One more time … the main reason countries like Norway, Scotland, Ireland and provinces like Newfoundland and Nova Scotia have problems with farming Atlantic salmon is past escapees breeding with wild fish. It is not because of disease transfer, or at the population level, lice infestation.
Farmed salmon breeding with wild salmon lowers the genetic diversity of a population, and when wild stocks are depressed ( like they are wherever wild Atlantic’s live, with the possible exception of Russia), this problem increases.
The fact Pacific and Atlantic salmon cannot reproduce is why BC and Washington State are in such an enviable position for farming these fish.
The recent release of farmed Atlantic’s is unfortunate but biologically is insignificant compared to the vast numbers of ranched salmon put out to sea every year.