What is Thermocline?

Can someone tell me how to fish and read thermocline? I don't understand anything about it. Thanks for any help understanding.

Using your depthfinder and high gain you can usually spot it, or take note at what depth most fish are suspended and usually that will give you an idea.

Fish will sit right on top of it, as there tends to be less oxygen underneath.

I think it is when the colder water stratifies with warmer water .?. Below thermocline it is very oxygen depleted . If you hear the term. Turnover that is when the 2 layers change place . Tough fishing when that happens . IMHO

Guy Skinner!

The thermocline is created (usually the first part of summer) when the homogenized water (basically all water one temp) starts to stratify (separate). That is, the water near the surface becomes warmer than the water near the bottom of the lake and forms layers of water. Where those two water layers meet, a thermocline is created. The upper layer of water will be highly oxygenated, while the lower layer of water will be very low oxygenated. The thermocline is a mix of the two and while it will definitely support life (fish), just immediately above the thermocline is where the oxygen is best. The picture shown is very typical of what it looks like on a graph. You will want to fish in or above where the thermocline is shown, but not necessarily below it. I say necessarily because there will always be an anomaly to any scenario.

Now to finish the story....colder water is heavier than warmer water (that's why the summer water will 'float' on the bottom water). But as Fall approaches, the upper layer will start to cool...and get heavier. When it gets too heavy for the bottom layer to support, the lake will 'turn'. Bottom comes up, top goes down. The lake will get stained and sometimes...stinky. What is happening is that it is homogenizing again, and will usually stay that way until the following summer.

Sorry for the long winded story, but this is sorta what happens. Watch your graph and fish accordingly. Good fishing to all!!!!

Water is densest at 4deg. C (39.4F) so when it get to that temp it will sink to the bottom, this is why is almost impossible for even small ponds to freeze solid. In order to free the water must go from 4 to 3 to 2 to1 and then to 0, so the warmer water will always be at the bottom

Oh....I always thought it was these: http://thermoclinelures.com/ocart/index.php?route=product/product&path=67&product_id=121

I've never seen a thermocline yet after fishing Texas waters for 14 years. I have seen major lake turnovers, most notably Fork and Grapevine, but not thermoclines. In fact, I have never seen it yet on Lake Arlington which is a power plant lake that averages water temps 4-10 degrees above other area lakes when the plants' working. I'm not saying that there is no such thing. I'm just saying that is has to be a pretty tranquil lake for that to happen. Our reservoirs and the wind we get in the spring/early summer mitigates the thermocline.

Guy's explanation and Wayne's pics should answer the question, they are right on, at least, that is my opinion.

What are all those little arches on your 2D pics? I never see those on my fish finder.

The water under the thermocline is significantly colder than the top water. While scuba diving you can literally be right above the thermocline and stick your arm down into it and feel how much of a difference there is.

Pretty much everyone else has already said to fish above it. I'd concur. Good luck

Dead on what fireman said, at times it almost like a line underwater, cold below warm above, when scuba diving you can sometimes keep your belly in the cold and back in the warm.

Good pictures, for those of you who are thinking about fishing using this. Here in Texas we also have a light zone where the sun shine drives them down. So all of this gives us a crappie zone in the middle of it. First part of the day, last part and nights the schooling crappie will leave this zone to feed but the old, smart, big crappie will stay in it for the most part. So after you get what you want to cook try fishing where you think the thermocline is. Good fishing

Thanks for all the response. Lots of good information.