We’ve come to expect assertive behavior from Gov. Mark Dayton, but even we were taken aback by his demand that Lake Mille Lacs be open for walleye during the ice-fishing season.

“It’s crucial that there be a season, and it be as generous in terms of limits and opportunities as possible,” Dayton said recently.

The last we checked, Dayton doesn’t have a wildlife management degree. That’s a decision best left to the fisheries division of the Minnesota Department of Natural Resources. The governor’s outspokenness on the issue undermines the credibility of the DNR staff, which is about to begin a new analysis of the lake’s walleye population, and won’t know until mid-­October whether it would open Mille Lacs for winter walleye fishing.

To his credit, DNR Commissioner Tom Landwehr deflected his governor’s comments in an evenhanded manner. Ever since the abrupt end of the open-water walleye season on Aug. 3, Landwehr and his staff have faced plenty of second-guessing from anglers and resort owners alike.

The walleye population on Minnesota’s most popular fishing lake is at a 40-year low, and it’s difficult to pinpoint a cause. The DNR suspects a confluence of factors.

Dayton’s comments notwithstanding, the DNR has signaled that it’s planning for an ice-fishing season, even if it’s a limited one. An internal planning document calls for the DNR to “aggressively pursue” ice-fishing options on Lake Mille Lacs.

It’s not lost on DNR officials that the winter season is lucrative to resorts and other fishing-related businesses. Anglers spend more hours on Mille Lacs during the winter months — 1.5 million hours from last December through March, compared with 337,000 hours during the open-water season — according to DNR data.

However, the walleye harvest in winter tends to be less in pounds than during the spring and summer months. If there is an ice-fishing season this winter, DNR officials are going to make sure it doesn’t affect the long-term viability of Mille Lacs’ walleye. It’s better to have a few down seasons than several years of a depleted walleye population.

We commend Dayton for his passion to promote Minnesota’s outdoors, which would be better served if he reminded anglers that Mille Lacs also is a destination for northern pike, smallmouth bass and perch. If he wants to promote winter walleye fishing, there are other Minnesota lakes where the walleye are thriving.

Just please leave it to the experts to set the season.

FROM AN EDITORIAL IN THE ROCHESTER POST-BULLETIN