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Captive Breeding Helps,but it won't Restore Sockeye Fishfrom the Editors of Idaho Statesman - August 30, 1999 |
The return of the fifth adult male sockeye salmon to the Sawtooth Valley adds to evidence that captive breeding works to help endangered populations.
But the single-digit number of returnees to Redfish Lake also shows how far scientists have to go to restore salmon to impressive numbers and to remove the sockeye from the endangered Species List.
Idaho just celebrated a captive-breeding success with the peregrine falcon, which was taken off the Endangered Species List on Aug. 20.
the peregrine's success is attributable to several elements -- the banning of some pesticides, including DDT, the captive-breeding work of biologists through the Peregrine Fund, and the Endangered Species Act, which protected nesting sites and poured millions of dollars into restoration.
The sockeye have plenty of help from scientists. The fifth returning male is part of a group of 60,000 sockeye that were hatched in Washington state and raised in the Bonneville National Hatchery in Oregon.
Scientists started captive breeding to preserve the fish's genetic diversity.
When scientists release the fish, the salmon embark on one of the most extraordinary life adventures in the animal world. Redfish Lake sockeye make a 900-mile journey from the Pacific Ocean and climb 6,500 feet during their journey to spawn.
The trek would be adventure enough, but the salmon must confront something they didn't face until 1910 -- dams. That year, the Sunbeam Dam was built on the Salmon River. When it was breached in 1931, the sockeye began to return in greater numbers.
Eventually, however, eight dams would block the sockeye's path ton the ocean. The numbers of sockeye and other salmon began to plummet. By the 1980s, their numbers fell into the single digits.
No one is suggesting the sockeye face serious threat from harvest, and the spawning habitat is sufficient. Dams are the key element in their decline.
The peregrine falcon's man-made foe is gone. But salmon continue to face theirs.
Ultimately, captive breeding will not be enough. The Northwest, will have to seriously address the issue of dams on the Snake River, and that means breaching.
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