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CILERTom Johengen, Ashley Burtner,
Sander Robinson
Wayne State Wayne State UniversityUniversity
Donna Kashian, Donna Kashian, Vijay Kannappan, Vijay Kannappan,
Hunter Oates, Hunter Oates, Carly CollinsCarly Collins
Fall 2010 Multiple Stressors PI
Workshop
Experimental work
x
• Predict and manage: - muck deposition on beaches &
- E. coli/pathogens outbreaks
• Identify management efforts or policy changes that would reduce the impacts of contaminants
(i.e. dredging of hot spots)
• Manage sediment loading
• Manage and understand the impacts of agriculture in Saginaw Bay (i.e. nutrient loads, sedimentation, E. coli)
Water Quality GroupWater Quality GroupTop Management ObjectivesTop Management Objectives
• What are the primary drivers of muck deposition on beaches? What is the composition of muck?
• What and where are the primary sources of pathogens?
Are there pathogens in the muck?
• What are the impacts of contaminants to water quality?
• How much is sediment loading contributing to nutrient loading?
• What aspects of agriculture impact water quality & what can be effectively implemented to mitigate impacts?
Water Quality GroupWater Quality Group Primary Knowledge Gaps Primary Knowledge Gaps
2010 Project Overviews and Results
• Assess the physicalphysical and bioticbiotic influences on internal phosphorus loading in Saginaw Bay
• Identify Hexagenia benthic habitats
• Determine the prevalence, persistence and proliferation of
E. coli and enterococci in muck
Objective 1 : Field Survey
• light• temperature • moisture
Fecal Indicators in Beach Muck
Objective 2: Laboratory Mesocosm Study
Determine the prevalence of E. coli and enterococci in two different types of muck deposits (dry vs. wet)
Asses the influence of environmental variables on the persistence and proliferation of E. coli and enterococci.
Prevalence of E. coli and enterococci in wet vs. dry muck deposits
Most
pro
bable
num
ber
(MPN
) per
gra
m
Wet Muck Dry Muck
Effects of temp. & moisture on fecal indicators
E. Coli Enterococci
Days
Most
pro
bab
le n
um
ber
(MPN
)p
er
gra
m
Top panels hydrated: Bottom dry heat
E. Coli Enterococci
Enterococci
E. Coli
E. coli and enterococci survived in muck over 5
months at 40C
Days of exposure to sunlight
Most
pro
bab
le n
um
ber
(MPN
)per
gra
m
Cold Storage at 4°C
Muck provides a suitable environment for fecal bacteria to persist and proliferate for extended periods under natural conditions. MAY CONTRIBUTE TO BEACH CLOSURES
Direct sunlight inhibits growth
- Characterize the sediments-nutrients/carbon/particle size
1) Determine the role of sediment flux in phosphorus availability
under aerobic and anoxic conditions.
2) Determine the role of dreissenid mussels in nutrient cycling and availability.
- Identify “hot spots” of P recycling in the Bay
Assess the physicalphysical and bioticbiotic influences on internal phosphorus loading in Saginaw Bay Michigan.
Objectives
QuaggaZebra
Hypothesis
H1: Under anoxic conditions sediment bound phosphorus will resuspended and become more available.
- This phenomenon will be greater in depositional zones
H2: Dreissena excrement will contribute to phosphorus loading
(Woods 1964)
510
14
Sampling Sampling sitessites
Site 5 Sandy, mussel beds, macrophytesdepth = 3 m
Site 10 Silt, loose depositional basin; depth = 12 m
Site 14 sand-pebble substrate; depth = 5 m
Treatments
aerobic anoxic
10
5 +O2 - O2
- O2+ O2
14 - O2+ O2
Site
Methods: Methods: Hypoxia experimentsHypoxia experiments
• Sediment cores collected by divers and incubated under ambient temperature & light.
