SACRAMENTO, Oct. 25, 2017 – A new state fish advisory issued yesterday provides safe eating advice for multiple fish species from the largest off-stream reservoir in the United States.
The advisory provides recommendations for five fish species from San Luis Reservoir, which has a capacity of more than 2 million acre-feet and covers almost 20 square miles, and for four species from the adjacent 3.5-square-mile O’Neill Forebay. The reservoir and forebay are located 12 miles west of Los Banos on State Route 152 in Merced County.
For San Luis Reservoir, the advisory provides recommendations for Tule Perch, American Shad, Striped Bass, Common Carp, and black bass species. For O’Neill Forebay, it provides recommendations for Inland Silverside, Striped Bass, black bass species, and catfish species.
The California Environmental Protection Agency’s Office of Environmental Health Hazard Assessment (OEHHA) developed the recommendations based on the levels of mercury and polychlorinated biphenyls (PCBs) found in fish caught from the reservoir and forebay.
“Many fish have nutrients that may reduce the risk of heart disease and are an excellent source of protein,” said Dr. Lauren Zeise, director of OEHHA. “By following our guidelines for fish caught at San Luis Reservoir and O’Neill Forebay, people can safely eat fish low in chemical contaminants and enjoy the well-known health benefits of fish consumption.”
These recommendations are based on the levels of mercury and PCBs measured in fish from San Luis Reservoir and O’Neill Forebay. They are independent of the Department of Water Resources’ warning(link is external)currently in place for San Luis Reservoir, which urges people to avoid shellfish and limit fish intake due to levels of toxic blue-green algae bloom (cyanobacteria) detected in water samples. While algal blooms are episodic and cyanobacteria levels are temporary, mercury and PCB levels in fish are persistent and generally remain consistent for many years.
When consuming fish from San Luis Reservoir, women 18-45 years and children 1-17 years may eat two total servings per week of Tule Perch or one total serving per week of American Shad. They should not, however, eat black bass species, Common Carp, or Striped Bass.
Women 46 years and older and men age 18 years and older may eat 5 total servings per week of Tule Perch, or two total servings per week of American Shad, or one total serving per week of black bass species, Common Carp, or Striped Bass.
When consuming fish from O’Neill Forebay, women 18-45 years and children 1-17 years may eat six total servings per week of Inland Silverside or one serving per week of black bass species, catfish species, or Striped Bass.
Women 46 years and older and men age 18 years and older may eat seven total servings per week of Inland Silverside, or two total servings per week of black bass species or Striped Bass, or one serving per week of catfish species.
One serving is an eight-ounce fish fillet, measured prior to cooking, which is roughly the size and thickness of your hand. Children should be given smaller servings.
For fish species found in San Luis Reservoir and O’Neill Forebay that are not included in this advisory, OEHHA recommends following the statewide advisory for eating fish from California’s lakes and reservoirs without site-specific advice.
Mercury is a naturally occurring metal that is released into the environment from mining and burning coal. It accumulates in fish in the form of methylmercury, which can damage the brain and nervous system, especially in developing children and fetuses. Because children and fetuses are especially sensitive to mercury, OEHHA provides a separate set of recommendations specifically for children up to age 17, and women of childbearing age (18-45 years).
PCBs are a group of industrial chemicals. At high levels of exposure, they can cause health problems, including cancer. Although they were banned in the United States in the late 1970s, they persist in the environment for many years and are still found in the environment from spills, leaks or improper disposal. PCBs accumulate in the skin, fat, and some internal organs of fish. In order to reduce exposure from PCB contaminated fish, OEHHA recommends eating only the skinless fillet (meat) portion of the fish.
Eating fish in amounts slightly greater than the advisory’s recommendations is not likely to cause health problems if it is done occasionally, such as eating fish caught during an annual vacation.
The San Luis Reservoir and O’Neill Forebay recommendations join more than 90 other OEHHA advisories that provide site-specific, health-based fish consumption advice for many of the places where people catch and eat fish in California, including lakes, rivers, bays, reservoirs, and the California coast.
The health advisory and eating advice for San Luis Reservoir and O’Neill Forebay – as well as eating guidelines for other fish species and California bodies of water – are available on OEHHA’s Fish Advisories webpage: http://www.oehha.ca.gov/fish/advisories. Pictorial versions of fish consumption advice are also available on this page in both English and Spanish.
OEHHA is the primary state entity for the assessment of risks posed by chemical contaminants in the environment. Its mission is to protect and enhance public health and the environment by scientific evaluation of risks posed by hazardous substances.