Mg2thorn
Ca2thorn Sr2thorn Si4thornAl3thorn Fe3thornZn2thornKthornNi2thorn
Ba2thornTi4thornMn2thornU6thorn) These relative abundances sug-gest that cores from the western side are dominated by Ca2thorn
carbonate minerals (likely calcite) whereas those from the eastside contain more dolomite The BAC1 core had the highestconcentrations of Al3thorn Si4thorn Kthorn Ti4thorn Mn2thorn and Fe3thorn likelyrepresenting some silicates and ironndashmanganese oxides fromterrigenous sources The highest Ni2thorn and Zn2thornconcentrationswere measured in the core from BAC2 and may represent
anthropogenic pollutant inputs The other elements analysedhad similar distributions in all cores
In general concentrations of Ba2thorn U6thorn and Zn2thorn werehigher in deeper sections of the cores and this may suggest
temporal changes in the input of these elements The rest of theelements (Ca2thorn and Mg2thorn) did not show variations with depthdown the core (r2 05)
The concentrations of elements span orders of magnitudetherefore the data do not satisfy the assumption of normality ASpearman correlation was performed using STATISTICA
(ver 133 Palo Alto CA USA) to test the relationship betweenthe trace elements in each core with significance level atP 005
Except for BAC3 the most significant correlation was forAlndash(FendashTi) (r2 090) In the BAC2 core significant correla-tions were found for SrndashMg AlndashTi KndashNi and SindashTi (r2frac14 090090 088 and 086 respectively) For BAC1 the highest
correlations were found for SrndashCa Alndash(Fe Ni) Kndash(Fe Ni)and BandashMg (r2frac14 095 098 098 and 081 respectively) Nega-tive correlationswere found at theCOC site (r2frac14090) forAlndash
(Zn Sr) Fendash(Ca U) Mnndash(U Ca) UndashSi and BandashZn but apositive correlation was found for Tindash(Mn Fe) with r2frac14 090In the BAC3 core relationships were found for only four
elements UndashSr and CandashMg (r2frac14 099)The relationship for Alndash(Ti Fe) in almost all cores is derived
from the fact that these elements represent silicates and otherrefractory minerals and hence aeolian or fluvial input of
particulate matter from land (Drever 2005) The correlationfor Candash(SrndashMg) in most cores is consistent with the maincarbonate minerology of these sediments Other correlations
are not universal and in general no pattern in spatial distribu-tion was found in the correlation between elements among allcores suggesting that these elements are not controlled by the
same parameters at each site
Hydrochemistry of Bacalar Lagoon Marine and Freshwater Research G
Sediment pollution
Some trace elements in Bacalar Lagoon sediments mayreflect anthropogenic pollution Here we used four indices
followingManoj and Padhy (2014 see Table 3)We normalisedconcentrations to Al because it is a conservative lithogenic
element and is resistant to chemical weathering hence it does
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
8000 9000 10 000 11 000
Sr (ppm) Ba (ppm) U (ppm) Mg (ppm)
8 10 12 14 16 18 0 01 02 03 04 05 06 300 000 400 000
Dep
th (
cm)
0 1000 5000
Al (ppm) Si (ppm) Ti (ppm) Ca (ppm)
Mn (ppm) Fe (ppm) Ni (ppm) Zn (ppm)
10 000 2020 000 2001000 0 200 000 400 000
0 1 2 3 4 0 400 1000 2000 0 20 40 60 500 100 150 25020080
COC BAC3 BAC1 BAC2
Fig 7 Concentrations of trace andmajor elements in sediment cores BAC1 Bacalar 1 BAC2 Bacalar 2 BAC3 Bacalar 3
COC Cocalitos
H Marine and Freshwater Research N I Tobon ndashVelazquez et al
not actively participate in the dominant geochemical cycles and
does not have a significant anthropogenic source (Boes et al2011 Dautovic et al 2014)
For normalisation to Al values for the Earthrsquos crust were
taken from Turekian and Wedepohl (1961) in which the valuesare mean concentrations in carbonates rocks of the upper crustKfrac14 27000 ppm Mnfrac14 11000 ppm Nifrac14 200 ppm
Znfrac14 200 ppm and Bafrac14 100 ppmTo determine whether the elements are from lithological or
anthropogenic sources the trace element concentrations were
compared with the crustal composition (Hernandez et al 2003)
frac12M lithogenic frac14 frac12Als ethfrac12M =frac12AlcTHORN eth1THORN
frac12M anthropogenic frac14 frac12M T frac12M lithogenic eth2THORN
where the lithogenic input ([M]lithogenic) is estimated throughthe concentration of Al in the sample ([Al]s) and the ratio of the
average of the Earthrsquos crust ([M][Al]c) The anthropogenic input([M]anthropogenic) was calculated based on the total concentration([M]T) and the lithogenic input
The results of these calculations are summarised in Table 4For all cores U6thorn Mn2thorn and Kthorn show negative values for theindex of geoaccumulation (Igeo) whereas the values of CF(contamination factor) and CD (contamination degree) are
lower than 20 All factors indicate that the sediment is notpolluted with these elements which are likely of lithogenicorigin For Ni2thorn the Igeo (0) CF (1) and CD (6) indices
also indicate low pollution except for the upper samples (depthsof 0ndash6 and 6ndash11 cm) of theBAC2 core where theCF is30 andIgeo is 10 suggesting unpolluted to moderately polluted
conditions In contrast the values of these indices for Zn2thorn
and Ba2thorn show some spatial variabilityThe CD of Zn2thorn at all sites is 15 The eastern samples
(BAC1 and BAC2) show higher CD values (822 and 1805
respectively) suggesting moderate to considerable contamina-
tion of the sediment The Ba2thorn concentration exhibits a spatialdistribution the western sites (COC RAP and BAC3) havehigher Ba2thorn concentrations compared than the eastern sites and
the calculated indices were correspondingly higher for thewestern side of the lagoon However overall the indicesindicated that the sediments on both sides of the lagoon are
unpollutedwith regard to Ba and the differences are likely due tohigher barite content on thewestern side Based on these indicesno influence of human activities was detected in eastern core
samples (BAC1 and BAC2)The higher Zn2thorn and Ba2thorn concentrations may be due to a
higher input of these elements into the area close to these sitesHowever water column distributions have to be assessed to
confirm this Zn2thorn and Ba2thorn in Bacalar Lagoon sediments couldbe derived from two sources (1) authigenic minerals found inthe sediment which on thewestern side contain barite (BaSO4)
and some sphalerite (ZnS) and (2) anthropogenic sources suchas agricultural fertiliser or cattle feed Commercial fertiliserscontain micronutrients such as Zn2thorn Mn2thorn Fe3thorn Cu2thorn Mo6thorn
and Ba2thorn in concentrations ranging from trace to several ppmwhich could infiltrate and cause pollution in the soil andgroundwater (Adriano 1986) Baize (1997) indicated that Znis found in animal feed used for pigs that are raised domestically
and commercially in the region The waste water generated bythis industry has been poorly handled resulting in adverseeffects on the environment (Drucker et al 2003) Near the town
of Bacalar fertilisers and agrochemicals are used regularly(Alvarez-Legorreta 2009) The agriculture practices in themunicipality include maize sugarcane and pepper and more
than 40 products are spread annually on these crops (fertilisersherbicides and pesticides Euan-Avila et al 2002) Garcıa-Rıosand Gold-Bouchot (2002) identified Fe V Ni Pb Zn Cu and
Cd in sediments of nearby Chetumal Bay Indeed Bacalar andOthon P Blanco municipalities have the highest fertilised area
Table 3 Indices as indicators of sediment quality based on Manoj and Padhy (2014) and Javan et al (2015)
Ms sample element concentration Mb background concentration of the element
Index Equation Sediment quality
Index of geoacumulation Igeofrac14 ln(Ms15Mb) 0frac14 unpolluted
0ndash1frac14 unpolluted to moderately polluted
1ndash2frac14moderately polluted
2ndash3frac14moderately polluted to highly polluted
3ndash4frac14 highly polluted
4ndash5frac14 highly polluted to very highly polluted
5frac14 very highly polluted
Contamination factor CF5MsMb 1frac14 low CF
1 CF 3frac14moderate CF
3 CF 6frac14 considerable CF
$6frac14 very high CF
Contamination degree CD frac14Pnifrac141
CF 6frac14 low CD
6 CD 12frac14moderate CD
12 CD 24frac14 considerable CD
$24frac14 high CD (anthropogenic contamination)
Pollution load index PLI5 (CF1CFsyCFn)1n 0frac14 unpolluted
1frac14 baseline levels of pollutants present
1frac14 progressive deterioration of site
Hydrochemistry of Bacalar Lagoon Marine and Freshwater Research I
Table4
Index
ofgeoacummulation(Igeo)anthropogenic(A
)inputcontaminationfactor(C
F)andcontaminationdegree(C
D)forBaUKMnNiandZnin
thesedim
entary
record
ofthe
BacalarLagoon
NAdatanoavailablePLIpollutionload
indexBAC1Bacalar
1BAC2Bacalar
2BAC3Bacalar
3COCCocalitosRAPLosRapidos
Site
Depth
(cm)
Ba
UK
Mn
Ni
Zn
PLI
I geo
Ainput
CF
CD
I geo
Ainput
CF
CD
I geo
Ainput
CF
CD
I geo
Ainput
CF
CD
I geo
Ainput
CF
CD
I geo
Ainput
CF
CD
COC
0ndash6
016
1236
134
701
503
013
005
065
688
24629
001
003
1119
11361
0001
0002
371
021
011
053
203
529
037
479
005
6ndash12
015
1314
135
469
005
006
675
5569
001
1160
3753
0000
409
107
009
004
2846
146
006
12ndash17
004
1421
146
336
024
015
NA
10001
000
1147
4016
0001
405
107
009
037
2254
116
000
17ndash22
014
1627
165
304
035
018
1158
6288
000
1257
2588
0000
362
196
012
010
3174
161
004
22ndash27
031
1156
121
282
035
021
NA
14125
000
1338
5739
0000
367
132
012
301
267
019
000
RAP
0ndash6
039
1074
115
264
538
008
004
009
889
18818
000
002
1067
7912
0001
0001
508
057
004
014
156
870
051
284
004
6ndash11
001
1360
149
475
017
006
651
31721
002
1189
14691
0000
391
069
010
063
4390
233
007
BAC1
0ndash5
024
267
127
956
402
201
009
069
230
189364
031
161
896
110398
0003
0023
300
1639
019
115
174
1118
045
822
014
5ndash10
035
302
118
416
174
008
276
176636
022
907
96021
0003
311
1404
017
066
2982
237
017
10ndash15
048
382
108
437
137
007
307
139830
018
913
76341
0003
327
1083
016
119
074
066
013
15ndash20
031
444
121
423
150
008
295
153179
019
896
83486
0003
330
1220
015
013
1225
137
015
20ndash25
031
488
121
420
142
008
301
145741
019
883
79449
0003
351
1189
013
424
1293
008
009
25ndash30
039
504
114
408
121
009
320
128917
016
925
70152
0002
363
1037
012
061
689
098
013
30ndash35
016
581
134
385
145
010
299
154625
019
904
83454
0003
353
1264
013
069
337
093
014
35ndash40
041
467
113
419
127
008
313
131772
017
917
72183
0003
392
1120
010
012
1446
138
013
BAC2
0ndash6
035
1141
117
734
515
002
004
086
743
6689
001
006
1094
3596
0001
0006
374
157
011
444
051
4203
214
1805
007
6ndash11
052
1005
105
462
004
006
834
10694
000
949
4638
0002
119
6764
343
012
2666
138
012
11ndash16
055
984
103
442
006
007
750
9268
001
1126
4617
0001
420
078
008
144
1018
055
005
16ndash21
055
985
102
400
013
009
597
3426
002
1119
3962
0001
421
089
008
001
2953
151
008
21ndash26
043
1093
111
296
038
019
828
3839
000
1178
2046
0000
412
135
009
293
22785
1141
009
26ndash31
068
925
094
254
054
026
832
2578
000
1194
1524
0000
273
424
023
104
1434
073
006
36ndash41
056
1001
102
337
028
014
875
3556
000
1113
1759
0001
182
819
043
219
626
033
006
BAC3
0ndash6
016
1283
134
407
607
009
002
007
682
12943
001
002
1266
6706
0000
0001
553
057
003
008
211
572
035
152
003
6ndash12
020
1270
131
607
003
002
989
9545
000
1308
4043
0000
580
020
003
081
1639
086
002
12ndash18
008
1389
142
613
003
002
891
8695
000
1341
3872
0000
593
021
002
223
567
032
002
J Marine and Freshwater Research N I Tobon ndashVelazquez et al
in Quintana Roo state (Instituto Nacional de Estadıstica yGeografıa 2016) Owing to the karstic nature of the area these
products can immediately infiltrate the aquifer and thereforecould be affecting the lagoon Because the concentration of ZnSminerals was low in the cores it is suggested that the source of
Zn2thorn could be derived from human activities Although theresults from the pollution load index (PLI) (1) for all samplesindicate that the sites are not highly polluted the excess Zn2thorn in
the sediment suggests some local pollution with regard to thiselement Conversely the concentrations of Ba2thorn can beexplained by the variable occurrence of barite in the cores
Minimal trace metal pollution is consistent with previous
metal work in the lagoon Castro-Contreras et al (2014)reported heavy metal concentrations in Bacalar Lagoon waterbelow the maximum limits of the Mexican legislation (NOM-
127-SSA1-1994) and ecological water quality criteria (CE-CCA-00189) that establish the limits of heavy metals fordrinking water irrigation and recreational activities
Nevertheless organochloride compounds (pesticides andpolychlorinated biphenyls) and hydrocarbons in sediments havebeen identified by Norena-Barroso et al (1998) in the ChetumalBay area near Bacalar Lagoon Organochlorine pesticides
(OCPs) are used in agriculture in the region (Alvarez-Legorreta2009) Furthermore heavymetals and OCPs have been detectedin crocodilian eggs near Chichorro Atoll (Charruau et al 2013
Buenfil-Rojas et al 2015)
Conclusions
Bacalar Lagoon is a shallow and oligotrophic system (low-
nutrient waters) with a mineralogical composition dominatedby calcite dolomite and evaporites dissolution Water geo-chemical analyses show a clear spatial distribution of different
parameters The western part of the study area is characterisedby high alkalinity and calcium and sulfate concentrations theratios of these constituents indicate groundwater sources and noseawater intrusion The decreases in these parameters towards
the north indicate a gradient in groundwater influencethroughout the lagoon The eastern part of the study area ischaracterised by a shallower water column resulting in high
evaporation and high electrical conductivity compared with thewestern side
We present the first measurements of trace elements in
carbonate sediments in Bacalar Lagoon The sediment exhibitsonly moderate contamination with Zn2thorn on the western side ofthe lagoon The high Ba concentration in the sediment corre-
sponds to barite but further work is necessary to identify thesource of Ba2thorn and Zn2thorn This study can be useful for Bacalarmunicipality to make decisions and define actions regarding themanagement and development of Bacalar Lagoon
Conflicts of interest
The authors declare that they have no conflicts of interest
Declaration of funding
This investigation was financed by the lsquoWater Security Project inthe South-eastMexico in the face of twoclimate change scenariosrsquoproject (CONACYT 247565) and lsquoProject networks CONACYTrsquo
(282240) The authors acknowledge a grant from CONACYT
towards a Masters of Water Sciences degree (awarded to NidiaTobon Velazquez)
Acknowledgements
The authors thank technical staff Daniela Ortega (Water Sciences Unit
Centro de Investigacion Cientıfica de Yucatan) and Kimberly Bitterwolf
(University of CaliforniamdashSanta Cruz)
References
Adriano D C (1986) lsquoTrace Elements in the Terrestrial Environmentrsquo
(Springer-Verlag Berlin Germany)
Alvarez-Legorreta T (2009) Contaminacion acuatica In lsquoEl sistema ecolo-
gico de la Bahıa de Chetumal Corozal costa occidental del Mar Caribersquo
(Eds J Espinoza Avalos G A Islebe and H A Hernandez Arana)
pp 205ndash217 (El Colegio de la Frontera Sur Chetumal Mexico)
Appelo C A and Postma D (2005) lsquoGeochemistry Groundwater and
Pollutionrsquo 2nd edn (A A Balkema Rotterdam Netherlands)
Baize D (1997) lsquoTeneurs totales en elements trace metalliques dans les sols
(France) References et strategies drsquointerpretationrsquo (INRA Paris France)
Bauer-Gottwein P Gondwe B Charvet G Marin L Rebolledo V M
andMerediz A G (2011) Review the Yucatan Peninsula karst aquifer
Mexico Hydrogeology Journal 19 507ndash524 doi101007S10040-010-
0699-5
Beddows P A (2002) lsquoWhere Does the Sewage Go The Karst
Groundwater System of the Municipalidad de Solidaridad Quintana
Roo Mexicorsquo (Association for Mexican Cave Studies Houston
TX USA)
Beltran D Y (2010) Estimacion de los patrones de fijacion de nitrogeno y
diversidad asociada (nifH) en tapices microbianos y estromatolitos
MSc Thesis Universidad Nacional Autonoma de Mexico Ciudad de
Mexico Mexico
Boes X Rydberg J Martinez C A Bindler R and Renberg I (2011)
Evaluation of conservative lithogenic elements (Ti Zr Al and Rb) to
study anthropogenic element enrichments in lake sediments Journal of
Paleolimnology 46 75ndash87 doi101007S10933-011-9515-Z
Boyle J F (2001) Inorganic geochemical methods in paleolimnology In
lsquoTracking Environmental Change Using Lake Sediments Vol 2 Physi-
cal andGeochemicalMethodsrsquo (EdsMW Last and P J Smol) pp 83ndash
143 (Kluwer Academic Publishers Dordrecht Netherlands)
Buenfil-Rojas A M Alvarez- Legorreta T and Cedeno-Vazquez J R
(2015) Metals and metallothioneins in Moreletrsquos Crocodile (Crocodile
moreletii) from a Transboundary River between Mexico and Belize
Archives of Environmental Contamination and Toxicology 68(2) 265ndash
273 doi101007S00244-014-0088-5
Castro-Contreras C Murray K G Pecoits E Aubet N R Petrash D
Castro C S Gregory D Planavsky N and Konhauser K O (2014)
Textural and geochemical features of freshwater microbialites from
LagunaBacalarQuintanaRooMexicoPalaios 29(5) 192ndash209 doi10
2110PALO2013063
Ceballos Martınez R R (2002) Geografıa y medio ambiente en el sistema
lagunar San FelipendashBacalarndashGuerrero In lsquoContribuciones de la ciencia al
manejo costero integrado de laBahıa deChetumal y su area de influenciarsquo
(Eds F J Rosado-May RRomeroMayo andADe Jesus Navarrete) pp
17ndash22 (Universidad de Quintana Roo Chetumal Mexico)
Centeno M C Legendre P Beltran Y Alcantara H R Lidstrom E U
Ashby N M and Falcon I L (2012) Microbialite genetic diversity
and composition relate to environmental variables FEMSMicrobiology
Ecology 82 724ndash735 doi101111J1574-6941201201447X
Chagas A P Webb E G Burne V R and Southam G (2016) Modern
lacustrine microbialites towards a synthesis of aqueous and carbonate
geochemistry and mineralogy Earth-Science Reviews 162 338ndash363
doi101016JEARSCIREV201609012
Charruau P Henaut Y and Alvarez-Legorreta T (2013) Organo-
chlorine pesticides in nest substratum and infertile eggs of American
Hydrochemistry of Bacalar Lagoon Marine and Freshwater Research K
crocodiles (Reptilia Crocodylidae) in a Mexican Caribbean atoll
Caribbean Journal of Science 47 1ndash12 doi1018475CJOSV47I1A2
Comision Nacional del Agua (2002) lsquoDeterminacion de la disponibilidad de
agua en el acuıfero Penınsula de Yucatan estado de Yucatanrsquo (CON-
AGUA Gerencia de Aguas Subterraneas Ciudad de Mexico Mexico)
Comision Nacional del Agua (2012) lsquoPrograma Hıdrico Regional Vision
2030 Region Hidrologico-Administrativa XII Penınsula de Yucatanrsquo
1st edn (Secretarıa de Medio Ambiente y Recursos Naturales Mexico
City Mexico)
Comision Nacional del Agua (2015) lsquoActualizacion de la disponibilidad
media anual de agua en el acuıfero Cerros y Valles (2301) Estado de
QuintanaRoorsquo (CONAGUADiarioOficial de la Federacion Ciudad de
Mexico Mexico)
Dautovic J Fiket Z Baresic J Ahel M and Mikac N (2014) Sources
distribution and behavior of major and trace elements in a complex karst
lake system Aquatic Geochemistry 20 19ndash38 doi101007S10498-
013-9204-9
Dıaz J E (2005) lsquoDecreto por el cual se establece el programa de
ordenamiento ecologico territorial de la region de Laguna Bacalar
Quintana Roo Mexicorsquo (Periodico Oficial Chetumal Mexico)
Dixon J Hamilton K Pagiola S and Segnestam L (2001) Tourism and
environment in the Caribbean an economic framework (The World
Bank Washington DC USA) Available at httpdocumentsworldbank
orgcurateden672281468770397455pdfmulti0pagepdf [Verified 18
October 2018]
Drever J I (2005) lsquoSurface and Ground Water Weathering and Soilsrsquo
(Elsevier Oxford UK)
Drucker A Escalante R Gomez V and Magana S (2003) La industria
porcina en Yucatan un analisis de la generacion de aguas residuales
Problemas del Desarrollo Revista Latinoamericana de Economıa 34
(135) 105ndash120
Dupraz C Reid R P andVisscher P T (2011)MicrobialitesModern In
lsquoEncyclopedia of Geobiology Encyclopedia of Earth Science Seriesrsquo
(Eds J Reitner and V Thiel) pp 617ndash635 (Springer Heidelberg
Germany)
Elango L andKannan R (2007) Rockndashwater interaction and its control on
chemical composition of groundwater In lsquoDevelopments in Environ-
mental Sciencersquo Vol 5 (Eds D Sarkar R Datta and R Hannigan) pp
229ndash243 (Elsevier Oxford UK)
Euan-Avila J I Liceaga-CorreaM A and Rodrıguez Sanchez H (2002)
Caracterizacion de fuentes no puntuales de contaminacion agrıcola en el
municipio deOthon P Blanco enQuintanaRoo y su potencial influencia
en la Bahıa de Chetumal In lsquoContribuciones de la ciencia al manejo
costero integrado de la Bahıa de Chetumal y su area de influenciarsquo (Eds
F J Rosado-May R Romero Mayo and A De Jesus Navarrete) pp
197ndash204 (Universidad de Quintana Roo Chetumal Mexico)
Fouke W B Zerkle L A Alvarez W Pope O K Ocampos A C
Wachtman J R Grajales J M Claeys P and Fischer G A (2002)
Cathodoluminescence petrography and isotope geochemistry of KT
impact ejecta deposited 360 km from the Chicxulub crater at Albion
Island Belize Sedimentology 49 117ndash138 doi101046J1365-3091
200200435X
Garcıa-Rıos V Y and Gold-Bouchot G (2002) Especiacion de metales
pesados en sedimentos de la Bahıa de Chetumal Quintana Roo y la
acumulacion en el tejido muscular de bagres (Ariopsis assimilis) In
lsquoContribuciones de la ciencia al manejo costero integrado de la Bahıa de
Chetumal y su area de influenciarsquo (Eds F J Rosado-May R Romero
Mayo and A De Jesus Navarrete) pp 143ndash148 (Universidad de
Quintana Roo Chetumal Mexico)
Gischler E Gibson M A and Oschmann W (2008) Giant Holocene
freshwater microbialites Laguna de Bacalar Quintana Roo Mexico
Sedimentology 55 1293ndash1309 doi101111J1365-3091200700946X
Gischler E Golubic S Gibson M Oschamann W and Hudson J H
(2011) Microbial mats and microbialites in the freshwater Laguna
Bacalar Yucatan Peninsula Mexico In lsquoAdvances in Stromatolite
Geobiologyrsquo (Eds J Reitner M H Trauth K Stuwe and D Yuen)
pp 187ndash205 (Springer Berlin Germany)
Gonzalez B J L Carrion J J Cuevas D J Flores M F Yam G J O
Moreno C J Perez V J and Calva C G (2014) Acumulacion de Hg
Pb Cd y Zn por Pomacea flagellata en tres balnearios ubicados en la
region urbana de la Laguna de Bacalar TecnoCultura 35 14ndash23
Hemley R J Prewitt C T and Kingma K (1994) High-pressure
behavior of silica In lsquoSilica ndash Physical Behavior Geochemistry and
Materials Applications Reviews in Mineralogy Vol 29rsquo (Eds P J
Heaney C T Prewitt and G V Gibbs) pp 41ndash82 (Mineralogical
Society of America Washington DC USA)
Hernandez L Probst A Probst L J and Ulrich E (2003) Heavy metal
distribution in some French forest soils evidence for atmospheric
contamination The Science of the Total Environment 312(1ndash3)
195ndash219 doi101016S0048-9697(03)00223-7
Hernandez-Terrones L Rebolledo-Vieyra M Merino-Ibarra M Soto
M Le-Cossec A and Monroy-Rıos E (2011) Groundwater pollution
in a karstic region (NE Yucatan) baseline nutrient content and flux to
coastal ecosystems Water Air and Soil Pollution 218(1ndash4) 517ndash528
doi101007S11270-010-0664-X
InstitutoNacional de Estadıstica yGeografıa (2002) EstudioHidrologico del
Estado de Quintana Roo (INEGI Aguascalientes Mexico) Available at
httpinternetcontenidosinegiorgmxcontenidosproductosprod_serv
contenidosespanolbvinegiproductoshistoricos2104702825224196
702825224196_1pdf [Verified 5 September 2018]
Instituto Nacional de Estadıstica y Geografıa (2016) Anuario Estadıstico y
Geografico de Quintana Roo (INEGI Aguascalientes Mexico) Avail-
able at httpinternetcontenidosinegiorgmxcontenidosProductos
prod_servcontenidosespanolbvinegiproductosnueva_estrucanuarios_
2016702825084370pdf [Verified 5 September 2018]
Javan S Hessam H A Gholamalizadeh A A and Soltani J (2015)
Fractionation of heavy metals in bottom sediments in Chahnimeh 1
Zabol Iran Environmental Monitoring and Assessment 187(6) 340
doi101007S10661-015-4510-X
Katip A Karaer F Ileri S Sarmasik S Aydogan N and Zenginay S
(2011) Analysis and assessment of trace elements pollution in sediments
of Lake Ulubat Turkey Journal of Environmental Biology 33 961ndash968
Kenkmann T and Schonian F (2006) Ries and Chicxulub impact craters
on Earth provide insights for Martian ejecta blankets Meteoritics amp
Planetary Science 41(10) 1587ndash1603 doi101111J1945-51002006
TB00437X
Khedidja A and Boudoukha A (2016) Lrsquoaquifere Superficiel de
Tadjnanet-Chelghoum laid (Nord-Est Algerien) Larhyss Journal 28
181ndash197
Lounejeva E Ostroumov M and Sanchez R G (2002) Polimorfos de
alta presion de sılice en las impactitas de ChicxulubMexico ndash resultados
de espectrometrıa de Raman Revista Mexicana de Ciencias Geologicas
17(2) 137ndash141
Manoj K and Padhy P K (2014) Distribution enrichment and ecological
risk assessment of six elements in bed sediments of a tropical river
Chottanagpur Plateau a spatial and temporal appraisal Journal of
Environmental Protection 5 1419ndash1434 doi104236JEP2014514136
Marfia A M Krishnamurthya R V Atekwanab E A and Panton W F
(2004) Isotopic and geochemical evolution of ground and surfacewaters
in a karst dominated geological setting a case study fromBelize Central
America Applied Geochemistry 19 937ndash946 doi101016JAPGEO
CHEM200310013
Massaferro J Correa M A Montes de Oca F and Mauad M (2018)
Contrasting responses of lake ecosystems to environmental disturbance
a paleoecological perspective from northern Patagonia (Argentina)
Hydrobiologia 816(1) 79ndash89 doi101007S10750-016-3081-3
Medina M S Jimenez G A Gutierrez R M and Lizardi J M (2014)
Hydrocarbon pollution studies of underwater sinkholes along Quintana
L Marine and Freshwater Research N I Tobon ndashVelazquez et al
Roo as function of tourism development in the Mexican Caribbean
Revista Mexicana de Ingenierıa Quımica 13(2) 509ndash516
Norena-Barroso E Zapata-Perez O Ceja-Moreno V and Gold-Bouchot
G (1998) Hydrocarbon and organochloride residue concentrations in
sediments from Bay of Chetumal Mexico Bulletin of Environmental
Contamination and Toxicology 61 80ndash87 doi101007S001289900732
Nriagu J and Pacyna J (1988) Quantitative assessment of worldwide
contamination of air water and soils by trace metals Nature 333 134ndash
139 doi101038333134A0
Ochoa J C Gonzalez B J and Jimenez C J (2016) Metales pesados
(Cd Cr Pb Hg) en Rhizophora mangle en rıo y bahıa de Chetumal
Revista Mexicana de Agroecosistemas 3(2) 263ndash271
Oliva R J Ocana F A de Jesus N A de Jesus C R and Vargas E A
(2016) Reproduccion dePomacea flagellata (Mollusca Ampullariidae)
en la laguna de Bacalar Quintana Roo Mexico Revista de Biologıa
Tropical 64(4) 1643ndash1650
Pacton M Hunger G Martinuzzi V Cusminsky G Burdin B
Barmettler K Vasconcelos C and Ariztegui D (2015) Organomi-
neralization processes in freshwater stromatolites a living example from
eastern Patagonia International Association of Sedimentologists Jour-
nal 1(2) 130ndash146
Perez L Bugja R Lorenschat J Brenner M Curtis J Hoelzmann P
Islebe G Scharf B and SchwalbA (2011) Aquatic ecosystems of the
Yucatan Peninsula (Mexico) Belize and Guatemala Hydrobiologia
661 407ndash433 doi101007S10750-010-0552-9
Perry E C Velazquez O G and Marin L (2002) The hydrogeochem-
istry of the karst aquifer system of the northern Yucatan Peninsula
Mexico International Geology Review 44 191ndash221 doi102747
0020-6814443191
Perry E Paytan A Pedersen B and Velazquez O G (2009) Ground-
water geochemistry of the Yucatan Peninsula Mexico constraints on
stratigraphy and hydrogeology Journal of Hydrology 367 27ndash40
doi101016JJHYDROL200812026
Pradit S Wattayarkorn G Angsupanich S Baeyens W and Leer-
makers M (2010) Distribution of trace elements in sediments and biota
of Songkhla Lake Southern Thailand Water Air and Soil Pollution
206 155ndash174 doi101007S11270-009-0093-X
Salomons W and Forstner U (1980) Trace metal analysis on polluted
sediments II evaluation of environmental impact Environmental
Technology Letters 1 506ndash517 doi10108009593338009384007
Sanchez S J Alvarez L T Pacheco A J Gonzalez H R and Carrillo
B L (2015) Caracterizacion hidrogeoquımica de las aguas subterraneas
del sur del Estado de Quintana Roo Mexico Revista Mexicana de
Ciencias Geologicas 32(1) 62ndash76
Schmitter-Soto J J Comın F A Escobar B E Herrera S J Alcocer J
Suarez M E Elıas G M Dıaz A V Marın L E and Steinich B
(2002) Hydrogeochemical and biological characteristics of cenotes in
the Yucatan Peninsula (SE Mexico) Hydrobiologia 467 215ndash228
doi101023A1014923217206
Siqueiros-Beltrones D Hernandez A U and Hernandez A O (2013)
Diagnosis prospectiva sobre la diversidad de diatomeas epilıticas en la
laguna Bacalar Quintana Roo Mexico Revista Mexicana de Biodiver-
sidad 84 865ndash875 doi107550RMB33960
Turekian K K andWedepohl K H (1961) Distribution of the elements in
some major units of the Earthrsquos crust Bulletin of the Geological Society
of America 72 175ndash192 doi1011300016-7606(1961)72[175
DOTEIS]20CO2
Handling Editor Russell Frew
wwwpublishcsiroaujournalsmfr
Hydrochemistry of Bacalar Lagoon Marine and Freshwater Research M
Piper diagram was made in Aquachem (ver 37 WaterlooHydrogeologic Kitchener ON Canada) using the proportionsofmajor cations and anions (Fig 3) All samples cluster together
in a group corresponding to a sulfatendashcalcium (CandashSO4) watertype Studies performed by Sanchez et al (2015) reported a CandashHCO3 water type in the northern part of the lagoon and Oliva
et al (2016) showed that the north side of Bacalar Lagoon ischaracterised by muddy sediments with murky water all yearlong In contrast the south of the lagoon is associatedwith sandy
sediments and high water transparency We attribute theobserved differences in water chemistry in the lagoon to theeffects of sulfate-rich groundwater inputs in the south compared
with the north where lower groundwater input and sulfateconcentrations were measured by Sanchez et al (2015) Thewater chemistry in the south can have a direct effect on theformation of stromatolites which are more abundant in the
southern part of theBacalar Lagoon Pacton et al (2015) showedthat stromatolites appear to prefer fresh water rather than turbidand brackish lake waters and turbidity is one of the most
important factors restraining stromatolite developmentAccording to the Piper diagram (Fig 3) the water type of
Bacalar Lagoon is dominated by sulfates (9620ndash
11740 mg L1) The SO4 Cl ratio may be indicative of waterorigin and the ratio at the western side ranged between 696 and2055 higher than at the eastern side (281ndash310) All theSO4 Cl ratios in Bacalar Lagoon are between 27- and 197-fold
greater than those of seawater (0103 Perry et al 2002)indicating that the sulfate source in the lagoon is not seawaterintrusion Therefore we interpret the findings to indicate high
