Historical methyl mercury in San Francisco Bay

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 Ridgway’s 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.

Data and Resources

Field Value
accessLevel public
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catalog_describedBy https://project-open-data.cio.gov/v1.1/schema/catalog.json
identifier USGS:558194c3e4b023124e8f0b10
metadata_type geospatial
modified 20200827
old-spatial -122.567, 37.364, -109.196, 43.328
publisher U.S. Geological Survey
publisher_hierarchy Department of the Interior > U.S. Geological Survey
resource-type Dataset
source_datajson_identifier true
source_hash 1496c980e91a750591d19d59fa3263cea67c3620
source_schema_version 1.1
spatial {"type": "Polygon", "coordinates": [[[-122.567, 37.364], [-122.567, 43.328], [ -109.196, 43.328], [ -109.196, 37.364], [-122.567, 37.364]]]}
theme {geospatial}
Groups
  • AmeriGEOSS
  • National Provider
  • North America
Tags
  • amerigeo
  • amerigeoss
  • california-ridgways-rail
  • ckan
  • feathers
  • geo
  • geoss
  • ice-cores
  • lake-tahoe
  • mercury
  • national
  • north-america
  • san-francisco-bay
  • sediment
  • structural-equation-model
  • united-states
  • usgs-558194c3e4b023124e8f0b10
  • wyoming
isopen False
license_id notspecified
license_title License not specified
maintainer Steven E Schwarzbach
maintainer_email steven_schwarzbach@usgs.gov
metadata_created 2025-11-20T14:17:30.775309
metadata_modified 2025-11-20T14:17:30.775313
notes 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 Ridgway’s 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.
num_resources 2
num_tags 18
title Historical methyl mercury in San Francisco Bay