I would cull a bunch of the bluegill. It is good to have some big bluegill for spawning purposes but too many and they will outcompete other fish. I don't know exactly why but when I remove big gills, there are always far more small gills around.
Theeck, I think you pretty much nailed why. Competition and predation. Taking some BG that are too big to be food for LMB reduces predation of fry and competition for a finite food resource. Thank you for sharing your experience. We often overlook that management for LMB can include removing older BG that we don't need so many of.. Some believe that BG should never be removed where LMB growth and ultimate size is the goal. Intraspecies competition can be offset by feeding/fertilization but there are limits to the degree one can expand carrying capacity each year. Harvesting skm BG that are no longer on the menu can help in either case as it will reduce BG intraspecies Competition and predation either way.
