PORTLAND, Ore. | By Courtney Sherwood
Unseasonably hot water has killed nearly half of the sockeye salmon migrating up the Columbia River through Oregon and Washington state, a wildlife official said on Monday. Only 272,000 out of the more than 507,000 sockeye salmon that have swum between two dams along a stretch of the lower Columbia River have survived the journey, said Oregon Department of Fish and Wildlife fisheries manager John North. “We’ve never had mortalities at this scale,” said North. The die-off comes as U.S. West Coast states grapple with drought conditions and the Columbia is seeing the third-highest count of sockeye returning from the ocean to spawn since 1960, federal figures show. Hot air combined with abnormally low mountain snow melt has increased water temperatures and prompted fishing restrictions and efforts to save beleaguered fish, including trucking salmon to cooler waters. The Columbia River hit 70 degrees Fahrenheit in mid-June, about a month earlier than usual, and the fish were not able to adjust, North said. Warm waters are at least partially to blame for more than 400,000 additional salmon deaths this year, hatchery officials say. The sockeye were counted between the lower Columbia’s Bonneville Dam and McNary Dam, about 150 miles upstream, en route to the Snake River tributary. Snake River sockeye, which lay their eggs in lakes, in 1991 became the first salmon named to the U.S. Endangered Species List….