The RMP Mercury Strategy: Studies Underway

Talk Presents Multiple Data Sets Katie Harrold, Aroon Melwani, Andy Jahn, Jay Davis, John Oram, Shira Bezalel, Jen Hunt, Sarah Lowe, Karen Taberski Regional Monitoring Program Joel Blum, Gretchen Gehrke University of Michigan Holger Hintelmann, Brian Dimock Trent University Mark Marvin-DiPasquale, David Krabbenhoft, Collin Eagles-Smith, Josh Ackerman US Geological Survey Mark Stephenson, Wes Heim Moss Landing Marine Laboratories Darell Slotton, Shaun Ayers University of California - Davis

What is being done to answer the questions in the Mercury Strategy?

Answering the Mercury Strategy Questions Question 1: Where is mercury entering the food web? RMP Studies –Small Fish –Sport Fish –Avian Eggs –Sediment –Water Other Studies –South Baylands Mercury Project

Answering the Mercury Strategy Questions Question 2: Which processes, sources, and pathways contribute disproportionately to food web accumulation? RMP Studies –Methylmercury Model –DGTs –Mercury Isotopes –Small fish Other Studies –WERF –Effluent Monitoring

Answering the Mercury Strategy Questions Question 3: What are the best opportunities for management intervention for the most important pollutant sources, pathways, and processes? RMP Studies –Methylmercury Model Development Other Studies –Prop 13: Control Options in Tidal Wetlands –Props 40/50: Control Options in Suisun Marsh –Prop 13: Urban stormwater BMPs

Answering the Mercury Strategy Questions Question 1: Where is mercury entering the food web?

MeHg in sediments – probabilistic stations

Mississippi silverside

Topsmelt

White sturgeon

Sediments - RMP and other studies Open Enclosed

Nearshore and enclosed sites higher Open Enclosed Sediments - RMP and other studies

Wetland/margin species Open water species Small fish also show nearshore/offshore pattern

Sediment

What do available data suggest? Question 1: Where is mercury entering the food web? Southern parts of Estuary South Bay Salt Ponds Nearshore areas Enclosed areas Marsh sloughs and vegetated marsh (sediments)

Answering the Mercury Strategy Questions Question 2: Which processes, sources, and pathways contribute disproportionately to food web accumulation?

What kinds of sites are higher in fish Hg Stratified probabilistic sampling Sampling 108 unique locations Expanded small fish

What kinds of sites are higher in fish Hg –Wetlands?

What kinds of sites are higher in fish Hg –Wetlands? –Enclosed sloughs?

What kinds of sites are higher in fish Hg –Wetlands? –Enclosed sloughs? –Industrial watershed drainages?

What kinds of sites are higher in fish Hg –Wetlands? –Enclosed sloughs? –Industrial watershed drainages? –WWTPs?

What kinds of sites are higher in fish Hg –Wetlands? –Enclosed sloughs? –Industrial watershed drainages? –WWTPs? –Contaminated sediments

What kinds of sites are higher in fish Hg –Wetlands? –Enclosed sloughs? –Industrial watershed drainages? –WWTPs? –Contaminated sediments –Hg mine drainages?

What kinds of sites are higher in fish Hg –Wetlands? –Enclosed sloughs? –Industrial watershed drainages? –WWTPs? –Contaminated sediments –Hg mine drainages? –Compare to ambient bay and long term sites

DGT = Diffusive Gradient in Thinfilm Surrogate for biotic MeHg exposure Integrates water or sediments longer duration than grab samples

DGTs in the field

Can be placed in any aquatic location

Goals of the San Francisco Bay Hg Isotope Study Determine the Hg isotopic composition of Bedrock Mine tailings Gold mining Hg from bedrock in the drainage basin Hg from Hg mine tailings Hg from placer Au mining Urban run-off Municipal waste water Atmospheric deposition Determine the spatial distribution of Hg isotopic compositions in Bay sediments (at least 9 sites) to investigate sources of Hg in sediments Determine the Hg isotopic compositions of fish from the same sites to investigate sources of Hg to fish

Answering the Mercury Strategy Questions Question 3: What are the best opportunities for management intervention for the most important pollutant sources, pathways, and processes?

Acknowledgements Katie Harrold, Aroon Melwani, Andy Jahn, Jay Davis, John Oram, Shira Bezalel, Jen Hunt, Sarah Lowe, Karen Taberski Regional Monitoring Program Joel Blum, Gretchen Gehrke University of Michigan Holger Hintelmann, Brian Dimock Trent University Mark Marvin-DiPasquale, David Krabbenhoft, Collin Eagles-Smith, Josh Ackerman US Geological Survey Mark Stephenson, Wes Heim Moss Landing Marine Laboratories Darell Slotton, Shaun Ayers University of California - Davis