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