Not many unwanted species yet. I got a few small trout that made it in after the first year of perch. I dont think they made it once in the pond. My pond is too warm and the perch were too hungry.
I have added log perch and there was one or two walleye that made it in when we got the fry from the dealer. I havent seen much of them once they are in there. I have a cement wall and feeder tubes into the pond that are now screened. Thus nothing can make itin unless it goes over the top or is smaller than 1/16th of an inch in size.
I fell I have been very lucky to keep things in balance thus far. Even when the heron comes in I don't see any other species hanging on for deal life on his legs
I think main reason for mine is that I am a small pond near Lake Ontario, Thus most of the traffic goes there for birds and suck and I only get the stray and the seasonal creek has very few other ponds/opportunites to pick up other fish and I screen things out before I let it into my pond.
