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Sources and Locations
of Sea Turtle Mortality
along the Coast of El Salvador
DEVELOPMENT ALTERNATIVES INC. (DAI) PREPARÓ ESTE P UBLICACIÓN POR LA AGENCIA PARA EL DESARROLLO INTERNACIONAL DE
LOS ESTADOS UNIDOS (USAID)
i
Title: Sources and Locations of Sea Turtle Mortality along the Coast of El Salvador
Program, activity, or project name and number: USAID Improved Management and
Conservation of Critical Watersheds
Contract No. Epp-I-00-04-00023-0
Strategic objective number: 519-022 Contractor name: Development Alternatives (DAI)
Christopher Kernan
Project Director Improved Management and Conservation of Critical Watersheds
Avenida Dr. José Zablah, 4-6 Col. Utila Sta. Tecla, La Libertad, El Salvador
Phone (503) 2288-4198, (503) 2288-4318 Cell (503) 7468-1125 Email: [email protected]
This report is made possible by the support of the American People through the United States Agency for International Development (USAID). The contents of this report are the sole responsibility of DAI and do not necessarily reflect the views of USAID or the United States Government.
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Sources and Locations
of Sea Turtle Mortality
along the Coast of El Salvador
AUTHORS:
MICHAEL LILES
CARLOS THOMAS
iii
TABLE OF CONTENTS
EXECUTIVE SUMMARY....................................................................................................................................... 1
ACKNOWLEDGEMENTS ...................................................................................................................................... 2
1. INTRODUCTION .................................................................................................................................................... 3
2. MATERIALS AND METHODS ...................................................................................................................... 4 2.1. Sea turtle beach stranding surveys .............................................................................................................5 2.2. Interviews with marine resource users ....................................................................................................6
3. RESULTS ..................................................................................................................................................................... 9 3.1. Sea turtle beach stranding data ....................................................................................................................9 3.2. Sea turtle mortality sources and areas of concern identified by marine resource users 12
3.2.1. Industrial shrimp trawls...................................................................................................................... 14 3.2.2. Blast fishing ............................................................................................................................................... 16 3.2.3. Long-lines ................................................................................................................................................... 19 3.2.4. Bottom-set lobster gillnets ................................................................................................................. 21
4. RECOMMENDATIONS ................................................................................................................................... 24 4.1. General.................................................................................................................................................................. 24 4.2. Industrial shrimp trawls ............................................................................................................................... 26 4.3. Blast fishing ........................................................................................................................................................ 26 4.4. Long-lines ............................................................................................................................................................ 26 4.5. Bottom-set lobster gillnets .......................................................................................................................... 27
5. LITERATURE CITED ....................................................................................................................................... 28 A.1. Sea turtle stranding protocol used to document stranding events. .......................................... 33 A.2. Sea turtle reference sheets used during interviews with marine resource users. ............. 34
A.2.1. Olive ridley turtle reference sheet .................................................................................................. 34 A.2.2. East Pacific green turtle reference sheet...................................................................................... 35 A.2.3. Hawksbill turtle reference sheet ..................................................................................................... 36 A.2.4. Leatherback turtle reference sheet. ............................................................................................... 37
A.3. Interview protocol developed and used to interview marine resource users along the coast of El Salvador.................................................................................................................................................. 38
iv
FIGURES
Figure 1. Species composition of sea turtles stranded along the coast of El Salvador. ......... 10 Figure 2. Composition of probable mortality of sea turtles stranded along the coast of El
Salvador. ................................................................................................................. 10 Figure 3. Reponses of marine resource users regarding the primary sea turtle mortality
sources in their area................................................................................................. 14 Figure 4. Shrimp and camaroncillo capture by industrial and artisanal fisheries in El
Salvador from 1960 through 2005. Source: FAO 2009. ......................................... 15 Figure 5. Blast fishing and sea turtle priority conservation areas in the Bahía de Jiquilisco. 18 Figure 6. Overlap of long- line fishing and the high-priority conservation area for olive ridley
and East Pacific green turtles lying between 50 m and 100 m depth along the coast
of El Salvador.......................................................................................................... 21 Figure 7. Distribution and overlap with sea turtle distributions of lobster gillnets in Los
Cóbanos................................................................................................................... 23 Figure 8. Distribution and overlap with sea turtle distributions of lobster gillnets in El
Maculís.................................................................................................................... 24 Figure 9. Circle hook alternatives to J-hooks currently in use. Source: Mug et al. 2008. ..... 27
TABLES
Table 1. The 3 geographic zones of study, including priority beaches for conservation and corresponding department.................................................................................................. 5
Table 2. Characteristics of marine resource users interviewed in the 3 geographic zones of
El Salvador. ........................................................................................................................ 8 Table 3. Morphometric information and sex of stranded sea turtles by species in the 3
geographic zones.............................................................................................................. 11 Table 4. Incidental capture of sea turtles by fishing method along the coast of El Salvador
according to marine resource users. ................................................................................. 13
1
EXECUTIVE SUMMARY
Four species of sea turtles occur in El Salvador: leatherback (Dermochelys coriacea),
hawksbill (Eretmochelys imbricata), green (Chelonia mydas), and olive ridley
(Lepidochelys olivacea). The objective of this study is to identify the sources and areas of
sea turtle mortality along the coast of El Salvador, and to identify protection areas to
reduce mortality.
From April through July 2010 we collected sea turtle stranding data from 31 sites, and
from June through August 2010 we used a semi-structured interview to capture
information from local marine resource users on fishing areas, fishing methods, target
species, sea turtle mortality, class size, and primary sources and areas of mortality. We
documented a total of 55 sea turtle strandings: 76% were olive ridley turtles; 11% were
hawksbill turtles; 6% were East Pacific green turtles; and 7% were unknown. Based on
the nature of the injuries we attributed the majority of strandings (65%) to shrimp
trawling vessels and 12% attributed to artisanal fisheries. Of the 115 marine resource
users we interviewed, 79% said that industrial fisheries, specifically shrimp trawling
vessels, killed sea turtles during their operations and 77% said that artisanal fishing
activities using long- lines, blast fishing, and bottom-set lobster gillnets were responsible
for sea turtle deaths. Using information from these interviews we were able to map the
locations and frequency of adult sea turtle sightings by species and the location and
intensity of industrial and artisanal fishing. The overlap identified areas of greatest
mortality and therefore highest priority for special conservation protection.
As long- lived organisms with slow reproductive rates, sea turtles are particularly
vulnerable to human-caused mortality. It is known that incidental deaths of sub-adults
and adults in industrial and artisanal fisheries is the leading source of sea turtle mortality
throughout the world, with shrimp trawls, gill-nets, and long- lines as the primary culprits.
