I have fished Deer lake off and on for the past ten years. I have noticed a problem that seems to be getting worse in the last few years. The fish from the deep end are covered with lesions that appear to be caused by something abrading the scales and skin. The fish fight well and when the lesions were few the fish tasted fine and appeared to be healthy internally. Does anyone know what is causing this? The fish have deteriorated to the point that I refuse to eat them.