The rebound in the Puyallup and White systems occurred simultaneously with the surge in pink salmon. At the same time, age data showed that the smolts got younger (more 1s, fewer 3s). As smolt age got younger, the R/S for the brood went up. On the White, last time I looked, the regression line predicted an R/S of 1 when smolt age averaged 1.5. This pretty much concurs with the Keogh data.

The Keogh also measured more smolts when the smolts were younger so if we decrease smolt age we increase smolt numbers for a given stream.

Where steelhead diverge from salmon is the reliance on repeat spawners. A salmon run with and R/S of .8 goes extinct. If the steelhead runs has somewhere between 10 and 20 % repeats, that R/S is sustainable.

When we calculate "allowable harvest rate" (at least when I was involved) the number was (say) 5%. We can take 5% per year. But, every steelhead killed in year 1 also kills some fish in year 2,3,4, etc. as that fish can't repeat spawn. So, the exploitation rate is higher.

IF westside steelhead behave like eastside summers then provision for enhanced fall flows (and associated cooler water temps) is actually selecting for the resident life history. An observation (as yet untested) has been that the streams where minimum spawning flows for salmon were set resulted in benefits to salmon but decline in anadromous rainbow.

Steelhead are a hell of a lot more complex than salmon. Couple that with a life history that may take at least 6 years to get ONE data point on the return from a single brood year and one can see that there needs to be a very long-term investment in monitoring that needs to be annual. If it takes six years to get one point, then missing one year in that six compromises six years of data.