The low water and heat caused a fish kill here. Only in one single pond out of 5. My RES/SMB pond had about 50 SMB and HSB floating along the south bank a couple days ago. All about the same size, about 14 inches long. Pond is about 18" low and we got a hard and fast cold 2.3" rain and cool down in air temperature. I suspect the quick change was just too much for the fish to handle. I am pretty sure the pond was over populated and needed some removed. Mother nature beat me to it.
The strange thing is, my old pond right next to it, no problem. My big main pond and the associated sediment pond and forage pond, no problem (but they all get night time aeration with the exception of the old pond). Just the one pond had the problem.
I suspect, but don't know for sure, the reason the old pond did not run into a problem was because of the size mix of fish. The RES/SMB pond had those 50 fish all nearly the same identical size. Only saw one or two slightly smaller. In the old pond I have a few larger LMB that I suspect keep the smaller fish thinned out. In the RES/SMB pond too many of the same size fish with no big lower number apex predators to thin out the smaller population. Thus over population of that one size class.
Was a sad thing to see but the way it goes sometimes. That sudden cold water runoff going to the bottom of an anoxic pond was a death blow to the larger fish in that pond. At least that is my theory. The other ponds with aeration or a better variety of fish predator sizes seemed to fair much better.
I've not been feeding anything because of the heat and low water situation. So added feed was not the problem.
