I'm struggling that aeration induced super chilling caused the kill. If I understand correctly, the fish died after the ice was gone and only the BG died. Also, the winter aeration was only in one small area and not in the deepest water.

My understanding...A spring turnover occurs when the surface water temp warms to 39 degrees(the temp where water is the most dense)and starts sinking. This water then mixes with the bottom water that is low in DO and high in nutrients and moves that "bad" bottom water up to where the fish are residing. This "turnover" can happen very quickly given the right weather conditions like a rapid warming air temp and/or a "warm" rain (rain warmer than 39 degrees). This mixing (turnover) of top and bottom water will continue until the entire pond reaches 39 degrees. It is my understanding that it is not unusual for only one size class and species to be impacted. This happened in a lake near me a couple years ago. The only fish that died were all the large gizzard shad and they pretty much all died in 24 hours or less. The entire shore was lined with big dead shad.

Fall turnovers also occur and are similar in that as the surface water cools to 39 degrees in the fall it sinks and causes a similar mixing with bottom water.

Tyler,

Did your kill occur shortly after or during a significant warmup and/or rain event?

Last edited by Bill D.; 04/13/18 04:00 PM.
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