I don't know the answers.

But I will say that, strictly anecdotally, the Skagit seems to be near barren for most of the steelhead season. I can also say that other nearby rivers, while not having "robust" runs, have what I'd consider to be populations of wild steelhead well worth fish for. Those fish are subject to much of the same "ocean conditions" as the Sauk/Skagit fish.

I can also say that I spend a lot of time in the San Juans and that baitfish, in general, are not exactly in short supply. Perhaps the biomass isn't even close to what it should be but taking someone out to show them baitfish wouldn't be much of a problem.

Overall, this whole topic is extremely depressing. I'm with Keith in that I'd probably still go up there to fish even if the river is barren. The time spent up there is of far more value than the fish I catch.