The deepest part of the pond is about 15 feet by the dam and it steadily shallows to the far side of the pond. I bet the Bluegill would thrive in the shallower end because a layer of vegetation sits on top of the water providing good cover. The fish kill happens in July-August, when the water level is at the lowest. The lowest water level I have ever seen was about 2 feet below the spillway. Will stunted fish grow bigger once the problem area is corrected, or does it take another generation?