Seeing lots of dead sunfish all within the same size class on a daily basis. I'm noticing about 3-10 new dead fish daily around the outside of the pond. I have all size classes of sunfish from fry, 1", 2, 3 and up to maybe 8/9" but only seeing that ~3" class floating around the edge.
Water has been down a little and its been warm but get plenty of wind across the pond for aeration.
I did see one sunfish in the shallow barely swimming and upon closer inspection it was missing an eye so I tossed it out. By the time I see these dead fish the eyes are usually missing but sometimes not.
disease attacks the weak, generally. It is possible you had a massive year class last year and they are down on food items in the right size. I'm not saying they are starving but possibly have a weakened immune system-possibly.