In the shallow lakes, and in those slow-moving tributaries, there are several that have been completely wiped out. The only thing they feed on now is themselves. They are real cannibalistic. California biologists were recently confronted with a similar problem when someone released northern pike into one of that state's lakes. Officials there responded with a biodegradable poison called Rotenone that killed every fish in the lake.
Officials plan to restock the lake with native trout and salmon.
Poison wouldn't work in the Susitna River. We have a lot of real productive streams that are the driving force of this system. In order to wipe out northern pike you'd wipe out every salmon stream in the whole valley. And you probably still wouldn't get to the northern pike. So to combat the pike, biologists in Alaska have lengthened the fishing season and eliminated catch limits.