Sockeye salmon released into central Idaho lakes to spawn

September 28, 2021 GMT

BOISE, Idaho (AP) — The number of sockeye salmon making it to central Idaho from the ocean this year is one of the worst returns in the last decade, with only 43 fish so far, state wildlife managers said Tuesday.

But the Idaho Department of Fish and Game said a hatchery program intended to prevent the species from going extinct allowed the release of 1,211 sockeye into Redfish and Pettit lakes to spawn naturally.

The agency in August also started an emergency trap-and-truck operation at Lower Granite Dam on the Snake River in Washington due to overly warm rivers and captured 201 fish. The agency brought the fish to its hatchery in Eagle in southwestern Idaho where it raises adult brood stock for spawning.

The agency also said it brought in captive brood stock from a safety net program operated by NOAA Fisheries in Washington. In all, the agency said it had 2,750 sockeye for spawning this year. Of those, 1,112 were released into Redfish lake and 99 in Pettit Lake.


“When I think about the program as a whole, I think that we have been incredibly successful in preventing extinction and preserving genetic diversity,” said John Powell, a fisheries research biologist with Fish and Game. “And that we’re currently transitioning to our second phase of the recovery plan, which is the recolonization phase.”

Powell said things were looking good in the spring when early indications showed the number of sockeye salmon passing Bonneville Dam on the Columbia River was above what was forecast.

However, a heat wave that warmed rivers changed that, cutting into what had been an expected 250 fish arriving in central Idaho. A few more fish might still return this year to bolster the 43 counted so far. If Fish and Game hadn’t trapped and trucked the 201 fish at Granite Dam, most likely would have died trying to make it to central Idaho.

“Our preference would have been to allow those fish to complete the last leg of their journey on their own, because from a genetic perspective, sockeye that make it back to the Sawtooth Basin have a level of fitness that we want in our captive breeding program,” said Lance Hebdon, Fisheries Bureau chief, in a news release. “But based on river conditions, trucking fish from Lower Granite Dam to Eagle was a necessary tradeoff to increase survival.”

Fish and Game hopes to eventually get enough fish returning to naturally recolonize Redfish and Pettit lakes. That plan involves the Springfield Fish Hatchery in eastern Idaho that is expected to produce a million young sockeye salmon to be released next spring in central Idaho.

Powell also said managers have been examining ways to increase the number of young fish, called smolts, that survive the journey from central Idaho to return as adults several years later.

Currently, that number is under 1%, and fishery experts say it needs to be between 2% and 6%.

An estimated 150,000 sockeye at one time made the 900-mile (14,500-kilometer) trip from the ocean to the central Idaho lakes near the town of Stanley. Redfish Lake was named for the abundant red-colored salmon that spawned there. Federal officials say the run declined starting in the early 1900s because of overfishing, irrigation diversions, dams and poisoning,