Ben Greenfield

1
Spatial patterns in forage fish Hg2008 update

• Ben Greenfield Katie Harrold, SFEI
• Darell Slotton Shaun Ayers, UC Davis

San Francisco Mercury Coordination
Meeting February 5, 2009
2
RMP Mercury Strategy Questions

• Where is mercury entering the Bay food web?
• What processes, sources, and pathways contribute
  disproportionately to food web accumulation?

3
General approach

• Spatial analysis
• Stratified random design
• Identify hotspots based on conceptual model
• Seasonal trend evaluation
• Interannual trend detection
• Field sampling for Hg isotopes and for DGT study

4
Spatial survey stratified random design

• Probabilistic sampling of entire bay shoreline
• Enclosed sites
• Open-water sites
• Potential Hg source sites
• Wetlands
• High elevation (high methylation)
• Low elevation (low methylation)
• Selected to correspond with other sampling in
  2008

5
Design Source Site Selection

• Mining sources
• Creeks draining probable source mines
• WWTP shallow water discharges
• Creeks draining urban/industrial areas
• High sediment Hg or MeHg

6
2008 Fish Sites
Long term site
Draft Data Do Not Cite
7
Previous data (2005 2007)
Hg (ug/g)
8
Organized by species/habitat
Bay margins
Hg (ug/g)
Open waters
9
Draft Data Do Not Cite
10
300
South Bay
280
Silverside Hg (mean ? SE)
260
240
220
200
San Pablo Bay
Suisun Bay
Central SF Bay
180
160
Hg (ng/g wet weight, whole body)
140
120
100

80
60
40
20
0
29BIR
KIRKE
06OTH
CHINA
04OTH
66OTH
64OTH
62OTH
93OTH
ALVSL
4ALVS
01OTH
05OTH
03OTH
COYSL
BENPK
306WE
EDENL
NEWSL
18PAB-A
WWTP-2
WWTP-3
11
300
South Bay
280
Silverside Hg (mean ? SE)
260
Silverside Hg
(

of Composites
240
)
SE
220
200
San Pablo Bay
Suisun Bay
Central SF Bay
180
160
Hg (ng/g wet weight, whole body)
140
120
100

80
60
40
20
0
29BIR
KIRKE
06OTH
CHINA
04OTH
66OTH
64OTH
62OTH
93OTH
ALVSL
4ALVS
01OTH
05OTH
03OTH
COYSL
BENPK
306WE
EDENL
NEWSL
18PAB-A
WWTP-2
WWTP-3
Not enclosed Enclosed
12
300
South Bay
280
Silverside Hg (mean ? SE)
260
240
220
San Pablo Bay
Suisun Bay
200
Central SF Bay
180
160
Hg (ng/g wet weight, whole body)
140
120
100

80
60
40
20
0
29BIR
KIRKE
06OTH
CHINA
04OTH
66OTH
64OTH
62OTH
93OTH
ALVSL
4ALVS
01OTH
05OTH
03OTH
COYSL
BENPK
306WE
EDENL
NEWSL
18PAB-A
WWTP-2
WWTP-3
Wetland sites
Draft Data Do Not Cite
13
300
South Bay
280
Silverside Hg (mean ? SE)
260
Silverside Hg
(

of Composites
240
)
SE
220
200
San Pablo Bay
Suisun Bay
Central SF Bay
180
160
Hg (ng/g wet weight, whole body)
140
120
100

80
60
40
20
0
29BIR
KIRKE
06OTH
CHINA
04OTH
66OTH
64OTH
62OTH
93OTH
ALVSL
4ALVS
01OTH
05OTH
03OTH
COYSL
BENPK
306WE
EDENL
NEWSL
18PAB-A
WWTP-2
WWTP-3
Hg contaminated sediment Industrial
watershed WWTP
14
Means of Comps SE
(WWTP)
Hg Mine (New Almaden)
WWTP
Silverside
Draft Data Do Not Cite
15
Means of Comps SE
(WWTP)
Hg Mine (New Almaden)
WWTP
Silverside
Draft Data Do Not Cite
16
Means of Comps SE
(WWTP)
Hg Mine (New Almaden)
WWTP
Silverside
Draft Data Do Not Cite
17
WWTP
Legacy, Industrial
Legacy, Industrial
WWTP
Draft Data Do Not Cite
18
Hg mine (Bella Oaks) Napa river
WWTP
Hg Mine
Legacy, Industrial
Legacy, Industrial
WWTP
Draft Data Do Not Cite
19
Prickly Sculpin Regional Mercury
Merced River
Sac R. RM44
Clear Creek
Tuolumne River
Sac R. Hamilton City
20
Prickly Sculpin Regional Mercury
Hg mine (Bella Oaks) Napa river
Merced River
Sac R. RM44
Clear Creek
Tuolumne River
Sac R. Hamilton City
21
Draft Data Do Not Cite
22
200
180
160
0.78
y 1.43x
140
2
R
0.67
120
Topsmelt Hg (ppb ww)
100
80
60
40
20
0
0
50
100
150
200
250
300
Silverside Hg (ppb ww)
23
300
280
Topsmelt Hg (mean ? SE)
260
Topsmelt Hg
South Bay
240
Mean of
(
220
San Pablo Bay
200
Suisun Bay
180
Central SF Bay
160
Hg (ng/g wet weight, whole body)
140
120
100

80
60
40
20
0
29BIR
KIRKE
CHINA
ALVSL
4ALVS
01OTH
05OTH
BENPK
03OTH
06OTH
04OTH
66OTH
64OTH
62OTH
93OTH
EDENL
COYSL
306WE
NEWSL
18PAB-A
WWTP-2
WWTP-3
24
Hg Mine (New Almaden)
Draft Data Do Not Cite
25
Preliminary findings 2008

• Where is mercury entering the Bay food web?
• A regional gradient
• What processes, sources, and pathways contribute
  disproportionately to food web accumulation?
• No evidence of wetlands
• No evidence of industrial watersheds
• Wastewater treatment plants apparent reduction
• Evidence of mining Hg source signal

26
Next steps

• Analyze data length corrected
• Analyze with model including spatial covariance
• Continue probabilistic study design in 2009 and
  2010

27
2009 Fish Sites
Long term site
Draft Data Do Not Cite