Evidence from the present study suggests that, while industrial fishing is the most
important source of adult sea turtle mortality in El Salvador, artisanal blast fishing and
long- lining may be relatively more important than elsewhere in the world. We discuss the
implications of this for designing the protection and recovery of sea turtle populations in
El Salvador
2
ACKNOWLEDGEMENTS
The authors thank and are indebted to the local marine resource users who participated in
this study and voluntarily assisted with data collection – this work would not have been
possible without their support and in-depth knowledge of industrial and artisanal fishing
practices, as well as interactions with sea turtles. We gratefully acknowledge the
organizations and entities that were integral to the success of this work, particularly
MARN (Barra de Santiago), FUNDARRECIFE, FUTECMA, Asociación Mangle,
CODEPA, and the many fishing cooperatives along the coast of El Salvador. We thank
Wallace J. Nichols for guidance on the development of the project’s methodology.
3
1. INTRODUCTION
Of the seven species of sea turtles recognized worldwide, six are considered to be
critically endangered, endangered, or vulnerable to extinction. Kemp’s ridley
(Lepidochelys kempii ), leatherback (Dermochelys coriacea), and hawksbill
(Eretmochelys imbricata) turtles are listed as critically endangered; loggerhead (Caretta
caretta) and green (Chelonia mydas) turtles as endangered; and the olive ridley
(Lepidochelys olivacea) turtle as vulnerable under the IUCN Red List of Threatened
Species (IUCN 2010). As long- living organisms with slow reproductive rates (Musick
1999), sea turtles are particularly vulnerable to anthropogenic sources of mortality,
especially the incidental capture of sub-adults and adults in marine fisheries (Lutcavage
et al. 1997). High survival rates of large juvenile and adult turtles are needed for long-
term population growth and recovery, especially for populations at already reduced levels
(Heppell 1998, Heppell et al. 2003, Lewison & Crowder 2008). The widespread,
persistent, human-caused deaths of sub-adult and adult sea turtles worldwide contribute
largely to the precarious conservation status of many populations and their inab ility to
recover (Lutcavage et al. 1997, Lewison et al. 2004, Watson et al. 2005, Frazier et al.
2007).
The incidental capture of sea turtles by industrial and artisanal fisheries is the
leading source of mortality throughout the world (Wallace et al. 2010), with shrimp
trawls (Magnuson et al. 1990), gill-nets (Cheng & Chen 1997, Lee Lum 2006), and long-
lines (Witzell 1999, Lewison & Crowder 2008) as the primary culprits. Industrial shrimp
trawls have long been identified as the single most important cause of sea turtle mortality
(Magnuson et al. 1990, Caillouet et al. 1991) resulting in approximately 150,000 deaths
per year globally (Oravetz 1999). By employing the Turtle Excluder Device (TED) on
trawls, the incidental capture of some species of sea turtles can be reduced by nearly 45%
(Crowder et al. 1995); however, some countries do not require TEDs or do not enforce
the requirement (Spotila 2004). Turtles captured in trawls without TEDs are likely to be
submerged and prevented from surfacing to breathe for lengths of time greater than their
average dive times, which caused them to become comatose and eventually drown
(Lutcavage & Lutz 1997).
4
Although artisanal fishers account for more than 95% of fishers globally (Pauly
2006), the impact of artisanal fisheries incidental capture on sea turtle populations
received little attention for many years (Soykan et al. 2008). Growing evidence suggests
that mortality caused by artisanal fisheries may be more significant than previously
thought (Lee Lum 2006, Koch et al 2006, Peckham et al. 2007, Gilman et al. 2009).
Regional variations in sea turtle mortality are expected due to differences in fishing
methods, intensity, and species-specific patterns (Polovina et al. 2003). The implications
of sea turtle deaths from artisanal fishing activity are important and deserve more focused
attention (Moore et al. 2010).
The waters and beaches of El Salvador are important nesting and/or feeding
grounds for olive ridley, East Pacific green, hawksbill, and leatherback turtles (Hasbun &
Vasquez 1999, Vasquez et al. 2008, Liles et al. 2010, Liles et al. In review). At the same
time, El Salvador is also the smallest and most densely-populated country in Central
America, with a total area of 21,040 km2 and an estimated population density of 342
people km-1. Both industrial and artisanal fisheries exist in El Salvador, but overfishing
has led to dwindling yields of certain target species (FAO 2009). Although human-turtle
interactions are common in shared spaces and human-caused sea turtle deaths have been
reported in El Salvador (e.g. Vasquez et al. 2008), the areas and importance of the
various potential sources of human-caused sea turtle mortality remain unclear. The
objectives of this study were to identify these sources, map the areas where they are most
likely to be occurring along the coast of El Salvador, and recommend measures to
minimize them.
2. MATERIALS AND METHODS
The study area consisted of the entire 321 km extension of Salvadoran coastline,
from 0 to 200 m of depth, with particular emphasis at the 31 beach sites identified by the
USAID Improved Management and Conservation of Critical Watersheds Project
(IMCCW) as priority areas for sea turtle nesting protection (Liles et al 2010).
5
2.1. Sea turtle beach stranding surveys
In collecting sea turtle stranding data, we collaborated with the technical staff of
the Fundación Zoológica de El Salvador (FUNZEL) and with residents of coastal
communities. To facilitate the logistics, this work was organized within 3 geographic
zones: Western (Bola de Monte-Toluca), Central (Boca Poza-El Espino), and Eastern (El
Cuco-El Tamarindo) (Table 1).
Table 1. The 3 geographic zones of study, including priority beaches for conservation and corresponding
department.
