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San Francisco Bay Delta

South Bay Salt Pond Mercury Studies Project

This project will fund mercury studies in the 15,000 acre South Bay Salt Pond Project area to provide information needed to determine the management regime of Pond A8 (the pond with the highest mercury concentrations) as well as other future management of the ponds as they are restored to tidal wetlands.  These studies have been identified as needed through a comprehensive planning process for the Salt Pond Project and recommended by an inter-disciplinary management team that oversees the restoration as well as peer reviewed by a Science Team.

Project Facts

Recipient: California State Coastal Conservancy
Funding: $500,000 (non-federal match = $500,000/leverage = $715,000)
Project Period: September 2012 – December 2014
Partners: USGS, UC Davis, Santa Clara Valley Water District, City of San Jose, USACE, San Francisco Estuary Institute

Environmental Results Summary: Assessing Impacts of South Bay Salt Pond Tidal Wetland Restoration on Mercury Methylation and Bioaccumulation

OUTPUTS (Activities, efforts, and/or work product during project period)

OUTCOMES (Environmental results)

(1-5 yrs)


Determine the amount of erosion in Alviso Slough and the release of mercury as a result of restoration of Pond A8 to muted tidal flows in 2011

Determine the amount of mud suspended in Alviso Slough, and the fate and transport of the mud – whether mud ends up in Pond A8, Pond A6 or the open bay

Investigate seasonal changes in the amount of mercury in the mud, as well as the first big storm event of the year, to see if mercury changes with the seasons

Determine the amount of mercury in fish in the 3 sloughs (Alviso, Mallard, and Guadalupe Slough) and bird eggs in the ponds after restoration in Pond A8

Provide biosentinel species results to agencies and scientists to inform other wetlands restoration projects in the Bay-Delta region

Further scientific understanding of mercury cycling in tidal wetlands and salt ponds to adaptively manage future restoration activities planned over the next 10 years

Depending on results of studies, confirm that opening additional gates in the Pond A8 notch is prudent in order to eventually support full tidal restoration of 1,400 acres

Depending on results of studies, implement Shoreline Study tidal wetland restoration projects (2,045 acres in Ponds A9-A15 and 856 acres in Pond A18) with shortest duration possible between phases

Depending on results of studies, design measures to minimize mercury impacts in future tidal restoration phases.

Restore 2,901 acres of tidal wetlands (Pond A8-15, Pond A18) that reduces mercury inputs to the food web

Full List of Project Summaries