trace metals in sf bay wigs group, ucsc multiple sources sf bay one of few estuaries nationwide with...
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Trace Trace Metals In Metals In SF BaySF BayWIGS Group, UCSC
Multiple sources SF Bay one of few
estuaries nationwide with temporal data on metals
Current WIGS work
Complexity of Metal Complexity of Metal Inputs to SF Bay Inputs to SF Bay (Flegal et (Flegal et al, 2005)al, 2005)
1) POTWs and industrial inputs
2) Diagenetic Remobilization: Ag, Co, Ni, Cu, Zn. (Flegal et al., 1996; Rivera-Duarte and Flegal, 1997)
3) Urban Runoff vs Fluvial Inputs
4) Atmospheric deposition (Conaway et al., 2005)
5) Historic Gold Mining (Conaway et al., 2004)
“The lack of peer-reviewed scientific reports on current levels of contaminants in those waters over (the past 30 years) precludes statistically valid measures of changes in contaminant levels over the past decade. One exception is the San Francisco Bay Regional Monitoring Program.”
Temporal trends in wastewater source loadings of Ag and Pb (Squire et al., 2002)
Clean water Act of 1972
Closure of a photograph processing plant located in the southern reach in the mid 1980’s
San Francisco’s Oceanside Water Pollution Control Plant rerouted ~ 12% of the total effluent to the Pacific ocean via a 4.5 mile ocean outfall.
930 tonnes of trace metals released from POTW of the estuary in 1960, reduced to
just 46 tonnes in 1999
Black = South Bay and Gray = North Bay
Pb Isotopes in SF Bay Pb Isotopes in SF Bay Water Water (Steding et al., 2000)(Steding et al., 2000) Dissolved Pb
has not decreased in South Bay
Dissolved Pb is largely composed of 1960-1970s gasoline
CurrentCurrentWIGS WIGS WorkWork
Effects of Hg on salmonids (Mary) Hg cycling (Kit) Mercury speciation and
complexation (Frank) Phytoplankton blooms and metals
(Allison)
Methods development (Ndung’u et al., 2005)
Pronounced Variations in Pronounced Variations in Nutrients and Trace Nutrients and Trace Metals During a Spring Metals During a Spring Phytoplankton Bloom in Phytoplankton Bloom in San Francisco BaySan Francisco BayAllison C. Luengen & A. Russell FlegalUniversity of California, Santa Cruz
Summary: Complexation prevents copper
uptake, but not nickel uptake Bloom decay important for
metal cycling Pb cycling during bloom
South SF Bay South SF Bay CharacteristicsCharacteristics Predictable phytoplankton bloom in South Bay occurs when water column stratifies in spring (Cloern, 1996)
The phytoplankton bloom depletes nutrients and some trace metals (Beck et al., 2002; Grenz et al., 2000; Luoma et al., 1998) Metals such as copper are organically complexed, limiting their bioavailability (Buck and Bruland, 2005; Donat et al., 1994 Sunda and Huntsman, 1998)
South Bay
North Bay
PacificOcean
Oakland
Berkeley
Richmond
San J ose
San J uanRiver
SacramentoRiver
37°45'N
122°W
Site 21 (Bay Bridge)
(Calaveras Point)
Site 32(Ravenswood Point)
Site 36
ObjectivesObjectives Characterize the Characterize the
biogeochemistry of biogeochemistry of Co, Cu, Ni, Pb, and Co, Cu, Ni, Pb, and Zn during a spring Zn during a spring bloombloom
Assess bioavailability Assess bioavailability of Niof Ni
Effect of bloom decayEffect of bloom decay
Use Principle Components Analysis Use Principle Components Analysis (PCA) to reduce the data into three (PCA) to reduce the data into three factorsfactors
Rise and Decay of a Bloom
10
200
300
400
500
600
700
800
900
Dis
solv
edor
gani
cca
rbon
( µM
)
213236
Site
Fe
bru
ary
24
Au
gust
27
Ma
y1
Apr
il2
3A
pril
17
Ap
ril1
Mar
ch27
Ma
rch
12
Ma
rch
4
Date
0
50
100
150
200
Ch
loro
ph
yll-a
(µg /
L)
Fe
brua
ry24
Au
gust
27
Ma
y1
Ap
ril2
3A
pril
17
Ap
ril1
Ma
rch
27
Ma
rch
12
Ma
rch
4
DateFeb
rua
ry19
Nutrients During Bloom: Diagnostic nutrient cycles
0
10
20
30
40
50
60
Dis
solv
ed in
orga
nic
nitr
ogen
(M
)213236
Site
DateDate
50
100
150
200
250
Dis
solv
ed s
ilica
te (
µM
)
0
Nutrient analyses by Steve Hager, USGS
Principal Component Principal Component AnalysesAnalysesFactor 1 –
Ascending bloomFactor 2 –
ScavengingFactor 3 – Bloom decay
Dissolved oxygen (0.703)
Log suspended particulate matter (0.748)
Log dissolved organic carbon (-0.657)
Temp (-0.622) Sigma T (-0.646) Log phaeophytin (0.697)
Salinity (-0.620) Log dissolved reactive phosphate (0.832)
Dissolved inorganic nitrogen (-0.607)
Unfiltered Fe (0.819)
Dissolved silicate (-0.834)
Unfiltered Mn (0.775)
Log chl-a (0.864) -3 -2 -1 0 1 2 3Factor 1
0.5
1.0
1.5
2.0
2.5
Log
chlo
roph
y ll-a
(µg/
L)
Dissolved Cu & Ni During Bloom:Speciation determines uptake
10
20
30
40
50
60
Dis
solv
edC
u(n
M)
Feb
rua
ry2
4
Au
gust
27
Ma
y1
Ap
ril2
3A
pril
17
Ap
ril1
Ma
rch
27
Mar
ch12
Ma
rch
4
Date
10
20
30
40
50
60
Dis
solv
ed
Ni(
nM
)213236
Site
Fe
bru
ary
24
Au
gust
27
Ma
y1
Ap
ril2
3A
pril
17
Apr
il1
Ma
rch
27
Ma
rch
12
Ma
rch
4
Date
Dissolved Ni: Uptake by Phytoplankton
-3 -2 -1 0 1 2 3Factor 1
10
20
30
40
50
60
Dis
solv
edN
i (nM
)
21
36
Site
32
1) Ni significantly (p<0.00) depleted during bloom
2) Ni significantly (p<0.00) affected by station
Nickel Is Bioavailable
Why is Ni bioavailable? (Sedlak et al., 1997)
– Degradation of EDTA-Ni
– Seasonal changes in EDTA-Ni complexation
Uptake of Ni consistent with Luoma et al. (1998) field study but different from Beck et al. (2002) lab study.
