Fish in Lake Washington among state's most tainted

Lake Washington is home to some of the most contaminated fish in Washington, and the culprits include toxic chemicals that society banned decades ago, new state studies report.

Those chemicals, a witch's brew of PCBs, dioxins, pesticides and flame retardants, are still contaminating the food chain and threatening people and the environment, the studies of freshwater fish and sediments by the state Department of Ecology say.

Now it's hoped the new research will guide the state and local governments to new efforts to identify and reduce sources of pollution and in some cases warn people from eating contaminated fish or to reduce their consumption.

Meanwhile, the state has already been warning people about eating many species from Lake Washington, which the new studies found has the second highest levels of contaminants in fish sampled anywhere in the state.

The Wenatchee River fish were by far the most toxic.

As a result of the findings Thursday, the state Department of Health officially advised against eating mountain whitefish from the Wenatchee River. Those fish had the highest levels of contaminants of any fish sampled in the entire state.

More information

About how to eat fish safely, how fish become contaminated and how you can help reduce contamination: www.doh.wa.gov

Healthful-fish eating guide, including fish preparation and chart showing which fish you can eat safely and how often: www.doh.wa.gov

Statewide map showing which fish and shellfish are contaminated and how much to eat: www.doh.wa.gov

Questions and answers about mercury: www.epa.gov

Seafood information and resources: www.cfsan.fda.gov

But the findings, released Thursday, show how difficult it is to eradicate some pollutants from the environment and food chain once contamination occurs.

Three studies

The three studies found unacceptably high levels of contaminants in 93 samples of freshwater fish collected from 45 sites around the state.

Larger rivers and more urbanized lake basins generally had fish with higher levels of contamination. Bigger, older fish were also usually more toxic.

In all, the Ecology Department sampled 21 sites in 2004 and 31 sites in 2005. It took years to scrutinize the data.

The department deliberately chose sampling sites where data was lacking or more than 10 years old. It looked for persistent, bioaccumulative and toxic chemicals in its survey, including mercury, dioxins, and PCBs — polychlorinated biphenyls, which have been banned since 1979 but were once widely used in everything from cooling fluid to paint.

While some fish sampled were cleaner than others, none was found to be pristine. At least some contaminants were found in fish from the Snake River in Southeastern Washington to the Queets River on the Olympic Peninsula.

Mercury was found in all but one sample of fish examined. Puget Sound chinook salmon turned out to have mercury levels about twice as high as chinook salmon from coastal rivers sampled in 2004.

Some native people were particularly alarmed by the findings because Indians tend to eat more fish than the rest of the population does.

Mountain whitefish are a delicacy for some Yakama tribal members, and the Wenatchee River is part of their traditional areas of use.

"It is sad news but not surprising," said Steve Parker, harvest manager for the Yakama Nation. Yet Parker said many tribal members, especially elders, will still eat fish.

The study for some is a cautionary tale. "The most important thing this tells us is we really need to be on the watch out for synthetic chemicals we are discharging to the environment now, without knowing what the consequences will be," said John Lombard, the former Lake Washington watershed coordinator for King County and author of a book on Puget Sound restoration. "To the extent that the things are coming basically from all of us, and activities that people are engaged in over the last 30 years across the whole area, it is not at all a surprise."

But Lombard also says he sees hope. Other studies of sediment in Puget Sound have shown some areas to be cleaner today than in the past. And in some areas sampled by the Ecology Department, the fish had less contamination than in previous tests.

Lynda V. Mapes: 206-464-2736

Washington State

Toxics Monitoring Program:

Contaminants in Fish Tissue from Freshwater Environments in 2004 and 2005: www.ecy.wa.gov/biblio/0703024.html

Measuring Mercury Trends in Freshwater Fish in Washington State 2005 Sampling Results: www.ecy.wa.gov/biblio/0703007.html

History of Mercury in Selected Washington Lakes Determined from Age-Dated Sediment Cores 2006 Sampling Results: www.ecy.wa.gov/biblio/0703019.html