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Metals in SF Estuary Only US estuary with systematic, long-term monitoring Most peer-reviewed publications of any US estuary (Sañudo-Wilhelmy et al., 2004)

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Presentation on theme: "Metals in SF Estuary Only US estuary with systematic, long-term monitoring Most peer-reviewed publications of any US estuary (Sañudo-Wilhelmy et al., 2004)"— Presentation transcript:

1 Metals in SF Estuary Only US estuary with systematic, long-term monitoring Most peer-reviewed publications of any US estuary (Sañudo-Wilhelmy et al., 2004)

2 Metals in SF Estuary OLD NEWS (Sañudo-Wilhelmy et al., 2004)

3 Environmental Research Pollutants in SF Bay (Sept. 2007) Synthesis of decades of high quality data - truly remarkable only possible for SF Bay Multiplicity & Diversity of Institutions - truly remarkable academia (UCD, UCSC, Maryland) state & federal agencies (SWRCB, USGS, USF&WS) ngo’s (SFEI) industry (AMS, CH2MHill, Tetra Tech)

4 Articles on Metals in Special Issue Buck et al. - copperYee et al - nickel Flegal et al. - silverConaway et al. - mercury Schoellhamer et al. - sedimentsAnderson et al. - toxicity Thompson et al. - toxicity Other new reports: Black et al. (2007) MMHg Complexation Huerta-Diaz et al.(2007) Metals in Porewater Luengen et al. (2007) Metals & Plankton Conaway et al. (in press) Hg Review (in press) …………

5 Metals in SF Bay Lots of Interest & Lots of Data (Buck et al., 2007)

6 Comparability of RMP Data Trace metal clean tech. valid Rigorous QA/QC statistical analyses Evolving methodologies intercalibrated Published - sci. journals accessible reproducible (Ndung’u et al., 2006)

7 Total Dissolved (< 0.45 µm)* Copper * Historic basis for water quality criteria (Cu in SF Bay > WQC) 17 - 44% decline throughout the estuary (1993-2001) positively correlated with DOC (p < 0.0005) Consistent with complementary speciation measurements organic ligands typically bind >99.9% dissolved Cu in SF Bay Site-specific criteria for copper in SF Bay are being developed (Buck et al., 2007)

8 Nickel Ni concentrations ~ constant (1992-2005) Most “total dissolved” Ni is also strongly complexed Water quality objectives for Ni also being reconsidered (Yee et al., 2007)

9 Silver Temporal decrease in Central & South Bays water & sediments & biota concentrations may still be toxic Temporal increase in northern reach new inputs or increased remobilization? (Flegal et al., 2007)

10 Mercury *Significant (p<0.05) decrease of Hg in sediments @ 8 locations (1993-2001) NO associated decrease of Hg in sport fish or bivalves Hg(total) ≠MMHg relative increase in MMHg production ? (Conaway et al., 2007)

11 Sediments ~ Metals Pronounced temporal & spatial variability of metals ~ sediment fluxes Suspended sediments (SSC) a proxy for metals faster & cheaper BUT sediment transport in the Bay is changing negative sediment budget (Schollhamer et al., 2007)

12 How can things be worse - when they’re better ? reduced contemporary industrial inputs+ negative sediment budget- erosion of surface sediments- increased remobilization of historic inputs ? (Conaway et al., 2005)

13 How can things be worse - when they’re better? on-going inputs of contaminated sediments historic & contempporary SF Bay is a trap for metals continuous recycling of metals metals never degrade (Steding et al., 2000)

14 Summary Hg is toxic in SF Bay (biota & humans) Cu appears to still be toxic in sediments Ag may still be toxic in sediments Cd may still be toxic in sediments Metal toxicity may be increasing in SF Bay

15 Acknowledgments USGS (McColluch, Conomos, Peterson, Nichols, …) SF-RWQCB (Carlin, Ritchie, Mumley, Taberski, …) AMS (Spies, Gunther, Salop, Johnson,…) SFEI (Thompson, Hoenicke, Davis, Yee, Lowe, Sedlak, …) Funding Agencies, Municipalities, Industries (Tucker, …)


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