Hatchery Raised Fish Hurt Wild Steelhead

Oregon research shows that steelhead raised in captivity are hurting wild-born fish. Oregon State University zoology professor Michael Blouin found the captive-born fish inter-breed and pass on their weaknesses to wild fish.

The new research undermines ongoing experiments by state and tribal fishery managers to crossbreed wild fish with fish raised in hatcheries.

LINK (Via: The Columbian)

Comments

[BigESlice]

This isn't a new finding. It's called genetic depression -- one of those things bioligists have known of ever since Darwin. The weak genes have become amplified in the hatchery fish because, by raising the fry out of their natural setting, the biologists have taken natural selection out of the equation and helped the weak genes to survive long enough to be replicated. The weak genes, if left alone, would otherwise represent a small part of the steelhead gene pool, but they are now present in amplified numbers due to our meddling.

This finding shouldn't undermine the cross-breeding of wild and hatchery fish, however, as long as politicians are kept out of the decision making. (I say this because very few politicians appear to have any background in biology, or with the scientific method in general, and should be kept from legislating things they know nothing about, but I digress.) I would expect that the biologists would want to introduce more wild genes into the hatchery gene pool in an effort to correct the genetic imbalance.

I think the whole concept of raising hatchery fish to save a wild population is a band-aid anyway. While it is a method for keeping the steelhead going in the short-term, we need to be better addressing the root causes of the population decline.

Z.L. for salmon and steelhead. Z.P.G. for us.