sulfate originating from dissolution of evaporitesAlthough all the lagoonwater samples cluster into one group
spatial differences are present within the lagoon and may
suggest differences in input sources or fluxes as well as inprocesses affecting solute concentrations within the lagoon The
western side of the lagoon is characterised by higher alkalinityand calcium concentrations (1570ndash2700 mg CaCO3 L
1 and3760ndash4220 mg L1 respectively) compared with the eastern
side (620ndash860 mg CaCO3 L1 and 860 mg L1 respectively)
The alkalinity of the western side is similar to the alkalinitymeasured at Caz and Ccoc (2440 and 2410 mg CaCO3 L1
respectively at a depth of 150 m) A gradient of increasingalkalinity is seen from north to south Because high alkalinity isassociated with groundwater input and the waters are undersat-urated with regard to carbonate minerals this alkalinity gradient
indicates a diminishing effect of groundwater towards the northof the lagoon Schmitter-Soto et al (2002) reported other factorsthat can affect alkalinity in the Yucatan Peninsula including the
contribution of meteoric water (rich in carbonate and bicarbon-ate) and precipitation which promotes the dissolution of carbo-nates and therefore affects alkalinity
The concentrations of Ca2thorn and SO42 are lower on the
eastern than western side of the lagoon potentially explainingthe formation of stromatolites in the western part of the lagoonwhere external sources of Ca2thorn and SO4
2 are present To reach
the saturation necessary for precipitation of microbialites Ca2thorn
and SO42 are needed which has been reported in other systems
(Chagas et al 2016) The EC (315ndash319 mS cm1) and Nathorn
(47ndash58 mg L1) and Cl (410ndash2830 mg L1) concentrationson the eastern side of the lagoon are higher than on the westernside (265ndash293 mS cm1) These differences most likely occur
because the eastern part of Bacalar Lagoon is shallower (04ndash06 m) than the western part (10ndash22 m) promoting higherevaporation on the eastern side Marfia et al (2004) identified
high-calcium high-sulfate water in the south-eastern area ofQuintana Roo including north-eastern Belize likely fromgypsum dissolution when the groundwater is mixed withseawater the mixture forms a caliche barrier preventing seawa-
ter intrusion characteristic of the north-east coastThe (Ca2thornthornMg2thornthornHCO3
) to (NathornthornClthorn SO42) ratio
has been used to determine the effect of carbonate and evaporite
solute sources in groundwater and surface waters (Appelo andPostma 2005 Khedidja and Boudoukha 2016) When plottingthis ratio against EC (Fig 4) it is clear that dissolution of
evaporitic substratum is the dominant source of cations in thissystem The lower EC (fresh water) and a carbonate to sulfateion ratio 10 also indicate that evaporite dissolution and notseawater intrusion controls ion composition in Bacalar Lagoon
The saturation indices (SI) for the different mineral speciesconsidered in our system (calcite dolomite aragonite gypsumand celestite) were calculated based on field pH and temperature
measurements using PHREEQC (ver 37 US Geological Sur-vey Denver CO USA) (Fig 5) Our calculations allowed us todetermine the SI of Bacalar Lagoon water (note SIfrac14 0 signifies
equilibrium SI 0 signifies oversaturation and thus mineralprecipitation and SI 0 signifies undersaturation and thusmineral dissolution (Appelo and Postma 2005)
According to the SI calculations three trends were identified(Fig 5) The first corresponds to four sites (RAP BAC3 Cazand Ccoc 15 m deep) and shows oversaturated conditions withregard to aragonite calcite and dolomite In the second group
(Coc and Ccoc surface sample) all the minerals are
C a t i o n s A n i o n s mEq L1
NaK HCO3CO3 Cl
Mg SO4
CaCalcium (Ca) Chloride (Cl)
(SO 4
) (C
l)
(Ca)
(Mg)
(CO 3
)(H
CO 3
)
(Na)
(K)
Sulfate (SO4 )
Mag
nesi
um (M
g)
80 60 40 20 20 40 60 80
8060
4020
20
40
60
80
2040
6080
80
60
40
20
2040
6080
20
40
60
80
80
60
4020
8060
4020
COCRAPBAC1BAC2BAC3CcocCaz
Fig 3 Piper diagram and groundwater composition Each symbol corre-
spond to lagoon sites white square and white triangle points correspond to
cenotes samples which represent the groundwater in the region BAC1
Bacalar 1 BAC2 Bacalar 2 BAC3 Bacalar 3 Caz cenote Azul Ccoc
cenote Cocalitos COC Cocalitos RAP Los Rapidos
Hydrochemistry of Bacalar Lagoon Marine and Freshwater Research E
experiencing dissolution (undersaturation) Finally the thirdgroup (BAC1 and BAC2) is associated with calcite equilibrium
and undersaturation of the other minerals Bacalar Lagoon islocated in a region whereMiocene rocks containing gypsum andanhydrite are common and waterndashrock interaction results in the
dissolution of evaporites (Perry et al 2002 2009) The highconcentrations of Ca2thorn SO4
2 and Sr2thorn could be derived fromthe dissolution of these minerals The water samples in Bacalar
Lagoon are all undersaturated with regard to gypsum andanhydrite indicating that these minerals would not precipitatewithin the lagoon Ceballos Martınez (2002) indicated that
gypsum and limestone in the Bacalar formation tend to beconcentrated in the surface due to weathering forming lamellarcaliche
The Sr2thorn concentrations in samples from the western side are
quite similar to concentrations measured at the cenotes indicat-ing an input of this element from groundwater The same wassuggested by Perry et al (2002 2009) when they compared
concentrations of Sr2thorn and SO42 and Sr isotopes in the lagoon
to those of cenote AzulStandardised principal component analysis (PCA) was per-
formed using R (ver 340 R Foundation for Statistical Com-puting Vienna Austria) to identify the dominant limnologicalgradients in the dataset Fig 6 shows the results of a PCAappliedto the 15 hydrochemical variables measured here (water tem-
perature pH EC TDS SiO2 HCO3
Cl SO42 NO3
NH4
thorn Ca2thorn Kthorn Mg2thorn Nathorn and Sr2thorn) We present only thefirst two components (PC1 and PC2) because these explained 47
and 22 of the total variance respectively (Table 2) PCArepresents standard deviations and when the distance among
COC RAP BAC3 BAC1 BAC2 Ccoc Ccoclowast Caz Cazlowast
Sat
urat
ion
inde
x
15
10
05
0
05
10
Anhydrite (CaSO4)Aragonite (CaCO3)
Calcite (CaCO3)
Celestite (SrSO4)Gypsum (CaSO42H2O)
Dolomite (Ca Mg(CO3))
Fig 5 Saturation index (SI) calculated for each sample site for all relevant
minerals Note SIfrac14 0 indicates the mineral equilibrium (grey line) SI 0
indicates oversaturation and SI 0 indicates undersaturation Asterisks
indicate cenote water samples at a depth of 15 m BAC1 Bacalar 1
BAC2 Bacalar 2 BAC3 Bacalar 3 Caz cenote Azul Ccoc cenote
Cocalitos COC Cocalitos RAP Los Rapidos
24
2
4
0
2
4
0
PC1
2 4
PC
2
Ca
pHSO4
HCO3
NO3
Temp
TDS
Mg
ECNaCl
Sr
NH4
Caz
Ccoc
BAC2 BAC1
RAP
BAC3
COC
SiO2SiO2
K
Fig 6 Principal component analysis based on 15 chemical variables (grey
arrows) at different sampling sites (lagoon and cenotes) PC1 principal
component 1 PC2 principal component 2 EC electrical conductivity
TDS total dissolved solids Temp temperature BAC1 Bacalar 1 BAC2
Bacalar 2 BAC3 Bacalar 3 Caz cenote Azul Ccoc cenote Cocalitos
COC Cocalitos RAP Los Rapidos
Table 2 Eigenvalues of principal component analysis components and
variance explained
Principal component Eigenvalue Variance explained ()
1 706 4712
2 338 2258
3 210 1402
4 127 851
0 05 10 15 20 25 30 3502
04
06
10
12
14
Effect ofevaporates
BAC3
RAP
COCCaz
CcocBAC2
BAC1
Ca
Mg
HC
O3
Na
Cl
SO
4
Conductivity (mS cm1)
Effect ofcarbonates
Fig 4 Mineralisation effect on water chemistry Dark grey points repre-
sent the sampling sites dashed circular areas indicate the range in which the
electrical conductivity and major element ratios are interpreted as resulting
from mineralisation of evaporites or carbonates according to Khedidja and
Boudoukha (2016) BAC1 Bacalar 1 BAC2 Bacalar 2 BAC3 Bacalar 3
Caz cenote Azul Ccoc cenote Cocalitos COC Cocalitos RAP Los
Rapidos
F Marine and Freshwater Research N I Tobon ndashVelazquez et al
samples is greater than 2 units this indicates that the physico-chemical conditions are distinct (Massaferro et al 2018) hence
variations could be interpreted as significant differencesbetween sites
Samples along PCA Axis 1 show two distinctive patterns
within the lagoon which are separated by pH EC TDS Nathorn
and HCO3 distribution The spread of samples within PC1 is
relatively large suggesting significant differences among sites
This spread reflects the distinct distributions of physicochemicalfeatures at the different sides of the lagoon the western side(Axis 1 from 4 to 0 units) is characterised by a high HCO3
content (COC RAP BAC3 Ccoc and Caz) whereas the eastern
side (Axis 1 from 0 to 4 units) is characterised by high EC NathornpH and TDS and corresponds to the BAC1 and BAC2 sites
PC2 is associated with SiO2 and Kthorn concentrations PC2
shows two groups with the first group corresponding to sampleswith low SiO2
and Kthorn concentrations (COC RAP BAC1BAC2 and BAC3) and positive values of Axis 2 (from 4 to 0)
The second group is characterised by high SiO2 and Kthorn
concentrations (Ccoc and Caz samples) and corresponds tonegative axis values (from 0 to 4) PC2 is associated withsilica content due to higher silica concentrations in the cenotes
compared with the rest of the lagoon samples This can beexplained by more rapid Si uptake in the sun-lit lagoon wherediatoms are abundant
Changes in pH and transparency by sediment disturbance canhave an effect on stromatolites Sulfate-reducing bacteria par-ticipate in the formation of stromatolites and appear to always be
associated with Mg calcite and low-salinity and low-turbiditywaters Although stromatolites were not analysed in the presentstudy we recommend that a water monitoring program be
established to survey nutrients and measure other variablessuch as transparency tourist and boat activity weatheringdisturbance of sediments and trace elements at least twice ayear to ensure that the stromatolites are not negatively affected
Sediment characterisation
X-Ray diffraction
The results from the XRD analyses indicate that the mainmineralogical composition for all sediment samples was calcite(CaCO3) dolomite (CaMg(CO3)2) and SiO2 (quartz and possi-
bly minor amounts of coesite) In general calcite was in highestabundance in all cores Dolomite was present in all samples atlower proportions
These results are in accordance with the SI where calcite is
oversaturated in the western part of the lagoon and Ca2thorn andHCO3
concentrations are elevated throughout the lagoonCoesite forms under conditions of high pressure (3ndash10 GPa
Hemley et al 1994) and the presence of this mineral could berelated to the impact of the Chicxulub meteorite (Lounejevaet al 2002) Fouke et al (2002) with an estimated diameter of
its effect 360 km The presence of coesite in Bacalar Lagooncould be associated with this event Fouke et al (2002) andKenkmann and Schonian (2006) reported Chicxulub ejecta
deposited in Belize and in some regions of the Rio Hondo (nearBacalar Lagoon) However identifying the origin of this min-eral in Bacalar Lagoon requires additional detailed studies withlonger scan times to confirm the presence of coesite Other
minerals that we found in lower proportions are barite (BaSO4)
and a few samples with sphalerite (ZnS) with higher propor-tions of barite in the western than eastern side of the lagoon
Geochemistry
Elemental concentrations in the sediment samples are shown
in Fig 7 All sediment cores had high concentrations of Ca2thornMg2thorn and Sr2thorn which were one to three orders of magnitudehigher than concentrations for the rest of the elements consis-
tent with carbonate minerals (calcite) dominating the sedimentElement abundance was similar in cores of sites located in
the western part of the lagoon (COC RAP and BAC3) in the
order Ca2thornMg2thornSr2thorn Si4thornAl3thorn Fe3thornZn2thorn
KthornBa2thornTi4thornNi2thornMn2thornU6thorn The order of ele-ment abundance for the eastern cores (BAC1 and BAC2) was
similar except that Mg was more abundant than Ca (Mg2thorn
Ca2thorn Sr2thorn Si4thornAl3thorn Fe3thornZn2thornKthornNi2thorn
Ba2thornTi4thornMn2thornU6thorn) These relative abundances sug-gest that cores from the western side are dominated by Ca2thorn
carbonate minerals (likely calcite) whereas those from the eastside contain more dolomite The BAC1 core had the highestconcentrations of Al3thorn Si4thorn Kthorn Ti4thorn Mn2thorn and Fe3thorn likelyrepresenting some silicates and ironndashmanganese oxides fromterrigenous sources The highest Ni2thorn and Zn2thornconcentrationswere measured in the core from BAC2 and may represent
anthropogenic pollutant inputs The other elements analysedhad similar distributions in all cores
In general concentrations of Ba2thorn U6thorn and Zn2thorn werehigher in deeper sections of the cores and this may suggest
temporal changes in the input of these elements The rest of theelements (Ca2thorn and Mg2thorn) did not show variations with depthdown the core (r2 05)
The concentrations of elements span orders of magnitudetherefore the data do not satisfy the assumption of normality ASpearman correlation was performed using STATISTICA
(ver 133 Palo Alto CA USA) to test the relationship betweenthe trace elements in each core with significance level atP 005
Except for BAC3 the most significant correlation was forAlndash(FendashTi) (r2 090) In the BAC2 core significant correla-tions were found for SrndashMg AlndashTi KndashNi and SindashTi (r2frac14 090090 088 and 086 respectively) For BAC1 the highest
correlations were found for SrndashCa Alndash(Fe Ni) Kndash(Fe Ni)and BandashMg (r2frac14 095 098 098 and 081 respectively) Nega-tive correlationswere found at theCOC site (r2frac14090) forAlndash
(Zn Sr) Fendash(Ca U) Mnndash(U Ca) UndashSi and BandashZn but apositive correlation was found for Tindash(Mn Fe) with r2frac14 090In the BAC3 core relationships were found for only four
elements UndashSr and CandashMg (r2frac14 099)The relationship for Alndash(Ti Fe) in almost all cores is derived
from the fact that these elements represent silicates and otherrefractory minerals and hence aeolian or fluvial input of
particulate matter from land (Drever 2005) The correlationfor Candash(SrndashMg) in most cores is consistent with the maincarbonate minerology of these sediments Other correlations
are not universal and in general no pattern in spatial distribu-tion was found in the correlation between elements among allcores suggesting that these elements are not controlled by the
same parameters at each site
Hydrochemistry of Bacalar Lagoon Marine and Freshwater Research G
Sediment pollution
Some trace elements in Bacalar Lagoon sediments mayreflect anthropogenic pollution Here we used four indices
followingManoj and Padhy (2014 see Table 3)We normalisedconcentrations to Al because it is a conservative lithogenic
element and is resistant to chemical weathering hence it does
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
8000 9000 10 000 11 000
Sr (ppm) Ba (ppm) U (ppm) Mg (ppm)
8 10 12 14 16 18 0 01 02 03 04 05 06 300 000 400 000
Dep
th (
cm)
0 1000 5000
Al (ppm) Si (ppm) Ti (ppm) Ca (ppm)
Mn (ppm) Fe (ppm) Ni (ppm) Zn (ppm)
10 000 2020 000 2001000 0 200 000 400 000
0 1 2 3 4 0 400 1000 2000 0 20 40 60 500 100 150 25020080
COC BAC3 BAC1 BAC2
Fig 7 Concentrations of trace andmajor elements in sediment cores BAC1 Bacalar 1 BAC2 Bacalar 2 BAC3 Bacalar 3
COC Cocalitos
H Marine and Freshwater Research N I Tobon ndashVelazquez et al
not actively participate in the dominant geochemical cycles and
does not have a significant anthropogenic source (Boes et al2011 Dautovic et al 2014)
For normalisation to Al values for the Earthrsquos crust were
taken from Turekian and Wedepohl (1961) in which the valuesare mean concentrations in carbonates rocks of the upper crustKfrac14 27000 ppm Mnfrac14 11000 ppm Nifrac14 200 ppm
Znfrac14 200 ppm and Bafrac14 100 ppmTo determine whether the elements are from lithological or
anthropogenic sources the trace element concentrations were
compared with the crustal composition (Hernandez et al 2003)
frac12M lithogenic frac14 frac12Als ethfrac12M =frac12AlcTHORN eth1THORN
frac12M anthropogenic frac14 frac12M T frac12M lithogenic eth2THORN
where the lithogenic input ([M]lithogenic) is estimated throughthe concentration of Al in the sample ([Al]s) and the ratio of the
average of the Earthrsquos crust ([M][Al]c) The anthropogenic input([M]anthropogenic) was calculated based on the total concentration([M]T) and the lithogenic input
The results of these calculations are summarised in Table 4For all cores U6thorn Mn2thorn and Kthorn show negative values for theindex of geoaccumulation (Igeo) whereas the values of CF(contamination factor) and CD (contamination degree) are
lower than 20 All factors indicate that the sediment is notpolluted with these elements which are likely of lithogenicorigin For Ni2thorn the Igeo (0) CF (1) and CD (6) indices
also indicate low pollution except for the upper samples (depthsof 0ndash6 and 6ndash11 cm) of theBAC2 core where theCF is30 andIgeo is 10 suggesting unpolluted to moderately polluted
conditions In contrast the values of these indices for Zn2thorn
and Ba2thorn show some spatial variabilityThe CD of Zn2thorn at all sites is 15 The eastern samples
(BAC1 and BAC2) show higher CD values (822 and 1805
respectively) suggesting moderate to considerable contamina-
tion of the sediment The Ba2thorn concentration exhibits a spatialdistribution the western sites (COC RAP and BAC3) havehigher Ba2thorn concentrations compared than the eastern sites and
the calculated indices were correspondingly higher for thewestern side of the lagoon However overall the indicesindicated that the sediments on both sides of the lagoon are
unpollutedwith regard to Ba and the differences are likely due tohigher barite content on thewestern side Based on these indicesno influence of human activities was detected in eastern core
samples (BAC1 and BAC2)The higher Zn2thorn and Ba2thorn concentrations may be due to a
higher input of these elements into the area close to these sitesHowever water column distributions have to be assessed to
confirm this Zn2thorn and Ba2thorn in Bacalar Lagoon sediments couldbe derived from two sources (1) authigenic minerals found inthe sediment which on thewestern side contain barite (BaSO4)
and some sphalerite (ZnS) and (2) anthropogenic sources suchas agricultural fertiliser or cattle feed Commercial fertiliserscontain micronutrients such as Zn2thorn Mn2thorn Fe3thorn Cu2thorn Mo6thorn
and Ba2thorn in concentrations ranging from trace to several ppmwhich could infiltrate and cause pollution in the soil andgroundwater (Adriano 1986) Baize (1997) indicated that Znis found in animal feed used for pigs that are raised domestically
and commercially in the region The waste water generated bythis industry has been poorly handled resulting in adverseeffects on the environment (Drucker et al 2003) Near the town
of Bacalar fertilisers and agrochemicals are used regularly(Alvarez-Legorreta 2009) The agriculture practices in themunicipality include maize sugarcane and pepper and more
than 40 products are spread annually on these crops (fertilisersherbicides and pesticides Euan-Avila et al 2002) Garcıa-Rıosand Gold-Bouchot (2002) identified Fe V Ni Pb Zn Cu and
Cd in sediments of nearby Chetumal Bay Indeed Bacalar andOthon P Blanco municipalities have the highest fertilised area
Table 3 Indices as indicators of sediment quality based on Manoj and Padhy (2014) and Javan et al (2015)
Ms sample element concentration Mb background concentration of the element
Index Equation Sediment quality
Index of geoacumulation Igeofrac14 ln(Ms15Mb) 0frac14 unpolluted
0ndash1frac14 unpolluted to moderately polluted
1ndash2frac14moderately polluted
2ndash3frac14moderately polluted to highly polluted
3ndash4frac14 highly polluted
4ndash5frac14 highly polluted to very highly polluted
5frac14 very highly polluted
Contamination factor CF5MsMb 1frac14 low CF
1 CF 3frac14moderate CF
3 CF 6frac14 considerable CF
$6frac14 very high CF
Contamination degree CD frac14Pnifrac141
CF 6frac14 low CD
6 CD 12frac14moderate CD
12 CD 24frac14 considerable CD
$24frac14 high CD (anthropogenic contamination)
Pollution load index PLI5 (CF1CFsyCFn)1n 0frac14 unpolluted
1frac14 baseline levels of pollutants present
1frac14 progressive deterioration of site
Hydrochemistry of Bacalar Lagoon Marine and Freshwater Research I
Table4
Index
ofgeoacummulation(Igeo)anthropogenic(A
)inputcontaminationfactor(C
F)andcontaminationdegree(C
D)forBaUKMnNiandZnin
thesedim
entary
record
ofthe
BacalarLagoon
NAdatanoavailablePLIpollutionload
indexBAC1Bacalar
1BAC2Bacalar
2BAC3Bacalar
3COCCocalitosRAPLosRapidos
Site
Depth
(cm)
Ba
UK
Mn
Ni
Zn
PLI
I geo
Ainput
CF
CD
I geo
Ainput
CF
CD
I geo
Ainput
CF
CD
I geo
Ainput
CF
CD
I geo
Ainput
CF
CD
I geo
Ainput
CF
CD
COC
0ndash6
016
1236
134
701
503
013
005
065
688
24629
001
003
1119
11361
0001
0002
371
021
011
053
203
529
037
479
005
6ndash12
015
1314
135
469
005
006
675
5569
001
1160
3753
0000
409
107
009
004
2846
146
006
12ndash17
004
1421
146
336
024
015
NA
10001
000
1147
4016
0001
405
107
009
037
2254
116
000
17ndash22
014
1627
165
304
035
018
1158
6288
000
1257
2588
0000
362
196
012
010
3174
161
004
22ndash27
031
1156
121
282
035
021
NA
14125
000
1338
5739
0000
367
132
012
301
267
019
000
RAP
0ndash6
039
1074
115
264
538
008
004
009
889
18818
000
002
1067
7912
0001
0001
508
057
004
014
156
870
051
284
004
6ndash11
001
1360
149
475
017
006
651
31721
002
1189
14691
0000
391
069
010
063
4390
233
007
BAC1
0ndash5
024
267
127
956
402
201
009
069
230
189364
031
161
896
110398
0003
0023
300
1639
019
115
174
1118
045
822
014
5ndash10
035
302
118
416
174
008
276
176636
022
907
96021
0003
311
1404
017
066
2982
237
017
10ndash15
048
382
108
437
137
007
307
139830
018
913
76341
0003
327
1083
016
119
074
066
013
15ndash20
031
444
121
423
150
008
295
153179
019
896
83486
0003
330
1220
015
013
1225
137
015
20ndash25
031
488
121
420
142
008
301
145741
019
883
79449
0003
351
1189
013
424
1293
008
009
25ndash30
039
504
114
408
121
009
320
128917
016
925
70152
0002
363
1037
012
061
689
098
013
30ndash35
016
581
134
385
145
010
299
154625
019
904
83454
0003
353
1264
013
069
337
093
014
35ndash40
041
467
113
419
127
008
313
131772
017
917
72183
0003
392
1120
010
012
1446
138
013
BAC2
0ndash6
035
1141
117
734
515
002
004
086
743
6689
001
006
1094
3596
0001
0006
374
157
011
444
051
4203
214
1805
007
6ndash11
052
1005
105
462
004
006
834
10694
000
949
4638
0002
119
6764
343
012
2666
138
012
11ndash16
055
984
103
442
006
007
750
9268
001
1126
4617
0001
420
078
008
144
1018
055
005
16ndash21
055
985
102
400
013
009
597
3426
002
1119
3962
0001
421
089
008
001
2953
151
008
21ndash26
043
1093
111
296
038
019
828
3839
000
1178
2046
0000
412
135
009
293
22785
1141
009
26ndash31
068
925
094
254
054
026
832
2578
000
1194
1524
0000
273
424
023
104
1434
073
006
36ndash41
056
1001
102
337
028
014
875
3556
000
1113
1759
0001
182
819
043
219
626
033
006
BAC3
0ndash6
016
1283
134
407
607
009
002
007
682
12943
001
002
1266
6706
0000
0001
553
057
003
008
211
572
035
152
003
6ndash12
020
1270
131
607
003
002
989
9545
000
1308
4043
0000
580
020
003
081
1639
086
002
12ndash18
008
1389
142
613
003
002
891
8695
000
1341
3872
0000
593
021
002
223
567
032
002
J Marine and Freshwater Research N I Tobon ndashVelazquez et al
in Quintana Roo state (Instituto Nacional de Estadıstica yGeografıa 2016) Owing to the karstic nature of the area these
products can immediately infiltrate the aquifer and thereforecould be affecting the lagoon Because the concentration of ZnSminerals was low in the cores it is suggested that the source of
Zn2thorn could be derived from human activities Although theresults from the pollution load index (PLI) (1) for all samplesindicate that the sites are not highly polluted the excess Zn2thorn in
the sediment suggests some local pollution with regard to thiselement Conversely the concentrations of Ba2thorn can beexplained by the variable occurrence of barite in the cores
Minimal trace metal pollution is consistent with previous
metal work in the lagoon Castro-Contreras et al (2014)reported heavy metal concentrations in Bacalar Lagoon waterbelow the maximum limits of the Mexican legislation (NOM-
127-SSA1-1994) and ecological water quality criteria (CE-CCA-00189) that establish the limits of heavy metals fordrinking water irrigation and recreational activities
Nevertheless organochloride compounds (pesticides andpolychlorinated biphenyls) and hydrocarbons in sediments havebeen identified by Norena-Barroso et al (1998) in the ChetumalBay area near Bacalar Lagoon Organochlorine pesticides
(OCPs) are used in agriculture in the region (Alvarez-Legorreta2009) Furthermore heavymetals and OCPs have been detectedin crocodilian eggs near Chichorro Atoll (Charruau et al 2013
Buenfil-Rojas et al 2015)
Conclusions
Bacalar Lagoon is a shallow and oligotrophic system (low-
nutrient waters) with a mineralogical composition dominatedby calcite dolomite and evaporites dissolution Water geo-chemical analyses show a clear spatial distribution of different
parameters The western part of the study area is characterisedby high alkalinity and calcium and sulfate concentrations theratios of these constituents indicate groundwater sources and noseawater intrusion The decreases in these parameters towards
the north indicate a gradient in groundwater influencethroughout the lagoon The eastern part of the study area ischaracterised by a shallower water column resulting in high
evaporation and high electrical conductivity compared with thewestern side
We present the first measurements of trace elements in
carbonate sediments in Bacalar Lagoon The sediment exhibitsonly moderate contamination with Zn2thorn on the western side ofthe lagoon The high Ba concentration in the sediment corre-
sponds to barite but further work is necessary to identify thesource of Ba2thorn and Zn2thorn This study can be useful for Bacalarmunicipality to make decisions and define actions regarding themanagement and development of Bacalar Lagoon
Conflicts of interest
The authors declare that they have no conflicts of interest
Declaration of funding
This investigation was financed by the lsquoWater Security Project inthe South-eastMexico in the face of twoclimate change scenariosrsquoproject (CONACYT 247565) and lsquoProject networks CONACYTrsquo
(282240) The authors acknowledge a grant from CONACYT
towards a Masters of Water Sciences degree (awarded to NidiaTobon Velazquez)
Acknowledgements
The authors thank technical staff Daniela Ortega (Water Sciences Unit
Centro de Investigacion Cientıfica de Yucatan) and Kimberly Bitterwolf
(University of CaliforniamdashSanta Cruz)
References
Adriano D C (1986) lsquoTrace Elements in the Terrestrial Environmentrsquo
(Springer-Verlag Berlin Germany)
Alvarez-Legorreta T (2009) Contaminacion acuatica In lsquoEl sistema ecolo-
gico de la Bahıa de Chetumal Corozal costa occidental del Mar Caribersquo
(Eds J Espinoza Avalos G A Islebe and H A Hernandez Arana)
pp 205ndash217 (El Colegio de la Frontera Sur Chetumal Mexico)
Appelo C A and Postma D (2005) lsquoGeochemistry Groundwater and
Pollutionrsquo 2nd edn (A A Balkema Rotterdam Netherlands)
Baize D (1997) lsquoTeneurs totales en elements trace metalliques dans les sols
(France) References et strategies drsquointerpretationrsquo (INRA Paris France)
Bauer-Gottwein P Gondwe B Charvet G Marin L Rebolledo V M
andMerediz A G (2011) Review the Yucatan Peninsula karst aquifer
Mexico Hydrogeology Journal 19 507ndash524 doi101007S10040-010-
0699-5
Beddows P A (2002) lsquoWhere Does the Sewage Go The Karst
Groundwater System of the Municipalidad de Solidaridad Quintana
Roo Mexicorsquo (Association for Mexican Cave Studies Houston
TX USA)
Beltran D Y (2010) Estimacion de los patrones de fijacion de nitrogeno y
diversidad asociada (nifH) en tapices microbianos y estromatolitos
MSc Thesis Universidad Nacional Autonoma de Mexico Ciudad de
Mexico Mexico
Boes X Rydberg J Martinez C A Bindler R and Renberg I (2011)
Evaluation of conservative lithogenic elements (Ti Zr Al and Rb) to
study anthropogenic element enrichments in lake sediments Journal of
Paleolimnology 46 75ndash87 doi101007S10933-011-9515-Z
Boyle J F (2001) Inorganic geochemical methods in paleolimnology In
lsquoTracking Environmental Change Using Lake Sediments Vol 2 Physi-
cal andGeochemicalMethodsrsquo (EdsMW Last and P J Smol) pp 83ndash
143 (Kluwer Academic Publishers Dordrecht Netherlands)
Buenfil-Rojas A M Alvarez- Legorreta T and Cedeno-Vazquez J R
(2015) Metals and metallothioneins in Moreletrsquos Crocodile (Crocodile
moreletii) from a Transboundary River between Mexico and Belize
Archives of Environmental Contamination and Toxicology 68(2) 265ndash
273 doi101007S00244-014-0088-5
Castro-Contreras C Murray K G Pecoits E Aubet N R Petrash D
Castro C S Gregory D Planavsky N and Konhauser K O (2014)
Textural and geochemical features of freshwater microbialites from
LagunaBacalarQuintanaRooMexicoPalaios 29(5) 192ndash209 doi10
2110PALO2013063
Ceballos Martınez R R (2002) Geografıa y medio ambiente en el sistema
lagunar San FelipendashBacalarndashGuerrero In lsquoContribuciones de la ciencia al
manejo costero integrado de laBahıa deChetumal y su area de influenciarsquo
(Eds F J Rosado-May RRomeroMayo andADe Jesus Navarrete) pp
17ndash22 (Universidad de Quintana Roo Chetumal Mexico)
Centeno M C Legendre P Beltran Y Alcantara H R Lidstrom E U
Ashby N M and Falcon I L (2012) Microbialite genetic diversity
and composition relate to environmental variables FEMSMicrobiology
Ecology 82 724ndash735 doi101111J1574-6941201201447X
Chagas A P Webb E G Burne V R and Southam G (2016) Modern
lacustrine microbialites towards a synthesis of aqueous and carbonate
geochemistry and mineralogy Earth-Science Reviews 162 338ndash363
doi101016JEARSCIREV201609012
Charruau P Henaut Y and Alvarez-Legorreta T (2013) Organo-
chlorine pesticides in nest substratum and infertile eggs of American
Hydrochemistry of Bacalar Lagoon Marine and Freshwater Research K
crocodiles (Reptilia Crocodylidae) in a Mexican Caribbean atoll
Caribbean Journal of Science 47 1ndash12 doi1018475CJOSV47I1A2
Comision Nacional del Agua (2002) lsquoDeterminacion de la disponibilidad de
agua en el acuıfero Penınsula de Yucatan estado de Yucatanrsquo (CON-
AGUA Gerencia de Aguas Subterraneas Ciudad de Mexico Mexico)
Comision Nacional del Agua (2012) lsquoPrograma Hıdrico Regional Vision
2030 Region Hidrologico-Administrativa XII Penınsula de Yucatanrsquo
1st edn (Secretarıa de Medio Ambiente y Recursos Naturales Mexico
City Mexico)
Comision Nacional del Agua (2015) lsquoActualizacion de la disponibilidad
