Becaise you see one laying on its side in winter do not asume otvos a fish kill they do that. I have no idea why. Had a nice siized stripper laying under myvneighbors dock like that. we got a net and tried to pick him up and the minute we rouched him he took off. have seen bass do that a few times as well in the winter. I havenever look up the reason for it but think it muctvhave something to do conserving energy.