The bite was hot, and Tony Roach was pulling panfish through 8 inches of new ice on a small central Minnesota lake last week.

"We were catching them one after another,'' said Roach, 36, of Malmo, Minn., a fishing guide, seminar speaker, and nephew of fishing legend Gary Roach. "The crappies were super aggressive. It was really fun.''

Frigid temperatures in November launched Minnesota's ice fishing season early this year, sending thousands of anglers scurrying onto frozen water for what is traditionally some of the hottest ice fishing of the season.

"Early ice is fantastic,'' Roach said. "Generally, the earlier you can get out the better.''

Henry Drewes of Bemidji is an avid angler and longtime Department of Natural Resources regional fisheries manager for northwestern Minnesota. Early-season ice fishing can be stellar everywhere, especially on famed Upper Red Lake and Lake of the Woods, far-north lakes that often freeze first, he said. Anglers already are finding hot action there and elsewhere.

"Absolutely early ice on Lake of the Woods is the best time to be up there,'' Drewes said. "There's no comparison.''

Fishing guide Tony Roach of Malmo, Minn., caught a bluegill on a Brainerd-area lake last week. “Early ice is fantastic,’’ he said. “Generally, the earlier you can get out the better.’’

Ditto for Upper Red.

"As soon as the ice comes on you have an incredible bite,'' said Jonny Petrowske, a longtime Upper Red Lake guide who operates Red Lake Remote Ice Fishing. "The walleyes go on a feeding frenzy.''

Why the hot bite?

So why do fish bite aggressively early, then become tight-lipped in mid-winter?

Drewes said he doesn't know of any research that explains the phenomenon. But he has theories.

In the fall, wind and waves and suspended sediment prevail in lakes. "[Then] as soon as the ice cap comes, suspended material settles out, and the water clears up,'' he said. Shallow waters and the minnows that live there attract fish.

"The ice brings stability and calm to the underwater world, and the fish move to underwater breaks,'' Drewes said. Female fish are developing their eggs for the spring spawn so they may be feeding heavily to help that development.

Roach has a different theory: "Fall is the time of year fish are feeding like crazy, getting ready for the winter months. Early ice is a continuation of that fall pattern. There are bait fish still in the shallows, oxygen levels are high, there's still a lot of sunlight penetration and fish — from bluegills to northerns — still are feeding. That's why the bite is still good.

"Every body of water is different," Roach added, "but when fish are shallow, they are there for a reason: to feed.''

Petrowske says when Upper Red Lake freezes, the ice moves bait fish from very shallow water out to 6 to 8 feet.

"You have a collision of walleyes and bait fish,'' he said. "The bite will continue as long as snow and ice conditions stay the same.''

By mid-January, the fish scatter and the bite slows.

"With more snowpack on lakes, there's less sunlight, and oxygen levels decrease,'' Roach said. "Fish retreat to deeper wintering areas. They feed less and are non-aggressive, almost like they are in slow motion.

"We call 'em staring-contest fish because on your electronics, they'll come up and look at your bait and it's like a staring contest: They'll just look at it.''

But right now, action is hot there and elsewhere.

"It's fun when the fish are aggressive, rather than working for every single bite like you do a lot of times in mid-winter,'' Roach said.

Safety is key

But the key to early-season ice fishing is safety. Numerous people and their vehicles have fallen through thin ice already this season. "We have at least six four-wheelers at the bottom of Red Lake already,'' Petrowske said. "Ice is sketchy; you've got to be careful. I'll go out when I know it's good and safe.''

Left: Light from the setting sun reflects off the ice as an angler drills an ice fishing hole. The “bite” is hot now on many northern lakes.

Said Roach: "I always error on the side of caution. The DNR guidelines say 4 inches [to safely walk on]; I don't like to go out until I have at least 6 inches. We walk with spud bars and carry ice picks. Just use caution. Safety is No. 1.''

The DNR suggests 5 inches are needed for a snowmobile or ATV, 8-12 inches to support a car and 12-15 inches for a medium-sized truck.

Said the DNR's Drewes: "My advice is to talk to the locals and trust their judgment; there's no substitute for good local information.''

Doug Smith • 612-673-7667