The beaver dug under the pig/cattle panels. I only stocked each pond with each species one time. None of my species of fish has ever been eradicated by the wildlife. Sometimes it takes a while for the big ones to be replaced though. I don't ask anyone to manage their ponds as I do. Just sharing my perspective. I did take exception to the beavers and am fortunate to have a neighbor who enjoys trapping. No otters yet, but the populations are growing in the state.