Skip to main content
U.S. flag

An official website of the United States government

Historical methyl mercury in San Francisco Bay

July 6, 2015

San Francisco Bay, California is considered a mercury-impaired watershed. Elevated concentrations of mercury are found in water and sediment as well as fish and estuarine birds. Sources of mercury to the watershed since 1845 include sediment-associated mercury from mercury mining, mercury losses from gold amalgamation activities in mines of the Sierra Nevada, aerial deposition of mercury from global and regional emissions to air, and the direct discharge of mercury to Bay waters associated with the urbanization and industrialization of the estuary. We assessed historical trends in mercury bioaccumulation by measuring mercury concentrations in feathers of the endangered California Ridgways rail (formerly California Clapper Rail) using museum specimens. We developed a structural equation model to attribute variation in historical mercury bioaccumulation in rails to sources of mercury, and estimated the toxicological consequences of extreme mercury exposure to rails from known correlations between feather and blood mercury concentrations.

Publication Year 2015
Title Historical methyl mercury in San Francisco Bay
DOI 10.5066/F78P5XKP
Authors Steven E. Schwarzbach, Josh T Ackerman, Collin A Eagles-Smith, Michael L Casazza, Julie L Yee, Alan C. Heyvaert, David P Krabbenhoft, Thuy-Vy D. Bui, John Y. Takekawa
Product Type Data Release
Record Source USGS Digital Object Identifier Catalog
USGS Organization Western Ecological Research Center - Headquarters