Guys, please DO NOT release aquarium fish into our waterways!
If you do catch a non-native in "the wild" do not release it back into the waterway, please either try to find it a new home or euthanize it.
Any non-native fish can affect an ecosystem, and if you remove just one non-native fish, it can help.
personaly i would have a rubbermaid or tank set up indoors during the winter for plecos, because they HATE cold weather. This past winter we had 7 freezes, some days the temp would not get warmer than 50, and my hottub cover had a thick sheet of ice on top. Ponds will not freeze (does not stay could enough at night to do that if the waters deep and moving, but the weather is cold! (at least for floridians!)
I don't get how plecos can eradicate a fish population.. Yes, they are carnivorous, but I highly doubt they are going to be hunting down masses of fish.. I have found that they are more scavengers than anything.