MERCURY: Calif. study finds widespread contamination of lake fish
Colin Sullivan, E&E Reporter
E&E Greenwire
05/04/2009
SAN FRANCISCO -- Fifteen percent of California's lakes are clean enough to sustain aquatic life free of toxic pollutants, according to a state study released today.
The State Water Resources Control Board found methylmercury contamination of lake fish is dire and widespread, particularly in largemouth bass species in Northern California.
Twenty-six percent of 152 lakes surveyed had methylmercury concentrations high enough to warrant a possible public health warning about fish consumption, the report says. And 76 percent of the lakes surveyed had samples high enough to justify eating less than three servings a week.
A random sampling of fish tissues suggests a similar pattern of contamination is found in the state's 9,000 lakes, the report says. The screening tested 6,000 fish from 18 species from 2007 and will be followed next year by a second study on research conducted in 2008.
Methylmercury -- an indirect product of the combustion of fossil fuels and wastes that contain inorganic mercury -- has been linked to developmental problems in children and increased risk in adults of cardiovascular disease.
Bill Jennings, chairman of the California Sportfishing Protection Alliance, noted that the study looked only at the effects on human health and did not take into account how such contamination affects other wildlife that feed on fish.
"The report is a damning assessment of the state of California's lakes," Jennings said. When factors beyond human health are taken into account, he said, "the situation is likely to be far bleaker."
State officials tested fish tissue for methylmercury, PCBs, dieldrin, DDTs, chlordanes and selenium. The highest methylmercury concentrations were found in bass at elevations below 2,000 feet, while the lowest levels were in trout above 2,000 feet...
