Smalma is right on on this one.

Its artificial (not darwin's natural )selection at work. If you want hatchery fish that are aggressive in the rivers, have the hatchery workers collect their brood stock by fishing the hatchery holding ponds with spinnners, etc. Only the biters would get to spawn. This might help counteract angling harvest to some extent.

Slabquest, I don't think they're full of food. I mostly fish area 10 and my boat has not bonked a silver with anything in its stomach since the last week of august. They just quit eating this by the beginning of september.