Based on the information I have seen, the problem for lower-48, and much of BC, is occurring in the Gulf of Alaska. We damn well have pretty good idea of the proximal cause but that is probably a reflection of overall N Pacific conditions.

The ocean is having huge problems in productivity for salmonids and is likely based in problems with the food chain. Whether or not the food chain problems are human(fishery) driven, human (climate) driven, or a combination remains to be seen but it must be looked into now.

What hasn't been mentioned here, or I missed it, is what has happened to the Big C wild stocks. Unless they are performing significantly better than their hatchery cousins, the problem is not how the hatcheries are being run.