One thing to consider is that the HatcheryXWild fish don't fair well in the long term. Which is to say that the hatchery genes don't fair well. I would think that if you removed a hatchery from a system, a result you might expect is that the overall adult wild fish will drop after all hatchery returns are over. Than, as time goes by, you would see a bump up in the wild fish as the true wild genes become more numerous and fill the void, so to speak, left by the dwindling hatchery genes. Only the fittest survive.

I have seen personally how pathetically adapted for rivers hatchery stock can be. They look out of place....