It is pretty sobering to see how poorly the wild Atlantic salmon rivers in Norway are doing.
To put this in perspective for the Pacific Ocean, Atlantic salmon should be compared with steelhead numbers as the two species are more closely related than they are to the five species of Pacific salmon.
Steelhead and Atlantic salmon originated in the Atlantic and steelhead moved west in global warming. Global cooling shut the passage way, and now steelhead are found only in the Pacific Ocean. Their numbers are small and they may return to spawn several times before dying.
Steelhead, unfortunately, are the species most likely to die of ISA, so the CFIA study quite correctly includes them as they may well be the first species to be eliminated in the Pacific by fish farm diseases. Lamprey might be a good fish to study, too.
Recently, the head of the Directorate for Nature Management said that the Norwegian fish farm industry must be reduced to save wild Atlantic salmon.
See a previous post: http://fishfarmnews.blogspot.ca/2012/04/lice-in-norwaylice-in-bc-april-13-2012.html.
In the Pacific, however, there are vastly more Pacific salmon than Atlantic salmon in the Atlantic ocean - my estimate is 100 million in BC in an average year.. So it is much more important to save them as they are a key species, unlike steelhead, that are in such small numbers.