I think, first of all, one has to consider the probability of Atlantic salmon establishing themselves off of the west coast. On balance—and this was one of the conclusions of the report— there is little evidence that this has happened.
And to be fair, it's rather unlikely, I think, that it would happen. Atlantic salmon does not transfer very well. People have tried to stock Atlantic salmon in the Maritimes, across the country, and in different parts of the world, and it has not taken very well. It's not a particularly good invasive species.