Darrel Binkley fishes the depths of Norfork Lake in northern Arkansas to catch trophy stripers.
By Brent Frazee
When the heat of summer arrives, Steve Street has a good idea of where the fish are going to be in clear-water reservoirs of the Ozarks.
Not only does he rely on the electronics in his boat, he also descends to the depths in his scuba-diving gear to get a fish-eye view of Norfork Lake in northern Arkansas.
His experiences confirm the importance of fishing the thermocline – the thin layer of water that separates the warmer upper zone and the much colder depths.
That layer is a transition zone, characterized by the most dramatic temperature change in clear reservoirs. Because the zone also has ample oxygen for most species, it can be a great place to fish, especially in the hot months when a reservoir’s stratification is most pronounced.
“When I am diving, there is a noticeable drop in water temperature once I hit the thermocline,” said Street, who is known as Scuba Steve in the Norfork Lake area. “It will be up in the 80s in the top layer, but it can be in the low 60s at the thermocline.”
And often, that’s where the fish will be.
Once Street descends to the thermocline, which is typically in 25 to 35 feet of water, he notices a definite change in activity.
“There is a noticeable difference in the number of fish, especially big ones,” said Street, who owns Blackburn’s Resort on Norfork. “Shad are out roaming for plankton, and there are a lot of gamefish.”
“I see two patterns – species such as white bass will be out chasing in open water. And species such as bass and crappies will be relating to cover and ambushing their prey.”
The thermocline is especially productive when it intersects with good cover, such as brush piles. That’s where Street will see some of his biggest concentrations of fish.
So how do fishermen locate the thermocline? They can turn up the sensitivity of their electronics and pick up the hazy line that often represents the layer just above the productive zone.
The best fishing typically is found at the top of the thermocline, where fish are invigorated by the change in water temperature and oxygen.
Darrell Binkley, a well-known guide at Norfork, specializes in vertical presentations to catch those fish. He designed a jigging spoon with the express purpose of reaching stripers, walleyes, bass and white bass that abide in deep water once summer heats up.
His Bink’s Spoon now comes in a variety of colors and weights and is deadly for catching large stripers and walleyes in the clear-water reservoirs of the Ozarks.
Binkley has since sold his lure company, but he continues to use the spoons to put his guide clients on big fish.
Rick LaPoint, a longtime guide at Table Rock Lake in southwest Missouri, also thrives in fishing the thermocline. He often uses jigging spoons, drop-shot rigs, grubs or live nightcrawlers to catch black bass in the productive zone.
When he marks fish suspended in the thermocline, he assumes they are actively feeding bass. And he often is right.
Fishing the treetops of deep flooded timber, channel breaks, and long points, he follows his electronics until he finds fish. With the sensitivity on his electronic units turned up, he can watch on the screen as his lure descends and he can drop it right in front of a specific fish and tease it to hit. Sometimes it works, sometimes it doesn’t.
Most fishermen refer to the water below the thermocline as a “dead zone.” But that isn’t necessarily true. While the water immediately below the thermocline has little oxygen, the extreme depths of some clear-water reservoirs have just enough oxygen for fish to survive. Stripers and walleyes often go as deep as 100 feet at Norfork in the heat of summer.
Binkley and his clients have caught fish in those depths. He remembers one trip in late August when a woman he was guiding caught a 52-pound striper in 100 feet of water on one of his heavy jigging spoons.
The only problem? Stripers pulled from those depths usually die. But for fishermen looking for a trophy for the wall or for good table fare, those fish are there for the taking.
Binkley often scopes out the deepest water in Norfork, usually within two miles of the dam, until he picks up fish on his electronics.
The thermocline often remains intact through the summer months and into early fall. Then as the surface temperature cools and the layers break down, the turnover takes place and the water temperature is fairly uniform from top to bottom.
But until that happens, the thermocline can be a magical place to catch big fish at a time of the year when most fishermen are sitting in the air conditioning.