ABSTRACT:
San Francisco Bay has a legacy of mercury contamination from historical mercury mining
in the Coast Range and gold extraction in the Sierra Nevadas. An estimated 220 million pounds of mercury were mined in the coastal mountains from the mid-1800s to the mid-1900s. Additionally, over 26 million pounds of mercury were used for gold recovery in the Sierras. During these mining activities, roughly 10% to 30% of all the mercury used was lost to the surrounding watersheds and has since been making its way, attached to sediment particles, into the San Francisco Bay-Delta. This pollution has resulted in San Francisco Bay being listed as an impaired water body under the Clean Water Act, and a Bay-wide fish consumption advisory has been enacted by the State. In a large collaborative project funded by the CalFed Ecosystem Restoration Program, biologists of the U.S. Geological Survey, U.S. Fish and Wildlife Service, San Francisco Bay Bird Observatory, and PRBO Conservation Science are investigating the risks of mercury to waterbirds breeding within the estuary. |
