Thermocline holds key to finding bass during summer

Special to the Southeast Missourian

Bass spent the last few months moving from their deep winter homes into the shallows to spawn.

Now that it is July, most of the bass are back in the deep water areas to spend the next several months. Exceptions to that would be bass in lakes with heavy vegetation (Lake of Egypt) and rivers with currents (Ohio, Tennessee and Cumberland).

The reason for this is a naturally occurring summer phenomenon called the thermocline. In brief, the thermoncline is a point in the water column below which there is very little dissolved oxygen and, therefore, few fish. Grassy lakes and rivers are the exception because plants produce oxygen in the shallows and the river current continually distributes oxygenated water throughout the system. In these waters, there will be bass both deep and shallow.

Most of our lakes fall into the thermocline scenario.

Most maps of a lake will mention where the thermocline historically forms. In our area, it is normally no more than 10 feet in murky lakes and 15 to 20 feet in the average lake. The exact level is determined by a host of both natural and manmade variables, and it is more pronounced on small lakes.

You can determine if a lake has a thermocline and the location of it by observing your depth finder. Simply look for fish and baitfish on the screen. If there is a thermocline, you will notice a depth below which you see little or no fish blips. The great thing is that predator fish like bass hold just above this invisible line.

Now, for an example of how to use this information. You observe that the pods of shad on your depth finder are no more than 15 feet deep. You can eliminate any water on the lake deeper than that. You also know that bass will be near the thermocline, so you eliminate everything less than 10 feet deep. Now study your map and find bottom structures -- points, humps, channel edges -- at 10 to 15 feet deep that may provide a resting place for bass and a place for them to ambush prey. A likely place in our area is a brush pile located on a point near a channel drop in 15 feet of water.

You will find that this exercise really cuts down the amount of area you need to cover to catch fish. In the summer, many tournaments are won by fishing specific "spots" vs running patterns.

After the morning topwater bite is over, I move out to the points, humps and ledges. I set my boat over the deep-water break (15 to 30 feet deep) near the structure or cover combination I plan to fish, usually 8 to 15 feet deep.

I keep my lure and equipment choices simple. I like a Bandit 200 or 300 series crankbait in natural shad colors fished with a medium action 7-foot Falcon Cara rod paired with a slow 5.2:1 speed Shimano Curado reel. The slower speed reel provides more leverage and is less tiring when fishing deep diving crankbaits. The medium action rod will lessen the chance of your crankbait being ripped out of the fish's mouth.

I use 10-pound P-line mono for my line. With crankbaits, I like the line stretch mono allows.

I also use several bottom baits, most often the 7/16-ounce Jewel Eakins Jig or a Southern Pro Pitching Tube on 1/2-ounce sinker -- both in a natural color like green pumpkin. I fish both of these baits with a Falcon Cara 6-foot-10 medium heavy rod designed to be fished with the Eakins Jig. I use a fast 6.2:1 speed Shimano Curado reel spooled with 15-pound fluorocarbon P-line. The fluorocarbon line has very low stretch that provides better bite detection and better hook sets in deep water.

And finally, I always have a Carolina rigged rod on deck for summer bass fishing, usually rigged with a Southern Pro Pitching Tube or a creature bait like a Baby Brush Hog. I use a Falcon Low Rider Lizard Dragger rod for my Carolina rigs. It's a 7-foot medium heavy rod specifically designed for Carolina rigging. Paired with a high-speed 6.2:1 Shimano Cuardo reel, I use braided for the main line and 10-pound mono for the leader and usually a 1/2-ounce brass weight.

With all the above lures, be sure you contact the "cover" located on the structure. It is usually this contact that triggers a strike.

If you want to catch summer bass, don't beat the bank. Narrow your search by finding the thermocline in deep water and enjoy catching big, strong, well-fed fighters all summer.

David Bortner is a tournament angler who competes in the Wal-mart BFL and Missouri Bass Federation events.