I was just going to say that it could be from pesticides and (literally) crap from cowyards or other farm animals. My parents live by a lake that has huge hilly pastures all around the lake. The "crap" and all that fun stuff slides right on down into the lake (they're trying to get this resolved, but some old haggy woman owns the farms and wont allow them to be moved, yadda yadda) but my whole point for posting was to say that lots of times when my dad catches fish, there are odd things about them - their eyes are cloudy or protruding, their scales are deformed, etc. So - my guess is that it could be either of those, or a combo of both. there have been lots of studies done on this lake and they've traced a LOT of the problems in the lake back to that.
Or parasites.
lol