I've never fished up there and I'm more of a wading tributary guy. That said, the choice of gear has a huge impact on fish mortality. I have a hard time seeing the need for hooks that big, especially multiple hooks, for 4-7 pound fish. The last coho I got was an 8 lber that took a spinner with a #1 hook square in the lip. There's gotta be a way to do it better up there. Perhaps the regs need to be changed to limit damage to the fish? I agree with the OP that it might be better to allow limited wild fish retention.
_________________________
If every fisherman would pick up one piece of trash, we'd have cleaner rivers and more access.