I'd guess that many west coasters here have heard of the Pacific Decadal Oscillation - PDO - a climate/ocean phenomenon that is correlated with fish run sizes in Alaska and the lower west coast (WA, OR). The PDO seems to flip flop every 20 or 30 years between these areas, and with it, so do fish populations.
It is thought that a flip is happening now. If so, fish runs should rebound in the lower west coast, and fall in Alaska for the next several decades. The "record" chinook runs in the Columbia this past year are often touted as the leading edge of this flip flop.
This is all cool, but superimposing ocean effects on all the other stuff that affects fish (4H's) makes it really difficult to pin down who and what has pushed many runs to the brink of extinction - and beyond. And that's not to say that humans can't affect climate, too, as we are seeing more and more.
I'm at least hoping for good fishing in Oregon over the next several decades!