Toxins detected in Klamath reservoirs

Toxicology tests performed by a state wildlife agency found that fish in two Klamath River reservoirs are contaminated with a toxin produced by algae blooms.

California Department of Fish and Game found that toxins were present in the flesh of yellow perch that reside in Iron Gate reservoir and Copco Lake about 200 miles upriver from the Pacific Ocean. Toxins were also detected in freshwater mussels in the river's main stem.

The Karuk Tribe issued a report on these studies and recommended that both reservoirs be posted with health advisories. Toxin levels detected in yellow perch and mussels both exceeded the allowable seasonal intake for children, the report says.

This toxin, known as microcystin, was previously detected in the livers of fish, but now tests show that toxins are present in their muscle flesh, a part that is usually eaten by people.

It is still unknown whether the flesh of salmon and steelhead in the Klamath's main stem also harbor toxins, though previous studies have detected trace amounts in the livers of fish, said Craig Tucker, Klamath campaign coordinator for the Karuk Tribe.

Samples for this study were collected during various months last year. Toxicology tests detected toxins in fish flesh and mussels during months when blue-green algae blooms on the reservoirs were thickest. High concentrations of this algae, called Microcystis aeruginosa, produce the toxin.

The Karuk Tribe and other supporters of dam removal on the Klamath say the reservoirs offer perfect conditions—warm, standing water—to promote algae growth. But Portland-based PacifiCorp, which operates the hydroelectric dams, has said algae growth is a common occurrence on bodies of water.

The power company is trying to relicense its dams to operate for another 30-50 years. A recent settlement proposal that calls for PacifiCorp to remove its Klamath River dams also sits on the table. Neither the relicensing nor the settlement has been finalized.