I fly fished a lake river system 25+ yrs ago for Sockeye in SE AK, on a pilot's recommendation. Stayed in a FS cabin on the lake where the river began. It had a boat there, we flew in an outboard w/ us. Used it to bomb around the lake. Discovered a camp half way up up the lake with discarded 55g drums all over the place. Pilot said Fisheries camped there to fertilize the lake to aid Sockeye production to benefit the commercials. Don't know what they dumped in there but the adult return sizes were large for Sockeye. I remember some males pushing 10#. Series ass kicking on a 7 wt. Not sure if that goes on any more.