media anual de agua en el acuıfero Cerros y Valles (2301) Estado de
QuintanaRoorsquo (CONAGUADiarioOficial de la Federacion Ciudad de
Mexico Mexico)
Dautovic J Fiket Z Baresic J Ahel M and Mikac N (2014) Sources
distribution and behavior of major and trace elements in a complex karst
lake system Aquatic Geochemistry 20 19ndash38 doi101007S10498-
013-9204-9
Dıaz J E (2005) lsquoDecreto por el cual se establece el programa de
ordenamiento ecologico territorial de la region de Laguna Bacalar
Quintana Roo Mexicorsquo (Periodico Oficial Chetumal Mexico)
Dixon J Hamilton K Pagiola S and Segnestam L (2001) Tourism and
environment in the Caribbean an economic framework (The World
Bank Washington DC USA) Available at httpdocumentsworldbank
orgcurateden672281468770397455pdfmulti0pagepdf [Verified 18
October 2018]
Drever J I (2005) lsquoSurface and Ground Water Weathering and Soilsrsquo
(Elsevier Oxford UK)
Drucker A Escalante R Gomez V and Magana S (2003) La industria
porcina en Yucatan un analisis de la generacion de aguas residuales
Problemas del Desarrollo Revista Latinoamericana de Economıa 34
(135) 105ndash120
Dupraz C Reid R P andVisscher P T (2011)MicrobialitesModern In
lsquoEncyclopedia of Geobiology Encyclopedia of Earth Science Seriesrsquo
(Eds J Reitner and V Thiel) pp 617ndash635 (Springer Heidelberg
Germany)
Elango L andKannan R (2007) Rockndashwater interaction and its control on
chemical composition of groundwater In lsquoDevelopments in Environ-
mental Sciencersquo Vol 5 (Eds D Sarkar R Datta and R Hannigan) pp
229ndash243 (Elsevier Oxford UK)
Euan-Avila J I Liceaga-CorreaM A and Rodrıguez Sanchez H (2002)
Caracterizacion de fuentes no puntuales de contaminacion agrıcola en el
municipio deOthon P Blanco enQuintanaRoo y su potencial influencia
en la Bahıa de Chetumal In lsquoContribuciones de la ciencia al manejo
costero integrado de la Bahıa de Chetumal y su area de influenciarsquo (Eds
F J Rosado-May R Romero Mayo and A De Jesus Navarrete) pp
197ndash204 (Universidad de Quintana Roo Chetumal Mexico)
Fouke W B Zerkle L A Alvarez W Pope O K Ocampos A C
Wachtman J R Grajales J M Claeys P and Fischer G A (2002)
Cathodoluminescence petrography and isotope geochemistry of KT
impact ejecta deposited 360 km from the Chicxulub crater at Albion
Island Belize Sedimentology 49 117ndash138 doi101046J1365-3091
200200435X
Garcıa-Rıos V Y and Gold-Bouchot G (2002) Especiacion de metales
pesados en sedimentos de la Bahıa de Chetumal Quintana Roo y la
acumulacion en el tejido muscular de bagres (Ariopsis assimilis) In
lsquoContribuciones de la ciencia al manejo costero integrado de la Bahıa de
Chetumal y su area de influenciarsquo (Eds F J Rosado-May R Romero
Mayo and A De Jesus Navarrete) pp 143ndash148 (Universidad de
Quintana Roo Chetumal Mexico)
Gischler E Gibson M A and Oschmann W (2008) Giant Holocene
freshwater microbialites Laguna de Bacalar Quintana Roo Mexico
Sedimentology 55 1293ndash1309 doi101111J1365-3091200700946X
Gischler E Golubic S Gibson M Oschamann W and Hudson J H
(2011) Microbial mats and microbialites in the freshwater Laguna
Bacalar Yucatan Peninsula Mexico In lsquoAdvances in Stromatolite
Geobiologyrsquo (Eds J Reitner M H Trauth K Stuwe and D Yuen)
pp 187ndash205 (Springer Berlin Germany)
Gonzalez B J L Carrion J J Cuevas D J Flores M F Yam G J O
Moreno C J Perez V J and Calva C G (2014) Acumulacion de Hg
Pb Cd y Zn por Pomacea flagellata en tres balnearios ubicados en la
region urbana de la Laguna de Bacalar TecnoCultura 35 14ndash23
Hemley R J Prewitt C T and Kingma K (1994) High-pressure
behavior of silica In lsquoSilica ndash Physical Behavior Geochemistry and
Materials Applications Reviews in Mineralogy Vol 29rsquo (Eds P J
Heaney C T Prewitt and G V Gibbs) pp 41ndash82 (Mineralogical
Society of America Washington DC USA)
Hernandez L Probst A Probst L J and Ulrich E (2003) Heavy metal
distribution in some French forest soils evidence for atmospheric
contamination The Science of the Total Environment 312(1ndash3)
195ndash219 doi101016S0048-9697(03)00223-7
Hernandez-Terrones L Rebolledo-Vieyra M Merino-Ibarra M Soto
M Le-Cossec A and Monroy-Rıos E (2011) Groundwater pollution
in a karstic region (NE Yucatan) baseline nutrient content and flux to
coastal ecosystems Water Air and Soil Pollution 218(1ndash4) 517ndash528
doi101007S11270-010-0664-X
InstitutoNacional de Estadıstica yGeografıa (2002) EstudioHidrologico del
Estado de Quintana Roo (INEGI Aguascalientes Mexico) Available at
httpinternetcontenidosinegiorgmxcontenidosproductosprod_serv
contenidosespanolbvinegiproductoshistoricos2104702825224196
702825224196_1pdf [Verified 5 September 2018]
Instituto Nacional de Estadıstica y Geografıa (2016) Anuario Estadıstico y
Geografico de Quintana Roo (INEGI Aguascalientes Mexico) Avail-
able at httpinternetcontenidosinegiorgmxcontenidosProductos
prod_servcontenidosespanolbvinegiproductosnueva_estrucanuarios_
2016702825084370pdf [Verified 5 September 2018]
Javan S Hessam H A Gholamalizadeh A A and Soltani J (2015)
Fractionation of heavy metals in bottom sediments in Chahnimeh 1
Zabol Iran Environmental Monitoring and Assessment 187(6) 340
doi101007S10661-015-4510-X
Katip A Karaer F Ileri S Sarmasik S Aydogan N and Zenginay S
(2011) Analysis and assessment of trace elements pollution in sediments
of Lake Ulubat Turkey Journal of Environmental Biology 33 961ndash968
Kenkmann T and Schonian F (2006) Ries and Chicxulub impact craters
on Earth provide insights for Martian ejecta blankets Meteoritics amp
Planetary Science 41(10) 1587ndash1603 doi101111J1945-51002006
TB00437X
Khedidja A and Boudoukha A (2016) Lrsquoaquifere Superficiel de
Tadjnanet-Chelghoum laid (Nord-Est Algerien) Larhyss Journal 28
181ndash197
Lounejeva E Ostroumov M and Sanchez R G (2002) Polimorfos de
alta presion de sılice en las impactitas de ChicxulubMexico ndash resultados
de espectrometrıa de Raman Revista Mexicana de Ciencias Geologicas
17(2) 137ndash141
Manoj K and Padhy P K (2014) Distribution enrichment and ecological
risk assessment of six elements in bed sediments of a tropical river
Chottanagpur Plateau a spatial and temporal appraisal Journal of
Environmental Protection 5 1419ndash1434 doi104236JEP2014514136
Marfia A M Krishnamurthya R V Atekwanab E A and Panton W F
(2004) Isotopic and geochemical evolution of ground and surfacewaters
in a karst dominated geological setting a case study fromBelize Central
America Applied Geochemistry 19 937ndash946 doi101016JAPGEO
CHEM200310013
Massaferro J Correa M A Montes de Oca F and Mauad M (2018)
Contrasting responses of lake ecosystems to environmental disturbance
a paleoecological perspective from northern Patagonia (Argentina)
Hydrobiologia 816(1) 79ndash89 doi101007S10750-016-3081-3
Medina M S Jimenez G A Gutierrez R M and Lizardi J M (2014)
Hydrocarbon pollution studies of underwater sinkholes along Quintana
L Marine and Freshwater Research N I Tobon ndashVelazquez et al
Roo as function of tourism development in the Mexican Caribbean
Revista Mexicana de Ingenierıa Quımica 13(2) 509ndash516
Norena-Barroso E Zapata-Perez O Ceja-Moreno V and Gold-Bouchot
G (1998) Hydrocarbon and organochloride residue concentrations in
sediments from Bay of Chetumal Mexico Bulletin of Environmental
Contamination and Toxicology 61 80ndash87 doi101007S001289900732
Nriagu J and Pacyna J (1988) Quantitative assessment of worldwide
contamination of air water and soils by trace metals Nature 333 134ndash
139 doi101038333134A0
Ochoa J C Gonzalez B J and Jimenez C J (2016) Metales pesados
(Cd Cr Pb Hg) en Rhizophora mangle en rıo y bahıa de Chetumal
Revista Mexicana de Agroecosistemas 3(2) 263ndash271
Oliva R J Ocana F A de Jesus N A de Jesus C R and Vargas E A
(2016) Reproduccion dePomacea flagellata (Mollusca Ampullariidae)
en la laguna de Bacalar Quintana Roo Mexico Revista de Biologıa
Tropical 64(4) 1643ndash1650
Pacton M Hunger G Martinuzzi V Cusminsky G Burdin B
Barmettler K Vasconcelos C and Ariztegui D (2015) Organomi-
neralization processes in freshwater stromatolites a living example from
eastern Patagonia International Association of Sedimentologists Jour-
nal 1(2) 130ndash146
Perez L Bugja R Lorenschat J Brenner M Curtis J Hoelzmann P
Islebe G Scharf B and SchwalbA (2011) Aquatic ecosystems of the
Yucatan Peninsula (Mexico) Belize and Guatemala Hydrobiologia
661 407ndash433 doi101007S10750-010-0552-9
Perry E C Velazquez O G and Marin L (2002) The hydrogeochem-
istry of the karst aquifer system of the northern Yucatan Peninsula
Mexico International Geology Review 44 191ndash221 doi102747
0020-6814443191
Perry E Paytan A Pedersen B and Velazquez O G (2009) Ground-
water geochemistry of the Yucatan Peninsula Mexico constraints on
stratigraphy and hydrogeology Journal of Hydrology 367 27ndash40
doi101016JJHYDROL200812026
Pradit S Wattayarkorn G Angsupanich S Baeyens W and Leer-
makers M (2010) Distribution of trace elements in sediments and biota
of Songkhla Lake Southern Thailand Water Air and Soil Pollution
206 155ndash174 doi101007S11270-009-0093-X
Salomons W and Forstner U (1980) Trace metal analysis on polluted
sediments II evaluation of environmental impact Environmental
Technology Letters 1 506ndash517 doi10108009593338009384007
Sanchez S J Alvarez L T Pacheco A J Gonzalez H R and Carrillo
B L (2015) Caracterizacion hidrogeoquımica de las aguas subterraneas
del sur del Estado de Quintana Roo Mexico Revista Mexicana de
Ciencias Geologicas 32(1) 62ndash76
Schmitter-Soto J J Comın F A Escobar B E Herrera S J Alcocer J
Suarez M E Elıas G M Dıaz A V Marın L E and Steinich B
(2002) Hydrogeochemical and biological characteristics of cenotes in
the Yucatan Peninsula (SE Mexico) Hydrobiologia 467 215ndash228
doi101023A1014923217206
Siqueiros-Beltrones D Hernandez A U and Hernandez A O (2013)
Diagnosis prospectiva sobre la diversidad de diatomeas epilıticas en la
laguna Bacalar Quintana Roo Mexico Revista Mexicana de Biodiver-
sidad 84 865ndash875 doi107550RMB33960
Turekian K K andWedepohl K H (1961) Distribution of the elements in
some major units of the Earthrsquos crust Bulletin of the Geological Society
of America 72 175ndash192 doi1011300016-7606(1961)72[175
DOTEIS]20CO2
Handling Editor Russell Frew
wwwpublishcsiroaujournalsmfr
Hydrochemistry of Bacalar Lagoon Marine and Freshwater Research M
experiencing dissolution (undersaturation) Finally the thirdgroup (BAC1 and BAC2) is associated with calcite equilibrium
and undersaturation of the other minerals Bacalar Lagoon islocated in a region whereMiocene rocks containing gypsum andanhydrite are common and waterndashrock interaction results in the
dissolution of evaporites (Perry et al 2002 2009) The highconcentrations of Ca2thorn SO4
2 and Sr2thorn could be derived fromthe dissolution of these minerals The water samples in Bacalar
Lagoon are all undersaturated with regard to gypsum andanhydrite indicating that these minerals would not precipitatewithin the lagoon Ceballos Martınez (2002) indicated that
gypsum and limestone in the Bacalar formation tend to beconcentrated in the surface due to weathering forming lamellarcaliche
The Sr2thorn concentrations in samples from the western side are
quite similar to concentrations measured at the cenotes indicat-ing an input of this element from groundwater The same wassuggested by Perry et al (2002 2009) when they compared
concentrations of Sr2thorn and SO42 and Sr isotopes in the lagoon
to those of cenote AzulStandardised principal component analysis (PCA) was per-
formed using R (ver 340 R Foundation for Statistical Com-puting Vienna Austria) to identify the dominant limnologicalgradients in the dataset Fig 6 shows the results of a PCAappliedto the 15 hydrochemical variables measured here (water tem-
perature pH EC TDS SiO2 HCO3
Cl SO42 NO3
NH4
thorn Ca2thorn Kthorn Mg2thorn Nathorn and Sr2thorn) We present only thefirst two components (PC1 and PC2) because these explained 47
and 22 of the total variance respectively (Table 2) PCArepresents standard deviations and when the distance among
COC RAP BAC3 BAC1 BAC2 Ccoc Ccoclowast Caz Cazlowast
Sat
urat
ion
inde
x
15
10
05
0
05
10
Anhydrite (CaSO4)Aragonite (CaCO3)
Calcite (CaCO3)
Celestite (SrSO4)Gypsum (CaSO42H2O)
Dolomite (Ca Mg(CO3))
Fig 5 Saturation index (SI) calculated for each sample site for all relevant
minerals Note SIfrac14 0 indicates the mineral equilibrium (grey line) SI 0
indicates oversaturation and SI 0 indicates undersaturation Asterisks
indicate cenote water samples at a depth of 15 m BAC1 Bacalar 1
BAC2 Bacalar 2 BAC3 Bacalar 3 Caz cenote Azul Ccoc cenote
Cocalitos COC Cocalitos RAP Los Rapidos
24
2
4
0
2
4
0
PC1
2 4
PC
2
Ca
pHSO4
HCO3
NO3
Temp
TDS
Mg
ECNaCl
Sr
NH4
Caz
Ccoc
BAC2 BAC1
RAP
BAC3
COC
SiO2SiO2
K
Fig 6 Principal component analysis based on 15 chemical variables (grey
arrows) at different sampling sites (lagoon and cenotes) PC1 principal
component 1 PC2 principal component 2 EC electrical conductivity
TDS total dissolved solids Temp temperature BAC1 Bacalar 1 BAC2
Bacalar 2 BAC3 Bacalar 3 Caz cenote Azul Ccoc cenote Cocalitos
COC Cocalitos RAP Los Rapidos
Table 2 Eigenvalues of principal component analysis components and
variance explained
Principal component Eigenvalue Variance explained ()
1 706 4712
2 338 2258
3 210 1402
4 127 851
0 05 10 15 20 25 30 3502
04
06
10
12
14
Effect ofevaporates
BAC3
RAP
COCCaz
CcocBAC2
BAC1
Ca
Mg
HC
O3
Na
Cl
SO
4
Conductivity (mS cm1)
Effect ofcarbonates
Fig 4 Mineralisation effect on water chemistry Dark grey points repre-
sent the sampling sites dashed circular areas indicate the range in which the
electrical conductivity and major element ratios are interpreted as resulting
from mineralisation of evaporites or carbonates according to Khedidja and
Boudoukha (2016) BAC1 Bacalar 1 BAC2 Bacalar 2 BAC3 Bacalar 3
Caz cenote Azul Ccoc cenote Cocalitos COC Cocalitos RAP Los
Rapidos
F Marine and Freshwater Research N I Tobon ndashVelazquez et al
samples is greater than 2 units this indicates that the physico-chemical conditions are distinct (Massaferro et al 2018) hence
variations could be interpreted as significant differencesbetween sites
Samples along PCA Axis 1 show two distinctive patterns
within the lagoon which are separated by pH EC TDS Nathorn
and HCO3 distribution The spread of samples within PC1 is
relatively large suggesting significant differences among sites
This spread reflects the distinct distributions of physicochemicalfeatures at the different sides of the lagoon the western side(Axis 1 from 4 to 0 units) is characterised by a high HCO3
content (COC RAP BAC3 Ccoc and Caz) whereas the eastern
side (Axis 1 from 0 to 4 units) is characterised by high EC NathornpH and TDS and corresponds to the BAC1 and BAC2 sites
PC2 is associated with SiO2 and Kthorn concentrations PC2
shows two groups with the first group corresponding to sampleswith low SiO2
and Kthorn concentrations (COC RAP BAC1BAC2 and BAC3) and positive values of Axis 2 (from 4 to 0)
The second group is characterised by high SiO2 and Kthorn
concentrations (Ccoc and Caz samples) and corresponds tonegative axis values (from 0 to 4) PC2 is associated withsilica content due to higher silica concentrations in the cenotes
compared with the rest of the lagoon samples This can beexplained by more rapid Si uptake in the sun-lit lagoon wherediatoms are abundant
Changes in pH and transparency by sediment disturbance canhave an effect on stromatolites Sulfate-reducing bacteria par-ticipate in the formation of stromatolites and appear to always be
associated with Mg calcite and low-salinity and low-turbiditywaters Although stromatolites were not analysed in the presentstudy we recommend that a water monitoring program be
established to survey nutrients and measure other variablessuch as transparency tourist and boat activity weatheringdisturbance of sediments and trace elements at least twice ayear to ensure that the stromatolites are not negatively affected
Sediment characterisation
X-Ray diffraction
The results from the XRD analyses indicate that the mainmineralogical composition for all sediment samples was calcite(CaCO3) dolomite (CaMg(CO3)2) and SiO2 (quartz and possi-
bly minor amounts of coesite) In general calcite was in highestabundance in all cores Dolomite was present in all samples atlower proportions
These results are in accordance with the SI where calcite is
oversaturated in the western part of the lagoon and Ca2thorn andHCO3
concentrations are elevated throughout the lagoonCoesite forms under conditions of high pressure (3ndash10 GPa
Hemley et al 1994) and the presence of this mineral could berelated to the impact of the Chicxulub meteorite (Lounejevaet al 2002) Fouke et al (2002) with an estimated diameter of
its effect 360 km The presence of coesite in Bacalar Lagooncould be associated with this event Fouke et al (2002) andKenkmann and Schonian (2006) reported Chicxulub ejecta
deposited in Belize and in some regions of the Rio Hondo (nearBacalar Lagoon) However identifying the origin of this min-eral in Bacalar Lagoon requires additional detailed studies withlonger scan times to confirm the presence of coesite Other
minerals that we found in lower proportions are barite (BaSO4)
and a few samples with sphalerite (ZnS) with higher propor-tions of barite in the western than eastern side of the lagoon
Geochemistry
Elemental concentrations in the sediment samples are shown
in Fig 7 All sediment cores had high concentrations of Ca2thornMg2thorn and Sr2thorn which were one to three orders of magnitudehigher than concentrations for the rest of the elements consis-
tent with carbonate minerals (calcite) dominating the sedimentElement abundance was similar in cores of sites located in
the western part of the lagoon (COC RAP and BAC3) in the
order Ca2thornMg2thornSr2thorn Si4thornAl3thorn Fe3thornZn2thorn
KthornBa2thornTi4thornNi2thornMn2thornU6thorn The order of ele-ment abundance for the eastern cores (BAC1 and BAC2) was
similar except that Mg was more abundant than Ca (Mg2thorn
Ca2thorn Sr2thorn Si4thornAl3thorn Fe3thornZn2thornKthornNi2thorn
Ba2thornTi4thornMn2thornU6thorn) These relative abundances sug-gest that cores from the western side are dominated by Ca2thorn
carbonate minerals (likely calcite) whereas those from the eastside contain more dolomite The BAC1 core had the highestconcentrations of Al3thorn Si4thorn Kthorn Ti4thorn Mn2thorn and Fe3thorn likelyrepresenting some silicates and ironndashmanganese oxides fromterrigenous sources The highest Ni2thorn and Zn2thornconcentrationswere measured in the core from BAC2 and may represent
anthropogenic pollutant inputs The other elements analysedhad similar distributions in all cores
In general concentrations of Ba2thorn U6thorn and Zn2thorn werehigher in deeper sections of the cores and this may suggest
temporal changes in the input of these elements The rest of theelements (Ca2thorn and Mg2thorn) did not show variations with depthdown the core (r2 05)
The concentrations of elements span orders of magnitudetherefore the data do not satisfy the assumption of normality ASpearman correlation was performed using STATISTICA
(ver 133 Palo Alto CA USA) to test the relationship betweenthe trace elements in each core with significance level atP 005
Except for BAC3 the most significant correlation was forAlndash(FendashTi) (r2 090) In the BAC2 core significant correla-tions were found for SrndashMg AlndashTi KndashNi and SindashTi (r2frac14 090090 088 and 086 respectively) For BAC1 the highest
correlations were found for SrndashCa Alndash(Fe Ni) Kndash(Fe Ni)and BandashMg (r2frac14 095 098 098 and 081 respectively) Nega-tive correlationswere found at theCOC site (r2frac14090) forAlndash
(Zn Sr) Fendash(Ca U) Mnndash(U Ca) UndashSi and BandashZn but apositive correlation was found for Tindash(Mn Fe) with r2frac14 090In the BAC3 core relationships were found for only four
elements UndashSr and CandashMg (r2frac14 099)The relationship for Alndash(Ti Fe) in almost all cores is derived
from the fact that these elements represent silicates and otherrefractory minerals and hence aeolian or fluvial input of
particulate matter from land (Drever 2005) The correlationfor Candash(SrndashMg) in most cores is consistent with the maincarbonate minerology of these sediments Other correlations
are not universal and in general no pattern in spatial distribu-tion was found in the correlation between elements among allcores suggesting that these elements are not controlled by the
same parameters at each site
Hydrochemistry of Bacalar Lagoon Marine and Freshwater Research G
Sediment pollution
Some trace elements in Bacalar Lagoon sediments mayreflect anthropogenic pollution Here we used four indices
followingManoj and Padhy (2014 see Table 3)We normalisedconcentrations to Al because it is a conservative lithogenic
element and is resistant to chemical weathering hence it does
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
8000 9000 10 000 11 000
Sr (ppm) Ba (ppm) U (ppm) Mg (ppm)
8 10 12 14 16 18 0 01 02 03 04 05 06 300 000 400 000
Dep
th (
cm)
0 1000 5000
Al (ppm) Si (ppm) Ti (ppm) Ca (ppm)
Mn (ppm) Fe (ppm) Ni (ppm) Zn (ppm)
10 000 2020 000 2001000 0 200 000 400 000
0 1 2 3 4 0 400 1000 2000 0 20 40 60 500 100 150 25020080
COC BAC3 BAC1 BAC2
Fig 7 Concentrations of trace andmajor elements in sediment cores BAC1 Bacalar 1 BAC2 Bacalar 2 BAC3 Bacalar 3
COC Cocalitos
H Marine and Freshwater Research N I Tobon ndashVelazquez et al
not actively participate in the dominant geochemical cycles and
does not have a significant anthropogenic source (Boes et al2011 Dautovic et al 2014)
For normalisation to Al values for the Earthrsquos crust were
taken from Turekian and Wedepohl (1961) in which the valuesare mean concentrations in carbonates rocks of the upper crustKfrac14 27000 ppm Mnfrac14 11000 ppm Nifrac14 200 ppm
Znfrac14 200 ppm and Bafrac14 100 ppmTo determine whether the elements are from lithological or
anthropogenic sources the trace element concentrations were
compared with the crustal composition (Hernandez et al 2003)
frac12M lithogenic frac14 frac12Als ethfrac12M =frac12AlcTHORN eth1THORN
frac12M anthropogenic frac14 frac12M T frac12M lithogenic eth2THORN
where the lithogenic input ([M]lithogenic) is estimated throughthe concentration of Al in the sample ([Al]s) and the ratio of the
average of the Earthrsquos crust ([M][Al]c) The anthropogenic input([M]anthropogenic) was calculated based on the total concentration([M]T) and the lithogenic input
The results of these calculations are summarised in Table 4For all cores U6thorn Mn2thorn and Kthorn show negative values for theindex of geoaccumulation (Igeo) whereas the values of CF(contamination factor) and CD (contamination degree) are
lower than 20 All factors indicate that the sediment is notpolluted with these elements which are likely of lithogenicorigin For Ni2thorn the Igeo (0) CF (1) and CD (6) indices
also indicate low pollution except for the upper samples (depthsof 0ndash6 and 6ndash11 cm) of theBAC2 core where theCF is30 andIgeo is 10 suggesting unpolluted to moderately polluted
conditions In contrast the values of these indices for Zn2thorn
and Ba2thorn show some spatial variabilityThe CD of Zn2thorn at all sites is 15 The eastern samples
(BAC1 and BAC2) show higher CD values (822 and 1805
respectively) suggesting moderate to considerable contamina-
tion of the sediment The Ba2thorn concentration exhibits a spatialdistribution the western sites (COC RAP and BAC3) havehigher Ba2thorn concentrations compared than the eastern sites and
the calculated indices were correspondingly higher for thewestern side of the lagoon However overall the indicesindicated that the sediments on both sides of the lagoon are
unpollutedwith regard to Ba and the differences are likely due tohigher barite content on thewestern side Based on these indicesno influence of human activities was detected in eastern core
samples (BAC1 and BAC2)The higher Zn2thorn and Ba2thorn concentrations may be due to a
higher input of these elements into the area close to these sitesHowever water column distributions have to be assessed to
confirm this Zn2thorn and Ba2thorn in Bacalar Lagoon sediments couldbe derived from two sources (1) authigenic minerals found inthe sediment which on thewestern side contain barite (BaSO4)
and some sphalerite (ZnS) and (2) anthropogenic sources suchas agricultural fertiliser or cattle feed Commercial fertiliserscontain micronutrients such as Zn2thorn Mn2thorn Fe3thorn Cu2thorn Mo6thorn
and Ba2thorn in concentrations ranging from trace to several ppmwhich could infiltrate and cause pollution in the soil andgroundwater (Adriano 1986) Baize (1997) indicated that Znis found in animal feed used for pigs that are raised domestically
and commercially in the region The waste water generated bythis industry has been poorly handled resulting in adverseeffects on the environment (Drucker et al 2003) Near the town
of Bacalar fertilisers and agrochemicals are used regularly(Alvarez-Legorreta 2009) The agriculture practices in themunicipality include maize sugarcane and pepper and more
than 40 products are spread annually on these crops (fertilisersherbicides and pesticides Euan-Avila et al 2002) Garcıa-Rıosand Gold-Bouchot (2002) identified Fe V Ni Pb Zn Cu and
Cd in sediments of nearby Chetumal Bay Indeed Bacalar andOthon P Blanco municipalities have the highest fertilised area
Table 3 Indices as indicators of sediment quality based on Manoj and Padhy (2014) and Javan et al (2015)
Ms sample element concentration Mb background concentration of the element
Index Equation Sediment quality
Index of geoacumulation Igeofrac14 ln(Ms15Mb) 0frac14 unpolluted
0ndash1frac14 unpolluted to moderately polluted
1ndash2frac14moderately polluted
2ndash3frac14moderately polluted to highly polluted
3ndash4frac14 highly polluted
4ndash5frac14 highly polluted to very highly polluted
5frac14 very highly polluted
Contamination factor CF5MsMb 1frac14 low CF
1 CF 3frac14moderate CF
3 CF 6frac14 considerable CF
$6frac14 very high CF
Contamination degree CD frac14Pnifrac141
CF 6frac14 low CD
6 CD 12frac14moderate CD
12 CD 24frac14 considerable CD
$24frac14 high CD (anthropogenic contamination)
Pollution load index PLI5 (CF1CFsyCFn)1n 0frac14 unpolluted
1frac14 baseline levels of pollutants present
1frac14 progressive deterioration of site
Hydrochemistry of Bacalar Lagoon Marine and Freshwater Research I
Table4
Index
ofgeoacummulation(Igeo)anthropogenic(A
)inputcontaminationfactor(C
F)andcontaminationdegree(C
D)forBaUKMnNiandZnin
thesedim
entary
record
ofthe
BacalarLagoon
NAdatanoavailablePLIpollutionload
indexBAC1Bacalar
1BAC2Bacalar
2BAC3Bacalar
3COCCocalitosRAPLosRapidos
Site
Depth
(cm)
Ba
UK
Mn
Ni
Zn
PLI
I geo
Ainput
CF
CD
I geo
Ainput
CF
CD
I geo
Ainput
CF
CD
I geo
Ainput
CF
CD
I geo
Ainput
CF
CD
I geo
Ainput
CF
CD
COC
0ndash6
016
1236
134
701
503
013
005
065
688
24629
001
003
1119
11361
0001
0002
371
021
011
053
203
529
037
479
005
6ndash12
015
1314
135
469
005
006
675
5569
001
1160
3753
0000
409
107
009
004
2846
146
006
12ndash17
004
1421
146
336
024
015
NA
10001
000
1147
4016
0001
405
107
009
037
2254
116
000
17ndash22
014
1627
165
304
035
018
1158
6288
000
1257
2588
0000
362
196
012
010
3174
161
004
22ndash27
031
1156
121
282
035
021
NA
14125
000
1338
5739
0000
367
132
012
301
267
019
000
RAP
0ndash6
039
1074
115
264
538
008
004
009
889
18818
000
002
1067
7912
0001
0001
508
057
004
014
156
870
051
284
004
6ndash11
001
1360
149
475
017
006
651
31721
002
1189
14691
0000
391
069
010
063
4390
233
007
BAC1
0ndash5
024
267
127
956
402
201
009
069
230
189364
031
161
896
110398
0003
0023
300
1639
019
115
174
1118
045
822
014
5ndash10
035
302
118
416
174
008
276
176636
022
907
96021
0003
311
1404
017
066
2982
237
017
10ndash15
048
382
108
437
137
007
307
139830
018
913
76341
0003
327
1083
016
119
074
066
013
15ndash20
031
444
121
423
150
008
295
153179
019
896
83486
0003
330
1220
015
013
1225
137
015
20ndash25
031
488
121
420
142
008
301
145741
019
883
79449
0003
351
1189
013
424
1293
008
009
25ndash30
039
504
114
408
121
009
320
128917
016
925
70152
0002
363
1037
012
061
689
098
013
30ndash35
016
581
134
385
145
010
299
154625
019
904
83454
0003
353
1264
013
069
337
093
014
35ndash40
041
467
113
419
127
008
313
131772
017
917
72183
0003
392
1120
010
012
1446
138
013
BAC2
0ndash6
035
1141
117
734
515
002
004
086
743
6689
001
006
1094
3596
0001
0006
374
157
011
444
051
4203
214
1805
007
6ndash11
052
1005
105
462
004
006
834
10694
000
949
4638
0002
119
6764
343
012
2666
138
012
11ndash16
055
984
103
442
006
007
750
9268
001
1126
4617
0001
420
078
008
144
1018
055
005
16ndash21
055
985
102
400
013
009
597
3426
002
1119
3962
0001
421
089
008
001
2953
151
008
21ndash26
043
1093
111
296
038
019
828
3839
000
1178
2046
0000
412
135
009
293
22785
1141
009
26ndash31
068
925
094
254
054
026
832
2578
000
1194
1524
0000
273
424
023
104
1434
073
006
36ndash41
056
1001
102
337
028
014
875
3556
000
1113
1759
0001
182
819
043
219
626
033
006
BAC3
0ndash6
016
1283
134
407
607
009
002
007
682
12943
001
002
1266
6706
0000
0001
553
057
003
008
211
572
035
152
003
6ndash12
020
1270
131
607
003
002
989
9545
000
1308
4043
0000
580
020
003
081
1639
086
002
12ndash18
008
1389
142
613
003
002
891
8695
000
1341
3872
0000
593
021
002
223
567
032
002
J Marine and Freshwater Research N I Tobon ndashVelazquez et al
in Quintana Roo state (Instituto Nacional de Estadıstica yGeografıa 2016) Owing to the karstic nature of the area these
products can immediately infiltrate the aquifer and thereforecould be affecting the lagoon Because the concentration of ZnSminerals was low in the cores it is suggested that the source of
Zn2thorn could be derived from human activities Although theresults from the pollution load index (PLI) (1) for all samplesindicate that the sites are not highly polluted the excess Zn2thorn in
the sediment suggests some local pollution with regard to thiselement Conversely the concentrations of Ba2thorn can beexplained by the variable occurrence of barite in the cores
Minimal trace metal pollution is consistent with previous
metal work in the lagoon Castro-Contreras et al (2014)reported heavy metal concentrations in Bacalar Lagoon waterbelow the maximum limits of the Mexican legislation (NOM-
127-SSA1-1994) and ecological water quality criteria (CE-CCA-00189) that establish the limits of heavy metals fordrinking water irrigation and recreational activities
Nevertheless organochloride compounds (pesticides andpolychlorinated biphenyls) and hydrocarbons in sediments havebeen identified by Norena-Barroso et al (1998) in the ChetumalBay area near Bacalar Lagoon Organochlorine pesticides
(OCPs) are used in agriculture in the region (Alvarez-Legorreta2009) Furthermore heavymetals and OCPs have been detectedin crocodilian eggs near Chichorro Atoll (Charruau et al 2013
