My bride and I drive long-haul, so we are home every 2 months or so. Came home this time to 140 dead medium to large BG, slightly decayed to relativey fresh. Here are the pond and weather facts.
200' X 300', 18' deep at this time. 45* sides.
Auto-Feeder off since late October
Lots (and I mean LOTS) of BG
175 LMB introduced last Fall
150 Channel Cats, mostly 6" but up to 10".
No dead Bass or Cats
Saw 2 almost dead BG but no others as I cleaned up the dead this morning.
All dead BG are of medium to large size, no babies.
Pond water pretty clear, no smell, BUT...
We had severe winds on the 14th of Dec.
We are in Southern Oregon and the pond does not freeze over. Temps have been cold to freezing though, no ice on pond at all.

Question: Could this die-off be caused by turn-over, or would "over-crowding" cause just a BG die-off? Help! Thanks for any help.