The numbers of pinks we get, only ever other year, are really nowhere near what is needed. Researchers have seen pretty good results with 0.6 Kg of spawners per square metre of stream. The benefit climbed steeply to about 1.9 and then the benefits slow, but don't stop.

Although I know it's bigger, let's say the Skagit is 100km long and averages 30m wide. I know this is a significant underestimate but that gives 3 million square metres. At 2kg per pink that would be 1.5 million spawners to half hit the need. Now calculate this for the other salmon species. We're nowhere close.