The bass in my pond are healthy in every way with the exception of the presence of some ulcers on a few of the bigger ones. It seems these bigger one have been caught in the past and possibly the handling (minimal) irritated them. I really don't know and I haven't marked any of the fish when they have been caught. Does anyone know what could be causing this? Some have them around the mouth and a few have them far back on their bodies. I haven't seen any single fish with more than two or three.