Recent findings, published in Proceedings of the National Academy of Sciences, show that the impact of hatcheries on salmonids is so profound that in just one generation traits are selected that allow fish to survive and prosper in the hatchery environment, at the cost of their ability to thrive and reproduce in a wild environment.

Researchers have long known that salmon born in captivity under-perform in the wild but were not sure why. The findings, which were based on a 19-year genetic analysis of steelhead in Oregon’s Hood River, confirmed that a primary impact of hatcheries is a change in fish genetics, as opposed to a temporary environmental effect.

Read More

New York Times (23 Dec 2011)