Doubt there is one. On the Kenai they start at 3 for sockeye and then go to six if the run supports it. Only thing I can figure is that WDFW wants to cycle guys through. Get your limit and leave.

Back when I started the steelhead (and all gamefish, actually) limit was 2 fish brought to hand. Release them and you're done. Actually, a kelt counted as one and needed to be punched. Most wardens would let you release it and not punch it but that was the rule. Again, the idea was to cycle guys through.

But I don't see why, in a situation like Hoodsport, the limit is not much much higher.