By using eggs from wild fish, hatcheries helped keep wild Snake River sockeye and chinook populations in northeast Oregon going when their numbers dipped dangerously low.
But without proper safeguards, returning hatchery fish can "stray" to wild spawning grounds and breed with wild fish, weakening productivity, numerous studies indicate. They also compete with wild fish for food and space.
In 2009, a scientific review group for NOAA concluded that hatchery fish have lower survival rates and are less successful reproducing than wild fish. Natural spawning of hatchery fish "clearly poses genetic risk to natural populations," the group said, as fish fed by humans and raised absent predators bypass the rigors of natural selection.
Fish and Wildlife officials have improved Sandy Hatchery to reduce those impacts. The hatchery produced 1 million smolts in 2010, including coho, spring chinook and steelhead.
They now mix wild fish into much of the hatchery stock, in part to reduce genetic harm if the fish do stray. They reduced releases of spring chinook, the species most likely to stray.
They built an "acclimation pond" to try to better attune hatchery fish to their home base. This spring they're putting traps at strategic points in the Sandy River to keep hatchery fish away from wild spawning grounds.
Oregon has moved aggressively on hatchery reforms, said Liz Hamilton, executive director of the Northwest Sportfishing Industry Association.
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