Zone Beach Name Department Length (km)
Western Bola de Monte Ahuachapán 3.97
Garita Palmera Ahuachapán 6.68 Barra de Santiago Ahuachapán 5.61 Costa Azul Sonsonate 1.71
Los Cóbanos (El Almendro-Los Cóbanos Centro) Sonsonate 4.10 Playa Dorada Sonsonate 4.87
El Zonte La Libertad 1.85 El Palmarcito La Libertad 0.30 El Majahual La Libertad 1.54
San Blas La Libertad 1.64 San Diego La Libertad 9.00
El Amatal La Libertad 1.02 Toluca La Libertad 3.89
Total 46.18
Central Boca Poza La Libertad 1.50 Cangrejera-Los Pinos La Libertad 4.13
Amatecampo La Paz 1.75 La Zunganera La Paz 2.79
El Pimental La Paz 4.49 Isla Tasajera La Paz 6.77 Isla Montecristo Usulután 7.14
San Juan del Gozo Usulután 15.05 Isla de Mendez Usulután 8.53
Corral de Mulas Usulután 4.81 El Icaco Usulután 8.94 Isla San Sebastián Usulután 12.57
El Espino Usulután 6.53
Total 85.00
Eastern El Cuco San Miguel 4.86 El Icacal La Unión 9.40
Las Tunas La Unión 0.59 El Maculís La Unión 3.83
El Tamarindo La Unión 1.91
Total 20.59
6
Between 1 April 2010 and 31 July 2010 six technical staff of FUNZEL, in
partnership with coastal communities and local institutions, recorded sea turtle stranding
events along 152 km of Salvadoran coastline using an approved national stranding
protocol (Appendix A.1). At each of the 31 selected beaches, the local hatchery manager
was responsible for documenting all mortality events according to protocol requirements,
which were collected weekly by FUNZEL technical staff. Only carcasses confirmed by
FUNZEL staff or hatchery managers were included in this study. To maintain the
anonymity of specific coastal community residents that collaborated with data collection,
stranding data were presented per geographic zone. When possible, the species, curved
carapace length (CCL), sex, and cause of death were reported for each individual.
2.2. Interviews with marine resource users
Interviews have been successfully employed to collect useful information on the
incidental capture of sea turtles in both industrial and artisanal fisheries when collecting
observer data was not feasible (Godley et al. 1998, Lee Lum 2006, Moore et al. 2010).
This is particularly true with dynamic artisanal fisheries, where thousands of fishers may
shift methods and target species frequently, and smaller boat sizes logistically restrict the
collection of observer data. In the absence of such empirical data, researchers have relied
upon the experience and knowledge of local fishers to assess the interplay between
artisanal fisheries and the marine environment (Godley et al. 1998, Drew 2005, Close &
Hall 2006, Moore et al. 2010).
We conducted marine resource user interviews at Estero Barra de Santiago, Los
Cóbanos Reef Marine Protected Area (MPA), Estero Jaltepeque, Bahia de Jiquilisco-
Xiriualtique Biosphere Reserve, and Golfo de Fonseca. We developed a semi-structured
interview format and sea turtle reference sheets (Appendix A.2) to capture information
from local fishers on fishing areas, fishing methods, target species, sea turtle mortality,
class size (small <30 cm, medium 30-50 cm, large >50 cm), and primary sources and
areas of mortality. We field-tested the interview protocol with 8 local fishers from
different coastal communities which produced the following results:
None of the fishers stated that they themselves had incidentally captured sea
turtles, even though their fishing methods were similar to those fishers and/or
fishing methods that they claimed did capture turtles;
7
Few fishers were able to orient themselves confidently with maps;
Most fishers had varying ways of measuring distance from shore and depth;
Few fishers could distinguish between the olive ridley and East Pacific green
turtles; and
Few fishers fished deeper than 100 m.
In accordance with these conclusions, the methodology and interview protocol
(Appendix A.3) were adjusted to reflect the on-the-ground reality of the study area and its
inhabitants:
our interview questions did not ask the interviewees about their individual fishing
experiences, rather the questions were directed toward a certain fishing method
and/or groups of fishers in general (e.g. long- line fishers);
we interviewed other local marine resource users (e.g. mangrove cockle
harvesters) along with fishers to incorporate individuals with diverse experiences,
fishing methods, and marine habitats into the study; and
we used sea turtle reference sheets to determine reliability in interviewee
knowledge of species and behaviors (fishers that were unable to accurately
distinguish between species were noted).
Trusted coastal community leaders in each zone identified and introduced project
staff to highly experienced marine resource users in their area, with the assurance that all
names would remain confidential. We interviewed those willing to share their knowledge
about industrial and artisanal fishing methods and sea turtle mortality using the interview
protocol in groups of no more than 3 individuals to ensure that each person interviewed
maintained his/her voice without fear of repercussions. From 1 June through 27 August
2010, we interviewed a total of 115 experienced marine resource users in the 3
geographic zones (Table 2). We categorized marine resources users that were active in
more than one resource use activity by their primary activity.
8
Table 2.Characteristics of marine resource users interviewed in the 3 geographic zones of El S alvador.
Zone Communities ----------------------------------------- No. of Interviewees ----------------------------------------- Fishers Cockle harvesters Oyster harvesters Egg harvesters Total Experience (yr)
Western Garita Palmera 2 0 0 0 2 22
Barra de Santiago 9 0 0 2 11 28 Los Cobanos 8 0 0 0 8 30
Barra Salada 8 0 0 0 8 12 Mizata 2 0 2 0 4 32 Taquillo 3 0 0 0 3 10
El Zonte 0 0 1 0 1 33 SUB-TOTAL 32 0 3 2 37 24
Central Isla Tasajera 5 0 0 0 5 18 El Icaco 6 5 0 5 16 21
Puerto El Triunfo 1 0 0 0 1 32 La Pirraya 9 1 0 0 10 19 El Cojollon 5 2 0 1 8 20
Puerto Ceiba 2 1 0 2 5 23 El Espino 2 0 0 0 2 27
SUB-TOTAL 30 9 0 8 47 23
Eastern Las Tunas 4 0 5 0 9 16 El Maculis 1 0 5 1 7 25
El Tamarindo 11 0 2 2 15 29 SUB-TOTAL 16 0 12 3 31 23
TOTAL 78 9 15 13 115 23
9
3. RESULTS
3.1. Sea turtle beach stranding data
Beach strandings (i.e. dead sea turtles washed ashore) are not necessarily an
accurate predictor of adult sea turtle mortality because they may account for only 7-13%
of total morality due to the variety of factors such as current regimes, wind, and distance
from shore, that determine the final resting place of a carcass. But stranding data do
indicate that deaths have occurred (Epperly et al. 1996) and provide useful life-history
information for sea turtle species (Magnuson et al. 1990). The absence of beach
strandings does not mean that mortality is not occurring (Epperly et al. 1996).
