Another part of the answer to your question, DU, is that the stocking of threadfin or gizzard shad or GSH, any one of the three, in addition to introducing competition for the bluegill's food, takes a significant amount of the bass's prey focus off of the bluegill, thereby causing the bluegill to overpopulate. I had suspected this just from the number of bluegill in the 56-acre lake I'm working with, and the studies I linked to above specifically note this factor.
