I don't grow corn, I am allergic to it.
I don't want herons, I do want to keep my larger fish!
I do feed my fish, they are in an unnatural environment, (man made pond) and I am responsible for them. They come out of dormancy in the spring before there are very many insects here.
Also if I let the pond become too populated, they will run out of oxygen in the winter when it freezes over and they will ALL die. Also too many fish use up too much oxygen in the summer when temps get up to 100F. So yes, I needed to take some out. I felt it cruel to give them away to 'goldfish bowl' homes after they had been in the freedom of a large pond.