SACRAMENTO (CBS/AP) — A new survey finds that sport fish from rivers and streams in the Sacramento-San Joaquin Delta have higher levels of mercury in their systems than fish taken from anywhere else in California.

The Sacramento Bee reported Sunday that the State Water Resources Control Board in 2011 surveyed 16 species from 63 locations. The study found that Sacramento pikeminiiow, smallmouth, largemouth and striped bass from the Delta watershed had the highest concentrations of mercury in their tissues.

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The state’s Office of Environmental Health Hazard Assessment lists mercury as unsafe for frequent consumption, especially for children and women of child-bearing age.

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Many of the fishing spots with the most contaminated fish have signs warning anglers of potential health hazards.

But UC Davis researcher Fraser Shilling tells the Bee that some people ignore the advisories and nonetheless consume what they catch.

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