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

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

Map from SBSPRP web site

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

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

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

Water Quality Concerns Increased mercury in the food web Increased mercury in the food web Endangered California Clapper Rail

Methylmercury (MeHg) Toxic to animals, including humans Toxic to animals, including humans Accumulates in food webs Accumulates in food webs Already a problem in Bay food web Already a problem in Bay food web Humans Humans Wildlife Wildlife 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)

See Pulse 2005 for data sources Clapper Rail Population Trends

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

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

Legacy Sediment Pollution Legacy pollutants in Bay marshes, salt ponds, and their food webs Legacy pollutants in Bay marshes, salt ponds, and their food webs PCBs, DDT, Hg PCBs, DDT, Hg South Bay sources South Bay sources Historic mercury mining New Almaden Historic mercury mining New Almaden Urban and industrial runoff Urban and industrial runoff More information is needed 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 Increased mercury in the food web Increased mercury in the food web Legacy sediment pollution Legacy sediment pollution Erosion and recirculation of polluted Bay sediment Erosion and recirculation of polluted Bay sediment

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

San Pablo Bay Core Lower South Bay Model Prediction San Pablo Bay Model Prediction

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

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

PBDEs Highest concentration ever observed in biota Forsters Tern egg Forsters Tern egg Hayward shoreline Hayward shoreline Near Baumberg salt ponds Near Baumberg salt ponds

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

How to Address Concerns Proceed with restoration Proceed with restoration Adaptive management Adaptive management Sound science Sound science Reduce risk Reduce risk © C. Benton 2004

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

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

© C. Benton 2004