Thanks for the reply. Maybe someone else knows more about this than I do but it is crazy to think that only a certain type of fish would disappear and others thrive
Walleye can hang out deep and not be easy to see but should be catchable especially since you caught one in spring 2019 and it was 14" Pretty big for even a big CC to eat. HSB, I have no experience but as they get bigger they usually are pretty easy to get to feed on pellets and should be seen schooling in open water.
YP if they are stocked as pellet trained YP should stay trained and should be willing to come to eat pellets in morning and early evening lighting conditions. IF there are still mature female YP in there which I would have to believe there are then they would lay eggs every spring still.
It doesn't sound like you would have a kill from poor water conditions or from excessive temperatures of the water.
I'm not confident that I can tell if you truly had a winter kill or not. I can't tell that for my own pond either as any fish that dies under the ice probably won't be seen as the critters under the ice clean it up.
Before I would pour more fish into it it might be interesting to see if you can set up a underwater GoPro like camera and see if you can capture image of any YP or Walleye (or HSB for that matter). I recently reviewed an ad for a $50 GoPro knock off that had as good or better features than the name brand GoPro. Fascinating what you might learn if you had an eye on the bottom of the pond. Some are able to stream live to WIFI but again I don't know how well they can stream from underwater to your wifi network.
