The thermocline is often the depth in most ponds and sometimes lakes where the DO drops to concentrations where fish can not survive especially trout and other DO 'loving' fish - usually the cooler water types except YP. YP will tolerate low DO for short periods. Length of time depends of several factors. This shallow depth stratification concept applies mainly to eutrophic ponds and those where water clarity is less than 3ft to sometimes 5 feet.
One practical way to check amount of DO in deeper water is a very good idea from PB Member "esshup":
Do you have any of those metal minnow traps? If you do, catch a few BG and put some in each trap. Close the entrances, suspend them beneath a bleach bottle or something else at the various depths for a day or two. Pull them up and see if the BG are still alive. If so, then you maybe have enough DO at those depths for a trout to survive, if they are dead, then definately a trout wouldn't survive. Note BG will survive at lower DO concentrations than trout. This test just provides a good 'ball park' guess and not a definite answer.
Last edited by Bill Cody; 03/24/14 09:16 AM.
