Just adding my 2 cents in here. I got a 100 or so papershells from Smith Creek a few years back. This was for a pond half your size that had been around for 30 years. No idea on what was in before then. But anyways, now 4-5 years later, I've got them everywhere. I have low visibility in my water, but no idea if my abundance of craws has anything to do with it. I have some burrowing on my shores, but I don't think that's the papershells. I assume it's a previous resident but I'm not positive.