Between 1 April 2010 and 31 July 2010, we documented 55 sea turtle strandings
along the coast of El Salvador: 76% (42) were olive ridley turtles, 11% (6) were
hawksbill turtles, 6% (3) were East Pacific green turtles, and 7% (4) were unknown
(Figure 1). Table 3 provides the morphometric and sex information of the stranded sea
turtles per species in the 3 geographic zones. Nearly 50% of the 42 olive ridley turtle
strandings occurred in the western zone, the majority of which were large individuals
(mean CCL=67.7 cm). 45% of these carcasses were male turtles. Of the 6 hawksbill
carcasses, 2 were medium sized from the western zone (mean CCL=46 cm), 3 carcasses
were large and from the central and western zones (mean CCL=76 cm), and 1 carcass
could not yield reliable measurements. All stranded hawksbill turtles were female. The 3
stranded East Pacific green turtles in the central and eastern zones were large individuals
(mean CCL=82.3 cm). Based on observation and interpretation of outward injuries and
marks, we attributed 65% of strandings of the 3 species to shrimp trawls, 12% to artisanal
fishing, and 17% to unknown sources (Figure 2). The “other” category of mortality
sources included sea turtles that were cut open to remove eggs, turtles hit by boats or
propellers, and those attacked by dogs. We generally were not able to perform necropsies
on the carcasses.
10
Figure 1. Species composition of sea turtles stranded along the coast of El Salvador.
76%
11%
6%7%
Olive Ridley
Hawksbill
East Pacific Green
Unknown
Figure 2. Composition of probable mortality of sea turtles stranded along the coast of El Salvador.
65%
12%
6%
17%
Shrimp Trawls
Artisanal Fisheries
Other
Unknown
11
Table 3. Morphometric information and sex of stranded sea turtles by s pecies in the 3 geographic zones. n=sample size; SD=standard deviation;
F=female; M=male; U=unknown; ST=shrimp trawls; AF=artisanal fisheries; O=other.
Species Zone n % --------- CCL (cm) --------- ---- Sex (%) ---- Source of Mortality (%)
Min Max Mean SD F M U ST AF O U
Olive Ridley Western 20 48 55.0 85.0 67.7 9.1 35 45 20 75 15 5 5
Central 12 28 58.0 85.0 72.5 9.1 50 42 8 50 8 8 33
Eastern 10 24 60.0 75.0 66.7 7.5 78 11 11 70 0 10 20
Total 42 100 55.0 85.0 69.3 8.8 51 34 15 67 10 7 17
Hawksbill Western 2 33 44.0 48.0 46.0 2.8 100 0 0 50 0 0 50
Central 2 33 74.5 85.0 79.8 7.4 100 0 0 0 100 0 0
Eastern 2 33 69.0 69.0 69.0 N/A 100 0 0 50 0 0 50
Total 6 99 44.0 85.0 64.1 17.6 100 0 0 33 33 0 33
East Pacific Green Western 0 0 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A
Central 1 33 86.0 86.0 86.0 N/A 0 0 100 100 0 0 0
Eastern 2 67 70.0 91.0 80.5 14.8 100 0 0 100 0 0 0
Total 3 100 70.0 91.0 82.3 11.0 67 0 33 100 0 0 0
12
In addition to the sea turtle strandings described above, hundreds of unconfirmed
but potentially stranded turtles were reported by local egg collectors and fishers to
FUNZEL staff, including at least 1 leatherback turtle (~1.25 m CCL) at Corral de Mulas
and 4 hawksbill turtles (2 individuals ~60 cm CCL at Playa Dorada, 1 male 76 cm CCL
at Barra de Santiago, and 1 individual 25-30 cm CCL in the Bahia de Jiquilisco).
However, carcasses not observed by FUNZEL staff or hatchery managers were not
included in the stranding database and we have not included them in this study.
Considering the critically endangered status of the leatherback and hawksbill turtles,
properly documenting all stranding events and identifying sources of mortality involving
these two species is of critical importance to direct conservation action and prevent
further reductions of their populations in the eastern Pacific Ocean.
3.2. Sea turtle mortality sources and areas of concern identified by marine resource users
During our interviews, all marine resource users mentioned that incidental capture
and death of sea turtles from fishing activity occurred along the coast of El Salvador. A
“mention” refers to the indication of sea turtle capture and/or mortality by a given fishing
method or other non-fishing source, where one marine resource user may have multiple
mentions. For example, an interviewee may have stated that bottom-set gillnets and long-
lines capture hawksbills and olive ridleys. We counted this as two mentions: 1 mention
being that bottom-set gillnets capture hawksbill turtles and 1 mention being that long-
lines capture olive ridley turtles. However, an interviewee may have stated that one
fishing method, such as bottom-set gillnets, capture olive ridley and hawksbill turtles. We
counted this as only 1 mention.
Of the 115 marine resource users we interviewed along the Salvadoran coast, 79%
(91) said that industrial fisheries incidentally captured sea turtles, while 77% (88) said
that sea turtles were incidentally captured in artisanal fisheries. As shown in Table 4,
shrimp trawls were blamed for capturing sea turtles in 100% of all industrial fisheries
incidental capture mentions, while long- lines (60%), blast fishing (30%), bottom-set
lobster gillnets
13
Table 4. Incidental capture of sea turtles by fishing method along the coast of El Salvador according to marine resource users.
Fishery Fishing Method Target Species Mentions ---------- Sea Turtle Species Captured (% of Mentions) ---------- Olive Ridley Green Hawksbill Leatherback Unknown
Industrial Trawls Shrimp 91 55 8 1 0 45
Artisanal Long-lines Shark, snapper, mahi-mahi 53 34 4 2 0 49 Blast fishing All commercially valuable 26 12 15 81 0 15 Bottom-set gillnets Spiny lobster 14 21 0 79 0 21
Drift nets Snook 12 17 0 0 0 83 Trammel/gillnets Corvina, shrimp, snapper 12 25 0 33 0 58
Hand-lines Snapper 6 33 0 0 0 67
14
(16%), drift nets (14%), trammel/gillnets (14%), and hand-lines (7%) were blamed for capturing
sea turtles in artisanal fisheries incidental capture mentions. Marine resource users said that
mortality was also caused by non-fishing activities: hit by boats/propellers (11%, 13);
contamination of marine environment (10%, 12); eggs cut out of live female turtles (6%, 7);
intoxication from “chichicaste” (6%, 7); red tide (4%, 4); and dogs on the beach (4%, 4).
During interviews with marine resource users, we asked interviewees what the primary
source of sea turtle mortality was in their area. 90% blamed some form of interaction between sea
turtles and fisheries: 61% (70) blamed industrial shrimp trawls, 20% (23) blast fishing, 9% (10)
long- lines, 3% (3) bottom-set lobster gillnets, and 7% (9) were uncertain (Figure 3). Over 70%
(83) said that stranded female turtle carcasses were found with eggs having been cut out, which
was blamed on fishers killing incidentally captured sea turtles during the nesting seasons. We
describe each primary source of mortality below.