Buenfil-Rojas et al 2015)
Conclusions
Bacalar Lagoon is a shallow and oligotrophic system (low-
nutrient waters) with a mineralogical composition dominatedby calcite dolomite and evaporites dissolution Water geo-chemical analyses show a clear spatial distribution of different
parameters The western part of the study area is characterisedby high alkalinity and calcium and sulfate concentrations theratios of these constituents indicate groundwater sources and noseawater intrusion The decreases in these parameters towards
the north indicate a gradient in groundwater influencethroughout the lagoon The eastern part of the study area ischaracterised by a shallower water column resulting in high
evaporation and high electrical conductivity compared with thewestern side
We present the first measurements of trace elements in
carbonate sediments in Bacalar Lagoon The sediment exhibitsonly moderate contamination with Zn2thorn on the western side ofthe lagoon The high Ba concentration in the sediment corre-
sponds to barite but further work is necessary to identify thesource of Ba2thorn and Zn2thorn This study can be useful for Bacalarmunicipality to make decisions and define actions regarding themanagement and development of Bacalar Lagoon
Conflicts of interest
The authors declare that they have no conflicts of interest
Declaration of funding
This investigation was financed by the lsquoWater Security Project inthe South-eastMexico in the face of twoclimate change scenariosrsquoproject (CONACYT 247565) and lsquoProject networks CONACYTrsquo
(282240) The authors acknowledge a grant from CONACYT
towards a Masters of Water Sciences degree (awarded to NidiaTobon Velazquez)
Acknowledgements
The authors thank technical staff Daniela Ortega (Water Sciences Unit
Centro de Investigacion Cientıfica de Yucatan) and Kimberly Bitterwolf
(University of CaliforniamdashSanta Cruz)
References
Adriano D C (1986) lsquoTrace Elements in the Terrestrial Environmentrsquo
(Springer-Verlag Berlin Germany)
Alvarez-Legorreta T (2009) Contaminacion acuatica In lsquoEl sistema ecolo-
gico de la Bahıa de Chetumal Corozal costa occidental del Mar Caribersquo
(Eds J Espinoza Avalos G A Islebe and H A Hernandez Arana)
pp 205ndash217 (El Colegio de la Frontera Sur Chetumal Mexico)
Appelo C A and Postma D (2005) lsquoGeochemistry Groundwater and
Pollutionrsquo 2nd edn (A A Balkema Rotterdam Netherlands)
Baize D (1997) lsquoTeneurs totales en elements trace metalliques dans les sols
(France) References et strategies drsquointerpretationrsquo (INRA Paris France)
Bauer-Gottwein P Gondwe B Charvet G Marin L Rebolledo V M
andMerediz A G (2011) Review the Yucatan Peninsula karst aquifer
Mexico Hydrogeology Journal 19 507ndash524 doi101007S10040-010-
0699-5
Beddows P A (2002) lsquoWhere Does the Sewage Go The Karst
Groundwater System of the Municipalidad de Solidaridad Quintana
Roo Mexicorsquo (Association for Mexican Cave Studies Houston
TX USA)
Beltran D Y (2010) Estimacion de los patrones de fijacion de nitrogeno y
diversidad asociada (nifH) en tapices microbianos y estromatolitos
MSc Thesis Universidad Nacional Autonoma de Mexico Ciudad de
Mexico Mexico
Boes X Rydberg J Martinez C A Bindler R and Renberg I (2011)
Evaluation of conservative lithogenic elements (Ti Zr Al and Rb) to
study anthropogenic element enrichments in lake sediments Journal of
Paleolimnology 46 75ndash87 doi101007S10933-011-9515-Z
Boyle J F (2001) Inorganic geochemical methods in paleolimnology In
lsquoTracking Environmental Change Using Lake Sediments Vol 2 Physi-
cal andGeochemicalMethodsrsquo (EdsMW Last and P J Smol) pp 83ndash
143 (Kluwer Academic Publishers Dordrecht Netherlands)
Buenfil-Rojas A M Alvarez- Legorreta T and Cedeno-Vazquez J R
(2015) Metals and metallothioneins in Moreletrsquos Crocodile (Crocodile
moreletii) from a Transboundary River between Mexico and Belize
Archives of Environmental Contamination and Toxicology 68(2) 265ndash
273 doi101007S00244-014-0088-5
Castro-Contreras C Murray K G Pecoits E Aubet N R Petrash D
Castro C S Gregory D Planavsky N and Konhauser K O (2014)
Textural and geochemical features of freshwater microbialites from
LagunaBacalarQuintanaRooMexicoPalaios 29(5) 192ndash209 doi10
2110PALO2013063
Ceballos Martınez R R (2002) Geografıa y medio ambiente en el sistema
lagunar San FelipendashBacalarndashGuerrero In lsquoContribuciones de la ciencia al
manejo costero integrado de laBahıa deChetumal y su area de influenciarsquo
(Eds F J Rosado-May RRomeroMayo andADe Jesus Navarrete) pp
17ndash22 (Universidad de Quintana Roo Chetumal Mexico)
Centeno M C Legendre P Beltran Y Alcantara H R Lidstrom E U
Ashby N M and Falcon I L (2012) Microbialite genetic diversity
and composition relate to environmental variables FEMSMicrobiology
Ecology 82 724ndash735 doi101111J1574-6941201201447X
Chagas A P Webb E G Burne V R and Southam G (2016) Modern
lacustrine microbialites towards a synthesis of aqueous and carbonate
geochemistry and mineralogy Earth-Science Reviews 162 338ndash363
doi101016JEARSCIREV201609012
Charruau P Henaut Y and Alvarez-Legorreta T (2013) Organo-
chlorine pesticides in nest substratum and infertile eggs of American
Hydrochemistry of Bacalar Lagoon Marine and Freshwater Research K
crocodiles (Reptilia Crocodylidae) in a Mexican Caribbean atoll
Caribbean Journal of Science 47 1ndash12 doi1018475CJOSV47I1A2
Comision Nacional del Agua (2002) lsquoDeterminacion de la disponibilidad de
agua en el acuıfero Penınsula de Yucatan estado de Yucatanrsquo (CON-
AGUA Gerencia de Aguas Subterraneas Ciudad de Mexico Mexico)
Comision Nacional del Agua (2012) lsquoPrograma Hıdrico Regional Vision
2030 Region Hidrologico-Administrativa XII Penınsula de Yucatanrsquo
1st edn (Secretarıa de Medio Ambiente y Recursos Naturales Mexico
City Mexico)
Comision Nacional del Agua (2015) lsquoActualizacion de la disponibilidad
media anual de agua en el acuıfero Cerros y Valles (2301) Estado de
QuintanaRoorsquo (CONAGUADiarioOficial de la Federacion Ciudad de
Mexico Mexico)
Dautovic J Fiket Z Baresic J Ahel M and Mikac N (2014) Sources
distribution and behavior of major and trace elements in a complex karst
lake system Aquatic Geochemistry 20 19ndash38 doi101007S10498-
013-9204-9
Dıaz J E (2005) lsquoDecreto por el cual se establece el programa de
ordenamiento ecologico territorial de la region de Laguna Bacalar
Quintana Roo Mexicorsquo (Periodico Oficial Chetumal Mexico)
Dixon J Hamilton K Pagiola S and Segnestam L (2001) Tourism and
environment in the Caribbean an economic framework (The World
Bank Washington DC USA) Available at httpdocumentsworldbank
orgcurateden672281468770397455pdfmulti0pagepdf [Verified 18
October 2018]
Drever J I (2005) lsquoSurface and Ground Water Weathering and Soilsrsquo
(Elsevier Oxford UK)
Drucker A Escalante R Gomez V and Magana S (2003) La industria
porcina en Yucatan un analisis de la generacion de aguas residuales
Problemas del Desarrollo Revista Latinoamericana de Economıa 34
(135) 105ndash120
Dupraz C Reid R P andVisscher P T (2011)MicrobialitesModern In
lsquoEncyclopedia of Geobiology Encyclopedia of Earth Science Seriesrsquo
(Eds J Reitner and V Thiel) pp 617ndash635 (Springer Heidelberg
Germany)
Elango L andKannan R (2007) Rockndashwater interaction and its control on
chemical composition of groundwater In lsquoDevelopments in Environ-
mental Sciencersquo Vol 5 (Eds D Sarkar R Datta and R Hannigan) pp
229ndash243 (Elsevier Oxford UK)
Euan-Avila J I Liceaga-CorreaM A and Rodrıguez Sanchez H (2002)
Caracterizacion de fuentes no puntuales de contaminacion agrıcola en el
municipio deOthon P Blanco enQuintanaRoo y su potencial influencia
en la Bahıa de Chetumal In lsquoContribuciones de la ciencia al manejo
costero integrado de la Bahıa de Chetumal y su area de influenciarsquo (Eds
F J Rosado-May R Romero Mayo and A De Jesus Navarrete) pp
197ndash204 (Universidad de Quintana Roo Chetumal Mexico)
Fouke W B Zerkle L A Alvarez W Pope O K Ocampos A C
Wachtman J R Grajales J M Claeys P and Fischer G A (2002)
Cathodoluminescence petrography and isotope geochemistry of KT
impact ejecta deposited 360 km from the Chicxulub crater at Albion
Island Belize Sedimentology 49 117ndash138 doi101046J1365-3091
200200435X
Garcıa-Rıos V Y and Gold-Bouchot G (2002) Especiacion de metales
pesados en sedimentos de la Bahıa de Chetumal Quintana Roo y la
acumulacion en el tejido muscular de bagres (Ariopsis assimilis) In
lsquoContribuciones de la ciencia al manejo costero integrado de la Bahıa de
Chetumal y su area de influenciarsquo (Eds F J Rosado-May R Romero
Mayo and A De Jesus Navarrete) pp 143ndash148 (Universidad de
Quintana Roo Chetumal Mexico)
Gischler E Gibson M A and Oschmann W (2008) Giant Holocene
freshwater microbialites Laguna de Bacalar Quintana Roo Mexico
Sedimentology 55 1293ndash1309 doi101111J1365-3091200700946X
Gischler E Golubic S Gibson M Oschamann W and Hudson J H
(2011) Microbial mats and microbialites in the freshwater Laguna
Bacalar Yucatan Peninsula Mexico In lsquoAdvances in Stromatolite
Geobiologyrsquo (Eds J Reitner M H Trauth K Stuwe and D Yuen)
pp 187ndash205 (Springer Berlin Germany)
Gonzalez B J L Carrion J J Cuevas D J Flores M F Yam G J O
Moreno C J Perez V J and Calva C G (2014) Acumulacion de Hg
Pb Cd y Zn por Pomacea flagellata en tres balnearios ubicados en la
region urbana de la Laguna de Bacalar TecnoCultura 35 14ndash23
Hemley R J Prewitt C T and Kingma K (1994) High-pressure
behavior of silica In lsquoSilica ndash Physical Behavior Geochemistry and
Materials Applications Reviews in Mineralogy Vol 29rsquo (Eds P J
Heaney C T Prewitt and G V Gibbs) pp 41ndash82 (Mineralogical
Society of America Washington DC USA)
Hernandez L Probst A Probst L J and Ulrich E (2003) Heavy metal
distribution in some French forest soils evidence for atmospheric
contamination The Science of the Total Environment 312(1ndash3)
195ndash219 doi101016S0048-9697(03)00223-7
Hernandez-Terrones L Rebolledo-Vieyra M Merino-Ibarra M Soto
M Le-Cossec A and Monroy-Rıos E (2011) Groundwater pollution
in a karstic region (NE Yucatan) baseline nutrient content and flux to
coastal ecosystems Water Air and Soil Pollution 218(1ndash4) 517ndash528
doi101007S11270-010-0664-X
InstitutoNacional de Estadıstica yGeografıa (2002) EstudioHidrologico del
Estado de Quintana Roo (INEGI Aguascalientes Mexico) Available at
httpinternetcontenidosinegiorgmxcontenidosproductosprod_serv
contenidosespanolbvinegiproductoshistoricos2104702825224196
702825224196_1pdf [Verified 5 September 2018]
Instituto Nacional de Estadıstica y Geografıa (2016) Anuario Estadıstico y
Geografico de Quintana Roo (INEGI Aguascalientes Mexico) Avail-
able at httpinternetcontenidosinegiorgmxcontenidosProductos
prod_servcontenidosespanolbvinegiproductosnueva_estrucanuarios_
2016702825084370pdf [Verified 5 September 2018]
Javan S Hessam H A Gholamalizadeh A A and Soltani J (2015)
Fractionation of heavy metals in bottom sediments in Chahnimeh 1
Zabol Iran Environmental Monitoring and Assessment 187(6) 340
doi101007S10661-015-4510-X
Katip A Karaer F Ileri S Sarmasik S Aydogan N and Zenginay S
(2011) Analysis and assessment of trace elements pollution in sediments
of Lake Ulubat Turkey Journal of Environmental Biology 33 961ndash968
Kenkmann T and Schonian F (2006) Ries and Chicxulub impact craters
on Earth provide insights for Martian ejecta blankets Meteoritics amp
Planetary Science 41(10) 1587ndash1603 doi101111J1945-51002006
TB00437X
Khedidja A and Boudoukha A (2016) Lrsquoaquifere Superficiel de
Tadjnanet-Chelghoum laid (Nord-Est Algerien) Larhyss Journal 28
181ndash197
Lounejeva E Ostroumov M and Sanchez R G (2002) Polimorfos de
alta presion de sılice en las impactitas de ChicxulubMexico ndash resultados
de espectrometrıa de Raman Revista Mexicana de Ciencias Geologicas
17(2) 137ndash141
Manoj K and Padhy P K (2014) Distribution enrichment and ecological
risk assessment of six elements in bed sediments of a tropical river
Chottanagpur Plateau a spatial and temporal appraisal Journal of
Environmental Protection 5 1419ndash1434 doi104236JEP2014514136
Marfia A M Krishnamurthya R V Atekwanab E A and Panton W F
(2004) Isotopic and geochemical evolution of ground and surfacewaters
in a karst dominated geological setting a case study fromBelize Central
America Applied Geochemistry 19 937ndash946 doi101016JAPGEO
CHEM200310013
Massaferro J Correa M A Montes de Oca F and Mauad M (2018)
Contrasting responses of lake ecosystems to environmental disturbance
a paleoecological perspective from northern Patagonia (Argentina)
Hydrobiologia 816(1) 79ndash89 doi101007S10750-016-3081-3
Medina M S Jimenez G A Gutierrez R M and Lizardi J M (2014)
Hydrocarbon pollution studies of underwater sinkholes along Quintana
L Marine and Freshwater Research N I Tobon ndashVelazquez et al
Roo as function of tourism development in the Mexican Caribbean
Revista Mexicana de Ingenierıa Quımica 13(2) 509ndash516
Norena-Barroso E Zapata-Perez O Ceja-Moreno V and Gold-Bouchot
G (1998) Hydrocarbon and organochloride residue concentrations in
sediments from Bay of Chetumal Mexico Bulletin of Environmental
Contamination and Toxicology 61 80ndash87 doi101007S001289900732
Nriagu J and Pacyna J (1988) Quantitative assessment of worldwide
contamination of air water and soils by trace metals Nature 333 134ndash
139 doi101038333134A0
Ochoa J C Gonzalez B J and Jimenez C J (2016) Metales pesados
(Cd Cr Pb Hg) en Rhizophora mangle en rıo y bahıa de Chetumal
Revista Mexicana de Agroecosistemas 3(2) 263ndash271
Oliva R J Ocana F A de Jesus N A de Jesus C R and Vargas E A
(2016) Reproduccion dePomacea flagellata (Mollusca Ampullariidae)
en la laguna de Bacalar Quintana Roo Mexico Revista de Biologıa
Tropical 64(4) 1643ndash1650
Pacton M Hunger G Martinuzzi V Cusminsky G Burdin B
Barmettler K Vasconcelos C and Ariztegui D (2015) Organomi-
neralization processes in freshwater stromatolites a living example from
eastern Patagonia International Association of Sedimentologists Jour-
nal 1(2) 130ndash146
Perez L Bugja R Lorenschat J Brenner M Curtis J Hoelzmann P
Islebe G Scharf B and SchwalbA (2011) Aquatic ecosystems of the
Yucatan Peninsula (Mexico) Belize and Guatemala Hydrobiologia
661 407ndash433 doi101007S10750-010-0552-9
Perry E C Velazquez O G and Marin L (2002) The hydrogeochem-
istry of the karst aquifer system of the northern Yucatan Peninsula
Mexico International Geology Review 44 191ndash221 doi102747
0020-6814443191
Perry E Paytan A Pedersen B and Velazquez O G (2009) Ground-
water geochemistry of the Yucatan Peninsula Mexico constraints on
stratigraphy and hydrogeology Journal of Hydrology 367 27ndash40
doi101016JJHYDROL200812026
Pradit S Wattayarkorn G Angsupanich S Baeyens W and Leer-
makers M (2010) Distribution of trace elements in sediments and biota
of Songkhla Lake Southern Thailand Water Air and Soil Pollution
206 155ndash174 doi101007S11270-009-0093-X
Salomons W and Forstner U (1980) Trace metal analysis on polluted
sediments II evaluation of environmental impact Environmental
Technology Letters 1 506ndash517 doi10108009593338009384007
Sanchez S J Alvarez L T Pacheco A J Gonzalez H R and Carrillo
B L (2015) Caracterizacion hidrogeoquımica de las aguas subterraneas
del sur del Estado de Quintana Roo Mexico Revista Mexicana de
Ciencias Geologicas 32(1) 62ndash76
Schmitter-Soto J J Comın F A Escobar B E Herrera S J Alcocer J
Suarez M E Elıas G M Dıaz A V Marın L E and Steinich B
(2002) Hydrogeochemical and biological characteristics of cenotes in
the Yucatan Peninsula (SE Mexico) Hydrobiologia 467 215ndash228
doi101023A1014923217206
Siqueiros-Beltrones D Hernandez A U and Hernandez A O (2013)
Diagnosis prospectiva sobre la diversidad de diatomeas epilıticas en la
laguna Bacalar Quintana Roo Mexico Revista Mexicana de Biodiver-
sidad 84 865ndash875 doi107550RMB33960
Turekian K K andWedepohl K H (1961) Distribution of the elements in
some major units of the Earthrsquos crust Bulletin of the Geological Society
of America 72 175ndash192 doi1011300016-7606(1961)72[175
DOTEIS]20CO2
Handling Editor Russell Frew
wwwpublishcsiroaujournalsmfr
Hydrochemistry of Bacalar Lagoon Marine and Freshwater Research M
samples is greater than 2 units this indicates that the physico-chemical conditions are distinct (Massaferro et al 2018) hence
variations could be interpreted as significant differencesbetween sites
Samples along PCA Axis 1 show two distinctive patterns
within the lagoon which are separated by pH EC TDS Nathorn
and HCO3 distribution The spread of samples within PC1 is
relatively large suggesting significant differences among sites
This spread reflects the distinct distributions of physicochemicalfeatures at the different sides of the lagoon the western side(Axis 1 from 4 to 0 units) is characterised by a high HCO3
content (COC RAP BAC3 Ccoc and Caz) whereas the eastern
side (Axis 1 from 0 to 4 units) is characterised by high EC NathornpH and TDS and corresponds to the BAC1 and BAC2 sites
PC2 is associated with SiO2 and Kthorn concentrations PC2
shows two groups with the first group corresponding to sampleswith low SiO2
and Kthorn concentrations (COC RAP BAC1BAC2 and BAC3) and positive values of Axis 2 (from 4 to 0)
The second group is characterised by high SiO2 and Kthorn
concentrations (Ccoc and Caz samples) and corresponds tonegative axis values (from 0 to 4) PC2 is associated withsilica content due to higher silica concentrations in the cenotes
compared with the rest of the lagoon samples This can beexplained by more rapid Si uptake in the sun-lit lagoon wherediatoms are abundant
Changes in pH and transparency by sediment disturbance canhave an effect on stromatolites Sulfate-reducing bacteria par-ticipate in the formation of stromatolites and appear to always be
associated with Mg calcite and low-salinity and low-turbiditywaters Although stromatolites were not analysed in the presentstudy we recommend that a water monitoring program be
established to survey nutrients and measure other variablessuch as transparency tourist and boat activity weatheringdisturbance of sediments and trace elements at least twice ayear to ensure that the stromatolites are not negatively affected
Sediment characterisation
X-Ray diffraction
The results from the XRD analyses indicate that the mainmineralogical composition for all sediment samples was calcite(CaCO3) dolomite (CaMg(CO3)2) and SiO2 (quartz and possi-
bly minor amounts of coesite) In general calcite was in highestabundance in all cores Dolomite was present in all samples atlower proportions
These results are in accordance with the SI where calcite is
oversaturated in the western part of the lagoon and Ca2thorn andHCO3
concentrations are elevated throughout the lagoonCoesite forms under conditions of high pressure (3ndash10 GPa
Hemley et al 1994) and the presence of this mineral could berelated to the impact of the Chicxulub meteorite (Lounejevaet al 2002) Fouke et al (2002) with an estimated diameter of
its effect 360 km The presence of coesite in Bacalar Lagooncould be associated with this event Fouke et al (2002) andKenkmann and Schonian (2006) reported Chicxulub ejecta
deposited in Belize and in some regions of the Rio Hondo (nearBacalar Lagoon) However identifying the origin of this min-eral in Bacalar Lagoon requires additional detailed studies withlonger scan times to confirm the presence of coesite Other
minerals that we found in lower proportions are barite (BaSO4)
and a few samples with sphalerite (ZnS) with higher propor-tions of barite in the western than eastern side of the lagoon
Geochemistry
Elemental concentrations in the sediment samples are shown
in Fig 7 All sediment cores had high concentrations of Ca2thornMg2thorn and Sr2thorn which were one to three orders of magnitudehigher than concentrations for the rest of the elements consis-
tent with carbonate minerals (calcite) dominating the sedimentElement abundance was similar in cores of sites located in
the western part of the lagoon (COC RAP and BAC3) in the
order Ca2thornMg2thornSr2thorn Si4thornAl3thorn Fe3thornZn2thorn
KthornBa2thornTi4thornNi2thornMn2thornU6thorn The order of ele-ment abundance for the eastern cores (BAC1 and BAC2) was
similar except that Mg was more abundant than Ca (Mg2thorn
Ca2thorn Sr2thorn Si4thornAl3thorn Fe3thornZn2thornKthornNi2thorn
Ba2thornTi4thornMn2thornU6thorn) These relative abundances sug-gest that cores from the western side are dominated by Ca2thorn
carbonate minerals (likely calcite) whereas those from the eastside contain more dolomite The BAC1 core had the highestconcentrations of Al3thorn Si4thorn Kthorn Ti4thorn Mn2thorn and Fe3thorn likelyrepresenting some silicates and ironndashmanganese oxides fromterrigenous sources The highest Ni2thorn and Zn2thornconcentrationswere measured in the core from BAC2 and may represent
anthropogenic pollutant inputs The other elements analysedhad similar distributions in all cores
In general concentrations of Ba2thorn U6thorn and Zn2thorn werehigher in deeper sections of the cores and this may suggest
temporal changes in the input of these elements The rest of theelements (Ca2thorn and Mg2thorn) did not show variations with depthdown the core (r2 05)
The concentrations of elements span orders of magnitudetherefore the data do not satisfy the assumption of normality ASpearman correlation was performed using STATISTICA
(ver 133 Palo Alto CA USA) to test the relationship betweenthe trace elements in each core with significance level atP 005
Except for BAC3 the most significant correlation was forAlndash(FendashTi) (r2 090) In the BAC2 core significant correla-tions were found for SrndashMg AlndashTi KndashNi and SindashTi (r2frac14 090090 088 and 086 respectively) For BAC1 the highest
correlations were found for SrndashCa Alndash(Fe Ni) Kndash(Fe Ni)and BandashMg (r2frac14 095 098 098 and 081 respectively) Nega-tive correlationswere found at theCOC site (r2frac14090) forAlndash
(Zn Sr) Fendash(Ca U) Mnndash(U Ca) UndashSi and BandashZn but apositive correlation was found for Tindash(Mn Fe) with r2frac14 090In the BAC3 core relationships were found for only four
elements UndashSr and CandashMg (r2frac14 099)The relationship for Alndash(Ti Fe) in almost all cores is derived
from the fact that these elements represent silicates and otherrefractory minerals and hence aeolian or fluvial input of
particulate matter from land (Drever 2005) The correlationfor Candash(SrndashMg) in most cores is consistent with the maincarbonate minerology of these sediments Other correlations
are not universal and in general no pattern in spatial distribu-tion was found in the correlation between elements among allcores suggesting that these elements are not controlled by the
same parameters at each site
Hydrochemistry of Bacalar Lagoon Marine and Freshwater Research G
Sediment pollution
Some trace elements in Bacalar Lagoon sediments mayreflect anthropogenic pollution Here we used four indices
followingManoj and Padhy (2014 see Table 3)We normalisedconcentrations to Al because it is a conservative lithogenic
element and is resistant to chemical weathering hence it does
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
8000 9000 10 000 11 000
Sr (ppm) Ba (ppm) U (ppm) Mg (ppm)
8 10 12 14 16 18 0 01 02 03 04 05 06 300 000 400 000
Dep
th (
cm)
0 1000 5000
Al (ppm) Si (ppm) Ti (ppm) Ca (ppm)
Mn (ppm) Fe (ppm) Ni (ppm) Zn (ppm)
10 000 2020 000 2001000 0 200 000 400 000
0 1 2 3 4 0 400 1000 2000 0 20 40 60 500 100 150 25020080
COC BAC3 BAC1 BAC2
Fig 7 Concentrations of trace andmajor elements in sediment cores BAC1 Bacalar 1 BAC2 Bacalar 2 BAC3 Bacalar 3
COC Cocalitos
H Marine and Freshwater Research N I Tobon ndashVelazquez et al
not actively participate in the dominant geochemical cycles and
does not have a significant anthropogenic source (Boes et al2011 Dautovic et al 2014)
For normalisation to Al values for the Earthrsquos crust were
taken from Turekian and Wedepohl (1961) in which the valuesare mean concentrations in carbonates rocks of the upper crustKfrac14 27000 ppm Mnfrac14 11000 ppm Nifrac14 200 ppm
Znfrac14 200 ppm and Bafrac14 100 ppmTo determine whether the elements are from lithological or
anthropogenic sources the trace element concentrations were
compared with the crustal composition (Hernandez et al 2003)
frac12M lithogenic frac14 frac12Als ethfrac12M =frac12AlcTHORN eth1THORN
frac12M anthropogenic frac14 frac12M T frac12M lithogenic eth2THORN
where the lithogenic input ([M]lithogenic) is estimated throughthe concentration of Al in the sample ([Al]s) and the ratio of the
average of the Earthrsquos crust ([M][Al]c) The anthropogenic input([M]anthropogenic) was calculated based on the total concentration([M]T) and the lithogenic input
The results of these calculations are summarised in Table 4For all cores U6thorn Mn2thorn and Kthorn show negative values for theindex of geoaccumulation (Igeo) whereas the values of CF(contamination factor) and CD (contamination degree) are
lower than 20 All factors indicate that the sediment is notpolluted with these elements which are likely of lithogenicorigin For Ni2thorn the Igeo (0) CF (1) and CD (6) indices
also indicate low pollution except for the upper samples (depthsof 0ndash6 and 6ndash11 cm) of theBAC2 core where theCF is30 andIgeo is 10 suggesting unpolluted to moderately polluted
conditions In contrast the values of these indices for Zn2thorn
and Ba2thorn show some spatial variabilityThe CD of Zn2thorn at all sites is 15 The eastern samples
(BAC1 and BAC2) show higher CD values (822 and 1805
respectively) suggesting moderate to considerable contamina-
tion of the sediment The Ba2thorn concentration exhibits a spatialdistribution the western sites (COC RAP and BAC3) havehigher Ba2thorn concentrations compared than the eastern sites and
the calculated indices were correspondingly higher for thewestern side of the lagoon However overall the indicesindicated that the sediments on both sides of the lagoon are
unpollutedwith regard to Ba and the differences are likely due tohigher barite content on thewestern side Based on these indicesno influence of human activities was detected in eastern core
samples (BAC1 and BAC2)The higher Zn2thorn and Ba2thorn concentrations may be due to a
higher input of these elements into the area close to these sitesHowever water column distributions have to be assessed to
confirm this Zn2thorn and Ba2thorn in Bacalar Lagoon sediments couldbe derived from two sources (1) authigenic minerals found inthe sediment which on thewestern side contain barite (BaSO4)
and some sphalerite (ZnS) and (2) anthropogenic sources suchas agricultural fertiliser or cattle feed Commercial fertiliserscontain micronutrients such as Zn2thorn Mn2thorn Fe3thorn Cu2thorn Mo6thorn
and Ba2thorn in concentrations ranging from trace to several ppmwhich could infiltrate and cause pollution in the soil andgroundwater (Adriano 1986) Baize (1997) indicated that Znis found in animal feed used for pigs that are raised domestically
and commercially in the region The waste water generated bythis industry has been poorly handled resulting in adverseeffects on the environment (Drucker et al 2003) Near the town
of Bacalar fertilisers and agrochemicals are used regularly(Alvarez-Legorreta 2009) The agriculture practices in themunicipality include maize sugarcane and pepper and more
than 40 products are spread annually on these crops (fertilisersherbicides and pesticides Euan-Avila et al 2002) Garcıa-Rıosand Gold-Bouchot (2002) identified Fe V Ni Pb Zn Cu and
Cd in sediments of nearby Chetumal Bay Indeed Bacalar andOthon P Blanco municipalities have the highest fertilised area
Table 3 Indices as indicators of sediment quality based on Manoj and Padhy (2014) and Javan et al (2015)
Ms sample element concentration Mb background concentration of the element
Index Equation Sediment quality
Index of geoacumulation Igeofrac14 ln(Ms15Mb) 0frac14 unpolluted
0ndash1frac14 unpolluted to moderately polluted
1ndash2frac14moderately polluted
2ndash3frac14moderately polluted to highly polluted
3ndash4frac14 highly polluted
4ndash5frac14 highly polluted to very highly polluted
5frac14 very highly polluted
Contamination factor CF5MsMb 1frac14 low CF
1 CF 3frac14moderate CF
3 CF 6frac14 considerable CF
$6frac14 very high CF
Contamination degree CD frac14Pnifrac141
CF 6frac14 low CD
6 CD 12frac14moderate CD
12 CD 24frac14 considerable CD
$24frac14 high CD (anthropogenic contamination)
Pollution load index PLI5 (CF1CFsyCFn)1n 0frac14 unpolluted
1frac14 baseline levels of pollutants present
1frac14 progressive deterioration of site
Hydrochemistry of Bacalar Lagoon Marine and Freshwater Research I
Table4
Index
ofgeoacummulation(Igeo)anthropogenic(A
)inputcontaminationfactor(C
F)andcontaminationdegree(C
D)forBaUKMnNiandZnin
thesedim
entary
record
ofthe
BacalarLagoon
NAdatanoavailablePLIpollutionload
indexBAC1Bacalar
1BAC2Bacalar
2BAC3Bacalar
3COCCocalitosRAPLosRapidos
Site
Depth
(cm)
Ba
UK
Mn
Ni
Zn
PLI
I geo
Ainput
CF
CD
I geo
Ainput
CF
CD
I geo
Ainput
CF
CD
I geo
Ainput
CF
CD
I geo
Ainput
CF
CD
I geo
Ainput
CF
CD
COC
0ndash6
016
1236
134
701
503
013
005
065
688
24629
001
003
1119
11361
0001
0002
371
021
011
053
203
529
037
479
005
6ndash12
015
1314
135
469
005
006
675
5569
001
1160
3753
0000
409
107
009
004
2846
146
006
12ndash17
004
1421
146
336
024
015
NA
10001
000
1147
4016
0001
405
107
009
037
2254
116
000
17ndash22
014
1627
165
304
035
018
1158
6288
000
1257
2588
0000
362
196
012
010
3174
161
004
22ndash27
031
1156
121
282
035
021
NA
14125
000
1338
5739
0000
367
132
012
301
267
019
000
RAP
0ndash6
039
1074
115
264
538
008
004
009
889
18818
000
002
1067
7912
0001
0001
508
057
004
014
156
870
051
284
004
6ndash11
001
1360
149
475
017
006
651
31721
002
1189
14691
0000
391
069
010
063
4390
233
007
BAC1
0ndash5
024
267
127
956
402
201
009
069
230
189364
031
161
896
110398
0003
0023
300
1639
019
115
174
1118
045
822
014
5ndash10
035
302
118
416
174
008
276
176636
022
907
96021
0003
311
1404
017
066
2982
237
017
10ndash15
048
382
108
437
137
007
307
139830
018
913
76341
0003
327
1083
016
119
074
066
013
15ndash20
031
444
121
423
150
008
295
153179
019
896
83486
0003
330
1220
015
013
1225
137
015
20ndash25
031
488
121
420
142
008
301
145741
019
883
79449
0003
351
1189
013
424
1293
008
009
25ndash30
039
504
114
408
121
009
320
128917
016
925
70152
0002
363
1037
012
061
689
098
013
30ndash35
016
581
134
385
145
010
299
154625
019
904
83454
0003
353
1264
013
069
337
093
014
35ndash40
041
467
113
419
127
008
313
131772
017
917
72183
0003
392
1120
010
012
1446
138
013
BAC2
0ndash6
035
1141
117
734
515
002
004
086
743
6689
001
006
1094
3596
0001
0006
374
157
011
444
051
4203
214
1805
007
6ndash11
052
1005
105
