One other interesting aspect to large Bluegill populations. In the 1990's there was a study done to determine the effect that large parental male Bluegills have on the reproductive functions of the entire population. Basically, they found that in the presence of large parental males, smaller males put less energy into reproductive functions and, as a result, the smaller males grew faster. Keep in mind that because of the huge amounts of energy Bluegills put into reproductive organs, nesting and spawning activity and nest defense, their growth rates are reduced after reproductive behavior begins. So, as a result, if the large parental males were removed from the population, then the smaller Bluegills matured sooner, which reduced growth rates. This happens quite often in locations with heavy fishing pressure where the large Bluegill are kept and the smaller ones are returned. However, you will usually find that if there are exceptionally large Bluegills present in abundance, there is little fishing pressure, or people are throwing back the big ones, which slows the sexual maturation of the smaller ones, making them grow faster.
