The South Bay Salt Pond Restoration Project and

The South Bay Salt Pond Restoration Project and Bay Water Quality SFEI Letitia Grenier, Jay Davis, Robin Grossinger

South Bay Salt Pond Restoration n Largest tidal wetland restoration project ever on the west coast n Comprises 16, 500 acres of salt ponds 15, 100 acres in South Bay n 1, 400 acres in Napa River watershed n

Map from SBSPRP web site

South Bay Salt Pond Restoration n Extensive geographic scope n Encompasses much of South Bay shoreline n Certain to have tremendous benefits n Concern about water quality

Marshes and Bay Strongly Linked water Restored Marsh sediment Bay food web Potential for regional impacts

Project Objectives n Mix of wetland habitats for wildlife n Flood management n Protect or improve water and sediment quality n Public access and recreation

Water Quality Concerns n Increased mercury in the food web www. cargillsalt. com Endangered California Clapper Rail

Methylmercury (Me. Hg) n Toxic to animals, including humans n Accumulates in food webs n Already a problem in Bay food web Humans n Wildlife n USGS

Human Health Screening Value Data from Greenfield et al. (2003)

Effects become apparent from 0. 5 – 0. 8 ppm Data from Schwarzbach and Adelsbach (2003)

Clapper Rail Population Trends See Pulse 2005 for data sources

Increased Food Web Mercury? n Wetlands Known to produce methylmercury n New wetlands may produce more Me. Hg n Regional effects on Me. Hg accumulation n n SBSP Restoration Project Could increase Me. Hg in food web n Potentially as important as all current sources n

Water Quality Concerns n Increased mercury in the food web n Legacy sediment pollution New Almaden Quicksilver Mine

Legacy Sediment Pollution n Legacy pollutants in Bay marshes, salt ponds, and their food webs n n PCBs, DDT, Hg South Bay sources Historic mercury mining ― New Almaden n Urban and industrial runoff n n More information is needed

Concentrations 10 times greater than Bay average Runoff from New Almaden mining district Beutel and Abu Saba 2004

Water Quality Concerns n Increased mercury in the food web n Legacy sediment pollution n Erosion and recirculation of polluted Bay sediment

Accelerated Erosion n Restoration will likely increase erosion of Bay and marsh sediments in some areas Increased tidal prism n Sediment sink n n Buried sediments from the 1950 s and 1960 s that contain high contaminant concentrations could be eroded and relocated

Bay San Pablo tion c i d e r P l e d Mo Lower South Bay Model Prediction San Pablo Bay Core

Water Quality Concerns n Increased mercury in the food web n Legacy sediment pollution n Erosion and recirculation of polluted Bay sediment n Ongoing inputs of pollutants

Ongoing Inputs n Contaminants Legacy pollutants (Hg, PCBs, etc. ) n Chemicals in current use (PBDEs, pyrethroids) n Combustion emissions (PAHs) n n Pathways Runoff from adjacent watersheds n Direct atmospheric deposition n

PBDEs Highest concentration ever observed in biota n Forster’s Tern egg n Hayward shoreline n Near Baumberg salt ponds

Pyrethroids n Use increasing in urban areas n Highly toxic to fish and aquatic arthropods n Could cause breakdown of food web as prey species are affected

How to Address Concerns n Proceed with restoration n Adaptive management Sound science n

Key Recommendations n Hg monitoring and research should be an on-going component of the SBSPRP n n Hg poses the greatest contaminant threat to achieving project goals Coordination with other research and monitoring projects (RMP, CBDA)

Further Information n SBSP Restoration Project http: //www. southbayrestoration. org/ n Article in Pulse of the Estuary 2005 (p. 72) n Davis et al. 2003. San Francisco Estuary and Watershed Science: Volume 1, Article 4. n For a longer paper on this topic written for the SBSPRP, contact me: letitia@sfei. org