Originally Posted By: Fishyfeller

So you are saying even when both parents are wild the young are no longer have wild DNA. I kinda find that statement to be absurd. So if a Chinese couple move to Italy and have children they will produce children with Italian DNA. Just because it was born in a hatchery doesn't ruin the DNA. (granted natural selection is less of a factor in hatcheries)



Evolution is constant. Their DNA will be 100 % wild, but they are no longer living in the wild, therefore the wild fish DNA no longer gives them the evolutionary advantages they had. They now have to survive in whatever fashion they are forced to by the hatchery operations. Therefore, starting with the first generation in the hatchery, genes that benefit hatchery fish will be promoted among surviving offspring. That there is an initial boost in the number of (wild Brood) hatchery offspring, yes, but each subsequent generation is less genetically fit in the wild.

You should read this article:

http://oregonstate.edu/ua/ncs/archives/2...ild-salmon-runs

"The underlying problem, experts say, is Darwinian natural selection.
Fish that do well in the safe, quiet world of the hatcheries are selected to be different than those that do well in a much more hostile and predatory real-world environment. Using wild fish as brood stock each year should lessen the problem, but it was just that type of hatchery fish that were used in the Hood River study. This demonstrates that even a single generation of hatchery culture can still have strong effects. "
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If every fisherman would pick up one piece of trash, we'd have cleaner rivers and more access.