Piper,
I think the argument would be that if the ocean returns did not materialize, then these resident fish would be needed to make up for that loss. The bigger question I have is why, when some runs started to show a much higher return, that the other runs then did not have their numbers adjusted. It would seem that if the limiting factor, ie. ocean conditions, did not reduce the number of fish in rivers A,B and C then why would we continue to assume that they same limiting factor would still limit rivers D, E and F. Here in Puget Sound we still do not have the south sound open for Coho, though all indications are that the runs materialized at a fair to good return. Minter currently shows a hatchery return of 12,000 coho. This is twice the normal return. If we assume the numbers are high due to a lack of fishing, then at least we could assume the numbers are close to normal. Even though it would be a circus, why not open it up. They do for Chum and the numbers are much lower. The Dewatto and Quilicene are probably worse.
What seems to be limiting opening the sound is the assumption that the Nisqually will have limited numbers. Of course, the nisqually hatchery does not list their numbers, but their 6000 king prediction ended up over 20,000 off. Add in the fact that the pen fish have come back in good numbers, and I am left wondering why we are not fishing. I suppose they will point out that they are protecting next year kings due to low prediction numbers. But, seeing as they came in at much higher than anticipated numbers this year, do these predictions still hold weight?