Channel catfish can when larger become BIG pellet hogs. I have seen in ponds where they actually dug back into the side to create a cave cavity for spawning. If you don't feed the fish their night time predatory nature will prey on fish thus they will compete with bass. Channel catfish are not bottom cleaners eating organics, leaves and muck off the bottom.

aka Pond Doctor & Dr. Perca Read Pond Boss Magazine -
America's Journal of Pond Management