Just a note on what happened to my little pond (1/4 acre). It was so full of crawdads that all you needed to do was dip a pole net in and you would have caught a couple craws. Water looked like a mud puddle. Then new 1 1/2 acre pond was made right next to it stocked with bluegill, bass and catfish. Within 2 years we had green sunfish in both ponds. The green sunfish ate all the craws. There is not a one to be caught. Also green sunfish have over populated and are only 3 inches long. So in my opinion I would say a pond with bass would keep them under control. One note that I should say is there is no rock or trees in pond so they have no where to hide.