Figure 3. Reponses of marine resource users regardi ng the primary sea turtle mortality sources in their area.
61%20%
9%
3%7%
Shrimp Trawls
Blast Fishing
Longlines
Bottom-set Lobster Gillnets
Uncertain
3.2.1. Industrial shrimp trawls
Since the 1950s, the industrial shrimping industry has been operating along the Pacific
coast of Central America with 55 to 80 foot vessels pulling one standard 50 to 65 foot headrope
length with two sea balloon trawls from each outrigger, or a standard flat net (Arauz 1996). In El
Salvador, target species include white (Litopenaeus vannamei, Litopenaeus stylirostris, L.
15
esengancha), brown (F. californiensis), and pink (F. brevirostris) shrimp, as well as
camaroncillos (Xiphopenaeus rivetti, Trachipenaeus byrdi) (López 2009). As Figure 4
demonstrates, persistent overfishing has reduced existing stock (FAO 2009), and the effects of
natural and man-made indirect stresses (e.g. Hurricane Mitch, mangrove deforestation,
contamination) have suppressed the population recovery of these target species. Shrimp and
camaroncillo exports have fallen from $40 million in 1995 to less than $4 million in 2007 (López
2009).
Figure 4. Shrimp and camaroncillo capture by industrial and artisanal fisheries in El Salvador from 1960
through 2005. Source: FAO 2009.
Industrial fishing, particularly shrimp trawls, has enormous impacts on sea turtle
populations worldwide (Spotila 2004) and has long been identified as an important source of sea
turtle mortality (Magnuson et al. 1990, Oravetz 1999). The industrial shrimp fishery of the eastern
central Pacific has been of particular concern. In 1990, Arauz (1996) repo rted an extremely high
incidental capture mortality of up to 60,000 sea turtles along the Pacific coast of Central America ;
El Salvador’s 70 industrial shrimp trawling vessels accounted for 21,280 (35%) of those captures
(66% were olive ridley turtles and 33% were East Pacific green turtles).
Interactions between shrimp trawls and sea turtles occur when fishing activities overlap
with areas of sea turtle congregation. Such is the case in El Salvador, where olive ridley and East
Pacific green turtles inhabit waters that are trawled for shrimp and camaroncillos at depths of 10
to 80 m (Arauz 1996, López 2009, Liles et al. 2010). Over 60% of marine resource users we
16
interviewed identified shrimp trawls as the most important mortality source of sea turtles in El
Salvador. To minimize sea turtle captures and mortality, the Turtle Excluder Device (TED) is
required on all active shrimp trawls (CENDEPESCA/MAG 1996). The Salvadoran fishing
authority, Centro de Desarrollo de la Pesca y la Acuicultura (CENDEPESCA), says that using
TEDs by the industrial fishing sector is an institutional priority (López 2009, Barahona &
Pacheco 2009). However, 33% (38) of the marine resource users we interviewed said that all
vessels did not use TEDs during all hours of operation at sea, and 37% (14) of these said that they
had personally seen trawls operating without TEDs or TEDs that had been sewn closed. In August
2010 a vessel inspected by CENDEPESCA was found operating without a TED (E. Ramirez per.
comm. to M. Liles).
Industrial shrimp trawling effort has decreased considerably in El Salvador over the last
decade, from 76 vessels operating a total of 18,713 days in territorial waters in 1999 to 28 vessels
operating 5,070 days in 2006 (FAO 2009). Sea turtle captures by shrimp trawling vessels can be
expected to have decreased as well, which may explain that 90% (104) of our marine resource
users informants said fewer sea turtle carcasses are washing up on beaches today than in the past,
with many attributing this to fewer shrimp trawlers operating along the coast. By employing the
catch per unit effort (CPUE) of 0.0511 turtles/hr that was used to determine 20,280 sea turtles
were captured in Salvadoran waters in 1990 (Arauz 1996) with the adjusted level of effort (5,070
days or 121,680 hours), a total of approximately 6,200 sea turtles would have been captured in
2006 if TEDs were not used by shrimp trawling vessels. However, with 18% (21) of marine
resource users saying that TEDs were used on shrimp trawls, it is likely that at least some
operating vessels employ TEDs, thus reducing the number of captured sea turtles.
Olive ridley turtles appear to be the species most impacted by shrimp trawling activities,
with 55% of mentions and 78% (28) of reported trawl-related beach strandings. Their larger
population size (Márquez 2000) and higher reproductive and growth rates compared to other sea
turtle species (Márquez et al. 1982) may allow their populations to recover faster if deaths from
shrimp trawls were reduced in El Salvador.
3.2.2. Blast fishing
Fishing with explosives, or blast fishing, is an unselective and destructive practice that can
have widespread and devastating effects on marine habitats and biodiversity. Although exact
methods may be country- or habitat-specific, blast fishers typically use contraband military-grade
17
explosives or homemade devices to target aggregations of commercially valuable fish. Blast
fishing indiscriminately stuns or kills all size classes of target and non-target species, with the
majority of fish sinking to the bottom, many of which are not collected (Fox & Erdmann 2000).
In El Salvador, blast fishing is illegal as established by Article 31 of the Ley General de
Ordenación y Promoción de Pesca y Acuicultura, which states that, “se prohíbe el ejercicio de la
extracción usando venenos, explosivos u otros de similar efecto destructivo”. However, 20% of
the marine resource users we interviewed along the coast of El Salvador said that blast fishing
occurred in the Bahia de Jiquilisco-Xiriualtique. This is particularly worrisome, as the Bahia was
designated a Ramsar wetland in 2005 and a UNESCO Biosphere Reserve in 2007. With an area of
63,500 hectares, it is the largest brackish and saltwater forest in El Salvador and includes
numerous estuaries, canals, beaches, and various isles of different sizes.
The impacts of blast fishing on tropical coral reef ecosystems are well documented (e.g.
Alcala & Gomez 1987, Jennings & Polunin 1996, Gray 1997, Wells 2009) and to a lesser extent
on mangrove estuaries (e.g. Corcoran et al. 2007, Adekanmbi & Ogundipe 2009), but little
information exists on blast fishing in mangrove estuaries as a source of sea turtle mortality (but
see Liles et al. In review). Of the 47 marine resource users we interviewed in the central zone,
55% said that blast fishing was killing sea turtles in the Bahia. 81% of these mentions were
hawksbill, 15% were East Pacific green turtles, and 12% were olive ridley turtles. This is
particularly concerning for the hawksbill turtle, as the population of the eastern Pacific Ocean is
one of the most endangered sea turtle populations in the world and the Bahia is a critical nesting
and foraging ground for this population (Gaos et al. unpublished data, Gaos et al. 2010). As
shown in Figure 5, blast fishing regularly occurs in areas inhabited by hawksbill turtles along
mangrove- lined channels and estuaries throughout the Bahia, of which El Rincon Grande and
Estero Arcos have been designated high priority areas for hawksbill conservation due to the
presence of high-densities of large and medium size individuals (Liles et al. 2010).
