SWAMP Report on Contaminants in Fish from California Rivers and Streams

The State Water Resources Control Board's Surface Water Ambient Monitoring Program (SWAMP) has published findings from a statewide survey of contaminants in sport fish in California rivers and streams. This study was the final of three statewide surveys that investigated sport fish contamination in California. The previous two reports detailed contaminant concentrations in California's lakes and reservoirs, and the coast.

The Rivers and Streams Survey was conducted in 2011; 568 fish representing 16 species were collected from 63 popular river and stream fishing locations. Contaminant concentrations were generally low. Methylmercury concentrations posed the greatest potential health concern to fish consumers. Most locations sampled (32 of 63, or 51%) had low concentrations of methylmercury (<0.07 ppm). A few locations, 8 of 63 (13%), were in the high contamination category, with an average for the most contaminated species exceeding 0.44 ppm. Most of the locations in the high contamination category were in the Delta region. Locations outside of the Delta region all had low or moderate methylmercury contamination, with the one exception of Laguna de Santa Rosa.

The public can access results for individual fishing locations included in the Rivers and Streams Survey (as well as the earlier SWAMP surveys and other studies) through the California Water Quality Monitoring Council’s “My Water Quality” web portal. Information on sport fish contamination can be accessed by clicking on “Is It Safe to Eat Fish and Shellfish from Our Waters?”

Fact sheet summarizing the findings of the Survey

Press release from the State Board

The full Rivers and Streams Survey Report, with citation information here

Media

May-25-13

Recordnet.com, by Alex Breitler, State fish survey finds mercury levels down

May-27-13

Lake County News, Statewide survey maps sport fish contamination in California rivers and streams

May-29-13

Santa Rosa Press Democrat, by Sean Scully, High mercury levels in fish caught at popular Laguna de Santa Rosa spot

June-2-13

The Sacramento Bee, by Edward Ortiz, Study finds unsafe mercury levels in fish from Delta watershed, reprinted in The Modesto Bee

An Associated Press summary based on the Sacramento Bee article was picked up by many outlets:

San Francisco Chronicle, MercuryNews.com, New England Cable News, Contra Costa Times, San Diego Source, Woodland Daily Democrat, Manteca Bulletin, San Diego CBS 8, Reno KRNV 4, KTVU 2 San Francisco, KCBS, and The Republic - Columbus, Indiana.