GREAT FALLS, Mont. (AP) — Art Nuthak stood on a foot of ice, a hood pulled over his head and ice cleats strapped on his boots to keep from slipping.

With a strong wind, it felt much colder than the 32-degree temperature, but perch fishing has been hot here.

"We like to eat perch, so that's why we come up here," Nuthak said as he monitored bobbers in two holes in the ice and hoped for a bite.

The lowly perch — not walleye or trout, the state's poster fish species — is attracting big numbers of ice anglers from across Montana to Holter Lake 60 miles southwest of Great Falls.

Nuthak traveled 100 miles from his home in Butte to try his luck at Holter Lake.

"There's no 'perch unlimited' like you see with trout or walleye," said Eric Roberts, a fisheries biologist for Montana Fish, Wildlife and Parks, on the perch's status in the fishing community, "but when this Holter perch thing turned on a few years ago, it was amazing."

Roberts says he's even started getting calls from Idaho and Washington residents planning trips to Holter Lake to ice fish for perch.

"When the bite's on, you can catch them on a bare hook at times," Roberts said.

Last week, when Nuthak was at the lake, fishing was comparatively slow, but the Holter Lake perch fishing has been phenomenal for a few years now, with anglers routinely pulling out pound-perch and larger from the frozen reservoir created by a dam in the Missouri River, Roberts said.

In 2011, total fishing pressure on Holter Lake for all seasons was 67,942.

By 2015, the most recent numbers available, fishing pressure had increased to 90,470.

Typically, winter fishing represents about a third of the total fishing pressure, and Roberts said much of the fishing pressure increase on Holter is attributable to ice anglers attracted by the large numbers of big perch.

The limit for perch is 50.

A few years ago, it was 25.

The limit was increased because of the abundance, Roberts said.

The change prompted some concerns about overfishing, he said.

There's no chance of that, Robert said.

"There are so many perch out there we can't harvest enough to put a dent into the population," he said.

While perch fishing is decent at Holter in July and August, it slows as the water cools in the fall and perch head to deeper water to hole up in refuge areas.

That also makes them easier to find in the winter.

"They seem to be a little more active in the wintertime, too," Roberts said.

An age class of perch made up of 7 or 8 year olds, hatched in 2010 or 2011, has become the most abundant age class of all the age classes of fish in the lake, he said.

That's behind the phenomenal fishing, Roberts said.

Such a large class of older fish is rare, Roberts said.

"It may not happen again in our lifetimes," he said.

It is so unusual because it takes four to five years before slow-growing perch reach 7 to 8 inches long, which is barely large enough to be caught.

Besides that, Roberts adds, "They are pretty vulnerable to predation."

Today, with large numbers of 7- or 8-year-olds ruling the lake, it is not uncommon for anglers to catch perch more than 12 inches and even some 13 to 14 inches long.

"As far as perch fishing, it doesn't get much better than that," Roberts said.

Most of the larger perch are in the pound range, with some pushing 2 pounds.

Roberts isn't positive what caused the proliferation of this particular age class of perch.

One possibility is that the record water year of 2011 flushed more nutrients and invertebrates through the Missouri River and the lake creating a nursery environment causing that year's perch hatch to flourish.

"That could have made ideal growing conditions," Roberts said.

Perhaps a very good hatch of some kind of perch food such as crayfish or snails occurred "to make it easy to be a perch," Roberts said.

"It may be a flash in the pan," Roberts said of the large age class of perch, "or there may be some sustainability to it."

The large older age class now dominating the lake, he noted, is reproducing, so it's possible another large cohort may be raised up behind them, he said.

However, many factors limit perch reproduction, he added.

Besides predation, big flushes of water can wipe out entire classes of perch after perch spawn in the spring, Roberts said.

Perch and walleye co-evolved and share ranges with perch, a favorite food of its larger cousin.

Even if other kinds of walleye food are abundant, such as suckers, Walleye prefer perch, Roberts said.

With a white, flaky flesh, perch are a popular sport fish, too.

"It's such a unique opportunity to catch a whole bunch of nice, nice perch," Roberts said of current perch fishing at Holter. "And they are so tasty."

One day last week, scattered groups of anglers and individuals kept watch over holes in the dark ice.

"These are nice perch," said Frank Nemec, 77, of Washington, sitting on a bucket as he monitored his lines in the water.

Green-yellow colored perch lay on the ice, 11 to 13 inches long, not far from a sled loaded with gear, including a portable fishing tent, a propane heater and a thermos of coffee.

"You could drive a car on here if you want," Nemec said of the ice, a foot thick.

"As long as it's your car and not mine," he added.

From the road overlooking the lake, some of the loners seated on buckets looked as if they were seated in outhouses without walls.

"I love it," Alex Krier of Lincoln said of ice fishing.

Krier was warm and wind-free inside the portable fishing house he shared with Elizabeth Reed of Missoula.

They produced a bucket. In the bottom was a single rainbow trout and several perch.

Living in Lincoln, near the Blackfoot River, Krier can fish for trout anytime.

But there's something about the atmosphere out on the frozen lake fishing through the ice that appeals to him. In the winter, with the help of fish finder, it's easier to locate the fish, he said.

Nuthak, the Butte man, was fishing in 40 feet of water, close to the bottom. Between Jan. 1 and March 1, he figures he goes ice fishing 12 to 14 times. It fills in the break between hunting seasons.

"We fish for perch here," he said of Holter.

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Information from: Great Falls Tribune, http://www.greatfallstribune.com