OEHHA Releases Draft “Safe Eating Guidelines” for Fish in the San Joaquin River and South Delta

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FOR IMMEDIATE RELEASE: 
Release No. 07-01

CONTACT: Allan Hirsch
(916) 324-2831
www.oehha.ca.gov

SACRAMENTO -- The California Environmental Protection Agency’s Office of Environmental Health Hazard Assessment (OEHHA) has released draft “safe eating guidelines” for sport fish in the San Joaquin River Delta and the San Joaquin River extending upstream to Friant Dam (Fresno County). Several species of bass and sturgeon in those water bodies may contain elevated levels of mercury.

“Many species of sport fish in the San Joaquin River and South Delta region can be consumed regularly as part of a healthy diet,” OEHHA Director Dr. Joan Denton said. “However, bass and sturgeon in those water bodies may pose hazards, particularly to women of childbearing age and children, due to the presence of mercury.”

A fact sheet and draft report containing the proposed guidelines and OEHHA’s evaluation of potential health threats posed by consumption of fish containing methylmercury (the most prevalent and toxic form of mercury in fish) are available for viewing online.  See the San Joaquin and South Delta Advisory.

OEHHA developed the guidelines using fish-sampling data produced by the CalFED Bay-Delta Program, the State Water Resources Control Board and the University of California, Davis. While virtually all fish contain some amount of mercury, OEHHA’s draft report concludes that many fish species from the water bodies are low enough in mercury to permit frequent consumption.

The draft “safe eating” guidelines include one set of recommendations for women of childbearing age and children age 17 and younger, who are particularly sensitive to methylmercury. A second set of guidelines is for women beyond their childbearing years and men. Recommended adult serving sizes cited in the guidelines are 3 ounces of cooked fish. Until final guidelines are issued, OEHHA recommends that the public follow the advice in the draft guidelines, as follows:

  • For the South Delta (defined as the San Joaquin River from the Sacramento River to the Port of Stockton, and all other rivers, sloughs and flooded tracts in the Delta south of the San Joaquin River):

Women of childbearing age and children age 17 and younger should not eat any striped bass over 27 inches, and should eat no more than two servings a month of smaller striped bass (18 to 27 inches) or sturgeon (and only if no other fish are consumed). They may eat up to four servings a week of bluegill or other sunfish, catfish, clams or crayfish; OR up to two servings a week of crappie, carp, sucker or largemouth, smallmouth or spotted bass.

Women beyond childbearing years and men should not eat any striped bass over 35 inches, and should eat no more than four servings a month of smaller striped bass (18 to 35 inches) or sturgeon (and only if no other fish are consumed). They may eat bluegill or other sunfish daily; OR may eat up to six servings a week of clams, crayfish, crappie or carp; OR up to four servings a week of catfish, sucker, or largemouth, smallmouth or spotted bass.

  • For the San Joaquin River between the Port of Stockton and Friant Dam:

Women of childbearing age and children 17 and under should not eat any largemouth, smallmouth or spotted bass. They may eat up to four servings a week of bluegill or other sunfish, or crayfish; OR up to two servings a week of catfish, crappie, carp or sucker.

Women beyond childbearing years and men may eat bluegill or other sunfish daily; OR eat up to six servings a week of crayfish, crappie or carp; OR up to four servings a week of catfish or sucker; OR up to two servings a week of largemouth, smallmouth or spotted bass.

In addition, anglers should follow the recommendations to not consume fish or shellfish from Port of Stockton locations (Old Mormon Slough, New Morman Slough, McLeod Lake, the Turning Basin, the Morelli Boat Ramp, and Lewis Park Boat Ramp) where signs have been posted.

Major sources of mercury in the environment are runoff from former gold-mining sites where mercury was used, emissions from coal-burning power plants, and the weathering of mercury-containing rocks. Mercury accumulates in river sediment and is converted by bacteria to the more toxic methylmercury, which fish take in from their diet.

Women can pass methylmercury on to their fetuses through the placenta. Excessive exposure to methylmercury may affect the nervous system in children, leading to subtle decreases in learning ability, language skills, attention and/or memory. These effects may occur through adolescence as the nervous system continues to develop.

OEHHA staff scientists will make a presentation, answer questions and accept public comments on the draft guidelines at a public workshop to be held at 9:30 a.m. on March 20, 2007, at the San Joaquin County Public Health Services office at 1601 E. Hazelton Ave., Stockton.

Written comments on the draft guidelines must be received by 5 p.m. on

April 23, 2007, at OEHHA’s Pesticide and Environmental Toxicology Branch, 1515 Clay Street, 16th floor, Oakland, CA 94612. OEHHA will review all comments, make any appropriate revisions and issue final guidelines.

The Office of Environmental Health Hazard Assessment is one of six entities within the California Environmental Protection Agency. OEHHA's mission is to protect and enhance public health and the environment by objective scientific evaluation of risks posed by hazardous substances.