Mercury

Mercury is found throughout the San Francisco Bay-Delta estuary and its watershed at elevated concentrations in water sediment and biota. Mercury is of concern from both an environmental and human health perspective. Methylmercury is the toxic form of mercury. Effects on fish include: death, reduced reproductive success, impaired growth and development, and behavior abnormalities. Methylmercury exposure in birds can cause reproductive effects, and in plants can in plants can cause death and sublethal effects. Finally methylmercury effects on humans include neurotoxicity in adults and developmental problems in fetuses and children.

ERP has supported projects that:

• Created a strategy for early work (PDF)
• Developed an understanding of the sources and sinks of mercury and methylmercury to the Delta (PDF)
• Provided monitoring data that contributed to the development and updating of fish consumption advisories
• Increased public awareness of fish consumption issues (PDF)
• Evaluated bird movements and habitat use in combination with blood and brood monitoring to assess mercury effects (PDF)
• Developed a detailed conceptual model for mercury in the environment (PDF)

Current projects include:

• A pilot mine remediation project
• A pilot study looking at methylmercury in seasonal and permanent wetlands to determine best management practices
• A pilot study to remove mercury from dredge tails, cleaning the gravels for use in the nearby creek as spawning gravels
• Support for the Central Valley Regional Water Control Board’s Technical Advisory Committee for the Methylmercury Total Maximum Daily Load

Mercury Related Links

California Office of Environmental Health Hazard Assessment

• Mercury in Sport Fish
• Fish consumption advisories

California Department of Public Health

• Safe consumption guidelines for fish

Central Valley Regional Water Quality Control Board

• Updates on Total Maximum Daily Loads for reducing mercury and methylmercury in waterways
• Updates on program to reduce exposure

California State Water Resources Control Board

• Updates on statewide monitoring of bioaccumulative substances, including mercury
• Reservoir Total Maximum Daily Load

California Department of Conservation

• Mine Inventory Assessment

U.S. Geological Survey

• Mercury Contamination from Historic Gold Mining in California Fact Sheet
• Mercury in the Environment Fact Sheet
• Mercury in the Florida Everglades
• Updates for ongoing mercury research projects

U.S. Environmental Protection Agency

• Mercury page

San Francisco Estuary Institute

• Project products from the Fish Mercury Project

Delta Tributaries Mercury Council

• History and update on current activities

Experimental Lakes Area

• General introduction
• Mercury Experiment to Assess Atmospheric Loading (PDF)

For more information, contact Carol Atkins at catkins@wildlife.ca.gov or (916) 445-0074.