View Full Version : Locating fish in summer months

07-29-2005, 10:28 AM
I was told and read that in the summer fish stay in the thermocylne. My question to all you master fisherman out there is how can i find what depth this layer of water is located? I'm sure you can figure it out just by looking at the fish finder and see what depth most of the fish are located but is there an easier and more precise way?

07-29-2005, 12:14 PM
Doc can probably give you a more scientific explanation but basically the thermocline is recognized by a relatively rapid drop in water temperature to the cooler temps of deeper water that the trout and kokanee etc. prefer in the summer months when the surface temperatures rise.

07-29-2005, 01:57 PM
I guess it would take a temprature gauge that you drop to depth and check the reading.

The easier way is a fish finder to see where the fish are holding... *But even this may do you little good because the food that trout eat may not hold at the depth the trout are holding at. *Trout will hold at one depth and feed at another and then return to their comfortable depth.

This is a lesson Doc points out in regard to fishing Pyrmid lake.

On the Left menu of the Sniffer there is a resources menu and a link there on Fishing Technique. One of the articles is "Catching more and bigger at Pyramid Lake" written by Doc. He covers this topic in detail and these strategies hold true for other Trout species as well.

07-29-2005, 03:34 PM
Yeah FC, I use the sonar too, if I see a lot of fish at 80 feet and a few at 50 or 60, I'll go after the shallower ones every time for the first try.

07-29-2005, 04:54 PM
Good point Oxbow.

07-29-2005, 11:43 PM
Generally speaking if the lake in question is shallow enough there are a few instruments people use to graph a thermocline. A standard YSI or DO (dissolved oxygen) meter with a long reaching cord can effectively graph the temperature of a lake as it is lowered down the water column. Unfortunately, a stardard thermometer attached to a rope will not work as each stratified layer of the lake will change the temperature of the thermometer as it passes through it, so unless you can read that thermometer underwater at each particular depth you wont know the correct temperature reading. Other instruments are out there however. Thermal imaging and other depth instruments with temperature sensors might also be used. (not sure how much these cost or how easily they can be fitted to boats) Unfortunately there isn't a nice NOAA sight or weather.com like website that shows lake thermoclines for us, at least that I know of.

If however you are looking to read a depth vs. temperature plot to figure out what a thermocline looks like it will generally look like this:


Other factors in addition to a thermocline may also dicate where fish might be hiding. While the thermocline is a good place to start your search during the summer months for fish, getting some info on where the nitrogen and ph and or plankton are located would be very helpful as well. Because a thermocline is like an invisible barrier it prevents the rich nutrient deep water from mixing with the sunny surface water. As such it can be a rate limiting area by allowing for or denying nutrients from the deep water to mix with the light penetrated areas of the water column for primary productivity (plankton growth). All said and done...finding good concentrations of plankton will tell you were your baitfish are, and baitfish can be a good place to find big lunkers as well. (most of this happens more or less at or slightly below a thermocline)

I hope this helps.

07-30-2005, 05:25 AM
Nice, easy to read and understand presentation UCDFisher. Welcome to the boards.

07-30-2005, 03:26 PM
Summer months are the easiest times to catch trout.I purchased a digital thermometer from Cabelas and it reads the temp every 5 ft.Lower it down to the botom then back up.I will then troll in the temp. range browns like to stay in.This method works.

07-30-2005, 07:22 PM
If you can find it, you should really read Docs thread,I thought It was very good.

08-01-2005, 07:23 AM
Thanks alot everyone.

08-04-2005, 06:58 PM
If you can find it, you should really read Docs thread,I thought It was very good.

how long ago was it...?
docs thread....<*}}}}><

07-01-2011, 12:52 AM
I know I am late to this party but just wanted to add this to make this thread more useful. I think this is the article about fishing in the summer that FishMischief referenced:
Catching More and Bigger Fish on Pyramid Lake, By Lee Weber, Ph.D. (http://www.fishsniffer.com/guest/041104pyramidtechnique.html)

07-01-2011, 08:23 AM
Oftentimes, the depth where only about 1% of light from the surface remains is where the thermocline can be found. The poor man's way of figuring out where this depth is located is dropping a white lure into the water until you can't see it, then multiplying that depth by 3. That'll get you close.

As far as how much trout use the thermocline, it depends on the lake. For example, in natural lakes with large, well-developed weedbeds and aquatic insect populations, trout'll hold in the thermocline when inactive, but they'll come up into the upper, warmer layer of water - the epilimnion - to feed, especially in the morning when it's a bit cooler. Even lakers will do this in lakes that lack open-water fishes but have near-shore fishes in abundance. However, in some reservoirs that lack lots of veg, trout will hold in the thermocline and feed there, too, primarily on zooplankton.