Fish Hatcheries
 

Hatcheries are efficient at producing fish for harvest, the researchers said, but this and other studies continue to raise concerns about the genetic impacts that hatchery fish may have when they interbreed with wild salmon, and whether or not they will help wild salmon runs to recover.

These findings were based on a 19-year genetic analysis of steelhead in Oregon's Hood River. It examined why hatchery fish struggle to reproduce in wild river conditions, a fact that has been made clear in previous research. Some of the possible causes explored were environmental effects of captive rearing, inbreeding among close relatives, and unintentional "domestication selection," or the ability of some fish to adapt to the unique hatchery environment.

The study confirmed that domestication selection was at work. When thousands of smolts are born in the artificial environment of a hatchery, those that survive best are the ones that can deal, for whatever reason, with hatchery conditions. But the same traits that help them in the hatchery backfire when they return to a wild river, where their ability to produce surviving offspring is much reduced.

I'm not surprised. When's the last time the hatchery environment changed? They look as they've always looked.
Maybe they could use sections of real river as a hatchery - it would take some fencing and some screening but at least it would be a natural environment. That's something good to hit Ted Turner up for the money to try it.