462
004
006
834
10694
000
949
4638
0002
119
6764
343
012
2666
138
012
11ndash16
055
984
103
442
006
007
750
9268
001
1126
4617
0001
420
078
008
144
1018
055
005
16ndash21
055
985
102
400
013
009
597
3426
002
1119
3962
0001
421
089
008
001
2953
151
008
21ndash26
043
1093
111
296
038
019
828
3839
000
1178
2046
0000
412
135
009
293
22785
1141
009
26ndash31
068
925
094
254
054
026
832
2578
000
1194
1524
0000
273
424
023
104
1434
073
006
36ndash41
056
1001
102
337
028
014
875
3556
000
1113
1759
0001
182
819
043
219
626
033
006
BAC3
0ndash6
016
1283
134
407
607
009
002
007
682
12943
001
002
1266
6706
0000
0001
553
057
003
008
211
572
035
152
003
6ndash12
020
1270
131
607
003
002
989
9545
000
1308
4043
0000
580
020
003
081
1639
086
002
12ndash18
008
1389
142
613
003
002
891
8695
000
1341
3872
0000
593
021
002
223
567
032
002
J Marine and Freshwater Research N I Tobon ndashVelazquez et al
in Quintana Roo state (Instituto Nacional de Estadıstica yGeografıa 2016) Owing to the karstic nature of the area these
products can immediately infiltrate the aquifer and thereforecould be affecting the lagoon Because the concentration of ZnSminerals was low in the cores it is suggested that the source of
Zn2thorn could be derived from human activities Although theresults from the pollution load index (PLI) (1) for all samplesindicate that the sites are not highly polluted the excess Zn2thorn in
the sediment suggests some local pollution with regard to thiselement Conversely the concentrations of Ba2thorn can beexplained by the variable occurrence of barite in the cores
Minimal trace metal pollution is consistent with previous
metal work in the lagoon Castro-Contreras et al (2014)reported heavy metal concentrations in Bacalar Lagoon waterbelow the maximum limits of the Mexican legislation (NOM-
127-SSA1-1994) and ecological water quality criteria (CE-CCA-00189) that establish the limits of heavy metals fordrinking water irrigation and recreational activities
Nevertheless organochloride compounds (pesticides andpolychlorinated biphenyls) and hydrocarbons in sediments havebeen identified by Norena-Barroso et al (1998) in the ChetumalBay area near Bacalar Lagoon Organochlorine pesticides
(OCPs) are used in agriculture in the region (Alvarez-Legorreta2009) Furthermore heavymetals and OCPs have been detectedin crocodilian eggs near Chichorro Atoll (Charruau et al 2013
Buenfil-Rojas et al 2015)
Conclusions
Bacalar Lagoon is a shallow and oligotrophic system (low-
nutrient waters) with a mineralogical composition dominatedby calcite dolomite and evaporites dissolution Water geo-chemical analyses show a clear spatial distribution of different
parameters The western part of the study area is characterisedby high alkalinity and calcium and sulfate concentrations theratios of these constituents indicate groundwater sources and noseawater intrusion The decreases in these parameters towards
the north indicate a gradient in groundwater influencethroughout the lagoon The eastern part of the study area ischaracterised by a shallower water column resulting in high
evaporation and high electrical conductivity compared with thewestern side
We present the first measurements of trace elements in
carbonate sediments in Bacalar Lagoon The sediment exhibitsonly moderate contamination with Zn2thorn on the western side ofthe lagoon The high Ba concentration in the sediment corre-
sponds to barite but further work is necessary to identify thesource of Ba2thorn and Zn2thorn This study can be useful for Bacalarmunicipality to make decisions and define actions regarding themanagement and development of Bacalar Lagoon
Conflicts of interest
The authors declare that they have no conflicts of interest
Declaration of funding
This investigation was financed by the lsquoWater Security Project inthe South-eastMexico in the face of twoclimate change scenariosrsquoproject (CONACYT 247565) and lsquoProject networks CONACYTrsquo
(282240) The authors acknowledge a grant from CONACYT
towards a Masters of Water Sciences degree (awarded to NidiaTobon Velazquez)
Acknowledgements
The authors thank technical staff Daniela Ortega (Water Sciences Unit
Centro de Investigacion Cientıfica de Yucatan) and Kimberly Bitterwolf
(University of CaliforniamdashSanta Cruz)
References
Adriano D C (1986) lsquoTrace Elements in the Terrestrial Environmentrsquo
(Springer-Verlag Berlin Germany)
Alvarez-Legorreta T (2009) Contaminacion acuatica In lsquoEl sistema ecolo-
gico de la Bahıa de Chetumal Corozal costa occidental del Mar Caribersquo
(Eds J Espinoza Avalos G A Islebe and H A Hernandez Arana)
pp 205ndash217 (El Colegio de la Frontera Sur Chetumal Mexico)
Appelo C A and Postma D (2005) lsquoGeochemistry Groundwater and
Pollutionrsquo 2nd edn (A A Balkema Rotterdam Netherlands)
Baize D (1997) lsquoTeneurs totales en elements trace metalliques dans les sols
(France) References et strategies drsquointerpretationrsquo (INRA Paris France)
Bauer-Gottwein P Gondwe B Charvet G Marin L Rebolledo V M
andMerediz A G (2011) Review the Yucatan Peninsula karst aquifer
Mexico Hydrogeology Journal 19 507ndash524 doi101007S10040-010-
0699-5
Beddows P A (2002) lsquoWhere Does the Sewage Go The Karst
Groundwater System of the Municipalidad de Solidaridad Quintana
Roo Mexicorsquo (Association for Mexican Cave Studies Houston
TX USA)
Beltran D Y (2010) Estimacion de los patrones de fijacion de nitrogeno y
diversidad asociada (nifH) en tapices microbianos y estromatolitos
MSc Thesis Universidad Nacional Autonoma de Mexico Ciudad de
Mexico Mexico
Boes X Rydberg J Martinez C A Bindler R and Renberg I (2011)
Evaluation of conservative lithogenic elements (Ti Zr Al and Rb) to
study anthropogenic element enrichments in lake sediments Journal of
Paleolimnology 46 75ndash87 doi101007S10933-011-9515-Z
Boyle J F (2001) Inorganic geochemical methods in paleolimnology In
lsquoTracking Environmental Change Using Lake Sediments Vol 2 Physi-
cal andGeochemicalMethodsrsquo (EdsMW Last and P J Smol) pp 83ndash
143 (Kluwer Academic Publishers Dordrecht Netherlands)
Buenfil-Rojas A M Alvarez- Legorreta T and Cedeno-Vazquez J R
(2015) Metals and metallothioneins in Moreletrsquos Crocodile (Crocodile
moreletii) from a Transboundary River between Mexico and Belize
Archives of Environmental Contamination and Toxicology 68(2) 265ndash
273 doi101007S00244-014-0088-5
Castro-Contreras C Murray K G Pecoits E Aubet N R Petrash D
Castro C S Gregory D Planavsky N and Konhauser K O (2014)
Textural and geochemical features of freshwater microbialites from
LagunaBacalarQuintanaRooMexicoPalaios 29(5) 192ndash209 doi10
2110PALO2013063
Ceballos Martınez R R (2002) Geografıa y medio ambiente en el sistema
lagunar San FelipendashBacalarndashGuerrero In lsquoContribuciones de la ciencia al
manejo costero integrado de laBahıa deChetumal y su area de influenciarsquo
(Eds F J Rosado-May RRomeroMayo andADe Jesus Navarrete) pp
17ndash22 (Universidad de Quintana Roo Chetumal Mexico)
Centeno M C Legendre P Beltran Y Alcantara H R Lidstrom E U
Ashby N M and Falcon I L (2012) Microbialite genetic diversity
and composition relate to environmental variables FEMSMicrobiology
Ecology 82 724ndash735 doi101111J1574-6941201201447X
Chagas A P Webb E G Burne V R and Southam G (2016) Modern
lacustrine microbialites towards a synthesis of aqueous and carbonate
geochemistry and mineralogy Earth-Science Reviews 162 338ndash363
doi101016JEARSCIREV201609012
Charruau P Henaut Y and Alvarez-Legorreta T (2013) Organo-
chlorine pesticides in nest substratum and infertile eggs of American
Hydrochemistry of Bacalar Lagoon Marine and Freshwater Research K
crocodiles (Reptilia Crocodylidae) in a Mexican Caribbean atoll
Caribbean Journal of Science 47 1ndash12 doi1018475CJOSV47I1A2
Comision Nacional del Agua (2002) lsquoDeterminacion de la disponibilidad de
agua en el acuıfero Penınsula de Yucatan estado de Yucatanrsquo (CON-
AGUA Gerencia de Aguas Subterraneas Ciudad de Mexico Mexico)
Comision Nacional del Agua (2012) lsquoPrograma Hıdrico Regional Vision
2030 Region Hidrologico-Administrativa XII Penınsula de Yucatanrsquo
1st edn (Secretarıa de Medio Ambiente y Recursos Naturales Mexico
City Mexico)
Comision Nacional del Agua (2015) lsquoActualizacion de la disponibilidad
media anual de agua en el acuıfero Cerros y Valles (2301) Estado de
QuintanaRoorsquo (CONAGUADiarioOficial de la Federacion Ciudad de
Mexico Mexico)
Dautovic J Fiket Z Baresic J Ahel M and Mikac N (2014) Sources
distribution and behavior of major and trace elements in a complex karst
lake system Aquatic Geochemistry 20 19ndash38 doi101007S10498-
013-9204-9
Dıaz J E (2005) lsquoDecreto por el cual se establece el programa de
ordenamiento ecologico territorial de la region de Laguna Bacalar
Quintana Roo Mexicorsquo (Periodico Oficial Chetumal Mexico)
Dixon J Hamilton K Pagiola S and Segnestam L (2001) Tourism and
environment in the Caribbean an economic framework (The World
Bank Washington DC USA) Available at httpdocumentsworldbank
orgcurateden672281468770397455pdfmulti0pagepdf [Verified 18
October 2018]
Drever J I (2005) lsquoSurface and Ground Water Weathering and Soilsrsquo
(Elsevier Oxford UK)
Drucker A Escalante R Gomez V and Magana S (2003) La industria
porcina en Yucatan un analisis de la generacion de aguas residuales
Problemas del Desarrollo Revista Latinoamericana de Economıa 34
(135) 105ndash120
Dupraz C Reid R P andVisscher P T (2011)MicrobialitesModern In
lsquoEncyclopedia of Geobiology Encyclopedia of Earth Science Seriesrsquo
(Eds J Reitner and V Thiel) pp 617ndash635 (Springer Heidelberg
Germany)
Elango L andKannan R (2007) Rockndashwater interaction and its control on
chemical composition of groundwater In lsquoDevelopments in Environ-
mental Sciencersquo Vol 5 (Eds D Sarkar R Datta and R Hannigan) pp
229ndash243 (Elsevier Oxford UK)
Euan-Avila J I Liceaga-CorreaM A and Rodrıguez Sanchez H (2002)
Caracterizacion de fuentes no puntuales de contaminacion agrıcola en el
municipio deOthon P Blanco enQuintanaRoo y su potencial influencia
en la Bahıa de Chetumal In lsquoContribuciones de la ciencia al manejo
costero integrado de la Bahıa de Chetumal y su area de influenciarsquo (Eds
F J Rosado-May R Romero Mayo and A De Jesus Navarrete) pp
197ndash204 (Universidad de Quintana Roo Chetumal Mexico)
Fouke W B Zerkle L A Alvarez W Pope O K Ocampos A C
Wachtman J R Grajales J M Claeys P and Fischer G A (2002)
Cathodoluminescence petrography and isotope geochemistry of KT
impact ejecta deposited 360 km from the Chicxulub crater at Albion
Island Belize Sedimentology 49 117ndash138 doi101046J1365-3091
200200435X
Garcıa-Rıos V Y and Gold-Bouchot G (2002) Especiacion de metales
pesados en sedimentos de la Bahıa de Chetumal Quintana Roo y la
acumulacion en el tejido muscular de bagres (Ariopsis assimilis) In
lsquoContribuciones de la ciencia al manejo costero integrado de la Bahıa de
Chetumal y su area de influenciarsquo (Eds F J Rosado-May R Romero
Mayo and A De Jesus Navarrete) pp 143ndash148 (Universidad de
Quintana Roo Chetumal Mexico)
Gischler E Gibson M A and Oschmann W (2008) Giant Holocene
freshwater microbialites Laguna de Bacalar Quintana Roo Mexico
Sedimentology 55 1293ndash1309 doi101111J1365-3091200700946X
Gischler E Golubic S Gibson M Oschamann W and Hudson J H
(2011) Microbial mats and microbialites in the freshwater Laguna
Bacalar Yucatan Peninsula Mexico In lsquoAdvances in Stromatolite
Geobiologyrsquo (Eds J Reitner M H Trauth K Stuwe and D Yuen)
pp 187ndash205 (Springer Berlin Germany)
Gonzalez B J L Carrion J J Cuevas D J Flores M F Yam G J O
Moreno C J Perez V J and Calva C G (2014) Acumulacion de Hg
Pb Cd y Zn por Pomacea flagellata en tres balnearios ubicados en la
region urbana de la Laguna de Bacalar TecnoCultura 35 14ndash23
Hemley R J Prewitt C T and Kingma K (1994) High-pressure
behavior of silica In lsquoSilica ndash Physical Behavior Geochemistry and
Materials Applications Reviews in Mineralogy Vol 29rsquo (Eds P J
Heaney C T Prewitt and G V Gibbs) pp 41ndash82 (Mineralogical
Society of America Washington DC USA)
Hernandez L Probst A Probst L J and Ulrich E (2003) Heavy metal
distribution in some French forest soils evidence for atmospheric
contamination The Science of the Total Environment 312(1ndash3)
195ndash219 doi101016S0048-9697(03)00223-7
Hernandez-Terrones L Rebolledo-Vieyra M Merino-Ibarra M Soto
M Le-Cossec A and Monroy-Rıos E (2011) Groundwater pollution
in a karstic region (NE Yucatan) baseline nutrient content and flux to
coastal ecosystems Water Air and Soil Pollution 218(1ndash4) 517ndash528
doi101007S11270-010-0664-X
InstitutoNacional de Estadıstica yGeografıa (2002) EstudioHidrologico del
Estado de Quintana Roo (INEGI Aguascalientes Mexico) Available at
httpinternetcontenidosinegiorgmxcontenidosproductosprod_serv
contenidosespanolbvinegiproductoshistoricos2104702825224196
702825224196_1pdf [Verified 5 September 2018]
Instituto Nacional de Estadıstica y Geografıa (2016) Anuario Estadıstico y
Geografico de Quintana Roo (INEGI Aguascalientes Mexico) Avail-
able at httpinternetcontenidosinegiorgmxcontenidosProductos
prod_servcontenidosespanolbvinegiproductosnueva_estrucanuarios_
2016702825084370pdf [Verified 5 September 2018]
Javan S Hessam H A Gholamalizadeh A A and Soltani J (2015)
Fractionation of heavy metals in bottom sediments in Chahnimeh 1
Zabol Iran Environmental Monitoring and Assessment 187(6) 340
doi101007S10661-015-4510-X
Katip A Karaer F Ileri S Sarmasik S Aydogan N and Zenginay S
(2011) Analysis and assessment of trace elements pollution in sediments
of Lake Ulubat Turkey Journal of Environmental Biology 33 961ndash968
Kenkmann T and Schonian F (2006) Ries and Chicxulub impact craters
on Earth provide insights for Martian ejecta blankets Meteoritics amp
Planetary Science 41(10) 1587ndash1603 doi101111J1945-51002006
TB00437X
Khedidja A and Boudoukha A (2016) Lrsquoaquifere Superficiel de
Tadjnanet-Chelghoum laid (Nord-Est Algerien) Larhyss Journal 28
181ndash197
Lounejeva E Ostroumov M and Sanchez R G (2002) Polimorfos de
alta presion de sılice en las impactitas de ChicxulubMexico ndash resultados
de espectrometrıa de Raman Revista Mexicana de Ciencias Geologicas
17(2) 137ndash141
Manoj K and Padhy P K (2014) Distribution enrichment and ecological
risk assessment of six elements in bed sediments of a tropical river
Chottanagpur Plateau a spatial and temporal appraisal Journal of
Environmental Protection 5 1419ndash1434 doi104236JEP2014514136
Marfia A M Krishnamurthya R V Atekwanab E A and Panton W F
(2004) Isotopic and geochemical evolution of ground and surfacewaters
in a karst dominated geological setting a case study fromBelize Central
America Applied Geochemistry 19 937ndash946 doi101016JAPGEO
CHEM200310013
Massaferro J Correa M A Montes de Oca F and Mauad M (2018)
Contrasting responses of lake ecosystems to environmental disturbance
a paleoecological perspective from northern Patagonia (Argentina)
Hydrobiologia 816(1) 79ndash89 doi101007S10750-016-3081-3
Medina M S Jimenez G A Gutierrez R M and Lizardi J M (2014)
Hydrocarbon pollution studies of underwater sinkholes along Quintana
L Marine and Freshwater Research N I Tobon ndashVelazquez et al
Roo as function of tourism development in the Mexican Caribbean
Revista Mexicana de Ingenierıa Quımica 13(2) 509ndash516
Norena-Barroso E Zapata-Perez O Ceja-Moreno V and Gold-Bouchot
G (1998) Hydrocarbon and organochloride residue concentrations in
sediments from Bay of Chetumal Mexico Bulletin of Environmental
Contamination and Toxicology 61 80ndash87 doi101007S001289900732
Nriagu J and Pacyna J (1988) Quantitative assessment of worldwide
contamination of air water and soils by trace metals Nature 333 134ndash
139 doi101038333134A0
Ochoa J C Gonzalez B J and Jimenez C J (2016) Metales pesados
(Cd Cr Pb Hg) en Rhizophora mangle en rıo y bahıa de Chetumal
Revista Mexicana de Agroecosistemas 3(2) 263ndash271
Oliva R J Ocana F A de Jesus N A de Jesus C R and Vargas E A
(2016) Reproduccion dePomacea flagellata (Mollusca Ampullariidae)
en la laguna de Bacalar Quintana Roo Mexico Revista de Biologıa
Tropical 64(4) 1643ndash1650
Pacton M Hunger G Martinuzzi V Cusminsky G Burdin B
Barmettler K Vasconcelos C and Ariztegui D (2015) Organomi-
neralization processes in freshwater stromatolites a living example from
eastern Patagonia International Association of Sedimentologists Jour-
nal 1(2) 130ndash146
Perez L Bugja R Lorenschat J Brenner M Curtis J Hoelzmann P
Islebe G Scharf B and SchwalbA (2011) Aquatic ecosystems of the
Yucatan Peninsula (Mexico) Belize and Guatemala Hydrobiologia
661 407ndash433 doi101007S10750-010-0552-9
Perry E C Velazquez O G and Marin L (2002) The hydrogeochem-
istry of the karst aquifer system of the northern Yucatan Peninsula
Mexico International Geology Review 44 191ndash221 doi102747
0020-6814443191
Perry E Paytan A Pedersen B and Velazquez O G (2009) Ground-
water geochemistry of the Yucatan Peninsula Mexico constraints on
stratigraphy and hydrogeology Journal of Hydrology 367 27ndash40
doi101016JJHYDROL200812026
Pradit S Wattayarkorn G Angsupanich S Baeyens W and Leer-
makers M (2010) Distribution of trace elements in sediments and biota
of Songkhla Lake Southern Thailand Water Air and Soil Pollution
206 155ndash174 doi101007S11270-009-0093-X
Salomons W and Forstner U (1980) Trace metal analysis on polluted
sediments II evaluation of environmental impact Environmental
Technology Letters 1 506ndash517 doi10108009593338009384007
Sanchez S J Alvarez L T Pacheco A J Gonzalez H R and Carrillo
B L (2015) Caracterizacion hidrogeoquımica de las aguas subterraneas
del sur del Estado de Quintana Roo Mexico Revista Mexicana de
Ciencias Geologicas 32(1) 62ndash76
Schmitter-Soto J J Comın F A Escobar B E Herrera S J Alcocer J
Suarez M E Elıas G M Dıaz A V Marın L E and Steinich B
(2002) Hydrogeochemical and biological characteristics of cenotes in
the Yucatan Peninsula (SE Mexico) Hydrobiologia 467 215ndash228
doi101023A1014923217206
Siqueiros-Beltrones D Hernandez A U and Hernandez A O (2013)
Diagnosis prospectiva sobre la diversidad de diatomeas epilıticas en la
laguna Bacalar Quintana Roo Mexico Revista Mexicana de Biodiver-
sidad 84 865ndash875 doi107550RMB33960
Turekian K K andWedepohl K H (1961) Distribution of the elements in
some major units of the Earthrsquos crust Bulletin of the Geological Society
of America 72 175ndash192 doi1011300016-7606(1961)72[175
DOTEIS]20CO2
Handling Editor Russell Frew
wwwpublishcsiroaujournalsmfr
Hydrochemistry of Bacalar Lagoon Marine and Freshwater Research M
Sediment pollution
Some trace elements in Bacalar Lagoon sediments mayreflect anthropogenic pollution Here we used four indices
followingManoj and Padhy (2014 see Table 3)We normalisedconcentrations to Al because it is a conservative lithogenic
element and is resistant to chemical weathering hence it does
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
50
40
30
20
10
0
8000 9000 10 000 11 000
Sr (ppm) Ba (ppm) U (ppm) Mg (ppm)
8 10 12 14 16 18 0 01 02 03 04 05 06 300 000 400 000
Dep
th (
cm)
0 1000 5000
Al (ppm) Si (ppm) Ti (ppm) Ca (ppm)
Mn (ppm) Fe (ppm) Ni (ppm) Zn (ppm)
10 000 2020 000 2001000 0 200 000 400 000
0 1 2 3 4 0 400 1000 2000 0 20 40 60 500 100 150 25020080
COC BAC3 BAC1 BAC2
Fig 7 Concentrations of trace andmajor elements in sediment cores BAC1 Bacalar 1 BAC2 Bacalar 2 BAC3 Bacalar 3
COC Cocalitos
H Marine and Freshwater Research N I Tobon ndashVelazquez et al
not actively participate in the dominant geochemical cycles and
does not have a significant anthropogenic source (Boes et al2011 Dautovic et al 2014)
For normalisation to Al values for the Earthrsquos crust were
taken from Turekian and Wedepohl (1961) in which the valuesare mean concentrations in carbonates rocks of the upper crustKfrac14 27000 ppm Mnfrac14 11000 ppm Nifrac14 200 ppm
Znfrac14 200 ppm and Bafrac14 100 ppmTo determine whether the elements are from lithological or
anthropogenic sources the trace element concentrations were
compared with the crustal composition (Hernandez et al 2003)
frac12M lithogenic frac14 frac12Als ethfrac12M =frac12AlcTHORN eth1THORN
frac12M anthropogenic frac14 frac12M T frac12M lithogenic eth2THORN
where the lithogenic input ([M]lithogenic) is estimated throughthe concentration of Al in the sample ([Al]s) and the ratio of the
average of the Earthrsquos crust ([M][Al]c) The anthropogenic input([M]anthropogenic) was calculated based on the total concentration([M]T) and the lithogenic input
The results of these calculations are summarised in Table 4For all cores U6thorn Mn2thorn and Kthorn show negative values for theindex of geoaccumulation (Igeo) whereas the values of CF(contamination factor) and CD (contamination degree) are
lower than 20 All factors indicate that the sediment is notpolluted with these elements which are likely of lithogenicorigin For Ni2thorn the Igeo (0) CF (1) and CD (6) indices
also indicate low pollution except for the upper samples (depthsof 0ndash6 and 6ndash11 cm) of theBAC2 core where theCF is30 andIgeo is 10 suggesting unpolluted to moderately polluted
conditions In contrast the values of these indices for Zn2thorn
and Ba2thorn show some spatial variabilityThe CD of Zn2thorn at all sites is 15 The eastern samples
(BAC1 and BAC2) show higher CD values (822 and 1805
respectively) suggesting moderate to considerable contamina-
tion of the sediment The Ba2thorn concentration exhibits a spatialdistribution the western sites (COC RAP and BAC3) havehigher Ba2thorn concentrations compared than the eastern sites and
the calculated indices were correspondingly higher for thewestern side of the lagoon However overall the indicesindicated that the sediments on both sides of the lagoon are
unpollutedwith regard to Ba and the differences are likely due tohigher barite content on thewestern side Based on these indicesno influence of human activities was detected in eastern core
samples (BAC1 and BAC2)The higher Zn2thorn and Ba2thorn concentrations may be due to a
higher input of these elements into the area close to these sitesHowever water column distributions have to be assessed to
confirm this Zn2thorn and Ba2thorn in Bacalar Lagoon sediments couldbe derived from two sources (1) authigenic minerals found inthe sediment which on thewestern side contain barite (BaSO4)
and some sphalerite (ZnS) and (2) anthropogenic sources suchas agricultural fertiliser or cattle feed Commercial fertiliserscontain micronutrients such as Zn2thorn Mn2thorn Fe3thorn Cu2thorn Mo6thorn
and Ba2thorn in concentrations ranging from trace to several ppmwhich could infiltrate and cause pollution in the soil andgroundwater (Adriano 1986) Baize (1997) indicated that Znis found in animal feed used for pigs that are raised domestically
and commercially in the region The waste water generated bythis industry has been poorly handled resulting in adverseeffects on the environment (Drucker et al 2003) Near the town
of Bacalar fertilisers and agrochemicals are used regularly(Alvarez-Legorreta 2009) The agriculture practices in themunicipality include maize sugarcane and pepper and more
than 40 products are spread annually on these crops (fertilisersherbicides and pesticides Euan-Avila et al 2002) Garcıa-Rıosand Gold-Bouchot (2002) identified Fe V Ni Pb Zn Cu and
Cd in sediments of nearby Chetumal Bay Indeed Bacalar andOthon P Blanco municipalities have the highest fertilised area
Table 3 Indices as indicators of sediment quality based on Manoj and Padhy (2014) and Javan et al (2015)
Ms sample element concentration Mb background concentration of the element
Index Equation Sediment quality
Index of geoacumulation Igeofrac14 ln(Ms15Mb) 0frac14 unpolluted
0ndash1frac14 unpolluted to moderately polluted
1ndash2frac14moderately polluted
2ndash3frac14moderately polluted to highly polluted
3ndash4frac14 highly polluted
4ndash5frac14 highly polluted to very highly polluted
5frac14 very highly polluted
Contamination factor CF5MsMb 1frac14 low CF
1 CF 3frac14moderate CF
3 CF 6frac14 considerable CF
$6frac14 very high CF
Contamination degree CD frac14Pnifrac141
CF 6frac14 low CD
6 CD 12frac14moderate CD
12 CD 24frac14 considerable CD
$24frac14 high CD (anthropogenic contamination)
Pollution load index PLI5 (CF1CFsyCFn)1n 0frac14 unpolluted
1frac14 baseline levels of pollutants present
1frac14 progressive deterioration of site
Hydrochemistry of Bacalar Lagoon Marine and Freshwater Research I
Table4
Index
ofgeoacummulation(Igeo)anthropogenic(A
)inputcontaminationfactor(C
F)andcontaminationdegree(C
D)forBaUKMnNiandZnin
thesedim
entary
record
ofthe
BacalarLagoon
NAdatanoavailablePLIpollutionload
indexBAC1Bacalar
1BAC2Bacalar
2BAC3Bacalar
3COCCocalitosRAPLosRapidos
Site
Depth
(cm)
Ba
UK
Mn
Ni
Zn
PLI
I geo
Ainput
CF
CD
I geo
Ainput
CF
CD
I geo
Ainput
CF
CD
I geo
Ainput
CF
CD
I geo
Ainput
CF
CD
I geo
Ainput
CF
CD
COC
0ndash6
016
1236
134
701
503
013
005
065
688
24629
001
003
1119
11361
0001
0002
371
021
011
053
203
529
037
479
005
6ndash12
015
1314
135
469
005
006
675
5569
001
1160
3753
0000
409
107
009
004
2846
146
006
12ndash17
004
1421
146
336
024
015
NA
10001
000
1147
4016
0001
405
107
009
037
2254
116
000
17ndash22
014
1627
165
304
035
018
1158
6288
000
1257
2588
0000
362
196
012
010
3174
161
004
22ndash27
031
1156
121
282
035
021
NA
14125
000
1338
5739
0000
367
132
012
301
267
019
000
RAP
0ndash6
039
1074
115
264
538
008
004
009
889
18818
000
002
1067
7912
0001
0001
508
057
004
014
156
870
051
284
004
6ndash11
001
1360
149
475
017
006
651
31721
002
1189
14691
0000
391
069
010
063
4390
233
007
BAC1
0ndash5
024
267
127
956
402
201
009
069
230
189364
031
161
896
110398
0003
0023
300
1639
019
115
174
1118
045
822
014
5ndash10
035
302
118
416
174
008
276
176636
022
907
96021
0003
311
1404
017
066
2982
237
017
10ndash15
048
382
108
437
137
007
307
139830
018
913
76341
0003
327
1083
016
119
074
066
013
15ndash20
031
444
121
423
150
008
295
153179
019
896
83486
0003
330
1220
015
013
1225
137
015
20ndash25
031
488
121
420
142
008
301
145741
019
883
79449
0003
351
1189
013
424
1293
008
009
25ndash30
039
504
114
408
121
009
320
128917
016
925
70152
0002
363
1037
012
061
689
098
013
30ndash35
016
581
134
385
145
010
299
154625
019
904
83454
0003
353
1264
013
069
337
093
014
35ndash40
041
467
113
419
127
008
313
131772
017
917
72183
0003
392
1120
010
012
1446
138
013
BAC2
0ndash6
035
1141
117
734
515
002
004
086
743
6689
001
006
1094
3596
0001
0006
374
157
011
444
051
4203
214
1805
007
6ndash11
052
1005
105
462
004
006
834
10694
000
949
4638
0002
119
6764
343
012
2666
138
012
11ndash16
055
984
103
442
006
007
750
9268
001
1126
4617
0001
420
078
008
144
1018
055
005
16ndash21
055
985
102
400
013
009
597
3426
002
1119
3962
0001
421
089
008
001
2953
151
008
21ndash26
043
1093
111
296
038
019
828
3839
000
1178
2046
0000
412
135
009
293
22785
1141
009
26ndash31
068
925
094
254
054
026
832
2578
000
1194
1524
0000
273
424
023
104
1434
073
006
36ndash41
056
1001
102
337
028
014
875
3556
000
1113
1759
0001
182
819
043
219
626
033
006
BAC3
0ndash6
016
1283
134
407
607
009
002
007
682
12943
001
002
1266
6706
0000
0001
553
057
003
008
211
572
035
152
003
6ndash12
020
1270
131
607
003
002
989
9545
000
1308
4043
0000
580
020
003
081
1639
086
002
12ndash18
008
1389
142
613
003
002
891
8695
000
1341
3872
0000
593
021
002
223
567
032
002
J Marine and Freshwater Research N I Tobon ndashVelazquez et al
in Quintana Roo state (Instituto Nacional de Estadıstica yGeografıa 2016) Owing to the karstic nature of the area these
products can immediately infiltrate the aquifer and thereforecould be affecting the lagoon Because the concentration of ZnSminerals was low in the cores it is suggested that the source of
Zn2thorn could be derived from human activities Although theresults from the pollution load index (PLI) (1) for all samplesindicate that the sites are not highly polluted the excess Zn2thorn in
the sediment suggests some local pollution with regard to thiselement Conversely the concentrations of Ba2thorn can beexplained by the variable occurrence of barite in the cores
Minimal trace metal pollution is consistent with previous
metal work in the lagoon Castro-Contreras et al (2014)reported heavy metal concentrations in Bacalar Lagoon waterbelow the maximum limits of the Mexican legislation (NOM-
127-SSA1-1994) and ecological water quality criteria (CE-CCA-00189) that establish the limits of heavy metals fordrinking water irrigation and recreational activities
Nevertheless organochloride compounds (pesticides andpolychlorinated biphenyls) and hydrocarbons in sediments havebeen identified by Norena-Barroso et al (1998) in the ChetumalBay area near Bacalar Lagoon Organochlorine pesticides
(OCPs) are used in agriculture in the region (Alvarez-Legorreta2009) Furthermore heavymetals and OCPs have been detectedin crocodilian eggs near Chichorro Atoll (Charruau et al 2013
Buenfil-Rojas et al 2015)
Conclusions
Bacalar Lagoon is a shallow and oligotrophic system (low-
nutrient waters) with a mineralogical composition dominatedby calcite dolomite and evaporites dissolution Water geo-chemical analyses show a clear spatial distribution of different
parameters The western part of the study area is characterisedby high alkalinity and calcium and sulfate concentrations theratios of these constituents indicate groundwater sources and noseawater intrusion The decreases in these parameters towards
the north indicate a gradient in groundwater influencethroughout the lagoon The eastern part of the study area ischaracterised by a shallower water column resulting in high
evaporation and high electrical conductivity compared with thewestern side
We present the first measurements of trace elements in
carbonate sediments in Bacalar Lagoon The sediment exhibitsonly moderate contamination with Zn2thorn on the western side ofthe lagoon The high Ba concentration in the sediment corre-
sponds to barite but further work is necessary to identify thesource of Ba2thorn and Zn2thorn This study can be useful for Bacalarmunicipality to make decisions and define actions regarding themanagement and development of Bacalar Lagoon
Conflicts of interest
The authors declare that they have no conflicts of interest
Declaration of funding
This investigation was financed by the lsquoWater Security Project inthe South-eastMexico in the face of twoclimate change scenariosrsquoproject (CONACYT 247565) and lsquoProject networks CONACYTrsquo
(282240) The authors acknowledge a grant from CONACYT
towards a Masters of Water Sciences degree (awarded to NidiaTobon Velazquez)
Acknowledgements
The authors thank technical staff Daniela Ortega (Water Sciences Unit
Centro de Investigacion Cientıfica de Yucatan) and Kimberly Bitterwolf
(University of CaliforniamdashSanta Cruz)
References
Adriano D C (1986) lsquoTrace Elements in the Terrestrial Environmentrsquo