Dissolved Mn & Co During Bloom: Inversely related to bloom
Fe
bru
ary
24
1
2
3
4
5
6
7
8
Dis
solv
edC
o(n
M)
213236
Site
Au
gust
27
Ma
y1
Ap
ril2
3A
pril
17
Apr
il1
Ma
rch
27
Ma
rch
12
Ma
rch
4
Date
0
1
2
3
Dis
solv
edM
n(µ
M)
Fe
bru
ary
24
Au
gust
27
Ma
y1
Ap
ril2
3A
pril
17
Apr
il1
Ma
rch
27
Ma
rch
12
Ma
rch
4
Date
Roitz et al. (2002) found remobilization of Mn from sediment following a bloom
Dissolved Co: Scavenging & Decay
-3 -2 -1 0 1 2 3Factor 3
-3
-2
-1
0
1
2
3
4
Co
resi
dual
(sta
ndar
dde
viat
ions
)-2 -1 0 1 2
Factor 2
-3
-2
-1
0
1
2
3
4
Co
resi
dual
(sta
ndar
dde
viat
ions
)
Increase in dissolved Co during bloom decay NOT due to sediment-water repartitioning
Kd controlled by station in the reduced model (p=0.00024)
-2 -1 0 1 2Factor 2
-0.4
-0.3
-0.2
-0.1
0.0
0.1
0.2
0.3
Zn
resi
du
al(
s tan
da
rdd
ev i
atio
ns)
-3 -2 -1 0 1 2 3Factor 3
-0.5
-0.4
-0.3
-0.2
-0.1
0.0
0.1
0.2
0.3
0.4
0.5
Zn
resi
dua
l(st
an
dar
dd
evia
tions
)
Scavenging and bloom decay do significantly (p=0.036 & 0.032, respectively) affect Kd
Dissolved Zn: Scavenging & Decay
Dissolved Pb During Bloom: Multiple linear regression to assess
contribution of individual factors
0.0
0.1
0.2
0.3
0.4
Dis
solv
edP
b(n
M)
213236
Site
Fe
bru
ary
24
Au
gust
27
Ma
y1
Ap
ril2
3A
pril
17
Apr
il1
Mar
ch27
Ma
rch
12
Ma
rch
4
Date
Pb: Rise, Scavenging, & Decay
-3 -2 -1 0 1 2 3Factor 1
-0.10
-0.05
0.00
0.05
0.10
Pb
resi
dua
l(st
an
dard
dev i
atio
ns)
-2 -1 0 1 2Factor 2
-0.2
-0.1
0.0
0.1
Pb
res i
du
al(s
tan
da r
dd
evia
tions
)
-3 -2 -1 0 1 2 3Factor 3
-0.2
-0.1
0.0
0.1
0.2
0.3
Pb
resi
du
al( s
tan
dar
dd
evia
tions
)
ConclusionsConclusions Speciation Speciation
prevents dissolved prevents dissolved Cu uptake, but not Cu uptake, but not dissolved Ni dissolved Ni uptakeuptake
Decay of the bloom Decay of the bloom is important for is important for dissolved Mn, Co, dissolved Mn, Co, ZnZn
Pb cycling is Pb cycling is affected by rise, affected by rise, scavenging, decayscavenging, decay
Acknowledgements
• calculationWIGS: Frank Black, Kit
Conaway, J.R. Flanders, Mari Gilmore, Ana Gonzalez, Sharon Hibdon, Brian Johnson, Fiona Morris, Charley Rankin, Mara Ranville, Genine Scelfo, Hans Schwing
USGS: Jim Cloern, Scott Conard, Steve Hager, Amy Little, Cary Lopez, Tara Schraga, and Byron Richards
COMMITTEE: Ken Bruland, Raphael Kudela,
Sam Luoma
ANALYTICAL: Rob Franks
STATISTICS: Pete Raimondi
FUNDING:ETOX Dept,
UC Toxics, RMP, C.DELSI