The main problem with raisng fish in a hatchery is that you get domestic hatchery fish, no matter what kind you start out with. The reason for this is both complex and simple at the same time. The simple version is that all fish have a suite of traits that allow them to adapt to a variety of situations. Fish that find themselves in a hatchery environment that have a tendency towards traits that would be useful in the wild, like territoriality, aggression, heightened fright reflex, etc., wind up on the tailscreen as pinheads, whereas fish that tend to be more domesticated and that tolerate crowding, are the first to the fish feeder when he comes by, are easily able to get over their natural flight reaction, etc. do great. Until they are released, that is, then they swim around looking for the pellets, stay in big crowded schools, swim up to the first heron they see looking for a handout, you get the picture. Nearly all die right away, a few revert to their wild tendencies in time to survive, most survive probably by dumb luck. None of these are going to compete well with their wild bretheren, however, especially when they find themselves in a big ocean with limited food during a El Nino year, still swimming around in big non-agressive schools. Do the math, 90% of wild fish die before they even migrate the ocean - it's a tough world. 90% of hatchery fish, however, survive to release size. However, in good years equal percentages return as adults. This means that 90% of those hatchery fish die before spawning, most in the first couple weeks after release. And when times are hard, the remainder are ill equipped to compete with wild fish, so nearly all die, like this year, whereas wild fish will return at a higher rate, maybe not as high as in good years, but not nearly as bad as the hatchery fish. What really sucks about all this is that a hatchery smolt is 1/10 as likely to survive as a wild smolt, so you would essentially need to release 10 times the hatchery fish as the river would produce naturally to get the same return, and you simply can't get there, any better than you can increase your beef production by putting 100 cows in a pasture that will support 10. When you do that you don't even get 10, you starve them all to death. That simple. You don't want to hear the complicated answer, with phenotypes and genotypes in it.