The Chinook have been shrining for a century. Initially, it was fishery related and is now food related too.

The chum fishery had nothing to do with Chinook, as the timing of fisheries are way different. There is some overlap with coho and chum but in my experience, we protected coho in chum fisheries by using larger mesh nets. Caught no coho. When mesh size was then dropped for steelhead lots of coho showed.