Thread: Scientific Thermocline (lots of pics)

T- Mike - Great Info - Thanks

Actually, it's not that there's no oxygen and not all fish respond the same way. For instance, here's a temp/oxygen chart for a local lake with the O2 levels for each depth:

D Temp Oxygen
0 82.4F° (28.0C°) 7.5
5 82.4F° (28.0C°) 7.5
10 82.4F° (28.0C°) 7.4
15 82.4F° (28.0C°) 7.3
20 81.3F° (27.4C°) 4.9
21 80.4F° (26.9C°) 3.6
22 78.1F° (25.6C°) 0.4
23 76.5F° (24.7C°) 0.2
24 75.0F° (23.9C°) 0.2
25 73.9F° (23.3C°) 0.2
26 71.4F° (21.9C°) 0.1
27 70.9F° (21.6C°) 0.1
28 69.1F° (20.6C°) 0.1
29 68.0F° (20.0C°) 0.1
30 66.4F° (19.1C°) 0.1
31 65.5F° (18.6C°) 0.1
32 64.4F° (18.0C°) 0.0

A thermocline isn't a hard line--it's a band of depth. You look for a temp drop of 1.5-2 degrees and that's the start. Above, the t-cline starts between 15 and 20 feet and is complete at 22 feet. Crappie can tolerate well down to about 4 parts per million O2. Fish like lake trout can tolerate alot less. And crappie don't always ride right on the t-cline. The other day, the t-cline was at 13 feet, but we caught fish all day long at 6-8 feet, sometimes shallower, as well as at 13 feet. The t-cline can eliminate alot of water, but I always try everywhere between the t-cline and the surface.

Thanks T. I definately saw the same stuff a little earlier on the local lake.

This is quite a good post. Very informative with great illustrations.
Thanks

great stuff guys....thanks!!

Good info. Thanks.

thanks for the info. great stuff.

this should be made into a sticky.

You are one sharp dude. THANKS FOR THE INFO

Here's a tip to maximize the use of your fish finders display area is once you find the thermocline is to maximize the screen area for "fishable" waters. Since most fish cannot survive below a thermocline since the oxygen level is too low. Instead of looking at the entire water column use the MAX Depth Feature and remove the "unfishable" water from the display and it will increase the amount details you can see in the waters fish can live.

Here is an image of the Humminbird 798c in Auto Depth Mode:



If your targeting fish or thermocline is at a know depth you can set a MAX Depth like I did in this image at 40 foot and increases the size of the details and makes it easier to target the fish.



IF you set Max Depth it will place an "M" next to the Bottom Depth Reading to show you are setting the Maximum Depth to view. Make sure you reset to auto if you want to navigate and see the bottom.