Hello folks. My name is Don and I'm new here and thank you in advance for any suggestions that you might have. I live in NE Ohio and my pond is approximately 1 acre and 9 ft. deep.

About 4 or 5 years ago, I had a winter kill that wiped out all the fish in my pond. I am pretty sure it was just too much ice covered with too much snow for too long. I had some nice sized bass and some catfish and the usual assortment of sunfish, perch, etc.

After the kill, I installed an aerator to ensure that it didn't happen again and I run it enough in the winter to keep the ice open. I then restocked the pond with fingerlings. Hybrid Blue Gill, Yellow Perch and Channel Cat. Also some minnows for food source. I only went with a few Channel cat, I don't remember for sure but probably only about 20. All has gone well. I feed very occasionally just because I enjoy watching the fish come eat. Usually only maybe half a coffee can full of food about twice a month.

The blue gill and catfish have grown very well. Not sure about the Yellow Perch, I never see any but haven't fished either. Over the 4 year period, the catfish had gotten pretty large, probably between 5 and 8 lbs. Loved watching them eat and they would almost eat out of your hand. Until today.

I went out to the pond today to find what is probably every single catfish dead and floating. Most around the edge of the pond now but a couple out in the middle. I can see nothing that might have caused them to die. There are also maybe a half dozen other fish dead but not many. I threw a bit of food out and the blue gill and sunfish still eat aggressively.

I hate that I lost the catfish. Is there some disease that would have killed them? I've had probably 25 or so Canadian Geese camped out here for a couple of months now but they usually come every year. There are also a couple of large Blue Herons that visit a couple times a day. Could the geese or Herons cause this?

I also have a deep well that I use only for irrigation. I have a float on the pond that is hooked to the well so that level stays constant. I've been doing this for over 4 years also and had the well water tested before doing so and it is good water, actually even suitable for drinking. Just mentioning it in an attempt to not leave any details out.

So, any ideas?