Anderson: Mille Lacs perch limits whacked, walleye limits increased — all in one week. What’s up?

Given recent announcements by the Department of Natural Resources that this summer’s Mille Lacs walleye limit will be increased from a year ago, while its yellow perch limit will be dramatically decreased, a reasonable conclusion could be that walleyes are doing pretty well in the lake, while yellow perch — which walleyes depend on for survival — are in tougher shape.

In fact, both fish appear to be doing pretty well.

Let’s take a look.

On March 10, the DNR said it was reducing, effective the next day, the Mille Lacs perch limit from 20 per day and 40 in possession to five daily and in possession.

The five-perch Mille Lacs limit will be effective through Nov. 30.

In its long history, the DNR has never cut a Mille Lacs perch limit, not even in ultra-high harvest years such as 1985, when anglers recorded a 541,000-pound catch.

Explaining the cutback, the DNR said that as of Feb. 23, anglers had exceeded their quota of perch allotted under the Mille Lacs fishery co-management agreement the agency has with eight Ojibwe bands.

That quota is 36,500 pounds, the same as it was last year and in 2023 — but only a fraction of the 135,000 pounds that anglers and the bands each were allotted from 1998 to 2022.

“With annual perch harvest never more than 7,000 pounds since 2012, this year’s [43,000 pound perch harvest] is a positive sign for the health of the lake,” DNR fisheries section chief Brad Parsons said in a statement announcing the cutback.

But whether this winter’s Mille Lacs perch harvest is entirely a measure of the lake’s health is an open question. Could it also be a testament to Mille Lacs’ good ice conditions this winter, combined with a hot perch bite, combined especially with gangbusters angling pressure applied to the lake by social media, and perhaps also thanks to anglers’ increased use of forward facing sonar?

Also shifting pressure to Mille Lacs perch this winter was the lake’s deadbeat harvest of keeper walleyes, which started last summer. By last fall, anglers had harvested only about a third of the 91,550 pounds of walleyes they were allotted under their 2024 quota. One reason for the falloff is that lots of perch, ciscoes and other forage are in the lake, keeping walleyes well fed and allowing them to ignore many anglers’ baits.

In fact, anglers who dropped underwater cameras into Mille Lacs this winter frequently spotted schools of perch and ciscoes swimming by. These were samples of the brood stock the DNR wanted to protect through the lower perch angling quotas it began in 2023.

Especially important, the DNR believes, are “age zero” perch and ciscoes — fish up to 1 year of age — because they can be easily consumed by walleyes.

In 1998, when the DNR and the bands joined management responsibility for Mille Lacs, neither knew how many yellow perch could be sustainably harvested from the lake. Using past harvests as a guide, they settled on 270,000 pounds, half for the bands and half for sport anglers.

That quota continued through 2022, at which time, concerned about the low perch harvests that started in 2013, the state and the band dropped their perch quotas to the aforementioned 36,500 pounds.

Whether the reduced perch harvests meant fewer of these fish were in the lake is uncertain. Perhaps instead the decline was because of lagging angler interest. Or poor ice conditions, as was the case in the winter of 2023-2024. Or some other reason.

To estimate the Mille Lacs walleye population, each fall DNR biologists and technicians drop nets into the lake. Walleye caught are measured and counted and the results are supplemented by tagging studies done every five years. This method has produced a reliable estimate — or index — of the lake’s walleye numbers.

Unfortunately, the same methods aren’t practical for perch.

Which is why, in 2023, the DNR began using a new method to count Mille Lacs perch. Developed in Canada and used on lakes there to assess perch numbers, the system might work on Mille Lacs, said the lake’s large lake specialist, Eric Jensen.

Or it might not.

“When it became obvious, based on recent perch harvests, that the 270,000 quota was no longer a good fit for Mille Lacs perch, we reduced the quotas and began using the Canada method to attempt to model the lake’s perch population in a different way,” Jensen said. “We’ll try it for a few years. If the number of adult perch we’re catching in our fall nets suggests the population estimates we’re producing are off, we’ll adjust.”

Meanwhile, regarding Mille Lacs walleyes, on March 14 the DNR announced that beginning with the May 10 opener, Mille Lacs anglers can keep two walleyes longer than 17 inches, provided only one is longer than 20 inches. This is a big improvement from last summer’s catch-and-release walleye fishing on Mille Lacs, which was in effect until mid-August, when two fish were allowed of specific lengths.

The DNR also increased anglers’ walleye quota this year to 113,600 pounds from last year’s 91,500 pounds.

If Mille Lacs anglers exceed the quota this summer — considered unlikely, given the increased quota and predicted moderate catch rate because of the lake’s high forage populations — catch and release walleye fishing can continue on the lake through the fall, provided the excess doesn’t reach 15%. (Any overage would be deducted from next year’s quota.)

This is considered a big win for anglers, resorts, bait shops and other Mille Lacs businesses because it lends predictability to the season length and limits.

“Going forward, we definitely need to keep the number of perch up in the lake because of their relationship with walleyes,” Jensen said. “The one thing that tends to predict how many of our walleyes survive their first year is the number of ‘age zero’ perch that are produced each year. So keeping the number of adult perch up in the lake is important.”