F&G catch and transport of sockeye salmon at Lower Granite Dam during heat wave

Idaho Fish and Game is seeing an above-average return of sockeye salmon this summer. Biologists are making sure the fish are available to spawn by catching them at Lower Granite Dam near Lewiston and trucking them to the Eagle Hatchery near Boise.

The Upper Salmon River is unusually warm and potentially deadly for sockeye. That stretch is the final leg of a 900-mile journey the endangered Idaho sockeye must make before reaching the Sawtooth Basin near Stanley. Fish and Game officials transported 142 sockeye from Lower Granite Dam through July 18, with more planned. The department also transported sockeye in 2015 and 2021 when weather conditions were similar.

“We’d rather let these fish return naturally, but we have to balance that with knowing that they’re headed into a heat wave, so we decided to safely divert some of them to Eagle to make sure we have fish to produce the next generation,” said Lance Hebdon, chief of the Fisheries Bureau for Idaho Fish and Game. “We’re only transporting a portion of the fish, so we still expect some to make their full migration.”

As of mid-July, more than 925 sockeyes had reached Lower Granite Dam, about 30 miles west of Lewiston. Sockeyes typically return to Lower Granite in mid-July, and the fish continue to return throughout the summer. The run is the seventh-highest return to Lower Granite since fish counts began there in 1975, and more fish are expected to arrive.

After crossing Lower Granite Dam, the fish must travel another 400 miles to reach the Sawtooth Basin. The first sockeye salmon typically arrive at the Sawtooth fish trap around the third week of July.

Since an intensive sockeye recovery project began in the early 1990s, involving Fish and Game and many other partners, Fish and Game has employed a “spread the risk” strategy to ensure their survival, which involves harvesting and transporting the fish. That strategy also includes allowing sockeye to migrate naturally to the Pacific and back, while raising others to adulthood in hatcheries to ensure that spawners are available if few or no sockeye return from the Pacific.

The combined efforts of the state, federal and tribal governments have bolstered a sockeye population that was on the brink of extinction. The Idaho sockeye was placed on the federal Endangered Species Act in 1991, and only 23 returned between 1991 and 1999, including two years when no sockeyes returned.

Annual runs into the Sawtooth Basin have averaged 369 fish over the past decade, with a high of 1,579 in 2014 and a low of 17 in 2019.

—Idaho Department of Fish and Game