• Hypoxia simulated by removing oxygen by continuously
purging with helium; aerobic cores bubbled with air
• Nutrients monitored daily (10 days)
10%67%42%Capillary Pore Space
347247Pore Space (%)
1.770.721.66Bulk Density (g/cm3)
SandClay LoamSandy Clay
LoamTextural Class
1410
5Site
Results: Sediment Characterization Results: Sediment Characterization
5017896Iron (ppm)
5%93%25%Water holding Capacity (1/10 Bar)
Have this data for sites 1,7,11, 13,16, 20
Site 5 Site 10Site 14
P (
µg
P/L
)
0
20
40
60
80
P (
µg
P/L
)
020406080
100120140
Time (Day)1 2 3 4 5 6 7 8 9 10
020406080100120140
02
4
6
8
10
12
1 2 3 4 5 6 7 8 9 10
Results : Influence of hypoxia on P availability
TDP - aerobic TDP - anoxic
SRP - aerobic SRP - anoxic
Surface vs bottom TP – avg for 2008-10
SB2
SB5
SB14
SB10
SB20
SB10 – 12m
SRP Flux Values
0
aerobicanoxic
TDP Flux
-1500-500
0500
1500
2500
5 10 14
Average P Fluxes
-400
0
400
800
aerobic anoxicP fl
ux (
µg
P/m
2 d
ay)
SRPTDP
P F
lux (
µg
P/m
2 d
ay)
Location (Site)
-500
5001500
2500
3500
2009: Influence of hypoxia on P availability(Validated with 2010 data)
Summary/Conclusion
• Internal loading of P from sediments in Saginaw Bay likely to occur under hypoxic conditions.
• Majority of P returning from sediments occurs in sediment type observed at Site 10.
Prediction and modeling of anoxia in Bay waters may lead to better forecasting of
nutrient loads.
• Cores were collected in same manner as experiment 1– site 5 only– nutrients monitored daily
• Dreissena excretion was collected and applied (27μg/L/core) as a treatment
Treatments
aerobic anoxic
No inputs
+ Dreissena Excretion (DE)
+O2 + DE - O2 + DE
- O2
Effects of dreissenid excretion on P recycling
+ O2
Dreissenid Excretion Impacts
-1000
-800
-600
-400
-200
0
200
TP TDP SRP
P F
lux (
µg
P/m
2/d
ay)
aerobic DE
aerobic control
anoxic DEanoxic control
Excrement Degradation Timescales
• Incubation of water amended with excrement (no sediments)
• Suggests water column process at work (Bacterial uptake?)
Bacterial Conc’ in cores
Excrement amended
Control
CFU
s/ 1
00 µ
L
• The presence of dreissenid excretion results in less phos. in the water column under
anoxic and aerobic conditions (over 10 days).
Effects of dreissenid excretion on P recycling
• Excrement degradation experiment showed P removal in oxic filtered river water.
• Bacterial counts were significantly greater (p <.001) in cores amended with dreissenid excretion
Hexagenia hatch 2009
Hexagenia mayfly hatch in Tawas, Michigan, July 2009
Hexagenia nymph sampling (June 21-24, 2010)
• Collected using 4in diameter cores - Where possible, established 100 ft parallel transects 4-5ft
from embankments; one sample collected every 20ft- Invertebrates quantified at the lab
• ONLY 3 nymphs FOUND, all in Big Creek
Hexagenia adult sampling (June 22-24)
Locals reported seeing larger swarms the previous week
Tawas Pier, Tawas City Park, Tawas gas station
- Circular quadrants were placed over non-reflective white material and positioned under local street lamps- Hexagenia were counted inside each quadrant every 10 min from 10:00 pm-12:00 am
AcknowledgementsAcknowledgements
Funding: NOAA Center for Sponsored Coastal Ocean Research
Thanks to our divers and ship captains:Thanks to our divers and ship captains:Tane Casserley, Russ Green, Tom JoyceTane Casserley, Russ Green, Tom Joyce, ,
Wayne Lusardi and Jack WorkmanWayne Lusardi and Jack Workman
SRP Flux-200
-100
0
50
Aerobic DEAerobic Control
Anoxic DEAnoxic Control
TDP Flux-200
-100
0
100
P F
lux (
µg
P/m
2/d
ay)
Ex 1:TDP & SRP Fluxes
-80
-40
0
40
80
SRP Aerobic
SRP Anoxic
TDP Aerobic
TDP Anoxic
Effects of dreissenid excretion on P recycling