Generally, if the body of water is completely private as in a pond or lake. Most states allow you to do as you please. However, if you part of a river, those fish can come and go as they please and thus would be under state laws for fish management. Just like if you fenced in 200 acres on your land and stocked it with whitetail deer. Those deer basically become livestock and you can shoot them any time of year in most states.
