Crappie Tips: What is a Thermocline
In the summer many lakes literally separate into temperature layers called a thermocline. How can you see and fish the thermocline?
by Tim Huffman
Every crappie angler knows that temperature is critical for successful crappie fishing. That is even more true in the summer when crappie often seek deeper, cooler water temperatures. But you can go searching too deep.
Many lakes separate into a thermal layer where there is an extreme cold layer of water toward the bottom. However, because it rarely sees sunlight to generate oxygen from phytoplankton, it will have extremely low oxygen content.
Crappie like it cool but it is pointless if there is no oxygen. But with nearly any good depth finder you can detect that thermocline simply by turning the sensitivity very high. As noted in the image above, the distinct layer of cold water will create a line on your depth finder.
That line tells you the depth where deep water crappie might be holding and feeding most actively. Whether you are trolling crankbaits, casting jigs to cover or vertical fishing minnows, you never want to go below the thermocline.
More on this and other great tips available in the book “Limiting Out for Crappie.”