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Summary of 10 years of sediment toxicity monitoring for the San Francisco Estuary Regional Monitoring Program
Brian Anderson, Bryn Phillips, John Hunt, Patricia Nicely, Ron Tjeerdema University of California, Davis
Bruce Thompson, Sarah Lowe, Jay Davis San Francisco Estuary Institute
Karen Taberski California Regional Water Quality Control Board – San Francisco Bay Region
Contaminants entering the estuary attach to particles which may then be deposited
as sediments
Contaminants may impact benthicorganisms or higher trophic level
species
Amphipod 10-d survival test
Laboratory Toxicity Testing(UC Davis – MarinePollution Studies Lab)
Measures acute effects
Mussel embryo development
48-h exposureSublethal endpoint
Sediment-water interface exposure
Sediment elutriate exposure
Sediment contamination
Sediment toxicity
Benthic community structure
Bioaccumulation
Results used to identify and map areas of impaired or potentially impaired beneficial uses:
Aquatic life
Human health
Wildlife
Sediment Quality Triad
Toxicity test data used in a weight-of-evidence
0%
50%
100%
0%
50%
100%
0%
50%
100%
Rivers
Grizzly BayNapa RiverSan Pablo Bay
0%
50%
100%
0%
50%
100%
South Bay
0%
50%
100%
Redwood Creek
0%
50%
100%
Yerba Buena Island
0%
50%
100%
Horseshoe Bay
0%
50%
100%Coyote Creek
San Jose
0%
50%
100%
Legend:
0%
50%
100%
Sampling Period (1993 to 2001)
Amph % Survival Biv % Norm. Dev.
Some stations are consistently toxic, others exhibit seasonal toxicity
Change in RMP Experimental Design:
1993 –2001: Winter and Summer Sampling of Fixed Stations
2002-2003: Summer Sampling Using Probabilistic Sampling Design (7 fixed stations + 21 random stations)
Winter Summer0
50
1001993-2000
% S
tati
ons
toxi
c to
am
ph
ipod
s
36%
10%
Summer0
50
1002002
% S
tati
ons
toxi
c to
am
ph
ipod
s
18%
0
20
40
60
80
100
0.06 0.20 0.40 0.60 0.80 1.00 1.40
toxic nontoxic
Never Toxic Always Toxic
r = - 0.685p = <0.0001n = 118
Am
ph
ipod
% s
urv
ival
mERMQ
Amphipod response vs. contaminant mixtures
Thompson et el. 1999
0
20
40
60
80
100
0.06 0.20 0.40 0.60 0.80 1.00 1.40
toxic nontoxic
Never Toxic Always Toxic
r = - 0.685p = <0.0001n = 118
Am
ph
ipod
% s
urv
ival
mERMQ
Amphipod response vs. contaminant mixtures
Benthic impact68% stations
Thompson et el. 1999Thompson and Lowe in review
Benthic impact100% stations
Toxicity Identification Evaluations (TIEs)
Phase I – characterization: e.g., metals vs organics, ammonia, H2S
Phase II – identification: specific metal or organic compound(s) responsible for toxicity
Phase III – confirmation
Consider confounding factors: grain size, ammonia, pH etc.
Once identified, chemical responsible for toxicity are emphasized in later studies : Source identification and control
0102030405060708090
100
Ba
se
lin
e
Filtr
ati
on
Ae
rati
on
ED
TA
ST
S
pH
7.9
pH
8.1
pH
8.4
C1
8 C
olu
mn
C1
8 E
lua
te
Ca
tio
n C
olu
mn
Mo
rtal
ity
(%)
Grizzly Bay Bivalve TIE w/ 25% Elutriate
Phillips et al. in press
0
20
40
60
80
100
Control Controlw/EDTA
Site Sitew/EDTA
Mo
rtal
ity
(%)
Sediment-Water Interface TIE w/ EDTA
Phillips et al. in press
Bivalve TIE Summary: Grizzly Bay
Copper is implicated as the primary cause of sediment toxicity to bivalves (elutriates, sediment-water interface)
Other divalent metals may also contribute to elutriate toxicity
Amphipod TIE Summary: Grizzly Bay
Toxicity is probably not due to organic chemicals
Sediment is toxic, pore water is not
Toxicity is due to some acid-soluble compound
Napa River
Redwood Creek
Coyote Creek
North Bay Rivers
Petaluma River
Guadalupe River
Future Work
Continued Status and Trends monitoring
Application of TIEs at consistently toxic stations
Winter samples
Possible Special Studies
Winter sampling at the base of key tributary streams
Dose-response toxicity tests with resident and surrogate toxicity test species
Recommended