"Dog days are tough because the walleyes are well fed," Johnson explained. "There's forage everywhere and it's the perfect size. Walleyes don't have to work hard for a meal -- they just swim into a school of minnows and pick off enough to keep them full until the dinner bell rings again."

To catch walleyes during dog days, pick a lake far enough north that water temperature will keep the fish's metabolism running but not so warm that the fish becomes lethargic.

"You're trolling during dog days," he said, "and it's all open water in the middle of nowhere. I don't even bring my boat up to Lake of the Woods during that period. I just go out on a charter boat."

Johnson prefers a jig-and-minnow to target Basswood Lake's autumn walleyes.

"You can cast this combination onto shallow rubble bars and drag it back," he said. "Or if the walleyes are on deeper rockpiles, you can vertical jig. When I go up to Basswood to fish for fall walleyes, I don't bring anything but 1/8-ounce jigs and a bucketful of minnows."

Profiling a body of water comes naturally to an aquatic biologist, so Johnson easily devises a program while driving to the lake.

Here's some simple questions.

What stage are the fish in?

Have they finished spawning?

Have they set up summer haunts?

Have they suspended yet?

There are even more transitions and stages. Get to know the species you like to chase and you'll know where to find them at any given time.