[Water_news] 4. DWR'S CALIFORNIA WATER NEWS -WATER QUALITY-5/26/09

Department of Water Resources

California Water News

A daily compilation of significant news articles and comment

 

May 26, 2009

 

4. Water Quality –

 

Toxic fish found in Inland lakes

The Riverside Press-Enterprise – 5/26/09

By Janet Zimmerman

 

Fish from Silverwood Lake contain some of the highest levels of mercury and toxic PCBs of 152 sites studied by state water quality experts, placing the reservoir in the San Bernardino Mountains among a growing number of contaminated California lakes.

 

Silverwood is one of 40 lakes where concentrations of mercury exceeded the point at which authorities recommend that people avoid eating certain fish caught there.

 

Also lurking in Silverwood's deep blue waters are bass with "exceptionally high" levels of PCBs, polychlorinated biphenyls. The heat-tolerant chemicals, used in electronics, are linked to cancer and other health problems, according to a report released this month by the state Water Resources Control Board.

 

The lake is a man-made reservoir that stores drinking water for San Bernardino and Metropolitan Water District, the wholesaler for Southern California.

 

Monthly tests of lake water show no heavy metals or PCBs and it is considered safe to drink once it is treated for delivery to consumers, said John Kemp, water quality supervisor for the state Department of Water Resources, which oversees Silverwood.

 

However, even tiny amounts of contaminants that fall or flow into a lake can concentrate as they move up the food chain from plants and microorganisms to small fish and then larger fish.

 

Several other Inland fishing spots also have pollution levels that could warrant warnings to limit consumption, the report says. One of the local lakes tested, Salton Sea, already has cautions in place based on previous tests that found other contaminants.

 

It's unknown, however, when such advisories could be issued for the affected lakes, because more testing is needed, said Sam Delson, spokesman for the state Office of Environmental Health Hazard Assessment.

 

"The lakes survey includes data only for the most-contaminated types of fish. ... Even in lakes with high contaminant levels in some species, there may be other species that can safely be eaten. To issue advice for a lake, we need a comprehensive survey of the other fish species," Delson said.

 

Harmful substances accumulate in fish tissue. Children who repeatedly consume high levels of the contaminants can suffer cancer, kidney damage and brain damage.

 

Among the lakes surveyed, largemouth bass from Lake Pillsbury in Northern California tested highest for mercury; a health advisory already warns people not to regularly eat fish caught there.

 

Brown bullhead from Pyramid Lake north of Valencia was the worst in the state for PCBs; tests showed more than three times the amount that triggers a warning not to eat the fish.

 

The affected lakes could be placed on a list of impaired bodies of water under the federal Clean Water Act, which could require responsible parties or stakeholders to help pay for cleanup. Authorities haven't determined the sources of contamination yet.

 

Caution Advised

 

In addition to Silverwood, lakes tested in San Bernardino and Riverside counties were Big Bear Lake, Lake Elsinore, Salton Sea, Lake Mathews, Spring Valley Lake in Victorville and Prado Lake in Chino.

 

Big Bear Lake already is being monitored for elevated mercury levels detected in largemouth bass as far back as 2001. The most recent study also found PCBs in carp at levels where the state recommends limiting consumption to no more than two servings per week.

 

Lake Elsinore carp also had elevated levels of PCBs.

 

Salton Sea tilapia samples showed selenium, a naturally occurring element that in high doses can cause developmental problems in children, in a range that normally warrants limiting consumption to no more than three servings a week. But a warning issued earlier this year already advises the public not to eat more than two servings a week of any fish caught in the Salton Sea.

 

"It is sad that any of these waters would have contaminants that would preclude eating the fish. That's not the American ideal," said Harry Morse, a spokesman for California Department of Fish and Game, which stocks lakes with fish.

 

Lake Mathews had a mercury measurement just over the minimal safety threshold, and a sample from Prado showed PCBs about twice the lowest acceptable level.

 

Fisherman John Beuttler hasn't eaten a striped bass in years because it is notorious for mercury. As conservation director for the California Sportfishing Protection Alliance near Sacramento, he's aware of consumption warnings, but many anglers aren't, he said.

 

The notifications are contained in the back of Fish and Game regulation booklets given out where fishing licenses are sold. Few people read them, Beuttler said.

 

His group wants lake-specific warnings, in numerous languages, posted on the banks around the water. Many disadvantaged people depend on sport fishing for a protein source they might not otherwise be able to afford, Beuttler said.

 

"Those are the people who run the greatest risk, and those are the ones least likely to check for health warnings," he said.

The study included tissue samples from thousands of bass, carp and other species that were taken in 2007. More samples were taken from another 130 lakes last year and will be reported in 2010. It is the largest screening study of its kind in California.

 

Only 21 of the lakes tested -- including Spring Valley -- had fish with no pollutants that exceeded minimum safety standards, but researchers warned that they probably are not without problems. At most of those "apparently clean" lakes, researchers couldn't catch the fish species that tend to have the highest concentrations of the toxins, the report states.

 

Most of the fish tested contained methylmercury, a form of mercury created when it reacts with bacteria in the water.

 

Mercury can be carried to the lake in air emissions from cement plants and in runoff from old mining operations. It can affect the neurological development of fetuses and children.

 

PCBs showed up in the highest concentrations in Southern California lakes. The chemicals are linked to learning deficits, low birth weight and problems with the immune, nervous, endocrine and reproductive systems.

 

Scientists also tested for the banned pesticides DDT, dieldrin and chlordane, which cause reduced fertility, genital birth defects, cancer, asthma, depression and damage to developing brains; and for selenium, a naturally occurring element that causes reproductive harm and deformities in fish and aquatic birds.

 

Worrisome Findings

 

Silverwood Lake, off Highway 138 north of San Bernardino, is known for its trout, catfish, bluegill and largemouth bass. Nestled among Douglas firs and oaks, Silverwood was formed in 1971 by construction of the Cedar Springs Dam. At more than 3,300 feet elevation, it is the highest reservoir in the State Water Project.

 

About 10 percent of the lake's 300,000 annual visitors are anglers, state parks officials said.

 

Tissue samples of bass from the lake contained PCBs at 131.4 parts per billion, more than three times the threshold for limiting consumption to twice a week and close to the 120 ppb at which the state recommends that people don't eat the fish.

 

Mercury in fish at Silverwood was measured at .49 parts per million; concentrations of .44 ppm trigger a warning that the fish should not be eaten by minors and women of child-bearing age.

 

"That's going to worry anybody," said Teresa South, manager of the marina store that sells bait, fishing licenses and snacks.

 

South fishes the lake often but always releases her catch. She doubts that study results will drive away anglers, many of whom also release their fish back into the lake.

 

Officials at Silverwood Lake State Recreation Area were unaware of the findings but will follow all recommendations, said Kathy Weatherman, district superintendent in Lancaster.

 

The Office of Environmental Health Hazard Assessment stressed that people should not stop eating fish, because it provides many health benefits.

 

General guidelines, available on the Web at www.oehha.ca.gov, say people should fish from different lakes and vary what they eat, focusing on less contaminated species such as trout and sunfish. Eat the filet portion of smaller fish, avoiding the organs and skin.

 

"People wonder, 'Should I stop eating fish from all the lakes in California?' Our answer to that is, 'No, that's not necessary,' " said Robert Brodberg, senior toxicologist with the office. #

 

http://www.pe.com/localnews/inland/stories/PE_News_Local_S_polluted26.4af553c.html

 

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