Reality is the river system is like a circular food chain.. You have to have salmon to come back in big #'s for them to die and nutrients to be recycled into the system.. Check all the rivers with a healthy or rivers that meet escapement goals for winter native steelhead and they all have a good solid fall salmon run..
Take a look at AK, it has the entire "circular" food chain that thrives off each species year in and year out. Once a part of that food chain or "cycle" is lost the whole system goes down...

I beleive that we are buying time for the wild steelhead with hatchery salmon being planted to make up for the wild runs of salmon that used to be in most systems in healthy runs..
Keith