Wednesday, June 17, 2009

New Study Shows Hatchery Steelhead Genetically Impaired

Researchers at Oregon State University who have been studying wild and hatchery steelhead interactions since 1991 have concluded that hatchery steelhead are less fit when it comes to reproduction than their wild counterparts. The ability to survive and successfully reproduce, also known as reproductive fitness, is markedly less even in the wild-born offspring of hatchery fish. In other words, the impairment can’t be “bred out” of these fish.

The OSU study found that a fish hatched in the wild of two hatchery-reared steelhead averaged 37% the reproductive fitness of fish with two wild parents, and 87% reproductive fitness if one parent was hatchery-reared and one parent was wild. The study also showed that reproductive fitness differences were still obvious after a full generation of natural selection in the wild. And this study is not the first of its kind: a 2007 report published in the journal Science showed that ocean migrating hatchery fish produced far less offspring than those with wild parents.

In the OSU study, conducted on the Hood River (tributary of the Columbia River), it was thought that using captive wild fish as brood stock would lessen the problem of impaired reproductive fitness. Wild brood stock did not lessen the problem. It comes down to natural selection – or the lack thereof. Fish that do well in the safe, predator-free world of the concrete raceway are not the same fish that do well in the danger-filled real world of a free-flowing river.

Death By A Thousand Cuts
The implication is that hatchery fish, which can and do survive to spawn in the wild, can harm wild fish by breeding with them and reducing their reproductive fitness. And while a few hatchery fish would not make a big difference in a strong wild population, a huge impact would be made on a wild salmonid population with few fish. Add this problem with competition for food and space as juveniles, loss of habitat, droughts, floods, poor ocean conditions, overharvest, poaching, pollution and dams, and its little wonder that salmonid populations are in peril.

Its Not Too Late
Fortunately for us, wild salmon and steelhead are still with us. Hatchery fish have been pumped into the Siuslaw and other rivers for decades, yet wild fish still return each fall and winter to spawn. This makes me optimistic that if we make the right decisions regarding wild fish, they will eventually return in greater and greater numbers.

See you on the water,
Action Jackson

(Please send comments or questions to Action Jackson at 268-6944 or www.actionjacksonfishing.com)

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