This metadata analysis of fish farm destruction of wild salmon is clear that fish farms kill wild salmon.Salmon farms need to be on dry land in closed containers, or go back to Norway.
See: http://www.plosbiology.org/article/info%3Adoi%2F10.1371%2Fjournal.pbio.0060033.
Here is the abstract:
Since the late 1980s, wild salmon catch and abundance
have declined dramatically in the North Atlantic and in much of the northeastern
Pacific south of Alaska. In these areas, there has been a concomitant increase
in the production of farmed salmon. Previous studies have shown negative impacts
on wild salmonids, but these results have been difficult to translate into
predictions of change in wild population survival and abundance. We compared
marine survival of salmonids in areas with salmon farming to adjacent areas
without farms in Scotland, Ireland, Atlantic Canada, and Pacific Canada to
estimate changes in marine survival concurrent with the growth of salmon
aquaculture. Through a meta-analysis of existing data, we show a reduction in
survival or abundance of Atlantic salmon; sea trout; and pink, chum, and coho
salmon in association with increased production of farmed salmon. In many cases,
these reductions in survival or abundance are greater than 50%. Meta-analytic
estimates of the mean effect are significant and negative, suggesting that
salmon farming has reduced survival of wild salmon and trout in many populations
and countries.