Mercury in the San Francisco Estuary.

This review presents some of the published and other important literature on mercury contamination in San Francisco Estuary. Studies on human consumption of contaminated sportfish and on detecting ecological impacts of this contamination in wetland areas validate concerns regarding mercury's toxicity in this system. Mining, industrial, and environmental uses of mercury have occurred for more than a century, resulting in its large historic and continuing transport to the estuary. Consequently, there is a widespread distribution in the estuary, but more work is needed to show its relative chemical and biological availability from these sources. The uptake of mercury in the estuary has been shown in phytoplankton, but studies on biomagnification in local food webs have yet to draw a clear path to impairment in sportfish and waterbirds. In light of these concerns of impairment and the need for further information, large restoration activities planned for the estuary will require new technical approaches to solve important management questions, such as the location of key areas of methylmercury production.