18
Figure 5. Blast fishing and sea turtle priori ty conservation areas in the Bahía de Jiquilisco.
All hawksbill turtle mentions by marine resource users said that large individuals were
killed by blast fishing, with an average of 13 large hawksbill turtles killed per year (n=15;
median=8). Figure 6 shows a large hawksbill turtle that was killed by blast fishing in the Bahia in
2008. As long-term sea turtle population growth and recovery requires high survival rates of sub-
adult and adult turtles, particularly for populations at already reduced levels (Heppell 1998,
Heppell et al. 2003), the annual loss of 13 large hawksbill turtles from a remnant population
whose status “is clearly of a highest concern for the Pacific” (NMFS & USFWS 1998) is
disastrous and unsustainable should be addressed with urgency.
19
Figure 6. Hawksbill turtle killed by blast fishing in the Bahía de Jiquilisco.
3.2.3. Long- lines
In the eastern Pacific Ocean, industrial and artisanal fisheries target pelagic and coastal
fish species of high commercial value using long- lines that may extend from hundreds of meters
to kilometers in length, and employ hundreds to thousands of hooks. Shallow-set long- lines
typically target larger pelagic species such as billfish, tuna, shark, and mahi-mahi, whereas deep-
set long- lines are often directed towards snapper, grouper, and catfish, with both methods
commonly utilizing baited J-hooks.
Pelagic long-lines are under intense scrutiny for their impact on sea turtle populations,
particularly shallow-set long- lines the eastern Pacific Ocean, as they tend to incidentally capture
higher numbers of older age classes (NMFS 2004, Lewison & Crowder 2008) that are critical for
population growth and recovery (Heppell 1998). As reproductively active olive ridley turtles
aggregate in large numbers offshore from nesting beaches (Kalb 1999), recent growth in long- line
fisheries in the region pose a serious and growing threat to this species and have the potential to
20
capture hundreds of thousands of individuals annually (Frazier et al. 2007). Along the Pacific
coast of Latin America, the artisanal long- line fleet is estimated to contain between 10,000 and
16,000 boats with the number of hooks used at an order of magnitude similar to the industrial
long- line fleet, indicating a level of sea turtle incidental capture that is likely significant (Mug et
al. 2008).
In El Salvador, a total of 762 long- line fishers employ nearly 345,000 hooks (90% of
which are J-hooks) to capture target fish species, with shallow-set and deep-set long- line fishers
dedicating 288 days and 144 days per year to fishing activities, respectively
(CENDEPESCA/MAG 2007). As Figure 7 demonstrates, preferred long- line fishing sites overlap
with areas inhabited by sea turtles, including the area between 50 m and 100 m with a high
frequency of large, reproductively active individuals of both olive ridley and East Pacific green
turtles (Liles et al. 2010). Of the 123 mentions by marine resource users of sea turtles captured in
artisanal fishing, 43% (53) said that the captures occurred during long-line fishing, with 34% of
these stating that olive ridley turtles that were captured (49% did not know the species). A recent
study on the incidental capture of sea turtles by the artisanal long-line fishery of El Salvador
reported that of 4,443 hooks sampled, 11 olive ridley turtles were hooked and 6 were entangled
(De Paz & Siu 2008). This same study calculated the following incidental capture rate: 10
turtles/1000 J4-hooks, 4 turtles/1,000 C13-hooks, 1.2 turtles/1,000 C15-hooks, and 0.7
turtles/1,000 C14-hooks (De Paz & Siu 2008). All olive ridley turtles captured in the study were
reportedly released alive, which is consistent with global long- line incidental capture patterns,
where only between 4 to 27% of captured turtles die on the line prior to retrieval (Aguilar et al.
1995, McCracken 2000, Camiñas 2004). However, the potential for high rates of post-release
mortality exists, particularly when turtles are released with hooks or lines remaining in their
mouths, throats, or gastrointestinal tracts that can lead to infection (Aguilar et al. 1995, Chaloupka
et al. 2004), which is the case for the many of turtles captured with swallowed J-hooks (Mug et al.
2008), or when captured turtles are not handled properly (Watson et al. 2005). 90% (311,981) of
the hooks currently used by artisanal long-line fishers in El Salvador are J-hooks, which suggests
that thousands of incidental sea turtle captures from long-line fishing are occurring annually, with
a potentially high post-release mortality rate. Of the marine resource user mentions saying that
artisanal long-line fishing captured sea turtles, 34% (18) said that turtles were released alive (line
cut or unhooked), 21% (11) said that turtles were drowned, 4% (2) said that they were entangled
21
in the buoys or line, and 42% (22) did not respond. The use of circle hooks would result in fewer
and less dangerous captures than J-hooks, thus reducing mortality (Gilman et al. 2005, Swimmer
et al. 2006), while maintaining similar or greater target species catch rates (Read 2007, Mug et al.
2008). The proper handling and unhooking of captured sea turtles by long- line fishers is also
critical in lowering the mortality rate of released turtles.
Figure 6. Overlap of long-line fishing and the high-priority conservation area for olive ridley and East Pacific
green turtles lying between 50 m and 100 m depth along the coast of El Salvador.
3.2.4. Bottom-set lobster gillnets
In low-income countries such as El Salvador, the extraction and direct use of natural
resources remains an essential livelihood strategy for many people (Hutton & Leader-Williams
2003), particularly in rural and coastal areas where poverty is most acute (Lehoucq et al. 2004).
Where expanding human populations are placing increasing pressure on diminishing marine
resources, there is growing evidence that small-scale, passive net fisheries are a significant
mortality source for some sea turtle populations (Gilman et al. 2009), particularly in low-income
nations where management and enforcement are limited (Peckham et al. 2007).
