Certainly, there are numerous factors that affect salmon populations, varying from population to population. In some cases, it would be the loss of freshwater habitat. In other cases, it could be pollution. In other cases, it could be dams. In others, it could be disease from aquaculture facilities or hatcheries. In others, it could be problems with the harvest and overharvesting. Another important factor is climate change, and that's a very big, looming factor.
All of these things contribute to the decline of wild salmon in British Columbia. Not all of these things are amenable to management solutions. If I were to rank the factors we were to focus on, I would look at disease transmission from aquaculture as a very important factor.
I would do so, first, because our experience from the rest of the world indicates that we should expect problems; second, because we are seeing problems in B.C.; and importantly, third, these problems are amenable to management change and solutions. Other problems such as climate change are a lot more difficult to deal with.