I had the same experience as you did ponds for fun. I started out having only a few turtles and then it seemed like hundreds. What bothered me the most was they were competing directly with my fish for the pellets. I bought a turtle trap from dunns fish farm and in the past few months have caught hundreds of the critters. In the spring I would catch as many as twenty in a week. Even after catching and "letting go" all these turtles there are still as many as twenty that I can count at feeding time. I had a stringer of fish the other day tied to the bank and after fishing on the other side of the pond came back to see my fish had been eaten half alive by the turtles. Some of the fish were still alive with big hunks bit out of them. I put the fish remains in the trap and caught a ton of turtles. I don't like turtles.