22
The rock reef ecosystems of Los Cóbanos and El Maculís are inhabited by the Pacific
green spiny lobster (Panulirus gracilis), a species of high commercial value targeted by artisanal
fishers in both areas. Los Cóbanos Reef (13°31’26”N 89°48’23”W), situated near to Acajutla in
the western zone of the country, is a marine protected area that contains 260 km of marine and
terrestrial habitat, with dominant features being a rocky coastline and submerged volcanic reef
formations ranging from 0 m to 30 m in depth. Los Cóbanos Reef is home to approximately 15
coral species and it boasts the highest diversity of marine algae, invertebrates, and fish in the
country. El Maculís Reef is located in the eastern zone of the country and borders the Salvadoran
portion of the Golfo de Fonseca (13°9´ and 13°20´N, and 87°45´ and 88°00´W). With a length of
approximately 5 km, little is known of the biophysical characteristics of this reef ecosystem.
To capture spiny lobsters, bottom-set gillnets (300 m long by 1 to 1.5 m deep; mesh size,
10 cm; line-test, 4 lbs) are set at preferred fishing sites once daily with a 12-hr soak time at depths
of between 3 m and 7 m (López et al. unpublished data). Gillnet characteristics and employment
may vary per site, depending on the biophysical conditions of specific fishing areas. Of the 14
marine resource user mentions that said that sea turtle incidental capture occurred in bottom-set
lobster gillnets along rock reefs, nearly 80% said that hawksbill turtles were captured. As the
reliance of hawksbill turtles on coral reefs as primary foraging grounds is well documented (e.g.
Meylan 1988, León & Bjorndal 2002, Spotila 2004), it is likely that the rock reef habitats of Los
Cóbanos (Figure 7) and El Maculís (Figure 8) preferred by spiny lobsters are also used as feeding
areas by hawksbill turtles (Liles et al. 2010). Potentially deadly incidental captures of hawksbill
turtles by bottom-set lobster gillnets will occur when gillnets are set in areas used by foraging
turtles (Liles et al. In review). In some parts of the world, sea turtle mortality rates in gillnet
fisheries has been reported to be 50% (Laurent et al. 1991; Argano et al. 1992). Nearly 65% (9) of
marine resource user mentions that said that lobster gillnets captured turtles also said that
captured turtles died, with an average of 12 medium size hawksbill turtles killed per year (n=9;
median=4). Population modeling has demonstrated that high survivorship of sub-adults may be
critical to the maintenance and recovery of sea turtle populations (Crouse et al. 1987, Crouse
1999), so the probable loss of this number of sub-adults in lobster gillnets in Los Cóbanos and El
Maculís is alarming for a population as severely depleted as the hawksbill turtle of the eastern
Pacific Ocean.
23
Figure 7. Distribution and overlap with sea turtle distributions of lobster gillnets in Los Cóbanos.
24
Figure 8. Distribution and overlap with sea turtle distributions of lobster gillnets in El Maculís.
4. RECOMMENDATIONS
As the leading source of sea turtle mortality throughout the world, incidental capture in industrial
and artisanal fisheries has severe impacts on populations and impedes their recovery. However,
modifications to fishing gear and methods can mitigate (avoid, reduce, and offset) deaths from
incidental capture in marine fisheries. We provide the following recommendations to reduce sea
turtle deaths from incidental capture in Salvadoran fisheries, to raise public awareness of the
impacts of incidental capture mortality on sea turtle populations, and to document incidental
capture deaths.
4.1. General
Quantify and map sea turtle incidental capture in industrial and artisanal fisheries using
independent observers on board fishing vessels to record data on fishing effort per-vessel,
target catch, and sea turtle captures (NMFS 2004, Moore et al. 2010)
25
Quantify and document the practice by marine fishers of illegally killing captured female
turtles and cutting or their eggs
Prosecute violators of existing laws protecting sea turtles from incidental capture
Strictly regulate or prohibit fishing activities in high-density sea turtle habitats,
particularly areas inhabited by the critically endangered hawksbill turtle.
Ban the use of bottom-set gillnets in areas used by foraging hawksbill turtles.
Establish industrial and artisanal fishing “vedas” (bans) in specific marine areas at times
when a high probability exists for incidental capture deaths of sea turtles
Organize seminars with the industrial and artisanal fishing sectors to discuss effective
measures to reduce incidental capture deaths of sea turtles in Salvadoran fisheries
Encourage the active participation of the fishing community and offer financial support
for the implementation (experimentation) of agreed upon approaches
Encourage community regulation and protection of marine resources
Encourage community denuncias of illegal fishing activities
Train fishers on best practices in handling, unhooking, and resuscitating captured sea
turtles that are brought aboard alive
Review and, when necessary, revise fisheries regulation and legislation to provide better
protection for sea turtles in Salvadoran waters
Empower and strengthen sea turtle beach stranding network, including egg collectors,
local fishers, and other concerned coastal community residents, to ensure the proper
documentation and reporting of all stranded turtles along the coast of El Salvador
Train sea turtle beach stranding network on best practices for performing in-field
necropsies on carcasses and for mortality source identification
Raise public awareness of the effect of sea turtle incidental capture on sea turtle
populations, particularly populations that are severely reduced in the eastern Pacific
Ocean, such as hawksbill and leatherback turtles
Promote public action by clarifying the link between an individual’s daily choices (i.e.
consumption of unsustainably caught sea food products) and sea turtle mortality, while
offering more preferable alternatives
26
4.2. Industrial shrimp trawls
Enforce the proper use of Turtle Excluder Devices (TEDs) on all operating shrimp
trawling vessels in El Salvador, as required by CENDEPESCA/MAG Resolution No. 112,
by deploying on-board observers and prosecuting violators
Establish a voluntary network of local fishers and fishing cooperatives to monitor the use
of TEDs by shrimp trawling vessels while at-sea and report violations to appropriate
authorities
Adopt as a high-priority policy of MARN and CENDEPESCA/MAG the enforcement of
sea turtle protection legislation
Reduce tow times of shrimp trawls
4.3. Blast fishing
Adopt as a high-priority policy of CENDEPESCA/MAG the enforcement of legislation
banning blast fishing in the Bahia de Jiquilisco-Xirihualtique Biosphere Reserve
Strictly enforce Article 31 of CENDPESCA/MAG Ley General de Ordenación y
Promoción de Pesca y Acuicultura and prosecute violators
Establish a baseline and annual monitoring of blast fishing practices and resulting sea
turtle deaths in the Bahia de Jiquilisco-Xirihualtique Biosphere Reserve
Engage blast fishers in discussions on the implications of blast fishing to the marine
environment and biodiversity, with an emphasis on sea turtle mortality, and jointly
develop potential income-generating alternatives and offer financial support for their
implementation
4.4. Long- lines
Replace J-hooks with circle hooks in the artisanal long- line fishery along the coast of El
Salvador (Figure 8). The use of circle hooks would result in fewer and less dangerous
captures than J-hooks, thus reducing mortality (Gilman et al. 2005, Swimmer et al. 2006),
while maintaining similar or greater target species catch rates (Read 2007, Mug et al.