(Springer-Verlag Berlin Germany)
Alvarez-Legorreta T (2009) Contaminacion acuatica In lsquoEl sistema ecolo-
gico de la Bahıa de Chetumal Corozal costa occidental del Mar Caribersquo
(Eds J Espinoza Avalos G A Islebe and H A Hernandez Arana)
pp 205ndash217 (El Colegio de la Frontera Sur Chetumal Mexico)
Appelo C A and Postma D (2005) lsquoGeochemistry Groundwater and
Pollutionrsquo 2nd edn (A A Balkema Rotterdam Netherlands)
Baize D (1997) lsquoTeneurs totales en elements trace metalliques dans les sols
(France) References et strategies drsquointerpretationrsquo (INRA Paris France)
Bauer-Gottwein P Gondwe B Charvet G Marin L Rebolledo V M
andMerediz A G (2011) Review the Yucatan Peninsula karst aquifer
Mexico Hydrogeology Journal 19 507ndash524 doi101007S10040-010-
0699-5
Beddows P A (2002) lsquoWhere Does the Sewage Go The Karst
Groundwater System of the Municipalidad de Solidaridad Quintana
Roo Mexicorsquo (Association for Mexican Cave Studies Houston
TX USA)
Beltran D Y (2010) Estimacion de los patrones de fijacion de nitrogeno y
diversidad asociada (nifH) en tapices microbianos y estromatolitos
MSc Thesis Universidad Nacional Autonoma de Mexico Ciudad de
Mexico Mexico
Boes X Rydberg J Martinez C A Bindler R and Renberg I (2011)
Evaluation of conservative lithogenic elements (Ti Zr Al and Rb) to
study anthropogenic element enrichments in lake sediments Journal of
Paleolimnology 46 75ndash87 doi101007S10933-011-9515-Z
Boyle J F (2001) Inorganic geochemical methods in paleolimnology In
lsquoTracking Environmental Change Using Lake Sediments Vol 2 Physi-
cal andGeochemicalMethodsrsquo (EdsMW Last and P J Smol) pp 83ndash
143 (Kluwer Academic Publishers Dordrecht Netherlands)
Buenfil-Rojas A M Alvarez- Legorreta T and Cedeno-Vazquez J R
(2015) Metals and metallothioneins in Moreletrsquos Crocodile (Crocodile
moreletii) from a Transboundary River between Mexico and Belize
Archives of Environmental Contamination and Toxicology 68(2) 265ndash
273 doi101007S00244-014-0088-5
Castro-Contreras C Murray K G Pecoits E Aubet N R Petrash D
Castro C S Gregory D Planavsky N and Konhauser K O (2014)
Textural and geochemical features of freshwater microbialites from
LagunaBacalarQuintanaRooMexicoPalaios 29(5) 192ndash209 doi10
2110PALO2013063
Ceballos Martınez R R (2002) Geografıa y medio ambiente en el sistema
lagunar San FelipendashBacalarndashGuerrero In lsquoContribuciones de la ciencia al
manejo costero integrado de laBahıa deChetumal y su area de influenciarsquo
(Eds F J Rosado-May RRomeroMayo andADe Jesus Navarrete) pp
17ndash22 (Universidad de Quintana Roo Chetumal Mexico)
Centeno M C Legendre P Beltran Y Alcantara H R Lidstrom E U
Ashby N M and Falcon I L (2012) Microbialite genetic diversity
and composition relate to environmental variables FEMSMicrobiology
Ecology 82 724ndash735 doi101111J1574-6941201201447X
Chagas A P Webb E G Burne V R and Southam G (2016) Modern
lacustrine microbialites towards a synthesis of aqueous and carbonate
geochemistry and mineralogy Earth-Science Reviews 162 338ndash363
doi101016JEARSCIREV201609012
Charruau P Henaut Y and Alvarez-Legorreta T (2013) Organo-
chlorine pesticides in nest substratum and infertile eggs of American
Hydrochemistry of Bacalar Lagoon Marine and Freshwater Research K
crocodiles (Reptilia Crocodylidae) in a Mexican Caribbean atoll
Caribbean Journal of Science 47 1ndash12 doi1018475CJOSV47I1A2
Comision Nacional del Agua (2002) lsquoDeterminacion de la disponibilidad de
agua en el acuıfero Penınsula de Yucatan estado de Yucatanrsquo (CON-
AGUA Gerencia de Aguas Subterraneas Ciudad de Mexico Mexico)
Comision Nacional del Agua (2012) lsquoPrograma Hıdrico Regional Vision
2030 Region Hidrologico-Administrativa XII Penınsula de Yucatanrsquo
1st edn (Secretarıa de Medio Ambiente y Recursos Naturales Mexico
City Mexico)
Comision Nacional del Agua (2015) lsquoActualizacion de la disponibilidad
media anual de agua en el acuıfero Cerros y Valles (2301) Estado de
QuintanaRoorsquo (CONAGUADiarioOficial de la Federacion Ciudad de
Mexico Mexico)
Dautovic J Fiket Z Baresic J Ahel M and Mikac N (2014) Sources
distribution and behavior of major and trace elements in a complex karst
lake system Aquatic Geochemistry 20 19ndash38 doi101007S10498-
013-9204-9
Dıaz J E (2005) lsquoDecreto por el cual se establece el programa de
ordenamiento ecologico territorial de la region de Laguna Bacalar
Quintana Roo Mexicorsquo (Periodico Oficial Chetumal Mexico)
Dixon J Hamilton K Pagiola S and Segnestam L (2001) Tourism and
environment in the Caribbean an economic framework (The World
Bank Washington DC USA) Available at httpdocumentsworldbank
orgcurateden672281468770397455pdfmulti0pagepdf [Verified 18
October 2018]
Drever J I (2005) lsquoSurface and Ground Water Weathering and Soilsrsquo
(Elsevier Oxford UK)
Drucker A Escalante R Gomez V and Magana S (2003) La industria
porcina en Yucatan un analisis de la generacion de aguas residuales
Problemas del Desarrollo Revista Latinoamericana de Economıa 34
(135) 105ndash120
Dupraz C Reid R P andVisscher P T (2011)MicrobialitesModern In
lsquoEncyclopedia of Geobiology Encyclopedia of Earth Science Seriesrsquo
(Eds J Reitner and V Thiel) pp 617ndash635 (Springer Heidelberg
Germany)
Elango L andKannan R (2007) Rockndashwater interaction and its control on
chemical composition of groundwater In lsquoDevelopments in Environ-
mental Sciencersquo Vol 5 (Eds D Sarkar R Datta and R Hannigan) pp
229ndash243 (Elsevier Oxford UK)
Euan-Avila J I Liceaga-CorreaM A and Rodrıguez Sanchez H (2002)
Caracterizacion de fuentes no puntuales de contaminacion agrıcola en el
municipio deOthon P Blanco enQuintanaRoo y su potencial influencia
en la Bahıa de Chetumal In lsquoContribuciones de la ciencia al manejo
costero integrado de la Bahıa de Chetumal y su area de influenciarsquo (Eds
F J Rosado-May R Romero Mayo and A De Jesus Navarrete) pp
197ndash204 (Universidad de Quintana Roo Chetumal Mexico)
Fouke W B Zerkle L A Alvarez W Pope O K Ocampos A C
Wachtman J R Grajales J M Claeys P and Fischer G A (2002)
Cathodoluminescence petrography and isotope geochemistry of KT
impact ejecta deposited 360 km from the Chicxulub crater at Albion
Island Belize Sedimentology 49 117ndash138 doi101046J1365-3091
200200435X
Garcıa-Rıos V Y and Gold-Bouchot G (2002) Especiacion de metales
pesados en sedimentos de la Bahıa de Chetumal Quintana Roo y la
acumulacion en el tejido muscular de bagres (Ariopsis assimilis) In
lsquoContribuciones de la ciencia al manejo costero integrado de la Bahıa de
Chetumal y su area de influenciarsquo (Eds F J Rosado-May R Romero
Mayo and A De Jesus Navarrete) pp 143ndash148 (Universidad de
Quintana Roo Chetumal Mexico)
Gischler E Gibson M A and Oschmann W (2008) Giant Holocene
freshwater microbialites Laguna de Bacalar Quintana Roo Mexico
Sedimentology 55 1293ndash1309 doi101111J1365-3091200700946X
Gischler E Golubic S Gibson M Oschamann W and Hudson J H
(2011) Microbial mats and microbialites in the freshwater Laguna
Bacalar Yucatan Peninsula Mexico In lsquoAdvances in Stromatolite
Geobiologyrsquo (Eds J Reitner M H Trauth K Stuwe and D Yuen)
pp 187ndash205 (Springer Berlin Germany)
Gonzalez B J L Carrion J J Cuevas D J Flores M F Yam G J O
Moreno C J Perez V J and Calva C G (2014) Acumulacion de Hg
Pb Cd y Zn por Pomacea flagellata en tres balnearios ubicados en la
region urbana de la Laguna de Bacalar TecnoCultura 35 14ndash23
Hemley R J Prewitt C T and Kingma K (1994) High-pressure
behavior of silica In lsquoSilica ndash Physical Behavior Geochemistry and
Materials Applications Reviews in Mineralogy Vol 29rsquo (Eds P J
Heaney C T Prewitt and G V Gibbs) pp 41ndash82 (Mineralogical
Society of America Washington DC USA)
Hernandez L Probst A Probst L J and Ulrich E (2003) Heavy metal
distribution in some French forest soils evidence for atmospheric
contamination The Science of the Total Environment 312(1ndash3)
195ndash219 doi101016S0048-9697(03)00223-7
Hernandez-Terrones L Rebolledo-Vieyra M Merino-Ibarra M Soto
M Le-Cossec A and Monroy-Rıos E (2011) Groundwater pollution
in a karstic region (NE Yucatan) baseline nutrient content and flux to
coastal ecosystems Water Air and Soil Pollution 218(1ndash4) 517ndash528
doi101007S11270-010-0664-X
InstitutoNacional de Estadıstica yGeografıa (2002) EstudioHidrologico del
Estado de Quintana Roo (INEGI Aguascalientes Mexico) Available at
httpinternetcontenidosinegiorgmxcontenidosproductosprod_serv
contenidosespanolbvinegiproductoshistoricos2104702825224196
702825224196_1pdf [Verified 5 September 2018]
Instituto Nacional de Estadıstica y Geografıa (2016) Anuario Estadıstico y
Geografico de Quintana Roo (INEGI Aguascalientes Mexico) Avail-
able at httpinternetcontenidosinegiorgmxcontenidosProductos
prod_servcontenidosespanolbvinegiproductosnueva_estrucanuarios_
2016702825084370pdf [Verified 5 September 2018]
Javan S Hessam H A Gholamalizadeh A A and Soltani J (2015)
Fractionation of heavy metals in bottom sediments in Chahnimeh 1
Zabol Iran Environmental Monitoring and Assessment 187(6) 340
doi101007S10661-015-4510-X
Katip A Karaer F Ileri S Sarmasik S Aydogan N and Zenginay S
(2011) Analysis and assessment of trace elements pollution in sediments
of Lake Ulubat Turkey Journal of Environmental Biology 33 961ndash968
Kenkmann T and Schonian F (2006) Ries and Chicxulub impact craters
on Earth provide insights for Martian ejecta blankets Meteoritics amp
Planetary Science 41(10) 1587ndash1603 doi101111J1945-51002006
TB00437X
Khedidja A and Boudoukha A (2016) Lrsquoaquifere Superficiel de
Tadjnanet-Chelghoum laid (Nord-Est Algerien) Larhyss Journal 28
181ndash197
Lounejeva E Ostroumov M and Sanchez R G (2002) Polimorfos de
alta presion de sılice en las impactitas de ChicxulubMexico ndash resultados
de espectrometrıa de Raman Revista Mexicana de Ciencias Geologicas
17(2) 137ndash141
Manoj K and Padhy P K (2014) Distribution enrichment and ecological
risk assessment of six elements in bed sediments of a tropical river
Chottanagpur Plateau a spatial and temporal appraisal Journal of
Environmental Protection 5 1419ndash1434 doi104236JEP2014514136
Marfia A M Krishnamurthya R V Atekwanab E A and Panton W F
(2004) Isotopic and geochemical evolution of ground and surfacewaters
in a karst dominated geological setting a case study fromBelize Central
America Applied Geochemistry 19 937ndash946 doi101016JAPGEO
CHEM200310013
Massaferro J Correa M A Montes de Oca F and Mauad M (2018)
Contrasting responses of lake ecosystems to environmental disturbance
a paleoecological perspective from northern Patagonia (Argentina)
Hydrobiologia 816(1) 79ndash89 doi101007S10750-016-3081-3
Medina M S Jimenez G A Gutierrez R M and Lizardi J M (2014)
Hydrocarbon pollution studies of underwater sinkholes along Quintana
L Marine and Freshwater Research N I Tobon ndashVelazquez et al
Roo as function of tourism development in the Mexican Caribbean
Revista Mexicana de Ingenierıa Quımica 13(2) 509ndash516
Norena-Barroso E Zapata-Perez O Ceja-Moreno V and Gold-Bouchot
G (1998) Hydrocarbon and organochloride residue concentrations in
sediments from Bay of Chetumal Mexico Bulletin of Environmental
Contamination and Toxicology 61 80ndash87 doi101007S001289900732
Nriagu J and Pacyna J (1988) Quantitative assessment of worldwide
contamination of air water and soils by trace metals Nature 333 134ndash
139 doi101038333134A0
Ochoa J C Gonzalez B J and Jimenez C J (2016) Metales pesados
(Cd Cr Pb Hg) en Rhizophora mangle en rıo y bahıa de Chetumal
Revista Mexicana de Agroecosistemas 3(2) 263ndash271
Oliva R J Ocana F A de Jesus N A de Jesus C R and Vargas E A
(2016) Reproduccion dePomacea flagellata (Mollusca Ampullariidae)
en la laguna de Bacalar Quintana Roo Mexico Revista de Biologıa
Tropical 64(4) 1643ndash1650
Pacton M Hunger G Martinuzzi V Cusminsky G Burdin B
Barmettler K Vasconcelos C and Ariztegui D (2015) Organomi-
neralization processes in freshwater stromatolites a living example from
eastern Patagonia International Association of Sedimentologists Jour-
nal 1(2) 130ndash146
Perez L Bugja R Lorenschat J Brenner M Curtis J Hoelzmann P
Islebe G Scharf B and SchwalbA (2011) Aquatic ecosystems of the
Yucatan Peninsula (Mexico) Belize and Guatemala Hydrobiologia
661 407ndash433 doi101007S10750-010-0552-9
Perry E C Velazquez O G and Marin L (2002) The hydrogeochem-
istry of the karst aquifer system of the northern Yucatan Peninsula
Mexico International Geology Review 44 191ndash221 doi102747
0020-6814443191
Perry E Paytan A Pedersen B and Velazquez O G (2009) Ground-
water geochemistry of the Yucatan Peninsula Mexico constraints on
stratigraphy and hydrogeology Journal of Hydrology 367 27ndash40
doi101016JJHYDROL200812026
Pradit S Wattayarkorn G Angsupanich S Baeyens W and Leer-
makers M (2010) Distribution of trace elements in sediments and biota
of Songkhla Lake Southern Thailand Water Air and Soil Pollution
206 155ndash174 doi101007S11270-009-0093-X
Salomons W and Forstner U (1980) Trace metal analysis on polluted
sediments II evaluation of environmental impact Environmental
Technology Letters 1 506ndash517 doi10108009593338009384007
Sanchez S J Alvarez L T Pacheco A J Gonzalez H R and Carrillo
B L (2015) Caracterizacion hidrogeoquımica de las aguas subterraneas
del sur del Estado de Quintana Roo Mexico Revista Mexicana de
Ciencias Geologicas 32(1) 62ndash76
Schmitter-Soto J J Comın F A Escobar B E Herrera S J Alcocer J
Suarez M E Elıas G M Dıaz A V Marın L E and Steinich B
(2002) Hydrogeochemical and biological characteristics of cenotes in
the Yucatan Peninsula (SE Mexico) Hydrobiologia 467 215ndash228
doi101023A1014923217206
Siqueiros-Beltrones D Hernandez A U and Hernandez A O (2013)
Diagnosis prospectiva sobre la diversidad de diatomeas epilıticas en la
laguna Bacalar Quintana Roo Mexico Revista Mexicana de Biodiver-
sidad 84 865ndash875 doi107550RMB33960
Turekian K K andWedepohl K H (1961) Distribution of the elements in
some major units of the Earthrsquos crust Bulletin of the Geological Society
of America 72 175ndash192 doi1011300016-7606(1961)72[175
DOTEIS]20CO2
Handling Editor Russell Frew
wwwpublishcsiroaujournalsmfr
Hydrochemistry of Bacalar Lagoon Marine and Freshwater Research M
not actively participate in the dominant geochemical cycles and
does not have a significant anthropogenic source (Boes et al2011 Dautovic et al 2014)
For normalisation to Al values for the Earthrsquos crust were
taken from Turekian and Wedepohl (1961) in which the valuesare mean concentrations in carbonates rocks of the upper crustKfrac14 27000 ppm Mnfrac14 11000 ppm Nifrac14 200 ppm
Znfrac14 200 ppm and Bafrac14 100 ppmTo determine whether the elements are from lithological or
anthropogenic sources the trace element concentrations were
compared with the crustal composition (Hernandez et al 2003)
frac12M lithogenic frac14 frac12Als ethfrac12M =frac12AlcTHORN eth1THORN
frac12M anthropogenic frac14 frac12M T frac12M lithogenic eth2THORN
where the lithogenic input ([M]lithogenic) is estimated throughthe concentration of Al in the sample ([Al]s) and the ratio of the
average of the Earthrsquos crust ([M][Al]c) The anthropogenic input([M]anthropogenic) was calculated based on the total concentration([M]T) and the lithogenic input
The results of these calculations are summarised in Table 4For all cores U6thorn Mn2thorn and Kthorn show negative values for theindex of geoaccumulation (Igeo) whereas the values of CF(contamination factor) and CD (contamination degree) are
lower than 20 All factors indicate that the sediment is notpolluted with these elements which are likely of lithogenicorigin For Ni2thorn the Igeo (0) CF (1) and CD (6) indices
also indicate low pollution except for the upper samples (depthsof 0ndash6 and 6ndash11 cm) of theBAC2 core where theCF is30 andIgeo is 10 suggesting unpolluted to moderately polluted
conditions In contrast the values of these indices for Zn2thorn
and Ba2thorn show some spatial variabilityThe CD of Zn2thorn at all sites is 15 The eastern samples
(BAC1 and BAC2) show higher CD values (822 and 1805
respectively) suggesting moderate to considerable contamina-
tion of the sediment The Ba2thorn concentration exhibits a spatialdistribution the western sites (COC RAP and BAC3) havehigher Ba2thorn concentrations compared than the eastern sites and
the calculated indices were correspondingly higher for thewestern side of the lagoon However overall the indicesindicated that the sediments on both sides of the lagoon are
unpollutedwith regard to Ba and the differences are likely due tohigher barite content on thewestern side Based on these indicesno influence of human activities was detected in eastern core
samples (BAC1 and BAC2)The higher Zn2thorn and Ba2thorn concentrations may be due to a
higher input of these elements into the area close to these sitesHowever water column distributions have to be assessed to
confirm this Zn2thorn and Ba2thorn in Bacalar Lagoon sediments couldbe derived from two sources (1) authigenic minerals found inthe sediment which on thewestern side contain barite (BaSO4)
and some sphalerite (ZnS) and (2) anthropogenic sources suchas agricultural fertiliser or cattle feed Commercial fertiliserscontain micronutrients such as Zn2thorn Mn2thorn Fe3thorn Cu2thorn Mo6thorn
and Ba2thorn in concentrations ranging from trace to several ppmwhich could infiltrate and cause pollution in the soil andgroundwater (Adriano 1986) Baize (1997) indicated that Znis found in animal feed used for pigs that are raised domestically
and commercially in the region The waste water generated bythis industry has been poorly handled resulting in adverseeffects on the environment (Drucker et al 2003) Near the town
of Bacalar fertilisers and agrochemicals are used regularly(Alvarez-Legorreta 2009) The agriculture practices in themunicipality include maize sugarcane and pepper and more
than 40 products are spread annually on these crops (fertilisersherbicides and pesticides Euan-Avila et al 2002) Garcıa-Rıosand Gold-Bouchot (2002) identified Fe V Ni Pb Zn Cu and
Cd in sediments of nearby Chetumal Bay Indeed Bacalar andOthon P Blanco municipalities have the highest fertilised area
Table 3 Indices as indicators of sediment quality based on Manoj and Padhy (2014) and Javan et al (2015)
Ms sample element concentration Mb background concentration of the element
Index Equation Sediment quality
Index of geoacumulation Igeofrac14 ln(Ms15Mb) 0frac14 unpolluted
0ndash1frac14 unpolluted to moderately polluted
1ndash2frac14moderately polluted
2ndash3frac14moderately polluted to highly polluted
3ndash4frac14 highly polluted
4ndash5frac14 highly polluted to very highly polluted
5frac14 very highly polluted
Contamination factor CF5MsMb 1frac14 low CF
1 CF 3frac14moderate CF
3 CF 6frac14 considerable CF
$6frac14 very high CF
Contamination degree CD frac14Pnifrac141
CF 6frac14 low CD
6 CD 12frac14moderate CD
12 CD 24frac14 considerable CD
$24frac14 high CD (anthropogenic contamination)
Pollution load index PLI5 (CF1CFsyCFn)1n 0frac14 unpolluted
1frac14 baseline levels of pollutants present
1frac14 progressive deterioration of site
Hydrochemistry of Bacalar Lagoon Marine and Freshwater Research I
Table4
Index
ofgeoacummulation(Igeo)anthropogenic(A
)inputcontaminationfactor(C
F)andcontaminationdegree(C
D)forBaUKMnNiandZnin
thesedim
entary
record
ofthe
BacalarLagoon
NAdatanoavailablePLIpollutionload
indexBAC1Bacalar
1BAC2Bacalar
2BAC3Bacalar
3COCCocalitosRAPLosRapidos
Site
Depth
(cm)
Ba
UK
Mn
Ni
Zn
PLI
I geo
Ainput
CF
CD
I geo
Ainput
CF
CD
I geo
Ainput
CF
CD
I geo
Ainput
CF
CD
I geo
Ainput
CF
CD
I geo
Ainput
CF
CD
COC
0ndash6
016
1236
134
701
503
013
005
065
688
24629
001
003
1119
11361
0001
0002
371
021
011
053
203
529
037
479
005
6ndash12
015
1314
135
469
005
006
675
5569
001
1160
3753
0000
409
107
009
004
2846
146
006
12ndash17
004
1421
146
336
024
015
NA
10001
000
1147
4016
0001
405
107
009
037
2254
116
000
17ndash22
014
1627
165
304
035
018
1158
6288
000
1257
2588
0000
362
196
012
010
3174
161
004
22ndash27
031
1156
121
282
035
021
NA
14125
000
1338
5739
0000
367
132
012
301
267
019
000
RAP
0ndash6
039
1074
115
264
538
008
004
009
889
18818
000
002
1067
7912
0001
0001
508
057
004
014
156
870
051
284
004
6ndash11
001
1360
149
475
017
006
651
31721
002
1189
14691
0000
391
069
010
063
4390
233
007
BAC1
0ndash5
024
267
127
956
402
201
009
069
230
189364
031
161
896
110398
0003
0023
300
1639
019
115
174
1118
045
822
014
5ndash10
035
302
118
416
174
008
276
176636
022
907
96021
0003
311
1404
017
066
2982
237
017
10ndash15
048
382
108
437
137
007
307
139830
018
913
76341
0003
327
1083
016
119
074
066
013
15ndash20
031
444
121
423
150
008
295
153179
019
896
83486
0003
330
1220
015
013
1225
137
015
20ndash25
031
488
121
420
142
008
301
145741
019
883
79449
0003
351
1189
013
424
1293
008
009
25ndash30
039
504
114
408
121
009
320
128917
016
925
70152
0002
363
1037
012
061
689
098
013
30ndash35
016
581
134
385
145
010
299
154625
019
904
83454
0003
353
1264
013
069
337
093
014
35ndash40
041
467
113
419
127
008
313
131772
017
917
72183
0003
392
1120
010
012
1446
138
013
BAC2
0ndash6
035
1141
117
734
515
002
004
086
743
6689
001
006
1094
3596
0001
0006
374
157
011
444
051
4203
214
1805
007
6ndash11
052
1005
105
462
004
006
834
10694
000
949
4638
0002
119
6764
343
012
2666
138
012
11ndash16
055
984
103
442
006
007
750
9268
001
1126
4617
0001
420
078
008
144
1018
055
005
16ndash21
055
985
102
400
013
009
597
3426
002
1119
3962
0001
421
089
008
001
2953
151
008
21ndash26
043
1093
111
296
038
019
828
3839
000
1178
2046
0000
412
135
009
293
22785
1141
009
26ndash31
068
925
094
254
054
026
832
2578
000
1194
1524
0000
273
424
023
104
1434
073
006
36ndash41
056
1001
102
337
028
014
875
3556
000
1113
1759
0001
182
819
043
219
626
033
006
BAC3
0ndash6
016
1283
134
407
607
009
002
007
682
12943
001
002
1266
6706
0000
0001
553
057
003
008
211
572
035
152
003
6ndash12
020
1270
131
607
003
002
989
9545
000
1308
4043
0000
580
020
003
081
1639
086
002
12ndash18
008
1389
142
613
003
002
891
8695
000
1341
3872
0000
593
021
002
223
567
032
002
J Marine and Freshwater Research N I Tobon ndashVelazquez et al
in Quintana Roo state (Instituto Nacional de Estadıstica yGeografıa 2016) Owing to the karstic nature of the area these
products can immediately infiltrate the aquifer and thereforecould be affecting the lagoon Because the concentration of ZnSminerals was low in the cores it is suggested that the source of
Zn2thorn could be derived from human activities Although theresults from the pollution load index (PLI) (1) for all samplesindicate that the sites are not highly polluted the excess Zn2thorn in
the sediment suggests some local pollution with regard to thiselement Conversely the concentrations of Ba2thorn can beexplained by the variable occurrence of barite in the cores
Minimal trace metal pollution is consistent with previous
metal work in the lagoon Castro-Contreras et al (2014)reported heavy metal concentrations in Bacalar Lagoon waterbelow the maximum limits of the Mexican legislation (NOM-
127-SSA1-1994) and ecological water quality criteria (CE-CCA-00189) that establish the limits of heavy metals fordrinking water irrigation and recreational activities
Nevertheless organochloride compounds (pesticides andpolychlorinated biphenyls) and hydrocarbons in sediments havebeen identified by Norena-Barroso et al (1998) in the ChetumalBay area near Bacalar Lagoon Organochlorine pesticides
(OCPs) are used in agriculture in the region (Alvarez-Legorreta2009) Furthermore heavymetals and OCPs have been detectedin crocodilian eggs near Chichorro Atoll (Charruau et al 2013
Buenfil-Rojas et al 2015)
Conclusions
Bacalar Lagoon is a shallow and oligotrophic system (low-
nutrient waters) with a mineralogical composition dominatedby calcite dolomite and evaporites dissolution Water geo-chemical analyses show a clear spatial distribution of different
parameters The western part of the study area is characterisedby high alkalinity and calcium and sulfate concentrations theratios of these constituents indicate groundwater sources and noseawater intrusion The decreases in these parameters towards
the north indicate a gradient in groundwater influencethroughout the lagoon The eastern part of the study area ischaracterised by a shallower water column resulting in high
evaporation and high electrical conductivity compared with thewestern side
We present the first measurements of trace elements in
carbonate sediments in Bacalar Lagoon The sediment exhibitsonly moderate contamination with Zn2thorn on the western side ofthe lagoon The high Ba concentration in the sediment corre-
sponds to barite but further work is necessary to identify thesource of Ba2thorn and Zn2thorn This study can be useful for Bacalarmunicipality to make decisions and define actions regarding themanagement and development of Bacalar Lagoon
Conflicts of interest
The authors declare that they have no conflicts of interest
Declaration of funding
This investigation was financed by the lsquoWater Security Project inthe South-eastMexico in the face of twoclimate change scenariosrsquoproject (CONACYT 247565) and lsquoProject networks CONACYTrsquo
(282240) The authors acknowledge a grant from CONACYT
towards a Masters of Water Sciences degree (awarded to NidiaTobon Velazquez)
Acknowledgements
The authors thank technical staff Daniela Ortega (Water Sciences Unit
Centro de Investigacion Cientıfica de Yucatan) and Kimberly Bitterwolf
(University of CaliforniamdashSanta Cruz)
References
Adriano D C (1986) lsquoTrace Elements in the Terrestrial Environmentrsquo
(Springer-Verlag Berlin Germany)
Alvarez-Legorreta T (2009) Contaminacion acuatica In lsquoEl sistema ecolo-
gico de la Bahıa de Chetumal Corozal costa occidental del Mar Caribersquo
(Eds J Espinoza Avalos G A Islebe and H A Hernandez Arana)
pp 205ndash217 (El Colegio de la Frontera Sur Chetumal Mexico)
Appelo C A and Postma D (2005) lsquoGeochemistry Groundwater and
Pollutionrsquo 2nd edn (A A Balkema Rotterdam Netherlands)
Baize D (1997) lsquoTeneurs totales en elements trace metalliques dans les sols
(France) References et strategies drsquointerpretationrsquo (INRA Paris France)
Bauer-Gottwein P Gondwe B Charvet G Marin L Rebolledo V M
andMerediz A G (2011) Review the Yucatan Peninsula karst aquifer
Mexico Hydrogeology Journal 19 507ndash524 doi101007S10040-010-
0699-5
Beddows P A (2002) lsquoWhere Does the Sewage Go The Karst
Groundwater System of the Municipalidad de Solidaridad Quintana
Roo Mexicorsquo (Association for Mexican Cave Studies Houston
TX USA)
Beltran D Y (2010) Estimacion de los patrones de fijacion de nitrogeno y
diversidad asociada (nifH) en tapices microbianos y estromatolitos
MSc Thesis Universidad Nacional Autonoma de Mexico Ciudad de
Mexico Mexico
Boes X Rydberg J Martinez C A Bindler R and Renberg I (2011)
Evaluation of conservative lithogenic elements (Ti Zr Al and Rb) to
study anthropogenic element enrichments in lake sediments Journal of
Paleolimnology 46 75ndash87 doi101007S10933-011-9515-Z
Boyle J F (2001) Inorganic geochemical methods in paleolimnology In
lsquoTracking Environmental Change Using Lake Sediments Vol 2 Physi-
cal andGeochemicalMethodsrsquo (EdsMW Last and P J Smol) pp 83ndash
143 (Kluwer Academic Publishers Dordrecht Netherlands)
Buenfil-Rojas A M Alvarez- Legorreta T and Cedeno-Vazquez J R
(2015) Metals and metallothioneins in Moreletrsquos Crocodile (Crocodile
moreletii) from a Transboundary River between Mexico and Belize
Archives of Environmental Contamination and Toxicology 68(2) 265ndash
273 doi101007S00244-014-0088-5
Castro-Contreras C Murray K G Pecoits E Aubet N R Petrash D
Castro C S Gregory D Planavsky N and Konhauser K O (2014)
Textural and geochemical features of freshwater microbialites from
LagunaBacalarQuintanaRooMexicoPalaios 29(5) 192ndash209 doi10
2110PALO2013063
Ceballos Martınez R R (2002) Geografıa y medio ambiente en el sistema
lagunar San FelipendashBacalarndashGuerrero In lsquoContribuciones de la ciencia al
manejo costero integrado de laBahıa deChetumal y su area de influenciarsquo
(Eds F J Rosado-May RRomeroMayo andADe Jesus Navarrete) pp
17ndash22 (Universidad de Quintana Roo Chetumal Mexico)
Centeno M C Legendre P Beltran Y Alcantara H R Lidstrom E U
Ashby N M and Falcon I L (2012) Microbialite genetic diversity
and composition relate to environmental variables FEMSMicrobiology
Ecology 82 724ndash735 doi101111J1574-6941201201447X
Chagas A P Webb E G Burne V R and Southam G (2016) Modern
lacustrine microbialites towards a synthesis of aqueous and carbonate
geochemistry and mineralogy Earth-Science Reviews 162 338ndash363
doi101016JEARSCIREV201609012
Charruau P Henaut Y and Alvarez-Legorreta T (2013) Organo-
chlorine pesticides in nest substratum and infertile eggs of American
Hydrochemistry of Bacalar Lagoon Marine and Freshwater Research K
crocodiles (Reptilia Crocodylidae) in a Mexican Caribbean atoll
Caribbean Journal of Science 47 1ndash12 doi1018475CJOSV47I1A2
Comision Nacional del Agua (2002) lsquoDeterminacion de la disponibilidad de
agua en el acuıfero Penınsula de Yucatan estado de Yucatanrsquo (CON-
AGUA Gerencia de Aguas Subterraneas Ciudad de Mexico Mexico)
Comision Nacional del Agua (2012) lsquoPrograma Hıdrico Regional Vision
2030 Region Hidrologico-Administrativa XII Penınsula de Yucatanrsquo
1st edn (Secretarıa de Medio Ambiente y Recursos Naturales Mexico
City Mexico)
Comision Nacional del Agua (2015) lsquoActualizacion de la disponibilidad
media anual de agua en el acuıfero Cerros y Valles (2301) Estado de
QuintanaRoorsquo (CONAGUADiarioOficial de la Federacion Ciudad de
Mexico Mexico)
Dautovic J Fiket Z Baresic J Ahel M and Mikac N (2014) Sources
distribution and behavior of major and trace elements in a complex karst
lake system Aquatic Geochemistry 20 19ndash38 doi101007S10498-
013-9204-9
Dıaz J E (2005) lsquoDecreto por el cual se establece el programa de
ordenamiento ecologico territorial de la region de Laguna Bacalar
Quintana Roo Mexicorsquo (Periodico Oficial Chetumal Mexico)
Dixon J Hamilton K Pagiola S and Segnestam L (2001) Tourism and
environment in the Caribbean an economic framework (The World
Bank Washington DC USA) Available at httpdocumentsworldbank
orgcurateden672281468770397455pdfmulti0pagepdf [Verified 18
October 2018]
Drever J I (2005) lsquoSurface and Ground Water Weathering and Soilsrsquo
(Elsevier Oxford UK)
Drucker A Escalante R Gomez V and Magana S (2003) La industria
porcina en Yucatan un analisis de la generacion de aguas residuales
Problemas del Desarrollo Revista Latinoamericana de Economıa 34
(135) 105ndash120
Dupraz C Reid R P andVisscher P T (2011)MicrobialitesModern In
lsquoEncyclopedia of Geobiology Encyclopedia of Earth Science Seriesrsquo
