Just like to add to the discussion that the in-river gill net fisheries are not the primary cause of fisheries changing age at maturity. That is almost wholly on marine hook and line fisheries, whether sport or troll. Any net fishery that catches immatures is also part of the problem.

I know that gill net fisheries are an obvious occurrence and a poke in the eye to those others sitting on the back but they take mature fish. No 4 year old Chinook taken in the river was, if not caught, going to return next year as a 5 year old.