2008)
Ban the use of shallow-set long- lines. This should substantially reduce the incidental
capture of olive ridley turtles, as they spend only about 10% of their time deeper than 100
27
m (Polovina et al. 2003). However, the mortality rate of turtles captured on deep-set long-
lines may be higher than sea turtles captured near the surface.
Figure 9. Circle hook alternatives to J-hooks currently in use. Source: Mug et al. 2008.
4.5. Bottom-set lobster gillnets
Prohibit the use of bottom-set gillnets in areas where hawksbill turtle foraging occurs.
Regulate the soak time of gillnets at less than the maximum dive times of the most
vulnerable sea turtle species (olive ridley). Although hawksbill turtles can remain
submerged longer than other species of sea turtles (mean=56 min; max=74 min) (Spotila
2004), the 12-hr soak time commonly employed for bottom-set lobster gillnets surpasses
their maximum dive times.
Experiment with lobster fishing gear and methods, particularly cage traps that do not
incidentally capture sea turtles.
Establish a baseline and annual monitoring of the bottom-set lobster gillnet fisheries at
Los Cóbanos Reef MPA, Costa Acantilada, and El Maculis Reef, including quantifying
sea turtle incidental captures, fishing methods employed, and fishing intensity at mapped
fishing sites.
28
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APPENDIX A
A.1. Sea turtle stranding protocol used to document stranding events.
34
A.2. Sea turtle reference sheets used during interviews with marine resource users.
A.2.1. Olive ridley turtle reference sheet
35
A.2.2. East Pacific green turtle reference sheet
36
A.2.3. Hawksbill turtle reference sheet
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A.2.4. Leatherback turtle reference sheet.
38
A.3. Interview protocol developed and used to interview marine resource users along the coast of El Salvador.
A. Datos del informante local:
1) Fecha_____________ 2) Nombre_______________________________________
3) Sexo ______
4) Edad ______ 5) Comunidad _________________________________
6) A que se dedica?_____________________________
7) Desde hace cuanto?________años
B. Especies de tortugas marinas presentes en el área:
8) Cuantos tipos de tortugas marinas hay en su comunidad?______ Cuales son?__________________________________________________
*Muéstrele fotos de las 4 especies y anote cuales pudo identificar correctamente*
Golfina Prieta Carey Baule
Si o No Si o No Si o No Si o No
9) Ha visto tortugas en alta mar? Si o No
Especie Tamaño En que áreas Profundidad Meses Que están haciendo
Frecuencia (de 10 veces)
Observaciones___________________________________________________________________________
**Marque las áreas en el mapa y anote el nombre del área POR ESPECIE y POR TAMANO de las
tortugas**
10) Ha visto tortugas en el estero/manglar? Si o No
Especie Tamaño En que áreas Profundidad Meses Que están haciendo
Frecuencia (de 10 veces)
Si se esta alimentando, de que se alimenta (por
especie)?______________________________________________ Como lo sabe?________________________________
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Observaciones_______________________________________________________________________
**Marque las áreas en el mapa y anote el nombre del área POR ESPECIE y POR TAMANO de las
tortugas**
11) Hay pastos marinos? Si o No
Donde están ubicados?________________________________________________________________________
Ha visto tortugas en los pastos? Si o No
Especie Tamaño En que áreas Profundidad Meses Que están haciendo
Frecuencia (de 10 veces)
Si se están alimentando, de que se alimenta (por especie)?____________________________________ Como lo sabe?________________________
Observaciones_______________________________________________________________________
**Marque las áreas en el mapa y anote el nombre del área POR ESPECIE y POR TAMANO de las
tortugas** 12) Ha visto tortugas en los arrecifes? Si o No
Especie Tamaño En que áreas Profundidad Meses Que están
haciendo
Frecuencia
(de 10 veces)
Si se están alimentando, de que se alimenta (por especie)?____________________________________
Como lo sabe?________________________ Observaciones_______________________________________________________________________
**Marque las áreas en el mapa y anote el nombre del área POR ESPECIE y POR TAMANO de las tortugas**
Se observa mas, menos, o la misma cantidad de tortugas hoy en día que cuando empezó a pescar/ostrear/etc.
(por especie)?________________________________
C. La pesca: Alta Mar □ Estero/Manglar □ Arrecife □
13) Se dedican muchas personas de su comunidad a la pesca? Si o No Cuantas personas?_______
14) Cuantas lanchas se dedican a la pesca en su comunidad?___________ Cuantos pescadores hay por lancha (si depende del tipo de pesca, anote por tipo)?________________________
40
Tipo de equipo (por especie de pez) En que áreas Profundidad
1.
2.
3.
En que meses (por especie de pez)?_________________________________________________________________
__________________________________________________________________________________________
___ 15) Cual tipo de equipo de pesca es lo mas utilizado?__________________________
El segundo mas utilizado?____________________________________________
16) Operan barcos camaroneros en frente de la pla ya de su comunidad? Si o No En que meses?___________________________
Cuantos barcos por mes (promedio)?__________________________ 17) Capturan tortugas marinas? Si o No
Cuantas
capturan
Especies Tamaño Que les pasa Como lo sabe Usan TED Como lo sabe
___ por año Si o No
Observaciones_______________________________________________________________________________
18) Hay otros tipos de pesca que accidentalmente capturan tortugas marinas? Si o No
Cuales Se
ocupan
Cuantas
capturan
Especies Tamaños En que áreas Que les pasa Como lo
sabe
Si o No __ por año
Observaciones______________________________________________________________________________
_
**Marque las áreas en el mapa y anote el nombre del área POR EQUIPO, POR ESPECIE y POR TAMANO
de las tortugas**
19) Hay tortugas que mueren dentro de los manglares? Si o no?
20) Hay tortugas que mueren por la pesca con bombas/explosivos? Si o No
Cuantas Especies Tamaños En que áreas
_____ por año
21) Hay tortugas que mueren por causas ajenas a la pesca? Si o No
Causa Cuantas Especies Tamaños En que áreas
____ por año
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Causa Cuantas Especies Tamaños En que áreas
____ por año
22) Tortugas que salen muertas
Cuantas normalmente No menos de No mas de En que playas
______ por mes ______ por mes ______ por mes
Salen mas, menos, o la misma cantidad de tortugas muertas que cuando empezó a pescar (por
especie)?___________
23) Cuales son las principales causas de muerte de las tortugas en su área?_____________________________________
