Why Hatchery Salmon and Steelhead Are Dangerous

Photo: Alaska Region U.S. Fish & Wildlife Service/Flickr

MidCurrent has recently reported on a few of the challenges facing wild salmon and steelhead across the world. Hatchery-raised salmon and steelhead pose a serious threat to wild fish, but it’s not always clear why, even to those who consider themselves well-versed in conservation.

This recent article in Fly Fisherman Magazine can help alleviate some of that confusion. John Larison writes that the four major problems facing salmon and steelhead are habitat degradation, over-fishing, hydroelectric dams, and hatchery fish.

It’s easy to see why the first three cause problems, but what exactly is wrong with hatchery fish? Don’t they support stocks of wild fish that are in serious decline?

The crux of Larison’s argument is this: “First and foremost, hatchery salmonids have been shown to dilute the fitness of native stocks when the two groups of fish interbreed.”

Larison goes on to give an example of how hatcheries work as a factory that wants the most output in exchange for the least input. In this case, input is considered the natural selection process by which weaker animals die off, leaving only the strongest of the breed available to spawn. In hatcheries, though, as many fish as possible survive, including some which likely wouldn’t have survived in the wild. Larison posits that these “dumb” fish pass on their lack of smarts when breeding with wild fish.

Larison doesn’t offer any solutions, although he does cite some scientific evidence to support his claims.

Other articles have been written on this topic, backing up what Larison claims here in his article, so it seems to be the widespread accepted reason for why salmon and steelhead runs still suffer, even with hatchery involvement.