Wildlife

Heat Killing Columbia River Spawning Salmon

A summer of unusual heat in the Pacific Northwest is threatening to kill at least a quarter million sockeye salmon swimming up the Columbia River to spawn.

Large numbers of the fish have already perished due to prolonged heat above 100 degrees this summer, which have combined with low flows on the Columbia to create conditions that stress the sockeye and make them more susceptible to disease.

The unusual warmth came as the Columbia saw the third-highest number of sockeye returning from the Pacific to spawn since 1960.

“Right now it's grim for adult sockeye," said Russ Kiefer of the Idaho Department of Fish and Game. "They're running out of energy reserves, and we're getting a lot of reports of fish dead and dying.”

With water temperatures in the waterway hitting the mid-70s, which is life-threatening to the fish, officials began releasing cold water from several reservoirs upstream in an attempt to prevent further fatalities.

“We’ve never had mortalities at this scale,” said Oregon Dept. of Fish and Wildlife fisheries manager John North.

Both Oregon and Washington have halted sports fishing in areas affected by the warmth.