There are marshes and ponds east of where I live that I have fished and hunted all my life. These ponds are full of Catfish and Carp. I've never eaten the Carp, but there are three varieties of catfish - Blue Gill, Channel Cats, and what we call Yellow Bellies. There are several ponds in this area, the deepest is about 10 feet, with the average depth of the others at 4 to 5 feet. The pond bottoms are dark mud, and a 160 lb. man will sink into it about a foot. Every winter, these shallower ponds freeze up solid. The winter temperature in these marshes varies from 5 F above zero, to 10 below zero with a variable wind chill of 5 to 30 mph on the average. And every spring, the Catfish and Carp return. According to my dad and the other old timers, the fish survive the winter by burrowing into the mud. So, If someone were attempting to raise Catfish for a food source I would say, be sure the bottom of your manmade pond was not hardpan, or of sandy soil. Let those fish burrow in the mud!
Offered by Brent.
Catfish will also burrow into the mud when a pond dries up, only to return again when there is water.
Offered by Ron.