22 Years After Lonesome Larry, Wild-Spawned Snake River Sockeye Regaining A Foothold

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Their study shows that the program to save Snake River sockeye can indeed reverse the so-called “extinction vortex,” where too few individuals remain for the species to sustain itself. Some thought that Snake River sockeye had entered that vortex in the 1990s, highlighted in 1992 when the sole returning male Redfish Lake sockeye, known as “Lonesome Larry” captured national attention. NOAA Fisheries earlier this year released a proposed recovery plan for Snake River sockeye, which calls for an average of 1,000 naturally spawned sockeye returning to Redfish Lake each year, with similar targets for other lakes in Idaho’s Sawtooth Valley. About 460 naturally spawned sockeye returned to Redfish Lake this year – the most since the program began – out of an overall record return of about 1,600.

The 20-year recovery program started with 16 remaining adult sockeye – 11 males and five females – taken into captivity from 1991 to 1998. Through advanced aquaculture techniques, the program has retained about 95 percent of the species’ remaining genetic variability, while boosting surviving offspring about 2,000 percent beyond what could be expected in the wild.

The program funded by the Bonneville Power Administration has released more than 3.8 million sockeye eggs and fish into lakes and streams in the Sawtooth Valley, and tracks the fish that return from the ocean. Hatchery fish returning as adults have also begun spawning again in Redfish Lake, increasingly producing naturally spawned offspring that are now also returning. Now, naturally spawned sockeye are returning at rates up to three times higher than those released from hatcheries as smolts, and more than 10 times greater than those released as even younger pre-smolts.

The higher returns indicate the naturally spawned fish are regaining the fitness the species needs to better survive their 900-mile migration to the ocean, their years at sea, and the return trip to Redfish Lake.

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http://summitcountyvoice.com/2014/11/26/idahos-sockeye-salmon-escape-the-extinction-vortex/