waterwolf--The chemical is antimycin, I believe. I'm not a scientist but do have to wonder if it is possible to render harmless, completely and irrevocably, something which is deadly above a waterfall after it drops down below the cascade.
I very much want specks to return, but I've always had some (make that considerable) reservations about killing other wild fish to restore them.
What I find really interesting, and no one seems to have a real explanation, is that mountain trout have, on their own and in my lifetime, expanded their range appreciably in some streams such as Straight Fork and Beech Flats Prong. This expansion has had nothing to do with management by man, although you have to figure that the best qualified of all fisheries biologists, nature, has figured in the equation in a significant way.