Question about Thermocline

Discussion in 'All Catfishing' started by JPritch, Jun 11, 2007.

  1. JPritch

    JPritch New Member

    Lynchburg, VA
    If a thermocline is present in a lake, is it present throughout the lake or can it just be in certain parts of it?

    Reason I ask, I was fishing Saturday night in one of the river channels in a lake, and there was that "line" on my fishfinder at 20ft, and alot of fish arches all around this line, and none on the bottom. I took this to be the thermocline. But then every other area I fished the line wasn't present and I was seeing fish arches along the bottom.

    Just wondering if I in fact saw the thermocline or if it could have been something else, maybe a school of bait fish or something? Water temps were high 80's.
  2. ryang

    ryang Well-Known Member

    Blacklick, Ohio
    Josh I would think it would depend on what was feeding that lake. If it was river fed then I would think that there would be some sort of a thermocline due to the temp difference between the Lake and River. I doubt tho that it would be the same thermocline throughout the whole lake tho it is different all over the oceans due to different currents and whatnot so I dont see why a lake would be much different. I was a SONAR Tech in the Navy with over 6 years of sea time Ive seen pleanty of thermoclines and they differed alot over all the seas an oceans out there

  3. jim

    jim New Member

    Jacksonville NC
    For a thermocline to set up in a body of water you have to have some reasonable depth.If your lake is shallow, for instance Santee, then the wind and wave action stirs up the shallow water and a thermocline cant set up. The thermocline is a boundary water between the warm surface layer and the colder depths.It is the area where the temp changes are the most rapid.You can often find it by simply swimming down through the surface layer until you feel the rapid temp change.Now if the lake has deeper areas,such as a river channel then a thermocline can develope and you will see what you saw.The fish will relate to it because it is more comfortable and holds sufficient oxygen.Lets say it sets up at 20 feet.The same condition of temp and oxy will pretty much be throughout the lake and when the bottom is at 20 ft you will see the fish relating to it.Go to 10 ft and there might be fish in there feeding but when done they will drop back to the comfort zone.You can tell when you are in the prefered zone by watching live bait.Suspend it at 20 ft and it remains lively and frisky.Drop it to 30-40 ft in the oxy depleted zone and you will reel him up dead with his eyes bugged out in short order.Hope this helps.:big_smile: