Adam Johnson use his formula to find late-summer walleyes. Photo courtesy of Adam Johnson.

Profilers. Television crime shows love them. They’re usually portrayed as cops trained in psychology or FBI agents who have the ability to observe a crime scene and determine a criminal’s psychological makeup as well as his future moves.

Adam Johnson is a profiler -- one of the best -- but instead of profiling criminals, he profiles fish, especially late-summer walleyes.

“Using a combination of variables,” Johnson said, “anglers can know exactly where a particular species of fish is located. I call it ‘The Profile’ and I use this formula to put me onto fish, because after all, if you can’t find them, you can’t catch them.”

Johnson explained that a particular fish species follows a consistent program over a 12-month period and when you add variables like weather, fishing pressure, recreational traffic, the forage base and others, pinpointing locations and adjusting your presentation becomes easy. Let’s look at an example to illustrate what happens during this late-season period.

“I prefer larger lakes for walleyes during the late season,” he said, “because smaller bodies of water tend to turn off during August, what we call dog days. Bigger lakes provide a more consistent bite during this period.

“If the forage base is predominantly ciscoes on the big lake, I’ll be in open water looking for suspended fish. If the primary forage is perch and shiners, I’ll be on either deep midlake structure or very shallow rockpiles and weedlines.”

The problem most anglers have, Johnson said, is they continue using tactics that worked during the peak bite months of June and July and fail to realize there had been a transition that requires a change of location and presentation.

Of course, the forage is high in numbers in August, which means your bait may be ignored, even in a crowd of walleyes, but if an angler isn’t fishing where walleyes are, chances of getting a bite are zero.

One thing is for certain about fishing during dog days, anglers must work harder for every walleye they catch. The smaller bodies of water seem to turn off and the big-lake bite seems to slow, but big-water walleyes don’t shut down completely.

Chris Kavanaugh, DNR area fisheries supervisor in the Grand Rapids office, oversees plenty of smaller bodies of water in the Itasca County regions including one of Minnesota’s well-known walleye factories, Lake Winnibigoshish.

“In the bigger lakes you have more diversity of habitat available to walleyes, so there are more places where they can go,” he explained. “Some of the bigger lakes, Winni, in particular, typically don’t stratify, so if it does stratify, it’s only for a very short time until the wind blows again and the water column mixes pretty uniformly from top to bottom. All fish have an optimal temperature range for growth and when they find that range, they feed most actively. In smaller lakes the water can get too warm, not quite a lethal temperature, but it’s not optimal, so their metabolism actually slows down and they’re not as active.”

Kavanaugh, like Johnson, thinks forage can be a factor in determining how well walleyes bite.

“I think there is more forage in midsummer,” he said. “Most species in Minnesota spawn in the spring or early summer, so when you get to midsummer you have a huge abundance of young-of-the-year fish that are approaching accessible size for larger predators to chasing after. The perch that spawned in late May that are now 1 1/2 to 2 inches long are a pretty desirable item for a lot of species of fish.”