Todd
I've probably read the same studies and am in the same boat...tooo may boxes of stuff. The one I liked the most was the one on north Vancouver Island where they substantially brought back the health of the ecosystem thru use of fertlizer pellets in the upper watersheds.
In this case there aren't any problems in the lower reaches with additional inputs from humans.
We might look at most of the OP rivers as candidates for this type of work. also the canadians see this as a temporary measure as when the rivers become saturated with fish then mother nature can take over in the long term.

gooose