(Eds J Reitner and V Thiel) pp 617ndash635 (Springer Heidelberg
Germany)
Elango L andKannan R (2007) Rockndashwater interaction and its control on
chemical composition of groundwater In lsquoDevelopments in Environ-
mental Sciencersquo Vol 5 (Eds D Sarkar R Datta and R Hannigan) pp
229ndash243 (Elsevier Oxford UK)
Euan-Avila J I Liceaga-CorreaM A and Rodrıguez Sanchez H (2002)
Caracterizacion de fuentes no puntuales de contaminacion agrıcola en el
municipio deOthon P Blanco enQuintanaRoo y su potencial influencia
en la Bahıa de Chetumal In lsquoContribuciones de la ciencia al manejo
costero integrado de la Bahıa de Chetumal y su area de influenciarsquo (Eds
F J Rosado-May R Romero Mayo and A De Jesus Navarrete) pp
197ndash204 (Universidad de Quintana Roo Chetumal Mexico)
Fouke W B Zerkle L A Alvarez W Pope O K Ocampos A C
Wachtman J R Grajales J M Claeys P and Fischer G A (2002)
Cathodoluminescence petrography and isotope geochemistry of KT
impact ejecta deposited 360 km from the Chicxulub crater at Albion
Island Belize Sedimentology 49 117ndash138 doi101046J1365-3091
200200435X
Garcıa-Rıos V Y and Gold-Bouchot G (2002) Especiacion de metales
pesados en sedimentos de la Bahıa de Chetumal Quintana Roo y la
acumulacion en el tejido muscular de bagres (Ariopsis assimilis) In
lsquoContribuciones de la ciencia al manejo costero integrado de la Bahıa de
Chetumal y su area de influenciarsquo (Eds F J Rosado-May R Romero
Mayo and A De Jesus Navarrete) pp 143ndash148 (Universidad de
Quintana Roo Chetumal Mexico)
Gischler E Gibson M A and Oschmann W (2008) Giant Holocene
freshwater microbialites Laguna de Bacalar Quintana Roo Mexico
Sedimentology 55 1293ndash1309 doi101111J1365-3091200700946X
Gischler E Golubic S Gibson M Oschamann W and Hudson J H
(2011) Microbial mats and microbialites in the freshwater Laguna
Bacalar Yucatan Peninsula Mexico In lsquoAdvances in Stromatolite
Geobiologyrsquo (Eds J Reitner M H Trauth K Stuwe and D Yuen)
pp 187ndash205 (Springer Berlin Germany)
Gonzalez B J L Carrion J J Cuevas D J Flores M F Yam G J O
Moreno C J Perez V J and Calva C G (2014) Acumulacion de Hg
Pb Cd y Zn por Pomacea flagellata en tres balnearios ubicados en la
region urbana de la Laguna de Bacalar TecnoCultura 35 14ndash23
Hemley R J Prewitt C T and Kingma K (1994) High-pressure
behavior of silica In lsquoSilica ndash Physical Behavior Geochemistry and
Materials Applications Reviews in Mineralogy Vol 29rsquo (Eds P J
Heaney C T Prewitt and G V Gibbs) pp 41ndash82 (Mineralogical
Society of America Washington DC USA)
Hernandez L Probst A Probst L J and Ulrich E (2003) Heavy metal
distribution in some French forest soils evidence for atmospheric
contamination The Science of the Total Environment 312(1ndash3)
195ndash219 doi101016S0048-9697(03)00223-7
Hernandez-Terrones L Rebolledo-Vieyra M Merino-Ibarra M Soto
M Le-Cossec A and Monroy-Rıos E (2011) Groundwater pollution
in a karstic region (NE Yucatan) baseline nutrient content and flux to
coastal ecosystems Water Air and Soil Pollution 218(1ndash4) 517ndash528
doi101007S11270-010-0664-X
InstitutoNacional de Estadıstica yGeografıa (2002) EstudioHidrologico del
Estado de Quintana Roo (INEGI Aguascalientes Mexico) Available at
httpinternetcontenidosinegiorgmxcontenidosproductosprod_serv
contenidosespanolbvinegiproductoshistoricos2104702825224196
702825224196_1pdf [Verified 5 September 2018]
Instituto Nacional de Estadıstica y Geografıa (2016) Anuario Estadıstico y
Geografico de Quintana Roo (INEGI Aguascalientes Mexico) Avail-
able at httpinternetcontenidosinegiorgmxcontenidosProductos
prod_servcontenidosespanolbvinegiproductosnueva_estrucanuarios_
2016702825084370pdf [Verified 5 September 2018]
Javan S Hessam H A Gholamalizadeh A A and Soltani J (2015)
Fractionation of heavy metals in bottom sediments in Chahnimeh 1
Zabol Iran Environmental Monitoring and Assessment 187(6) 340
doi101007S10661-015-4510-X
Katip A Karaer F Ileri S Sarmasik S Aydogan N and Zenginay S
(2011) Analysis and assessment of trace elements pollution in sediments
of Lake Ulubat Turkey Journal of Environmental Biology 33 961ndash968
Kenkmann T and Schonian F (2006) Ries and Chicxulub impact craters
on Earth provide insights for Martian ejecta blankets Meteoritics amp
Planetary Science 41(10) 1587ndash1603 doi101111J1945-51002006
TB00437X
Khedidja A and Boudoukha A (2016) Lrsquoaquifere Superficiel de
Tadjnanet-Chelghoum laid (Nord-Est Algerien) Larhyss Journal 28
181ndash197
Lounejeva E Ostroumov M and Sanchez R G (2002) Polimorfos de
alta presion de sılice en las impactitas de ChicxulubMexico ndash resultados
de espectrometrıa de Raman Revista Mexicana de Ciencias Geologicas
17(2) 137ndash141
Manoj K and Padhy P K (2014) Distribution enrichment and ecological
risk assessment of six elements in bed sediments of a tropical river
Chottanagpur Plateau a spatial and temporal appraisal Journal of
Environmental Protection 5 1419ndash1434 doi104236JEP2014514136
Marfia A M Krishnamurthya R V Atekwanab E A and Panton W F
(2004) Isotopic and geochemical evolution of ground and surfacewaters
in a karst dominated geological setting a case study fromBelize Central
America Applied Geochemistry 19 937ndash946 doi101016JAPGEO
CHEM200310013
Massaferro J Correa M A Montes de Oca F and Mauad M (2018)
Contrasting responses of lake ecosystems to environmental disturbance
a paleoecological perspective from northern Patagonia (Argentina)
Hydrobiologia 816(1) 79ndash89 doi101007S10750-016-3081-3
Medina M S Jimenez G A Gutierrez R M and Lizardi J M (2014)
Hydrocarbon pollution studies of underwater sinkholes along Quintana
L Marine and Freshwater Research N I Tobon ndashVelazquez et al
Roo as function of tourism development in the Mexican Caribbean
Revista Mexicana de Ingenierıa Quımica 13(2) 509ndash516
Norena-Barroso E Zapata-Perez O Ceja-Moreno V and Gold-Bouchot
G (1998) Hydrocarbon and organochloride residue concentrations in
sediments from Bay of Chetumal Mexico Bulletin of Environmental
Contamination and Toxicology 61 80ndash87 doi101007S001289900732
Nriagu J and Pacyna J (1988) Quantitative assessment of worldwide
contamination of air water and soils by trace metals Nature 333 134ndash
139 doi101038333134A0
Ochoa J C Gonzalez B J and Jimenez C J (2016) Metales pesados
(Cd Cr Pb Hg) en Rhizophora mangle en rıo y bahıa de Chetumal
Revista Mexicana de Agroecosistemas 3(2) 263ndash271
Oliva R J Ocana F A de Jesus N A de Jesus C R and Vargas E A
(2016) Reproduccion dePomacea flagellata (Mollusca Ampullariidae)
en la laguna de Bacalar Quintana Roo Mexico Revista de Biologıa
Tropical 64(4) 1643ndash1650
Pacton M Hunger G Martinuzzi V Cusminsky G Burdin B
Barmettler K Vasconcelos C and Ariztegui D (2015) Organomi-
neralization processes in freshwater stromatolites a living example from
eastern Patagonia International Association of Sedimentologists Jour-
nal 1(2) 130ndash146
Perez L Bugja R Lorenschat J Brenner M Curtis J Hoelzmann P
Islebe G Scharf B and SchwalbA (2011) Aquatic ecosystems of the
Yucatan Peninsula (Mexico) Belize and Guatemala Hydrobiologia
661 407ndash433 doi101007S10750-010-0552-9
Perry E C Velazquez O G and Marin L (2002) The hydrogeochem-
istry of the karst aquifer system of the northern Yucatan Peninsula
Mexico International Geology Review 44 191ndash221 doi102747
0020-6814443191
Perry E Paytan A Pedersen B and Velazquez O G (2009) Ground-
water geochemistry of the Yucatan Peninsula Mexico constraints on
stratigraphy and hydrogeology Journal of Hydrology 367 27ndash40
doi101016JJHYDROL200812026
Pradit S Wattayarkorn G Angsupanich S Baeyens W and Leer-
makers M (2010) Distribution of trace elements in sediments and biota
of Songkhla Lake Southern Thailand Water Air and Soil Pollution
206 155ndash174 doi101007S11270-009-0093-X
Salomons W and Forstner U (1980) Trace metal analysis on polluted
sediments II evaluation of environmental impact Environmental
Technology Letters 1 506ndash517 doi10108009593338009384007
Sanchez S J Alvarez L T Pacheco A J Gonzalez H R and Carrillo
B L (2015) Caracterizacion hidrogeoquımica de las aguas subterraneas
del sur del Estado de Quintana Roo Mexico Revista Mexicana de
Ciencias Geologicas 32(1) 62ndash76
Schmitter-Soto J J Comın F A Escobar B E Herrera S J Alcocer J
Suarez M E Elıas G M Dıaz A V Marın L E and Steinich B
(2002) Hydrogeochemical and biological characteristics of cenotes in
the Yucatan Peninsula (SE Mexico) Hydrobiologia 467 215ndash228
doi101023A1014923217206
Siqueiros-Beltrones D Hernandez A U and Hernandez A O (2013)
Diagnosis prospectiva sobre la diversidad de diatomeas epilıticas en la
laguna Bacalar Quintana Roo Mexico Revista Mexicana de Biodiver-
sidad 84 865ndash875 doi107550RMB33960
Turekian K K andWedepohl K H (1961) Distribution of the elements in
some major units of the Earthrsquos crust Bulletin of the Geological Society
of America 72 175ndash192 doi1011300016-7606(1961)72[175
DOTEIS]20CO2
Handling Editor Russell Frew
wwwpublishcsiroaujournalsmfr
Hydrochemistry of Bacalar Lagoon Marine and Freshwater Research M
Table4
Index
ofgeoacummulation(Igeo)anthropogenic(A
)inputcontaminationfactor(C
F)andcontaminationdegree(C
D)forBaUKMnNiandZnin
thesedim
entary
record
ofthe
BacalarLagoon
NAdatanoavailablePLIpollutionload
indexBAC1Bacalar
1BAC2Bacalar
2BAC3Bacalar
3COCCocalitosRAPLosRapidos
Site
Depth
(cm)
Ba
UK
Mn
Ni
Zn
PLI
I geo
Ainput
CF
CD
I geo
Ainput
CF
CD
I geo
Ainput
CF
CD
I geo
Ainput
CF
CD
I geo
Ainput
CF
CD
I geo
Ainput
CF
CD
COC
0ndash6
016
1236
134
701
503
013
005
065
688
24629
001
003
1119
11361
0001
0002
371
021
011
053
203
529
037
479
005
6ndash12
015
1314
135
469
005
006
675
5569
001
1160
3753
0000
409
107
009
004
2846
146
006
12ndash17
004
1421
146
336
024
015
NA
10001
000
1147
4016
0001
405
107
009
037
2254
116
000
17ndash22
014
1627
165
304
035
018
1158
6288
000
1257
2588
0000
362
196
012
010
3174
161
004
22ndash27
031
1156
121
282
035
021
NA
14125
000
1338
5739
0000
367
132
012
301
267
019
000
RAP
0ndash6
039
1074
115
264
538
008
004
009
889
18818
000
002
1067
7912
0001
0001
508
057
004
014
156
870
051
284
004
6ndash11
001
1360
149
475
017
006
651
31721
002
1189
14691
0000
391
069
010
063
4390
233
007
BAC1
0ndash5
024
267
127
956
402
201
009
069
230
189364
031
161
896
110398
0003
0023
300
1639
019
115
174
1118
045
822
014
5ndash10
035
302
118
416
174
008
276
176636
022
907
96021
0003
311
1404
017
066
2982
237
017
10ndash15
048
382
108
437
137
007
307
139830
018
913
76341
0003
327
1083
016
119
074
066
013
15ndash20
031
444
121
423
150
008
295
153179
019
896
83486
0003
330
1220
015
013
1225
137
015
20ndash25
031
488
121
420
142
008
301
145741
019
883
79449
0003
351
1189
013
424
1293
008
009
25ndash30
039
504
114
408
121
009
320
128917
016
925
70152
0002
363
1037
012
061
689
098
013
30ndash35
016
581
134
385
145
010
299
154625
019
904
83454
0003
353
1264
013
069
337
093
014
35ndash40
041
467
113
419
127
008
313
131772
017
917
72183
0003
392
1120
010
012
1446
138
013
BAC2
0ndash6
035
1141
117
734
515
002
004
086
743
6689
001
006
1094
3596
0001
0006
374
157
011
444
051
4203
214
1805
007
6ndash11
052
1005
105
462
004
006
834
10694
000
949
4638
0002
119
6764
343
012
2666
138
012
11ndash16
055
984
103
442
006
007
750
9268
001
1126
4617
0001
420
078
008
144
1018
055
005
16ndash21
055
985
102
400
013
009
597
3426
002
1119
3962
0001
421
089
008
001
2953
151
008
21ndash26
043
1093
111
296
038
019
828
3839
000
1178
2046
0000
412
135
009
293
22785
1141
009
26ndash31
068
925
094
254
054
026
832
2578
000
1194
1524
0000
273
424
023
104
1434
073
006
36ndash41
056
1001
102
337
028
014
875
3556
000
1113
1759
0001
182
819
043
219
626
033
006
BAC3
0ndash6
016
1283
134
407
607
009
002
007
682
12943
001
002
1266
6706
0000
0001
553
057
003
008
211
572
035
152
003
6ndash12
020
1270
131
607
003
002
989
9545
000
1308
4043
0000
580
020
003
081
1639
086
002
12ndash18
008
1389
142
613
003
002
891
8695
000
1341
3872
0000
593
021
002
223
567
032
002
J Marine and Freshwater Research N I Tobon ndashVelazquez et al
in Quintana Roo state (Instituto Nacional de Estadıstica yGeografıa 2016) Owing to the karstic nature of the area these
products can immediately infiltrate the aquifer and thereforecould be affecting the lagoon Because the concentration of ZnSminerals was low in the cores it is suggested that the source of
Zn2thorn could be derived from human activities Although theresults from the pollution load index (PLI) (1) for all samplesindicate that the sites are not highly polluted the excess Zn2thorn in
the sediment suggests some local pollution with regard to thiselement Conversely the concentrations of Ba2thorn can beexplained by the variable occurrence of barite in the cores
Minimal trace metal pollution is consistent with previous
metal work in the lagoon Castro-Contreras et al (2014)reported heavy metal concentrations in Bacalar Lagoon waterbelow the maximum limits of the Mexican legislation (NOM-
127-SSA1-1994) and ecological water quality criteria (CE-CCA-00189) that establish the limits of heavy metals fordrinking water irrigation and recreational activities
Nevertheless organochloride compounds (pesticides andpolychlorinated biphenyls) and hydrocarbons in sediments havebeen identified by Norena-Barroso et al (1998) in the ChetumalBay area near Bacalar Lagoon Organochlorine pesticides
(OCPs) are used in agriculture in the region (Alvarez-Legorreta2009) Furthermore heavymetals and OCPs have been detectedin crocodilian eggs near Chichorro Atoll (Charruau et al 2013
Buenfil-Rojas et al 2015)
Conclusions
Bacalar Lagoon is a shallow and oligotrophic system (low-
nutrient waters) with a mineralogical composition dominatedby calcite dolomite and evaporites dissolution Water geo-chemical analyses show a clear spatial distribution of different
parameters The western part of the study area is characterisedby high alkalinity and calcium and sulfate concentrations theratios of these constituents indicate groundwater sources and noseawater intrusion The decreases in these parameters towards
the north indicate a gradient in groundwater influencethroughout the lagoon The eastern part of the study area ischaracterised by a shallower water column resulting in high
evaporation and high electrical conductivity compared with thewestern side
We present the first measurements of trace elements in
carbonate sediments in Bacalar Lagoon The sediment exhibitsonly moderate contamination with Zn2thorn on the western side ofthe lagoon The high Ba concentration in the sediment corre-
sponds to barite but further work is necessary to identify thesource of Ba2thorn and Zn2thorn This study can be useful for Bacalarmunicipality to make decisions and define actions regarding themanagement and development of Bacalar Lagoon
Conflicts of interest
The authors declare that they have no conflicts of interest
Declaration of funding
This investigation was financed by the lsquoWater Security Project inthe South-eastMexico in the face of twoclimate change scenariosrsquoproject (CONACYT 247565) and lsquoProject networks CONACYTrsquo
(282240) The authors acknowledge a grant from CONACYT
towards a Masters of Water Sciences degree (awarded to NidiaTobon Velazquez)
Acknowledgements
The authors thank technical staff Daniela Ortega (Water Sciences Unit
Centro de Investigacion Cientıfica de Yucatan) and Kimberly Bitterwolf
(University of CaliforniamdashSanta Cruz)
References
Adriano D C (1986) lsquoTrace Elements in the Terrestrial Environmentrsquo
(Springer-Verlag Berlin Germany)
Alvarez-Legorreta T (2009) Contaminacion acuatica In lsquoEl sistema ecolo-
gico de la Bahıa de Chetumal Corozal costa occidental del Mar Caribersquo
(Eds J Espinoza Avalos G A Islebe and H A Hernandez Arana)
pp 205ndash217 (El Colegio de la Frontera Sur Chetumal Mexico)
Appelo C A and Postma D (2005) lsquoGeochemistry Groundwater and
Pollutionrsquo 2nd edn (A A Balkema Rotterdam Netherlands)
Baize D (1997) lsquoTeneurs totales en elements trace metalliques dans les sols
(France) References et strategies drsquointerpretationrsquo (INRA Paris France)
Bauer-Gottwein P Gondwe B Charvet G Marin L Rebolledo V M
andMerediz A G (2011) Review the Yucatan Peninsula karst aquifer
Mexico Hydrogeology Journal 19 507ndash524 doi101007S10040-010-
0699-5
Beddows P A (2002) lsquoWhere Does the Sewage Go The Karst
Groundwater System of the Municipalidad de Solidaridad Quintana
Roo Mexicorsquo (Association for Mexican Cave Studies Houston
TX USA)
Beltran D Y (2010) Estimacion de los patrones de fijacion de nitrogeno y
diversidad asociada (nifH) en tapices microbianos y estromatolitos
MSc Thesis Universidad Nacional Autonoma de Mexico Ciudad de
Mexico Mexico
Boes X Rydberg J Martinez C A Bindler R and Renberg I (2011)
Evaluation of conservative lithogenic elements (Ti Zr Al and Rb) to
study anthropogenic element enrichments in lake sediments Journal of
Paleolimnology 46 75ndash87 doi101007S10933-011-9515-Z
Boyle J F (2001) Inorganic geochemical methods in paleolimnology In
lsquoTracking Environmental Change Using Lake Sediments Vol 2 Physi-
cal andGeochemicalMethodsrsquo (EdsMW Last and P J Smol) pp 83ndash
143 (Kluwer Academic Publishers Dordrecht Netherlands)
Buenfil-Rojas A M Alvarez- Legorreta T and Cedeno-Vazquez J R
(2015) Metals and metallothioneins in Moreletrsquos Crocodile (Crocodile
moreletii) from a Transboundary River between Mexico and Belize
Archives of Environmental Contamination and Toxicology 68(2) 265ndash
273 doi101007S00244-014-0088-5
Castro-Contreras C Murray K G Pecoits E Aubet N R Petrash D
Castro C S Gregory D Planavsky N and Konhauser K O (2014)
Textural and geochemical features of freshwater microbialites from
LagunaBacalarQuintanaRooMexicoPalaios 29(5) 192ndash209 doi10
2110PALO2013063
Ceballos Martınez R R (2002) Geografıa y medio ambiente en el sistema
lagunar San FelipendashBacalarndashGuerrero In lsquoContribuciones de la ciencia al
manejo costero integrado de laBahıa deChetumal y su area de influenciarsquo
(Eds F J Rosado-May RRomeroMayo andADe Jesus Navarrete) pp
17ndash22 (Universidad de Quintana Roo Chetumal Mexico)
Centeno M C Legendre P Beltran Y Alcantara H R Lidstrom E U
Ashby N M and Falcon I L (2012) Microbialite genetic diversity
and composition relate to environmental variables FEMSMicrobiology
Ecology 82 724ndash735 doi101111J1574-6941201201447X
Chagas A P Webb E G Burne V R and Southam G (2016) Modern
lacustrine microbialites towards a synthesis of aqueous and carbonate
geochemistry and mineralogy Earth-Science Reviews 162 338ndash363
doi101016JEARSCIREV201609012
Charruau P Henaut Y and Alvarez-Legorreta T (2013) Organo-
chlorine pesticides in nest substratum and infertile eggs of American
Hydrochemistry of Bacalar Lagoon Marine and Freshwater Research K
crocodiles (Reptilia Crocodylidae) in a Mexican Caribbean atoll
Caribbean Journal of Science 47 1ndash12 doi1018475CJOSV47I1A2
Comision Nacional del Agua (2002) lsquoDeterminacion de la disponibilidad de
agua en el acuıfero Penınsula de Yucatan estado de Yucatanrsquo (CON-
AGUA Gerencia de Aguas Subterraneas Ciudad de Mexico Mexico)
Comision Nacional del Agua (2012) lsquoPrograma Hıdrico Regional Vision
2030 Region Hidrologico-Administrativa XII Penınsula de Yucatanrsquo
1st edn (Secretarıa de Medio Ambiente y Recursos Naturales Mexico
City Mexico)
Comision Nacional del Agua (2015) lsquoActualizacion de la disponibilidad
media anual de agua en el acuıfero Cerros y Valles (2301) Estado de
QuintanaRoorsquo (CONAGUADiarioOficial de la Federacion Ciudad de
Mexico Mexico)
Dautovic J Fiket Z Baresic J Ahel M and Mikac N (2014) Sources
distribution and behavior of major and trace elements in a complex karst
lake system Aquatic Geochemistry 20 19ndash38 doi101007S10498-
013-9204-9
Dıaz J E (2005) lsquoDecreto por el cual se establece el programa de
ordenamiento ecologico territorial de la region de Laguna Bacalar
Quintana Roo Mexicorsquo (Periodico Oficial Chetumal Mexico)
Dixon J Hamilton K Pagiola S and Segnestam L (2001) Tourism and
environment in the Caribbean an economic framework (The World
Bank Washington DC USA) Available at httpdocumentsworldbank
orgcurateden672281468770397455pdfmulti0pagepdf [Verified 18
October 2018]
Drever J I (2005) lsquoSurface and Ground Water Weathering and Soilsrsquo
(Elsevier Oxford UK)
Drucker A Escalante R Gomez V and Magana S (2003) La industria
porcina en Yucatan un analisis de la generacion de aguas residuales
Problemas del Desarrollo Revista Latinoamericana de Economıa 34
(135) 105ndash120
Dupraz C Reid R P andVisscher P T (2011)MicrobialitesModern In
lsquoEncyclopedia of Geobiology Encyclopedia of Earth Science Seriesrsquo
(Eds J Reitner and V Thiel) pp 617ndash635 (Springer Heidelberg
Germany)
Elango L andKannan R (2007) Rockndashwater interaction and its control on
chemical composition of groundwater In lsquoDevelopments in Environ-
mental Sciencersquo Vol 5 (Eds D Sarkar R Datta and R Hannigan) pp
229ndash243 (Elsevier Oxford UK)
Euan-Avila J I Liceaga-CorreaM A and Rodrıguez Sanchez H (2002)
Caracterizacion de fuentes no puntuales de contaminacion agrıcola en el
municipio deOthon P Blanco enQuintanaRoo y su potencial influencia
en la Bahıa de Chetumal In lsquoContribuciones de la ciencia al manejo
costero integrado de la Bahıa de Chetumal y su area de influenciarsquo (Eds
F J Rosado-May R Romero Mayo and A De Jesus Navarrete) pp
197ndash204 (Universidad de Quintana Roo Chetumal Mexico)
Fouke W B Zerkle L A Alvarez W Pope O K Ocampos A C
Wachtman J R Grajales J M Claeys P and Fischer G A (2002)
Cathodoluminescence petrography and isotope geochemistry of KT
impact ejecta deposited 360 km from the Chicxulub crater at Albion
Island Belize Sedimentology 49 117ndash138 doi101046J1365-3091
200200435X
Garcıa-Rıos V Y and Gold-Bouchot G (2002) Especiacion de metales
pesados en sedimentos de la Bahıa de Chetumal Quintana Roo y la
acumulacion en el tejido muscular de bagres (Ariopsis assimilis) In
lsquoContribuciones de la ciencia al manejo costero integrado de la Bahıa de
Chetumal y su area de influenciarsquo (Eds F J Rosado-May R Romero
Mayo and A De Jesus Navarrete) pp 143ndash148 (Universidad de
Quintana Roo Chetumal Mexico)
Gischler E Gibson M A and Oschmann W (2008) Giant Holocene
freshwater microbialites Laguna de Bacalar Quintana Roo Mexico
Sedimentology 55 1293ndash1309 doi101111J1365-3091200700946X
Gischler E Golubic S Gibson M Oschamann W and Hudson J H
(2011) Microbial mats and microbialites in the freshwater Laguna
Bacalar Yucatan Peninsula Mexico In lsquoAdvances in Stromatolite
Geobiologyrsquo (Eds J Reitner M H Trauth K Stuwe and D Yuen)
pp 187ndash205 (Springer Berlin Germany)
Gonzalez B J L Carrion J J Cuevas D J Flores M F Yam G J O
Moreno C J Perez V J and Calva C G (2014) Acumulacion de Hg
Pb Cd y Zn por Pomacea flagellata en tres balnearios ubicados en la
region urbana de la Laguna de Bacalar TecnoCultura 35 14ndash23
Hemley R J Prewitt C T and Kingma K (1994) High-pressure
behavior of silica In lsquoSilica ndash Physical Behavior Geochemistry and
Materials Applications Reviews in Mineralogy Vol 29rsquo (Eds P J
Heaney C T Prewitt and G V Gibbs) pp 41ndash82 (Mineralogical
Society of America Washington DC USA)
Hernandez L Probst A Probst L J and Ulrich E (2003) Heavy metal
distribution in some French forest soils evidence for atmospheric
contamination The Science of the Total Environment 312(1ndash3)
195ndash219 doi101016S0048-9697(03)00223-7
Hernandez-Terrones L Rebolledo-Vieyra M Merino-Ibarra M Soto
M Le-Cossec A and Monroy-Rıos E (2011) Groundwater pollution
in a karstic region (NE Yucatan) baseline nutrient content and flux to
coastal ecosystems Water Air and Soil Pollution 218(1ndash4) 517ndash528
doi101007S11270-010-0664-X
InstitutoNacional de Estadıstica yGeografıa (2002) EstudioHidrologico del
Estado de Quintana Roo (INEGI Aguascalientes Mexico) Available at
httpinternetcontenidosinegiorgmxcontenidosproductosprod_serv
contenidosespanolbvinegiproductoshistoricos2104702825224196
702825224196_1pdf [Verified 5 September 2018]
Instituto Nacional de Estadıstica y Geografıa (2016) Anuario Estadıstico y
Geografico de Quintana Roo (INEGI Aguascalientes Mexico) Avail-
able at httpinternetcontenidosinegiorgmxcontenidosProductos
prod_servcontenidosespanolbvinegiproductosnueva_estrucanuarios_
2016702825084370pdf [Verified 5 September 2018]
Javan S Hessam H A Gholamalizadeh A A and Soltani J (2015)
Fractionation of heavy metals in bottom sediments in Chahnimeh 1
Zabol Iran Environmental Monitoring and Assessment 187(6) 340
doi101007S10661-015-4510-X
Katip A Karaer F Ileri S Sarmasik S Aydogan N and Zenginay S
(2011) Analysis and assessment of trace elements pollution in sediments
of Lake Ulubat Turkey Journal of Environmental Biology 33 961ndash968
Kenkmann T and Schonian F (2006) Ries and Chicxulub impact craters
on Earth provide insights for Martian ejecta blankets Meteoritics amp
Planetary Science 41(10) 1587ndash1603 doi101111J1945-51002006
TB00437X
Khedidja A and Boudoukha A (2016) Lrsquoaquifere Superficiel de
Tadjnanet-Chelghoum laid (Nord-Est Algerien) Larhyss Journal 28
181ndash197
Lounejeva E Ostroumov M and Sanchez R G (2002) Polimorfos de
alta presion de sılice en las impactitas de ChicxulubMexico ndash resultados
de espectrometrıa de Raman Revista Mexicana de Ciencias Geologicas
17(2) 137ndash141
Manoj K and Padhy P K (2014) Distribution enrichment and ecological
risk assessment of six elements in bed sediments of a tropical river
Chottanagpur Plateau a spatial and temporal appraisal Journal of
Environmental Protection 5 1419ndash1434 doi104236JEP2014514136
Marfia A M Krishnamurthya R V Atekwanab E A and Panton W F
(2004) Isotopic and geochemical evolution of ground and surfacewaters
in a karst dominated geological setting a case study fromBelize Central
America Applied Geochemistry 19 937ndash946 doi101016JAPGEO
CHEM200310013
Massaferro J Correa M A Montes de Oca F and Mauad M (2018)
Contrasting responses of lake ecosystems to environmental disturbance
a paleoecological perspective from northern Patagonia (Argentina)
Hydrobiologia 816(1) 79ndash89 doi101007S10750-016-3081-3
Medina M S Jimenez G A Gutierrez R M and Lizardi J M (2014)
Hydrocarbon pollution studies of underwater sinkholes along Quintana
L Marine and Freshwater Research N I Tobon ndashVelazquez et al
Roo as function of tourism development in the Mexican Caribbean
Revista Mexicana de Ingenierıa Quımica 13(2) 509ndash516
Norena-Barroso E Zapata-Perez O Ceja-Moreno V and Gold-Bouchot
G (1998) Hydrocarbon and organochloride residue concentrations in
sediments from Bay of Chetumal Mexico Bulletin of Environmental
Contamination and Toxicology 61 80ndash87 doi101007S001289900732
Nriagu J and Pacyna J (1988) Quantitative assessment of worldwide
contamination of air water and soils by trace metals Nature 333 134ndash
139 doi101038333134A0
Ochoa J C Gonzalez B J and Jimenez C J (2016) Metales pesados
(Cd Cr Pb Hg) en Rhizophora mangle en rıo y bahıa de Chetumal
Revista Mexicana de Agroecosistemas 3(2) 263ndash271
Oliva R J Ocana F A de Jesus N A de Jesus C R and Vargas E A
(2016) Reproduccion dePomacea flagellata (Mollusca Ampullariidae)
en la laguna de Bacalar Quintana Roo Mexico Revista de Biologıa
Tropical 64(4) 1643ndash1650
Pacton M Hunger G Martinuzzi V Cusminsky G Burdin B
Barmettler K Vasconcelos C and Ariztegui D (2015) Organomi-
neralization processes in freshwater stromatolites a living example from
eastern Patagonia International Association of Sedimentologists Jour-
nal 1(2) 130ndash146
Perez L Bugja R Lorenschat J Brenner M Curtis J Hoelzmann P
Islebe G Scharf B and SchwalbA (2011) Aquatic ecosystems of the
Yucatan Peninsula (Mexico) Belize and Guatemala Hydrobiologia
661 407ndash433 doi101007S10750-010-0552-9
Perry E C Velazquez O G and Marin L (2002) The hydrogeochem-
istry of the karst aquifer system of the northern Yucatan Peninsula
Mexico International Geology Review 44 191ndash221 doi102747
0020-6814443191
Perry E Paytan A Pedersen B and Velazquez O G (2009) Ground-
water geochemistry of the Yucatan Peninsula Mexico constraints on
stratigraphy and hydrogeology Journal of Hydrology 367 27ndash40
doi101016JJHYDROL200812026
Pradit S Wattayarkorn G Angsupanich S Baeyens W and Leer-
makers M (2010) Distribution of trace elements in sediments and biota
of Songkhla Lake Southern Thailand Water Air and Soil Pollution
206 155ndash174 doi101007S11270-009-0093-X
Salomons W and Forstner U (1980) Trace metal analysis on polluted
sediments II evaluation of environmental impact Environmental
Technology Letters 1 506ndash517 doi10108009593338009384007
Sanchez S J Alvarez L T Pacheco A J Gonzalez H R and Carrillo
B L (2015) Caracterizacion hidrogeoquımica de las aguas subterraneas
del sur del Estado de Quintana Roo Mexico Revista Mexicana de
Ciencias Geologicas 32(1) 62ndash76
Schmitter-Soto J J Comın F A Escobar B E Herrera S J Alcocer J
Suarez M E Elıas G M Dıaz A V Marın L E and Steinich B
(2002) Hydrogeochemical and biological characteristics of cenotes in
the Yucatan Peninsula (SE Mexico) Hydrobiologia 467 215ndash228
doi101023A1014923217206
Siqueiros-Beltrones D Hernandez A U and Hernandez A O (2013)
Diagnosis prospectiva sobre la diversidad de diatomeas epilıticas en la
laguna Bacalar Quintana Roo Mexico Revista Mexicana de Biodiver-
sidad 84 865ndash875 doi107550RMB33960
Turekian K K andWedepohl K H (1961) Distribution of the elements in
some major units of the Earthrsquos crust Bulletin of the Geological Society
of America 72 175ndash192 doi1011300016-7606(1961)72[175
DOTEIS]20CO2
Handling Editor Russell Frew
wwwpublishcsiroaujournalsmfr
Hydrochemistry of Bacalar Lagoon Marine and Freshwater Research M
in Quintana Roo state (Instituto Nacional de Estadıstica yGeografıa 2016) Owing to the karstic nature of the area these
products can immediately infiltrate the aquifer and thereforecould be affecting the lagoon Because the concentration of ZnSminerals was low in the cores it is suggested that the source of
Zn2thorn could be derived from human activities Although theresults from the pollution load index (PLI) (1) for all samplesindicate that the sites are not highly polluted the excess Zn2thorn in
the sediment suggests some local pollution with regard to thiselement Conversely the concentrations of Ba2thorn can beexplained by the variable occurrence of barite in the cores
Minimal trace metal pollution is consistent with previous
metal work in the lagoon Castro-Contreras et al (2014)reported heavy metal concentrations in Bacalar Lagoon waterbelow the maximum limits of the Mexican legislation (NOM-
127-SSA1-1994) and ecological water quality criteria (CE-CCA-00189) that establish the limits of heavy metals fordrinking water irrigation and recreational activities
