rationalskepticism.org

I think that's what environments are supposed to do, ain't it? Try replacing 'hatcheries' with 'New York City' and salmonids with humans...

The impact of New York City on humans is so profound that in just one generation traits are selected that allow humans to survive and prosper in the city environment, at the cost of their ability to thrive and reproduce in another environment.

There is no way to increase the amount of mutation, so I guess the statement is equally valid for any environment and for any species.