while local commercial harvests may have had an effect, people have to consider that several years ago chum populations collapsed all over the coast. That could not have been caused by a localized fishery no matter how intense.
Stocks have been rebuilding since then. South of us many Oregon rivers were all but depopulated of chum for reasons that aren't clear.
this year was supposed to be a big return - something well over a million & perhaps 2. But where are they? Most of the rivers I have been on this fall certainly are not crowded with chum. The Harrison the last few weeks has been all but empty of them, just as it has been the last several years.
My guess is that most of the chum abundance is solely due to artificial production and natural stocks are still not in any kind of shape.