You can feed your BG with a floating feeder that uses road kill or fish scraps. Basically it is a floating platform with screen on it to create an area where the material sits and use a plastic container over it with a few holes drilled in it. Flies will find it lay their eggs maggots will hatch consume the feed stock and when they are ready to pupate they crawl off and bury in the ground but there's no ground there so they fall into the water and the fish will be there to eat them.