WALKER, MINN.

"There's a nice one!" said David Keen, his fishing rod quivering as he pulled a 9-inch perch from a hole in the ice. "That's what we're after."

Keen, 66, of Winona, Minn., knelt on a frozen Leech Lake — a vast white expanse dotted with an occasional fish house — and coaxed beautiful green perch from the icy water 12 feet below. Under a blue sky, the temperature hovered around minus-15 degrees. But with nary a breeze it was almost balmy compared with the previous day, when a howling wind produced a minus-30-degree windchill.

So Keen and his son, Travis, 31, also of Winona, left their heated rental ice fishing shack and angled in the open, kneeling old-style, landing an occasional perch.

"We enjoy fishing outside," the elder Keen said. "Seems like the only way to catch them is to move around."

That's exactly what Tim Campbell, co-owner of Brindley's Harbor Resort, told me and two friends when we arrived at his resort for a two-day, midweek fishing outing recently on Leech. The lake is Minnesota's third largest, and in recent years has been a winter hot spot for perch.

"When the fish are moving, you can sit in an icehouse and do pretty good," Campbell said. "But if they're not moving around, you have to go after them.

"Some of our guys won't leave an icehouse, no matter what's happening. We have others who won't go in the icehouse. They know the more they move around, the more fish they will catch."

We arrived during yet another arctic blast, one of many subzero cold snaps that have pummeled Minnesota this season. A howling north wind combined with minus-20-degree temperature sent the windchill to a skin-numbing minus-30 on our first afternoon and a minus-40 that evening.

The wind rattled our heated fishhouse and we were content to stare down the luminous holes, watching small perch mostly ignore our minnows, instead of fish outside in the brutal cold. Guides Kevin Peterson and Mike Bridges drove around the lake in their pickups, drilling holes and dropping lines, fishing from their trucks through an open door, trying to find schools of perch.

They caught a few, but the action — like the weather — wasn't hot.

"It was brutal out there," Bridges said as he popped into our shack. "The holes kept icing up and the snow blew in them. It's unfortunate it's this cold." The fish also weren't aggressive. "We were killing 'em here earlier," he said.

Said Campbell: "That's what winter really is, battling Mother Nature as much as finding fish."

Less wind, more fish

But the next day, the wind subsided when we drove across the snow-drifted lake to our rental shack. Once we got settled we ventured outside, moving 50 to 100 yards away, trying a half-dozen spots. Keen and his son, who rented a fish house near ours, did the same.

"We enjoy coming up here," he said, jigging his rod. "For us, it's a chance to get together."

They occasionally pulled a perch from the depths, and so did we, finding the action sporadic. But, given the weather, we were just happy to be catching fish.

"The last two days, no one did well," Campbell said later.

The bite was hotter earlier in the season, he said. "We sent groups home with nice batches of fish," he said.

Still, we caught enough for a fish fry and enjoyed relaxing out on the frozen lake and returning to a cozy cabin at sunset.

For Leech Lake resorts, it's been a rough few months. First came the unusually cold spring and a late ice-out — several days after the May fishing opener. Then earlier this winter, slush hindered lake travel on Leech and other northern Minnesota lakes.

"We lost our fishing opener [last May] because of the ice, and we had to cancel our first two weeks of ice fishing because of the slush," Campbell said. "Not good starts."

Now the winter season is humming along nicely.

Walleye affect perch

Campbell said his winter customers primarily target perch, not Leech's famous walleyes — which might be seen as odd considering the lake's walleye population is so high that the Department of Natural Resources plans to loosen fishing regulations next May to allow anglers to keep more fish.

The current 18- to 26-inch protected slot will be relaxed to a 20- to 26-inch protected slot. The four-fish bag limit, with one fish allowed over 26 inches, will be retained.

The lake's walleye biomass is at a near-record high, which officials say is not sustainable and likely is at least partly responsible for a recent decline in the perch population. The DNR's gill net survey last year found 12 perch per net, down almost two-thirds from 35 per net in 2007.

Perch, of course, are a primary forage fish for walleyes.

"We've had poor perch year classes in recent years," said Doug Schultz, DNR area fisheries manager. "Predation has probably had a lot to do with that. And we had a record perch harvest [in 2010-11]. The word has gotten out that Leech has pretty good perch fishing in the wintertime."

Cormorants also aren't to blame for the perch decline, Schultz said. The cormorant population on the lake has been culled annually since 2005 because of concerns the fish-eating waterfowl were hurting the walleye population.

Walleye fry have been stocked in the lake annually since 2005, and 22 million are scheduled to be stocked this spring. The DNR will discuss with a local advisory committee next month whether that stocking should be done.

Meanwhile, though the perch population is down, some good perch fishing can be found, Schultz said.

"There's still fish to catch; it just requires a little more work," he said.

With a high walleye population and perch still available, Campbell, too, remains optimistic.

"If you get where there are fish, it seems like there still are lots of them," he said. "But finding them is always difficult, even when numbers are high."

Doug Smith • dsmith@startribune.com