Pond is fished quite heavily, bass are recaught even on the same day sometimes on minnows (GSH).
There are some diseases that could be affecting them that only show up in certain species and there may be no external indication-which is what we seem to have and with temps warming, the timing is such the bacteria could be "Popping" and causing a toxic, spring kill.
Feed is first-run Endurance, some of the very first bags, no old feed.
I did some reading on this and am somewhat concerned on the addition of farm raised trout, this could be playing a role as a stresser as well, not sure, but sounds like it could be possible.
jpsdad, based on sampling, the estimate on total bass weight last fall would be well over 250lbs for the total 3/4 ac.
As of tonight, I'm estimating 49lbs of bass morts in roughly 16 days or so, yet catch rates of this size bass and larger are still very decent. It sounds very conflicting but it's happening. Again, in (I think) 9 years, these morts are the only bass above 14" that have been removed from day 1.