Thermocline?

[Jesse Ours]

I've been reading some books on locating bass and keep running in to this Thermocline thing. The authors all stress the importance of it but never really explain it. I was wondering if anyone out there could explain it in terms i can understand. Thanks

[s13john]

http://en.wikipedia.org/wiki/Thermocline

Basically its a separation of cooler less oxygenated water with warmer water on top. Fish tend to be above the thermocline line. it looks kinda like this.

Hopefully Wayne p will chime in, i learned most of the stuff i know from him.

[BobP]

Water in a lake will always tend to stratify according to it's temperature, warmer water on top, colder water beneath it. That's because warm water is less dense and weighs less than cold water. Sometimes the demarcation between the warmer upper layer and the colder lower layer is very distinct - that defines a thermocline. The significance is this: the warmer water is not mixing with the water beneath the thermocline. If it did, there would of course be no thermocline. The deeper water just sits there and does not get re-oxygenated, so most fish will not be able to live below the thermocline. Fish and other organism in a lake often congregate just above a thermocline. It's the coolest water available that also contains enough oxygen to sustain life. If you have a decent sonar, you can see a thermocline in many lakes in summer. If you can't see the actual line on sonar, you can often see that baitfish are holding at a specific depth line throughout a large part of the lake on a given day - and you can assume the thermocline is just below them.

Thermoclines help you locate fish. If it's at 25 ft deep, there's no reason to fish deeper. But you may want to check out the areas where the thermocline hits the 25 ft deep banks of the lake, especially if those areas have cover that can hide hungry bass. As water cools in the fall, the upper water layer will eventually cool to the same temperature as the water below the thermocline, at which point the two layers will mix and the thermocline will disappear. This is called "turnover'. In most lakes, the water will become very cloudy and you will see lots of small debris floating on the surface. That's junk that was sitting on the bottom of the lake. The turnover is not a good time to fish.

[senile1]

BobP has explained it perfectly.

[K_Mac]

Well done BobP. Your reply could, and maybe should, be bookmarked.

[Hyrule Bass]

thanks BobP, thats the first time anyone has explained what a thermocline is that ive actually understood it...

[Jesse Ours]

Thanks alot BobP, i got it now. I do appreciate it.