Tilapia usually die out in the fall once water temperatures fall below a certain point. I believe it is in the range of 50-55 degrees F. Somehow one who has more experience can answer this better.
Tilapia also convert biomass into weight. They have a similar body shape to a bluegill. So adding them is making your pond more efficient essentially. They also take pressure off of the bluegill by giving the bass another food source.
