Pond Boss Forums Thread Like Summary - Catfish Die Off

My pond is 1 1/4 acre and was stocked with channel and blue catfish from Overton Fisheries two and a half years ago. We've had a very dry winter and spring and yesterday we got a 4 1/2" rain that raised the water level 6". This morning I saw buzzards lining the bank and when I went to see why, there were two dozen big catfish floating on top. No small fish floating at all. Can this die off be weather related or has someone poisoned my pond? I've been feeding Sportsman's Choice Floating Pond and Catfish Food from TSC - hope that's not the problem. Please let me know what you think.

Thx,

fowells

Just thinking. If the rain influx was cold enough to displace water near the pond bottom and mix it into the water column ... and if the water was anoxic and laden with organics not fully decomposed ... the rain event might have created a low DO event. So part of what I am thinking is that some species are more resistant than others at surviving dips in DO. My impressions from study and personal experience is that the different species ordered from most risk of death to most probable survivors would go like this:

Blue Catfish, BG, GSF, GSH, CC, Gambusia.

If anyone sees any cracks in this order feel free to add your two cents. But if Blue Catfish and some BG/GSF succumbed then there is the possibility that the CC filled up on weakened and dead BG/GSF. Could possibly explain why the CC are not coming to feed. One way to test may be to fish for CC and remaining Blues with BG or GSF cut bait and to verify whether the proposition holds water. fowells, you need to do a little harvesting anyways so you could check stomach contents if you happen to catch any.

I hear several clues.

If any of the fish food is "gray" it's likely moldy. Typically, in a bag of moldy fish food, you'll see a variety of color. You'll see some pellets gray, some are normal color, some are faded. In a normal bag of fish food the color is consistent. Moldy feed has aflatoxin, which is fatal to fish. When moisture hits feed, it molds.

Second, when your pond drew down, all that left was water. If the level dropped more than two feet, then around 1/3-1/2 the actual volume of water evaporated over months of drought. As that happened, concentrations of minerals and metals and nutrients increased. Since that happened slowly, your fish adjusted. When the rain hit, it diluted months of dissolved stuff. That can add to the issues by quickly changing osmoregulation.

Third, if you had a plankton bloom, which is likely since you are feeding the fish, a fresh heavy rain can immediately kill enough of the bloom to cause rapid water degradation and oxygen depletion.

Fourth, almost three years into a catfish feeding program, your pond is beginning to reach its capacity for fish.

When you combine an expanding standing crop, moldy fish food, a drought and rain, you have the set-up for a perfect storm to kill fish.