It would be interesting to know how often fish either get caught in a low D.O. zone or know enough to seek higher D.O. I say that because I had a catfish farm manager in Mississippi tell me that when they monitored D.O. in large catfish ponds at night, if the D.O. started to crash, they would crank up the PTO paddlewheels and the catfish would immediately head for the higher D.O. even in a 20 acre pond.
Cecil, the guy I have grow my Tilapia to pond stocker size is also a huge catfish farmer producing over 1M pounds annually. He is Amish and has no electricity in his home, but has a $10M, fully computerized aeration system with DO monitors/alarms, paddle-wheels, liquid oxygen injection and massive powerhouse style agitators all on automated back up generators, just in case, that he has full control over from his smartphone...he commented how the fish will get stressed and and gravitate toward the aeration before the alarms go off and the system kicks on.
I find it hard to believe fish could get "trapped" in open water with no forage or low DO. The fish live there and know the patterns of their prey and when there is O2, especially if fish stocked densely for food production know where safety is going to come from in these production ponds after only one or two events.
