Central Idaho's Redfish Lake is teeming, in a comparative sense, with sockeye salmon once again after decades of relative dormancy.
Through Tuesday a total of 1,145 of the reddening spawners had been counted this year at either Sawtooth Hatchery or Redfish Lake Creek after completing a 900-mile freshwater journey up the Columbia, Snake and Salmon rivers to Idaho's Sawtooth Valley. That's the most sockeye known to have entered the valley in any year since 4,361 were counted swimming up Redfish Lake Creek in 1955. No other known return, dating back to at least 1954, has even totaled as much as 2,000.
Of this year's total return to-date, about 400 were sampled at a Redfish Lake Creek fish trap by Idaho Department of Fish and Game researchers to determine their condition and ancestry and then allowed to continue their trip toward spawning grounds in Redfish Lake.
The rest of the trapped fish were taken to Eagle Hatchery near Boise for holding and sampling. Most of those fish are being returned to the creek this week and next as spawning time approaches. About 100 of the sockeye held at Eagle will be spawned at the hatchery so that their genetic makeup is infused into the Snake River Sockeye Salmon Captive Broodstock Program, which is responsible for most of the returning fish
Through Aug. 31, 174 of the 1,118 sockeye that had returned to the valley had been categorized as "natural" fish that are the product of residual sockeye that had never left freshwater, of adults returned from the ocean that had been released into the lake in prior years or of the outplanting of fertilized eggs in Redfish and nearly Pettit and Alturas lakes.
Most of the rest of this year's return are returns from smolts raised at Oxbow Hatchery near Cascade Locks, Ore., or Sawtooth Hatchery and released either at Sawtooth or in Redfish Lake Creek. All of those fish got their start in the captive broodstock program, which was initiated in 1991 to protect the population's genetic structure and to prevent the further decline of Idaho sockeye salmon.
The population had reached such a low ebb that in 1991 the stock was listed as endangered under the Endangered Species Act. Between 1991 and 1998, only 16 wild sockeye salmon returned to Idaho. All of these adults were incorporated into the captive breeding program and spawned at the Eagle Fish Hatchery.
Historically sockeye salmon returned up the Columbia to the Snake and then Salmon rivers to five Sawtooth Valley lakes: Alturas, Pettit, Redfish, Stanley and Yellowbelly. In the 1880s, observers reported lakes and streams in the Stanley Basin teeming with redfish. Returns then were estimated between 25,000 and 35,000 sockeye annually.
Construction of the Sunbeam Dam in 1913 blocked upstream fish passage. The dam was partially destroyed in 1934 to reopen the upper Salmon River, but no one tried to restore the salmon runs until the captive broodstock program began, according to the IDFG.
The IDFG planned to release about 300 of the spawners held at Eagle today and the rest, more than 400, early next week, according to the hatchery's manager, Dan Baker.
And NOAA Fisheries was scheduled to release 270 adult fish Wednesday that had been reared in captivity at facilities in Washington. Nearly 200 fish raised to adulthood at Eagle are also scheduled to be released.
And the sockeye are still arriving daily, though in very small numbers. A total of 2,186 have been counted passing Lower Granite Dam on the lower Snake River, which is about 400 river miles from the Sawtooth Valley.
And what has become an annual event -- the sockeye roundup -- was scheduled to take place Thursday (Sept. 9). Each year a certain number of the sockeye halt their progress in the Salmon River below Sawtooth Hatchery, seemingly wary of the weir blocking their path.
"We're going to go up tomorrow and try to collect everything that's holding below Sawtooth," Baker said Wednesday of the annual seining to capture the fish and deliver them to Redfish. "We're thinking there's still 100 or more below the weir."
A total of about 1,700 spawners are expected to enter the lake this year, which would be the most since the 1950s. The total last year was 1,349, including 833 anadromous fish that had returned from the ocean.
The past three years have been by far the best in the history of the program. The anadromous return was 650 in 2008. The previous high going back to 1999 was 257 in 2000 but the next best return from 1999-2007 was only 27.
The number of hatchery-reared adult releases has also been increased in recent years.
"The program wanted to hit the ground running with the expansion and increased smolt program, so starting in 2004 Eagle Fish Hatchery started to increase the number of eyed-eggs kept for the captive broodstock," Baker said. An expansion of the Eagle facility completed last year doubled its capacity and the program is at work to increase its smolt production from about 150,000 releases each year to as many as 1 million.
"This increase and the incorporation of anadromous adults (2008-2010) resulted in additional captive adults from Eagle Fish Hatchery available for release (131 in 2007, 145 in 2008, 391 in 2009 and 180 in 2010)," Baker said.
"Once Springfield Hatchery is completed the number of adults released will decrease, so the hatchery programs at Eagle and NOAA can produce additional eyed-eggs for Springfield Hatchery" from captive broodstock," Baker said. Springfield Hatchery was purchased this summer. The plan is to retrofit the former trout hatchery so that as many as 1 million sockeye smolts can be raised there.