A state environmental health agency has issued its first-ever set of statewide guidelines for eating fish from California's lakes and reservoirs, including many in Northern California and the Sierra.
The California Office of Environmental Health Hazard Assessment's advisories are meant to help the public decide what fish can be safely eaten especially from hundreds of lakes and for reservoirs that have not had fish consumption advisories established.
Most bodies of water with fish-eating advisories because fish sampled there have high levels of methyl mercury are found in Northern California and the Gold Rush country, as well as in the Sacramento-San Joaquin Delta.
"Prior to these new guidelines, hundreds of lakes and reservoirs in the Sierra had no fish consumption warnings which led the public to believe that the fish from those locations were safe to eat," said Amber Taxiera, community outreach coordinator with the Sierra Fund. "This is a big step forward for OEHHA."
The new advisory recommends that women between the ages of 18 and 45 and children under 18 should avoid eating bass, carp and brown trout larger than 16 inches because of a risk of methyl mercury exposure, which has been shown to damage the brain and nervous system.
Some species of fish, including bullhead, catfish and bluegill, are acceptable for consumption at one serving a week. Species that are safe to eat include wild-caught rainbow trout and small brown trout. The advisory and guidelines stem from OEHHA's evaluation of 272 lakes and reservoirs, and 2,600 fish samples.
The advisory combined mercury data from fish in California lakes that currently do not have advisories and compared those mercury levels to acceptable human exposure levels.
In the Sacramento region, at Folsom Lake and Lake Natoma, the advisory recommends following the new guidelines if the fish caught are not covered by already set location-specific guidelines.
In the Sierra, the guidelines apply to lakes including Lake Wildwood, Scotts Flat and Bullards Bar, as well as the Union Valley Reservoir.
The guidelines dovetail with what is known about streams in the Delta, where fish sampling has established the presence of high mercury levels due to historic mining operations in the late 19th century, where mercury was widely used. A recently released study found that sportfish in the Sacramento-San Joaquin Delta watershed had higher concentrations of mercury and polychlorinated biphenyls (PCBs) than anywhere else in the state.
The advisories can be found at www.oehha.ca.gov/fish.html.
Call The Bee's Edward Ortiz, (916) 321-1071. Follow him on Twitter @edwardortiz.