In an unprecedented move, state officials Wednesday slashed the walleye limit on Lake Mille Lacs to one and banned night fishing for the entire season, marking new lows for one of the state’s premier fishing destinations.

The regulations — the most restrictive in the lake’s history — begin with the season opener May 9, and were imposed because Mille Lacs walleye numbers have plummeted to a 40-year low.

For resort owners along the lake, fluctuating walleye regulations have become a fact of life. But the new rules represent a fresh and heavy setback.

“The night ban will hurt,” said Bill Eno of Twin Pines Resort near Garrison, which operates launches. “It cut our business a lot last year, and will do the same this year.”

The big question is whether anglers will continue to fish on the 200-square-mile lake under Department of Natural Resources rules that allow them to keep only a single walleye.

“Some will and some won’t come,” said Mike Christensen, owner of Hunter Winfield’s Resort at Isle. “At least it gives them the opportunity to keep something.”

Anglers will be allowed to keep one walleye 19 to 21 inches long, or one over 28 inches. All others will have to be released. Last year anglers could keep two walleyes 18 to 20 inches long, with one over 28 inches. The new rules apply to daily bag and possession regulations.

The good news: DNR officials said they expect more walleyes to be biting this year than last.

The night ban, which begins May 11, will especially impact businesses that operate boat launches, which take groups of anglers fishing. Night fishing is popular because the walleye bite then can be excellent.

The DNR lifted the ban in midsummer last year, something officials said won’t happen this year, meaning boats will have to be off the water by 10 p.m.

DNR: Don’t blame nets

Don Pereira, DNR fisheries chief, said the tight walleye regulations are necessary so the harvest doesn’t exceed the 28,600 pounds allocated to state anglers under the 1837 Treaty with eight Chippewa bands.

The bands and state determined the safe harvest this year was just 40,000 pounds, a 33 percent reduction from last year. The bands were allocated 11,400 pounds.

That 40,000-pound safe harvest target is the lowest ever and an 84 percent decline from the 250,000 pounds allowed in 2013. Since 2000, the safe harvest ranged from 370,000 to 600,000 pounds.

Pereira said the controversial spring walleye netting by Chippewa bands isn’t responsible for the decline in the Mille Lacs walleye fishery. The problem is the low survival of young fish since 2008, he said.

“We have plenty of spawners in the lake, and they are producing lots of fish; they just aren’t surviving,” he said. “If tribal fishing was interfering with spawning, we wouldn’t see the production of young fish that we are seeing.”

He said the DNR and bands were wrong over the years to focus too much harvest on fish between 15 and 18 inches, and said that management approach likely will change. “But it’s the decline of juvenile fish [aged] 1 to 3 that is the most vexing problem,” he said.

DNR officials said factors affecting survival include clearer water that may limit habitat and increase predation, climate change and impacts from invasive species, including zebra mussels, spiny water fleas and Eurasian watermilfoil.

The bands are likely to supplement their relatively small Mille Lacs walleye harvest with fish netted or speared on 73 other lakes in east-central Minnesota, under the 1837 Treaty.

Bass, northerns a draw?

Pereira said the tight walleye restrictions should keep the harvest low enough so there’s just a 20 percent chance the agency will be forced to ban anglers from keeping any walleyes this season — a nightmare scenario for most area businesses. The DNR also will continue to offer liberal bag limits for northern pike and bass, both of which are at or near population highs.

Anglers again will be allowed to keep up to 10 northerns and six bass. But they can only keep a northern longer than 30 inches if they catch and possess two northerns shorter than 30 inches.

The “earn-a-trophy” approach was taken because anglers, and perhaps spearers even more so, last season killed 20 percent of the northerns 36 inches and larger — an unsustainable rate.

“We’d be more comfortable with half that rate,” Pereira said. Spearing was opened on Mille Lacs for the first time last winter, and while Pereira said the DNR has no regrets about doing so, he acknowledged that “a number” of large fish were taken.

“I think the benefits of allowing spearing far outweigh he negatives,” he said.

Pereira defended the bass regulation, which allows six fish, but only one smallmouth bass over 18 inches.

“We know some trophy anglers are concerned about excessive harvest, but we haven’t seen any indication that that is an issue,” he said.

Said Pereira: “We’re trying to provide as much opportunity for other species as possible.”

But Mille Lacs historically has been a walleye lake, and it remains to be seen whether anglers will flock to the lake to fish other species, even if their numbers are high.

“Walleyes are king in this state, and it’s hard to get over that,” said Christensen, the resort owner. “Most of our customers are just happy catching some big walleyes. It’s tough not being able to keep fish, but we just have to appreciate the quality fishery. The pike and smallmouth bass fisheries are in great shape.”

Eno said he believes only a small percentage of people come to Mille Lacs to fish for something other than walleye. But he said that could change, and the walleye population should improve, giving him hope.

“We’ll do the best we can,” Eno said. “We still offer a lot of fun.”