New guidelines were released yesterday for safely eating fish caught in San Francisco Bay. The Office of Environmental Health Hazard Assessment (OEHHA) has released an updated health advisory and safe eating guidelines for fish and shellfish caught from the Bay. This advisory replaces guidelines dating back to 1994 and is informed by a wealth of data collected over the last decade, particularly in relation to the presence and concentration of mercury and polychlorinated biphenyls (PCBs) within the Bay and how these toxic contaminants are magnified as they pass through the food chain.
Excessive exposure to methylmercury (the form of mercury prevalent in fish) in humans can affect the nervous system and harm learning ability, language skills and memory. PCBs are common industrial contaminants known to build up in fish. They have been found to cause cancer in animals and also cause health problems in young children and adults.
The revised guidelines recognize that some kinds of fish contain more mercury and PCBs than others: sharks had the highest levels of mercury, and shiner perch had the most PCBs. OEHHA recommends avoiding shiner perch and other surfperch species from San Francisco Bay. In addition, because of heavy contamination by PCBs and the pesticide dieldrin, OEHHA recommends that no one eat any fish or shellfish from the Lauritzen Channel in Richmond Inner Harbor.
OEHHA provides further specific recommendations for species and servings that are safe for pregnant women, children and others. OEHHA intends to post the new guidelines along the Bay, presumably in known fishing areas. The full guidelines and easy to read charts can be found here.