[bdwalter]

As someone who has avidly fished for salmon in the NW for the last 30 years (~75 days per year), I can at least give my opinion that this is mostly BS.

Pervasive, non-selective, commercial and tribal gill-netting that is optimized to remove the largest specimens from the gene-pool is a big part of where I point my finger. Throw in the dams and massive increases in non-native, invasive California sea lions in the lower Columbia and you have a mess in the making. Lots of factors but I believe most of the problems are in-river, not in-ocean.

Also disclaimer, my opinions mostly come from experience on the Columbia (The largest Chinook runs in the world), not the Sound or further north.

[tastyfreeze]

I wish I could find the selective breeding paper I read years ago. It is as you say. The human practice of keeping the largest fish in both sport and commercial catches is to blame. A 75 year king salmon derby here shows progressively smaller fish winning every year. Its not really hard to reason that if you kill the big fish before they breed the fish are going to get smaller.

We even see short unnaturally fat fish that are just under the minimum length that has been the same for 30+ years. The gene pool is being pressured to shorter fish for survival.