Nevertheless organochloride compounds (pesticides andpolychlorinated biphenyls) and hydrocarbons in sediments havebeen identified by Norena-Barroso et al (1998) in the ChetumalBay area near Bacalar Lagoon Organochlorine pesticides
(OCPs) are used in agriculture in the region (Alvarez-Legorreta2009) Furthermore heavymetals and OCPs have been detectedin crocodilian eggs near Chichorro Atoll (Charruau et al 2013
Buenfil-Rojas et al 2015)
Conclusions
Bacalar Lagoon is a shallow and oligotrophic system (low-
nutrient waters) with a mineralogical composition dominatedby calcite dolomite and evaporites dissolution Water geo-chemical analyses show a clear spatial distribution of different
parameters The western part of the study area is characterisedby high alkalinity and calcium and sulfate concentrations theratios of these constituents indicate groundwater sources and noseawater intrusion The decreases in these parameters towards
the north indicate a gradient in groundwater influencethroughout the lagoon The eastern part of the study area ischaracterised by a shallower water column resulting in high
evaporation and high electrical conductivity compared with thewestern side
We present the first measurements of trace elements in
carbonate sediments in Bacalar Lagoon The sediment exhibitsonly moderate contamination with Zn2thorn on the western side ofthe lagoon The high Ba concentration in the sediment corre-
sponds to barite but further work is necessary to identify thesource of Ba2thorn and Zn2thorn This study can be useful for Bacalarmunicipality to make decisions and define actions regarding themanagement and development of Bacalar Lagoon
Conflicts of interest
The authors declare that they have no conflicts of interest
Declaration of funding
This investigation was financed by the lsquoWater Security Project inthe South-eastMexico in the face of twoclimate change scenariosrsquoproject (CONACYT 247565) and lsquoProject networks CONACYTrsquo
(282240) The authors acknowledge a grant from CONACYT
towards a Masters of Water Sciences degree (awarded to NidiaTobon Velazquez)
Acknowledgements
The authors thank technical staff Daniela Ortega (Water Sciences Unit
Centro de Investigacion Cientıfica de Yucatan) and Kimberly Bitterwolf
(University of CaliforniamdashSanta Cruz)
References
Adriano D C (1986) lsquoTrace Elements in the Terrestrial Environmentrsquo
(Springer-Verlag Berlin Germany)
Alvarez-Legorreta T (2009) Contaminacion acuatica In lsquoEl sistema ecolo-
gico de la Bahıa de Chetumal Corozal costa occidental del Mar Caribersquo
(Eds J Espinoza Avalos G A Islebe and H A Hernandez Arana)
pp 205ndash217 (El Colegio de la Frontera Sur Chetumal Mexico)
Appelo C A and Postma D (2005) lsquoGeochemistry Groundwater and
Pollutionrsquo 2nd edn (A A Balkema Rotterdam Netherlands)
Baize D (1997) lsquoTeneurs totales en elements trace metalliques dans les sols
(France) References et strategies drsquointerpretationrsquo (INRA Paris France)
Bauer-Gottwein P Gondwe B Charvet G Marin L Rebolledo V M
andMerediz A G (2011) Review the Yucatan Peninsula karst aquifer
Mexico Hydrogeology Journal 19 507ndash524 doi101007S10040-010-
0699-5
Beddows P A (2002) lsquoWhere Does the Sewage Go The Karst
Groundwater System of the Municipalidad de Solidaridad Quintana
Roo Mexicorsquo (Association for Mexican Cave Studies Houston
TX USA)
Beltran D Y (2010) Estimacion de los patrones de fijacion de nitrogeno y
diversidad asociada (nifH) en tapices microbianos y estromatolitos
MSc Thesis Universidad Nacional Autonoma de Mexico Ciudad de
Mexico Mexico
Boes X Rydberg J Martinez C A Bindler R and Renberg I (2011)
Evaluation of conservative lithogenic elements (Ti Zr Al and Rb) to
study anthropogenic element enrichments in lake sediments Journal of
Paleolimnology 46 75ndash87 doi101007S10933-011-9515-Z
Boyle J F (2001) Inorganic geochemical methods in paleolimnology In
lsquoTracking Environmental Change Using Lake Sediments Vol 2 Physi-
cal andGeochemicalMethodsrsquo (EdsMW Last and P J Smol) pp 83ndash
143 (Kluwer Academic Publishers Dordrecht Netherlands)
Buenfil-Rojas A M Alvarez- Legorreta T and Cedeno-Vazquez J R
(2015) Metals and metallothioneins in Moreletrsquos Crocodile (Crocodile
moreletii) from a Transboundary River between Mexico and Belize
Archives of Environmental Contamination and Toxicology 68(2) 265ndash
273 doi101007S00244-014-0088-5
Castro-Contreras C Murray K G Pecoits E Aubet N R Petrash D
Castro C S Gregory D Planavsky N and Konhauser K O (2014)
Textural and geochemical features of freshwater microbialites from
LagunaBacalarQuintanaRooMexicoPalaios 29(5) 192ndash209 doi10
2110PALO2013063
Ceballos Martınez R R (2002) Geografıa y medio ambiente en el sistema
lagunar San FelipendashBacalarndashGuerrero In lsquoContribuciones de la ciencia al
manejo costero integrado de laBahıa deChetumal y su area de influenciarsquo
(Eds F J Rosado-May RRomeroMayo andADe Jesus Navarrete) pp
17ndash22 (Universidad de Quintana Roo Chetumal Mexico)
Centeno M C Legendre P Beltran Y Alcantara H R Lidstrom E U
Ashby N M and Falcon I L (2012) Microbialite genetic diversity
and composition relate to environmental variables FEMSMicrobiology
Ecology 82 724ndash735 doi101111J1574-6941201201447X
Chagas A P Webb E G Burne V R and Southam G (2016) Modern
lacustrine microbialites towards a synthesis of aqueous and carbonate
geochemistry and mineralogy Earth-Science Reviews 162 338ndash363
doi101016JEARSCIREV201609012
Charruau P Henaut Y and Alvarez-Legorreta T (2013) Organo-
chlorine pesticides in nest substratum and infertile eggs of American
Hydrochemistry of Bacalar Lagoon Marine and Freshwater Research K
crocodiles (Reptilia Crocodylidae) in a Mexican Caribbean atoll
Caribbean Journal of Science 47 1ndash12 doi1018475CJOSV47I1A2
Comision Nacional del Agua (2002) lsquoDeterminacion de la disponibilidad de
agua en el acuıfero Penınsula de Yucatan estado de Yucatanrsquo (CON-
AGUA Gerencia de Aguas Subterraneas Ciudad de Mexico Mexico)
Comision Nacional del Agua (2012) lsquoPrograma Hıdrico Regional Vision
2030 Region Hidrologico-Administrativa XII Penınsula de Yucatanrsquo
1st edn (Secretarıa de Medio Ambiente y Recursos Naturales Mexico
City Mexico)
Comision Nacional del Agua (2015) lsquoActualizacion de la disponibilidad
media anual de agua en el acuıfero Cerros y Valles (2301) Estado de
QuintanaRoorsquo (CONAGUADiarioOficial de la Federacion Ciudad de
Mexico Mexico)
Dautovic J Fiket Z Baresic J Ahel M and Mikac N (2014) Sources
distribution and behavior of major and trace elements in a complex karst
lake system Aquatic Geochemistry 20 19ndash38 doi101007S10498-
013-9204-9
Dıaz J E (2005) lsquoDecreto por el cual se establece el programa de
ordenamiento ecologico territorial de la region de Laguna Bacalar
Quintana Roo Mexicorsquo (Periodico Oficial Chetumal Mexico)
Dixon J Hamilton K Pagiola S and Segnestam L (2001) Tourism and
environment in the Caribbean an economic framework (The World
Bank Washington DC USA) Available at httpdocumentsworldbank
orgcurateden672281468770397455pdfmulti0pagepdf [Verified 18
October 2018]
Drever J I (2005) lsquoSurface and Ground Water Weathering and Soilsrsquo
(Elsevier Oxford UK)
Drucker A Escalante R Gomez V and Magana S (2003) La industria
porcina en Yucatan un analisis de la generacion de aguas residuales
Problemas del Desarrollo Revista Latinoamericana de Economıa 34
(135) 105ndash120
Dupraz C Reid R P andVisscher P T (2011)MicrobialitesModern In
lsquoEncyclopedia of Geobiology Encyclopedia of Earth Science Seriesrsquo
(Eds J Reitner and V Thiel) pp 617ndash635 (Springer Heidelberg
Germany)
Elango L andKannan R (2007) Rockndashwater interaction and its control on
chemical composition of groundwater In lsquoDevelopments in Environ-
mental Sciencersquo Vol 5 (Eds D Sarkar R Datta and R Hannigan) pp
229ndash243 (Elsevier Oxford UK)
Euan-Avila J I Liceaga-CorreaM A and Rodrıguez Sanchez H (2002)
Caracterizacion de fuentes no puntuales de contaminacion agrıcola en el
municipio deOthon P Blanco enQuintanaRoo y su potencial influencia
en la Bahıa de Chetumal In lsquoContribuciones de la ciencia al manejo
costero integrado de la Bahıa de Chetumal y su area de influenciarsquo (Eds
F J Rosado-May R Romero Mayo and A De Jesus Navarrete) pp
197ndash204 (Universidad de Quintana Roo Chetumal Mexico)
Fouke W B Zerkle L A Alvarez W Pope O K Ocampos A C
Wachtman J R Grajales J M Claeys P and Fischer G A (2002)
Cathodoluminescence petrography and isotope geochemistry of KT
impact ejecta deposited 360 km from the Chicxulub crater at Albion
Island Belize Sedimentology 49 117ndash138 doi101046J1365-3091
200200435X
Garcıa-Rıos V Y and Gold-Bouchot G (2002) Especiacion de metales
pesados en sedimentos de la Bahıa de Chetumal Quintana Roo y la
acumulacion en el tejido muscular de bagres (Ariopsis assimilis) In
lsquoContribuciones de la ciencia al manejo costero integrado de la Bahıa de
Chetumal y su area de influenciarsquo (Eds F J Rosado-May R Romero
Mayo and A De Jesus Navarrete) pp 143ndash148 (Universidad de
Quintana Roo Chetumal Mexico)
Gischler E Gibson M A and Oschmann W (2008) Giant Holocene
freshwater microbialites Laguna de Bacalar Quintana Roo Mexico
Sedimentology 55 1293ndash1309 doi101111J1365-3091200700946X
Gischler E Golubic S Gibson M Oschamann W and Hudson J H
(2011) Microbial mats and microbialites in the freshwater Laguna
Bacalar Yucatan Peninsula Mexico In lsquoAdvances in Stromatolite
Geobiologyrsquo (Eds J Reitner M H Trauth K Stuwe and D Yuen)
pp 187ndash205 (Springer Berlin Germany)
Gonzalez B J L Carrion J J Cuevas D J Flores M F Yam G J O
Moreno C J Perez V J and Calva C G (2014) Acumulacion de Hg
Pb Cd y Zn por Pomacea flagellata en tres balnearios ubicados en la
region urbana de la Laguna de Bacalar TecnoCultura 35 14ndash23
Hemley R J Prewitt C T and Kingma K (1994) High-pressure
behavior of silica In lsquoSilica ndash Physical Behavior Geochemistry and
Materials Applications Reviews in Mineralogy Vol 29rsquo (Eds P J
Heaney C T Prewitt and G V Gibbs) pp 41ndash82 (Mineralogical
Society of America Washington DC USA)
Hernandez L Probst A Probst L J and Ulrich E (2003) Heavy metal
distribution in some French forest soils evidence for atmospheric
contamination The Science of the Total Environment 312(1ndash3)
195ndash219 doi101016S0048-9697(03)00223-7
Hernandez-Terrones L Rebolledo-Vieyra M Merino-Ibarra M Soto
M Le-Cossec A and Monroy-Rıos E (2011) Groundwater pollution
in a karstic region (NE Yucatan) baseline nutrient content and flux to
coastal ecosystems Water Air and Soil Pollution 218(1ndash4) 517ndash528
doi101007S11270-010-0664-X
InstitutoNacional de Estadıstica yGeografıa (2002) EstudioHidrologico del
Estado de Quintana Roo (INEGI Aguascalientes Mexico) Available at
httpinternetcontenidosinegiorgmxcontenidosproductosprod_serv
contenidosespanolbvinegiproductoshistoricos2104702825224196
702825224196_1pdf [Verified 5 September 2018]
Instituto Nacional de Estadıstica y Geografıa (2016) Anuario Estadıstico y
Geografico de Quintana Roo (INEGI Aguascalientes Mexico) Avail-
able at httpinternetcontenidosinegiorgmxcontenidosProductos
prod_servcontenidosespanolbvinegiproductosnueva_estrucanuarios_
2016702825084370pdf [Verified 5 September 2018]
Javan S Hessam H A Gholamalizadeh A A and Soltani J (2015)
Fractionation of heavy metals in bottom sediments in Chahnimeh 1
Zabol Iran Environmental Monitoring and Assessment 187(6) 340
doi101007S10661-015-4510-X
Katip A Karaer F Ileri S Sarmasik S Aydogan N and Zenginay S
(2011) Analysis and assessment of trace elements pollution in sediments
of Lake Ulubat Turkey Journal of Environmental Biology 33 961ndash968
Kenkmann T and Schonian F (2006) Ries and Chicxulub impact craters
on Earth provide insights for Martian ejecta blankets Meteoritics amp
Planetary Science 41(10) 1587ndash1603 doi101111J1945-51002006
TB00437X
Khedidja A and Boudoukha A (2016) Lrsquoaquifere Superficiel de
Tadjnanet-Chelghoum laid (Nord-Est Algerien) Larhyss Journal 28
181ndash197
Lounejeva E Ostroumov M and Sanchez R G (2002) Polimorfos de
alta presion de sılice en las impactitas de ChicxulubMexico ndash resultados
de espectrometrıa de Raman Revista Mexicana de Ciencias Geologicas
17(2) 137ndash141
Manoj K and Padhy P K (2014) Distribution enrichment and ecological
risk assessment of six elements in bed sediments of a tropical river
Chottanagpur Plateau a spatial and temporal appraisal Journal of
Environmental Protection 5 1419ndash1434 doi104236JEP2014514136
Marfia A M Krishnamurthya R V Atekwanab E A and Panton W F
(2004) Isotopic and geochemical evolution of ground and surfacewaters
in a karst dominated geological setting a case study fromBelize Central
America Applied Geochemistry 19 937ndash946 doi101016JAPGEO
CHEM200310013
Massaferro J Correa M A Montes de Oca F and Mauad M (2018)
Contrasting responses of lake ecosystems to environmental disturbance
a paleoecological perspective from northern Patagonia (Argentina)
Hydrobiologia 816(1) 79ndash89 doi101007S10750-016-3081-3
Medina M S Jimenez G A Gutierrez R M and Lizardi J M (2014)
Hydrocarbon pollution studies of underwater sinkholes along Quintana
L Marine and Freshwater Research N I Tobon ndashVelazquez et al
Roo as function of tourism development in the Mexican Caribbean
Revista Mexicana de Ingenierıa Quımica 13(2) 509ndash516
Norena-Barroso E Zapata-Perez O Ceja-Moreno V and Gold-Bouchot
G (1998) Hydrocarbon and organochloride residue concentrations in
sediments from Bay of Chetumal Mexico Bulletin of Environmental
Contamination and Toxicology 61 80ndash87 doi101007S001289900732
Nriagu J and Pacyna J (1988) Quantitative assessment of worldwide
contamination of air water and soils by trace metals Nature 333 134ndash
139 doi101038333134A0
Ochoa J C Gonzalez B J and Jimenez C J (2016) Metales pesados
(Cd Cr Pb Hg) en Rhizophora mangle en rıo y bahıa de Chetumal
Revista Mexicana de Agroecosistemas 3(2) 263ndash271
Oliva R J Ocana F A de Jesus N A de Jesus C R and Vargas E A
(2016) Reproduccion dePomacea flagellata (Mollusca Ampullariidae)
en la laguna de Bacalar Quintana Roo Mexico Revista de Biologıa
Tropical 64(4) 1643ndash1650
Pacton M Hunger G Martinuzzi V Cusminsky G Burdin B
Barmettler K Vasconcelos C and Ariztegui D (2015) Organomi-
neralization processes in freshwater stromatolites a living example from
eastern Patagonia International Association of Sedimentologists Jour-
nal 1(2) 130ndash146
Perez L Bugja R Lorenschat J Brenner M Curtis J Hoelzmann P
Islebe G Scharf B and SchwalbA (2011) Aquatic ecosystems of the
Yucatan Peninsula (Mexico) Belize and Guatemala Hydrobiologia
661 407ndash433 doi101007S10750-010-0552-9
Perry E C Velazquez O G and Marin L (2002) The hydrogeochem-
istry of the karst aquifer system of the northern Yucatan Peninsula
Mexico International Geology Review 44 191ndash221 doi102747
0020-6814443191
Perry E Paytan A Pedersen B and Velazquez O G (2009) Ground-
water geochemistry of the Yucatan Peninsula Mexico constraints on
stratigraphy and hydrogeology Journal of Hydrology 367 27ndash40
doi101016JJHYDROL200812026
Pradit S Wattayarkorn G Angsupanich S Baeyens W and Leer-
makers M (2010) Distribution of trace elements in sediments and biota
of Songkhla Lake Southern Thailand Water Air and Soil Pollution
206 155ndash174 doi101007S11270-009-0093-X
Salomons W and Forstner U (1980) Trace metal analysis on polluted
sediments II evaluation of environmental impact Environmental
Technology Letters 1 506ndash517 doi10108009593338009384007
Sanchez S J Alvarez L T Pacheco A J Gonzalez H R and Carrillo
B L (2015) Caracterizacion hidrogeoquımica de las aguas subterraneas
del sur del Estado de Quintana Roo Mexico Revista Mexicana de
Ciencias Geologicas 32(1) 62ndash76
Schmitter-Soto J J Comın F A Escobar B E Herrera S J Alcocer J
Suarez M E Elıas G M Dıaz A V Marın L E and Steinich B
(2002) Hydrogeochemical and biological characteristics of cenotes in
the Yucatan Peninsula (SE Mexico) Hydrobiologia 467 215ndash228
doi101023A1014923217206
Siqueiros-Beltrones D Hernandez A U and Hernandez A O (2013)
Diagnosis prospectiva sobre la diversidad de diatomeas epilıticas en la
laguna Bacalar Quintana Roo Mexico Revista Mexicana de Biodiver-
sidad 84 865ndash875 doi107550RMB33960
Turekian K K andWedepohl K H (1961) Distribution of the elements in
some major units of the Earthrsquos crust Bulletin of the Geological Society
of America 72 175ndash192 doi1011300016-7606(1961)72[175
DOTEIS]20CO2
Handling Editor Russell Frew
wwwpublishcsiroaujournalsmfr
Hydrochemistry of Bacalar Lagoon Marine and Freshwater Research M
crocodiles (Reptilia Crocodylidae) in a Mexican Caribbean atoll
Caribbean Journal of Science 47 1ndash12 doi1018475CJOSV47I1A2
Comision Nacional del Agua (2002) lsquoDeterminacion de la disponibilidad de
agua en el acuıfero Penınsula de Yucatan estado de Yucatanrsquo (CON-
AGUA Gerencia de Aguas Subterraneas Ciudad de Mexico Mexico)
Comision Nacional del Agua (2012) lsquoPrograma Hıdrico Regional Vision
2030 Region Hidrologico-Administrativa XII Penınsula de Yucatanrsquo
1st edn (Secretarıa de Medio Ambiente y Recursos Naturales Mexico
City Mexico)
Comision Nacional del Agua (2015) lsquoActualizacion de la disponibilidad
media anual de agua en el acuıfero Cerros y Valles (2301) Estado de
QuintanaRoorsquo (CONAGUADiarioOficial de la Federacion Ciudad de
Mexico Mexico)
Dautovic J Fiket Z Baresic J Ahel M and Mikac N (2014) Sources
distribution and behavior of major and trace elements in a complex karst
lake system Aquatic Geochemistry 20 19ndash38 doi101007S10498-
013-9204-9
Dıaz J E (2005) lsquoDecreto por el cual se establece el programa de
ordenamiento ecologico territorial de la region de Laguna Bacalar
Quintana Roo Mexicorsquo (Periodico Oficial Chetumal Mexico)
Dixon J Hamilton K Pagiola S and Segnestam L (2001) Tourism and
environment in the Caribbean an economic framework (The World
Bank Washington DC USA) Available at httpdocumentsworldbank
orgcurateden672281468770397455pdfmulti0pagepdf [Verified 18
October 2018]
Drever J I (2005) lsquoSurface and Ground Water Weathering and Soilsrsquo
(Elsevier Oxford UK)
Drucker A Escalante R Gomez V and Magana S (2003) La industria
porcina en Yucatan un analisis de la generacion de aguas residuales
Problemas del Desarrollo Revista Latinoamericana de Economıa 34
(135) 105ndash120
Dupraz C Reid R P andVisscher P T (2011)MicrobialitesModern In
lsquoEncyclopedia of Geobiology Encyclopedia of Earth Science Seriesrsquo
(Eds J Reitner and V Thiel) pp 617ndash635 (Springer Heidelberg
Germany)
Elango L andKannan R (2007) Rockndashwater interaction and its control on
chemical composition of groundwater In lsquoDevelopments in Environ-
mental Sciencersquo Vol 5 (Eds D Sarkar R Datta and R Hannigan) pp
229ndash243 (Elsevier Oxford UK)
Euan-Avila J I Liceaga-CorreaM A and Rodrıguez Sanchez H (2002)
Caracterizacion de fuentes no puntuales de contaminacion agrıcola en el
municipio deOthon P Blanco enQuintanaRoo y su potencial influencia
en la Bahıa de Chetumal In lsquoContribuciones de la ciencia al manejo
costero integrado de la Bahıa de Chetumal y su area de influenciarsquo (Eds
F J Rosado-May R Romero Mayo and A De Jesus Navarrete) pp
197ndash204 (Universidad de Quintana Roo Chetumal Mexico)
Fouke W B Zerkle L A Alvarez W Pope O K Ocampos A C
Wachtman J R Grajales J M Claeys P and Fischer G A (2002)
Cathodoluminescence petrography and isotope geochemistry of KT
impact ejecta deposited 360 km from the Chicxulub crater at Albion
Island Belize Sedimentology 49 117ndash138 doi101046J1365-3091
200200435X
Garcıa-Rıos V Y and Gold-Bouchot G (2002) Especiacion de metales
pesados en sedimentos de la Bahıa de Chetumal Quintana Roo y la
acumulacion en el tejido muscular de bagres (Ariopsis assimilis) In
lsquoContribuciones de la ciencia al manejo costero integrado de la Bahıa de
Chetumal y su area de influenciarsquo (Eds F J Rosado-May R Romero
Mayo and A De Jesus Navarrete) pp 143ndash148 (Universidad de
Quintana Roo Chetumal Mexico)
Gischler E Gibson M A and Oschmann W (2008) Giant Holocene
freshwater microbialites Laguna de Bacalar Quintana Roo Mexico
Sedimentology 55 1293ndash1309 doi101111J1365-3091200700946X
Gischler E Golubic S Gibson M Oschamann W and Hudson J H
(2011) Microbial mats and microbialites in the freshwater Laguna
Bacalar Yucatan Peninsula Mexico In lsquoAdvances in Stromatolite
Geobiologyrsquo (Eds J Reitner M H Trauth K Stuwe and D Yuen)
pp 187ndash205 (Springer Berlin Germany)
Gonzalez B J L Carrion J J Cuevas D J Flores M F Yam G J O
Moreno C J Perez V J and Calva C G (2014) Acumulacion de Hg
Pb Cd y Zn por Pomacea flagellata en tres balnearios ubicados en la
region urbana de la Laguna de Bacalar TecnoCultura 35 14ndash23
Hemley R J Prewitt C T and Kingma K (1994) High-pressure
behavior of silica In lsquoSilica ndash Physical Behavior Geochemistry and
Materials Applications Reviews in Mineralogy Vol 29rsquo (Eds P J
Heaney C T Prewitt and G V Gibbs) pp 41ndash82 (Mineralogical
Society of America Washington DC USA)
Hernandez L Probst A Probst L J and Ulrich E (2003) Heavy metal
distribution in some French forest soils evidence for atmospheric
contamination The Science of the Total Environment 312(1ndash3)
195ndash219 doi101016S0048-9697(03)00223-7
Hernandez-Terrones L Rebolledo-Vieyra M Merino-Ibarra M Soto
M Le-Cossec A and Monroy-Rıos E (2011) Groundwater pollution
in a karstic region (NE Yucatan) baseline nutrient content and flux to
coastal ecosystems Water Air and Soil Pollution 218(1ndash4) 517ndash528
doi101007S11270-010-0664-X
InstitutoNacional de Estadıstica yGeografıa (2002) EstudioHidrologico del
Estado de Quintana Roo (INEGI Aguascalientes Mexico) Available at
httpinternetcontenidosinegiorgmxcontenidosproductosprod_serv
contenidosespanolbvinegiproductoshistoricos2104702825224196
702825224196_1pdf [Verified 5 September 2018]
Instituto Nacional de Estadıstica y Geografıa (2016) Anuario Estadıstico y
Geografico de Quintana Roo (INEGI Aguascalientes Mexico) Avail-
able at httpinternetcontenidosinegiorgmxcontenidosProductos
prod_servcontenidosespanolbvinegiproductosnueva_estrucanuarios_
2016702825084370pdf [Verified 5 September 2018]
Javan S Hessam H A Gholamalizadeh A A and Soltani J (2015)
Fractionation of heavy metals in bottom sediments in Chahnimeh 1
Zabol Iran Environmental Monitoring and Assessment 187(6) 340
doi101007S10661-015-4510-X
Katip A Karaer F Ileri S Sarmasik S Aydogan N and Zenginay S
(2011) Analysis and assessment of trace elements pollution in sediments
of Lake Ulubat Turkey Journal of Environmental Biology 33 961ndash968
Kenkmann T and Schonian F (2006) Ries and Chicxulub impact craters
on Earth provide insights for Martian ejecta blankets Meteoritics amp
Planetary Science 41(10) 1587ndash1603 doi101111J1945-51002006
TB00437X
Khedidja A and Boudoukha A (2016) Lrsquoaquifere Superficiel de
Tadjnanet-Chelghoum laid (Nord-Est Algerien) Larhyss Journal 28
181ndash197
Lounejeva E Ostroumov M and Sanchez R G (2002) Polimorfos de
alta presion de sılice en las impactitas de ChicxulubMexico ndash resultados
de espectrometrıa de Raman Revista Mexicana de Ciencias Geologicas
17(2) 137ndash141
Manoj K and Padhy P K (2014) Distribution enrichment and ecological
risk assessment of six elements in bed sediments of a tropical river
Chottanagpur Plateau a spatial and temporal appraisal Journal of
Environmental Protection 5 1419ndash1434 doi104236JEP2014514136
Marfia A M Krishnamurthya R V Atekwanab E A and Panton W F
(2004) Isotopic and geochemical evolution of ground and surfacewaters
in a karst dominated geological setting a case study fromBelize Central
America Applied Geochemistry 19 937ndash946 doi101016JAPGEO
CHEM200310013
Massaferro J Correa M A Montes de Oca F and Mauad M (2018)
Contrasting responses of lake ecosystems to environmental disturbance
a paleoecological perspective from northern Patagonia (Argentina)
Hydrobiologia 816(1) 79ndash89 doi101007S10750-016-3081-3
Medina M S Jimenez G A Gutierrez R M and Lizardi J M (2014)
Hydrocarbon pollution studies of underwater sinkholes along Quintana
L Marine and Freshwater Research N I Tobon ndashVelazquez et al
Roo as function of tourism development in the Mexican Caribbean
Revista Mexicana de Ingenierıa Quımica 13(2) 509ndash516
Norena-Barroso E Zapata-Perez O Ceja-Moreno V and Gold-Bouchot
G (1998) Hydrocarbon and organochloride residue concentrations in
sediments from Bay of Chetumal Mexico Bulletin of Environmental
Contamination and Toxicology 61 80ndash87 doi101007S001289900732
Nriagu J and Pacyna J (1988) Quantitative assessment of worldwide
contamination of air water and soils by trace metals Nature 333 134ndash
139 doi101038333134A0
Ochoa J C Gonzalez B J and Jimenez C J (2016) Metales pesados
(Cd Cr Pb Hg) en Rhizophora mangle en rıo y bahıa de Chetumal
Revista Mexicana de Agroecosistemas 3(2) 263ndash271
Oliva R J Ocana F A de Jesus N A de Jesus C R and Vargas E A
(2016) Reproduccion dePomacea flagellata (Mollusca Ampullariidae)
en la laguna de Bacalar Quintana Roo Mexico Revista de Biologıa
Tropical 64(4) 1643ndash1650
Pacton M Hunger G Martinuzzi V Cusminsky G Burdin B
Barmettler K Vasconcelos C and Ariztegui D (2015) Organomi-
neralization processes in freshwater stromatolites a living example from
eastern Patagonia International Association of Sedimentologists Jour-
nal 1(2) 130ndash146
Perez L Bugja R Lorenschat J Brenner M Curtis J Hoelzmann P
Islebe G Scharf B and SchwalbA (2011) Aquatic ecosystems of the
Yucatan Peninsula (Mexico) Belize and Guatemala Hydrobiologia
661 407ndash433 doi101007S10750-010-0552-9
Perry E C Velazquez O G and Marin L (2002) The hydrogeochem-
istry of the karst aquifer system of the northern Yucatan Peninsula
Mexico International Geology Review 44 191ndash221 doi102747
0020-6814443191
Perry E Paytan A Pedersen B and Velazquez O G (2009) Ground-
water geochemistry of the Yucatan Peninsula Mexico constraints on
stratigraphy and hydrogeology Journal of Hydrology 367 27ndash40
doi101016JJHYDROL200812026
Pradit S Wattayarkorn G Angsupanich S Baeyens W and Leer-
makers M (2010) Distribution of trace elements in sediments and biota
of Songkhla Lake Southern Thailand Water Air and Soil Pollution
206 155ndash174 doi101007S11270-009-0093-X
Salomons W and Forstner U (1980) Trace metal analysis on polluted
sediments II evaluation of environmental impact Environmental
Technology Letters 1 506ndash517 doi10108009593338009384007
Sanchez S J Alvarez L T Pacheco A J Gonzalez H R and Carrillo
B L (2015) Caracterizacion hidrogeoquımica de las aguas subterraneas
del sur del Estado de Quintana Roo Mexico Revista Mexicana de
Ciencias Geologicas 32(1) 62ndash76
Schmitter-Soto J J Comın F A Escobar B E Herrera S J Alcocer J
Suarez M E Elıas G M Dıaz A V Marın L E and Steinich B
(2002) Hydrogeochemical and biological characteristics of cenotes in
the Yucatan Peninsula (SE Mexico) Hydrobiologia 467 215ndash228
doi101023A1014923217206
Siqueiros-Beltrones D Hernandez A U and Hernandez A O (2013)
Diagnosis prospectiva sobre la diversidad de diatomeas epilıticas en la
laguna Bacalar Quintana Roo Mexico Revista Mexicana de Biodiver-
sidad 84 865ndash875 doi107550RMB33960
Turekian K K andWedepohl K H (1961) Distribution of the elements in
some major units of the Earthrsquos crust Bulletin of the Geological Society
of America 72 175ndash192 doi1011300016-7606(1961)72[175
DOTEIS]20CO2
Handling Editor Russell Frew
wwwpublishcsiroaujournalsmfr
Hydrochemistry of Bacalar Lagoon Marine and Freshwater Research M
Roo as function of tourism development in the Mexican Caribbean
Revista Mexicana de Ingenierıa Quımica 13(2) 509ndash516
Norena-Barroso E Zapata-Perez O Ceja-Moreno V and Gold-Bouchot
G (1998) Hydrocarbon and organochloride residue concentrations in
sediments from Bay of Chetumal Mexico Bulletin of Environmental
Contamination and Toxicology 61 80ndash87 doi101007S001289900732
Nriagu J and Pacyna J (1988) Quantitative assessment of worldwide
contamination of air water and soils by trace metals Nature 333 134ndash
139 doi101038333134A0
Ochoa J C Gonzalez B J and Jimenez C J (2016) Metales pesados
(Cd Cr Pb Hg) en Rhizophora mangle en rıo y bahıa de Chetumal
Revista Mexicana de Agroecosistemas 3(2) 263ndash271
Oliva R J Ocana F A de Jesus N A de Jesus C R and Vargas E A
(2016) Reproduccion dePomacea flagellata (Mollusca Ampullariidae)
en la laguna de Bacalar Quintana Roo Mexico Revista de Biologıa
Tropical 64(4) 1643ndash1650
Pacton M Hunger G Martinuzzi V Cusminsky G Burdin B
Barmettler K Vasconcelos C and Ariztegui D (2015) Organomi-
neralization processes in freshwater stromatolites a living example from
eastern Patagonia International Association of Sedimentologists Jour-
nal 1(2) 130ndash146
Perez L Bugja R Lorenschat J Brenner M Curtis J Hoelzmann P
Islebe G Scharf B and SchwalbA (2011) Aquatic ecosystems of the
Yucatan Peninsula (Mexico) Belize and Guatemala Hydrobiologia
661 407ndash433 doi101007S10750-010-0552-9
Perry E C Velazquez O G and Marin L (2002) The hydrogeochem-
istry of the karst aquifer system of the northern Yucatan Peninsula
Mexico International Geology Review 44 191ndash221 doi102747
0020-6814443191
Perry E Paytan A Pedersen B and Velazquez O G (2009) Ground-
water geochemistry of the Yucatan Peninsula Mexico constraints on
stratigraphy and hydrogeology Journal of Hydrology 367 27ndash40
doi101016JJHYDROL200812026
Pradit S Wattayarkorn G Angsupanich S Baeyens W and Leer-
makers M (2010) Distribution of trace elements in sediments and biota
of Songkhla Lake Southern Thailand Water Air and Soil Pollution
206 155ndash174 doi101007S11270-009-0093-X
Salomons W and Forstner U (1980) Trace metal analysis on polluted
sediments II evaluation of environmental impact Environmental
Technology Letters 1 506ndash517 doi10108009593338009384007
Sanchez S J Alvarez L T Pacheco A J Gonzalez H R and Carrillo
B L (2015) Caracterizacion hidrogeoquımica de las aguas subterraneas
del sur del Estado de Quintana Roo Mexico Revista Mexicana de
Ciencias Geologicas 32(1) 62ndash76
Schmitter-Soto J J Comın F A Escobar B E Herrera S J Alcocer J
Suarez M E Elıas G M Dıaz A V Marın L E and Steinich B
(2002) Hydrogeochemical and biological characteristics of cenotes in
the Yucatan Peninsula (SE Mexico) Hydrobiologia 467 215ndash228
doi101023A1014923217206
Siqueiros-Beltrones D Hernandez A U and Hernandez A O (2013)
Diagnosis prospectiva sobre la diversidad de diatomeas epilıticas en la
laguna Bacalar Quintana Roo Mexico Revista Mexicana de Biodiver-
sidad 84 865ndash875 doi107550RMB33960
Turekian K K andWedepohl K H (1961) Distribution of the elements in
some major units of the Earthrsquos crust Bulletin of the Geological Society
of America 72 175ndash192 doi1011300016-7606(1961)72[175
DOTEIS]20CO2
Handling Editor Russell Frew
wwwpublishcsiroaujournalsmfr
Hydrochemistry of Bacalar Lagoon Marine and Freshwater Research M