There is a type of gar in lake erie, not sure if they eat carp though. I see several baby gar each year in my marina back the portage river every year. They are only 3 or 4 inch, but I am sure they did not swim up the river, but never seen a big one back there but had to be at some time. When I was a kid 30 years ago u remember catching several in a cup at harbor winds in east harbor