Why can’t we just release more hatchery fish to solve the problem?
When the dams were built it was thought that hatcheries would produce “replacement” salmon and steelhead to make up for the loss of natural production. Since then, our scientific understanding of what hatcheries can and can’t do has grown by leaps and bounds.
Today, we now know definitively that hatcheries can’t substitute for wild salmon and steelhead. The Congressionally-established Hatchery Scientific Review Group stated this reality in no uncertain terms in 2015 in a report to Congress:
“…the traditional mitigation policy of replacing wild populations with hatchery fish is not consistent with today’s conservation goals, environmental values, and prevailing science. Hatcheries cannot replace lost habitat and the natural populations that rely on it. It is now clear that the widespread use of traditional hatchery programs has actually contributed to the overall decline of wild populations.”
If hatchery fish were the answer to the loss of wild salmon and steelhead in the Snake River basin, we would not have a problem today. Though hatcheries have been essential in preventing Snake River sockeye from going extinct and have provided harvest and fishing opportunity that could not have been sustained on depressed wild salmon and steelhead populations, wild salmon and steelhead continue to decline despite massive releases of hatchery fish.
“…It is now clear that the widespread use of traditional hatchery programs has actually contributed to the overall decline of wild populations.”2015 report to Congress by the Hatchery Scientific Review Group