Just spit balling another one of my crazy ideas.

Dig a 10' wide slot with about 4' of water depth into one of the banks of the pond. Run a wood-fired hot tub heater with all of the crap brush you cleared off your land that year. Have the water supply come from the main pond and dump the heated water at the far end of the cut slot.

Run it overnight once in the fall. Go out the next morning and seine your 10' wide slot for all of the tilapia that went towards the source of warm water.

I have no idea how many MMBTU's you would have to use to heat the water enough to make it sufficiently attractive to draw in the tilapia? However, some of the DIY hot tub heaters are pretty efficient.

I don't know if any of our tilapia experts will drop in and say that idea is ridiculous, or if they might offer some useful modifications.