Lake Texoma Fishing Report :: Understanding the Thermocline
Posted on June 20, 2023
It is interesting to observe how the fish behave as the seasons change. As their behaviors change, so too do the methods with which can be used to trigger them to bite. To me, one of the most interesting and dramatic changes of the year happens right here around Father's Day every year. I don't fully understand it, likely no one does, I don't really know why but being a fishing guide, it is my job to know how. Though, through my observations over the years, I do have theories as to why they do some of the things that they do. There are many variables at play that dictate why fish behave the way they do but mainly fish are looking for food and comfort, and not necessarily in that order.
First, lets observe the patterns. Each year in the spring the fish will move into the shallows to enjoy the warmer waters. Around April through early May lure fishing is great on topwaters and swimbaits. The bait fishing is also good during this time drifting flats and fishing along the ledges with live shad. Really you can catch fish with whatever method you wish to use and potentially come home with a limit of fish. But as the temperatures begin to heat up in May, the fish start to move deeper to stay in their preferred water temperature which in the 60's. As this happens the lure bite will begin to taper off and the bait bite will really turn on. During this time, shad are spawning along the banks which will produce a good topwater bite for the lure fishermen in the first part of the morning but as June sets in that too will begin disappear. This time period is some of the worst lure fishing of the year while at the same time, the bait fishing is as about as good as it gets. During the shad spawn, bait can be caught in one throw of the cast net so it is easy to catch bait and easy to catch fish. Now, I'm primarily a lure fisherman but during this time I'm not above switching over to bait to enjoy the easy abundance of catching fish after fish as soon as you drop a bait in the water, so every year I'll put away my lure rods and pull out my bait rods for about a month or two during May and June.
So, as June sets in and the temperatures continue to rise, the fish will move into the deepest parts of the lake to escape the heat, this is when lure fishing can be really tough because all the fish seem to be hanging out in 50-80ft. of water and they will not touch a lure down there, though offer them a live shad and it is game on. Now every year around Father's Day, a couple of big events happen that will drastically change the fish behavior over night. At this time, the shad are completely through spawning and most of their eggs have hatch out and filled the lake will billions of tiny shad that are swimming along the surface in open water all over the lake. The baby stripers have already began a feeding frenzy each day on these tiny morsels while all of the larger fish have been relaxing in the cool waters on the bottom of the lake without any concern for these little shad, but as the temperatures continue to rise, the thermocline begins to set in.
What is a thermocline? During the warmer months of the year, the water column becomes stratified, cold water is denser and will sit at the bottom of the lake while the warmer water floats above it on the surface. Since night time temperatures no longer fall below the temperature of the water at the bottom of the lake, the water on the surface of the lake never gets cold enough to sink to the bottom. The wind will mechanically mix and oxygenate this warmer top layer of 20-30 ft. or so but the bottom of the water column below 30ft. or so will be sealed off so to speak since there is no flow between the 2 layers. This means that the oxygen that is mixed in at the surface does not penetrate to the depths and whatever oxygen that is available below the thermocline is slowly being depleted as the fish and microbes use it to sustain life.
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Ok, now that we have observed this pattern, it is now around Father's Day weekend, the thermocline has set in and the fish have moved into the depths to stay cool, there is not much oxygen down there so they are lethargic so they will hit a live shad but will not touch a lure, I really don't know why, that is just the way it is. One day you go out and they are in this pattern and fishing is awesome anchored out in deep water dropping bait down to 60ft. then the next day you go out and the fish have disappeared from the depths and when drop a live shad below 30ft. it dies. It seems to happen every year like a switch, they finally run out of oxygen and have to come out of the depths and all you can find is fish scattered around the thermocline as they transition into their next pattern. Now these fish come out of the depths and find all of the shad fry that are roaming around the surface and begin to feed. This is great if you are a lure fisherman but if you are trying to fish bait it is hard to keep up with a moving school of fish. It seems as soon as you get baits down, you may catch 1 or 2 and then the fish have moved on. When they were on the bottom of the lake, they would stay under the boat all day, now you have to continually stay on the move to stay with the fish. After this sudden switch, because fish will no longer stay still under the boat, lures will often produce more fish than the live bait. That switch seemed to flip this past Saturday, on June 17th to signal the beginning of lure season which will last until next May for me. That doesn't mean you can't still go out there and do well on live bait, you can, but you have to work a little harder to stay on the fish, any why bother with catching bait when lures are more fun and will often produce more fish anyway.
This time of year is really excellent fly fishing, the topwater action is really turning on and these stripers will readily take a fly. It is also a great time for big fish! Some of our biggest fish of the year will come in the next few weeks. We will catch them on the fly, topwaters, swim baits and on slabs. Fly fishing has quickly become my passion and I'm looking to attract more fly fishing clients. Keep in mind, if you are into fly fishing, you don't have to come by yourself, I can fish 2 fly fishermen or we can do a mixed trip where we have one person fly fishing in the front with up to 4-5 more people in the back of the boat using conventional tackle. We have also updated our website to include a new fly fishing section so be sure to check it out.
Please be aware that the fishing will be best during the week to avoid the crowd, I usually have a week day available a week or so in advance. Though if you have to have a weekend and don't mind slower fishing in the crowd, you will need to act fast as our weekends are booked up through the end of July. You can book your trip online at www.stripersinc.com or give me a call at (903)815-1609 and I'll get you setup. If you have any questions about our trips, don't hesitate to call or text. I'll be looking forward to fishing with you!
Your Lake Texoma Fishing Guide,
Brian Prichard
Stripers Inc.
(903)815-1609