Surveys show walleye population increasing, but some year classes remain below normal
Winter anglers on Lake Mille Lacs will again enjoy a walleye harvest this winter for the third season in a row, according to the Department of Natural Resources. Similar to last season, anglers will be allowed to keep walleye on Mille Lacs starting Saturday, Dec. 1, with no bait restrictions and a limit of one walleye between 21-23 inches, or one fish over 28 inches.
Winter regulations are set after completion of the DNR's annual fall gill net assessment on Mille Lacs. In 2018, this assessment was supplemented by a population estimate, in which the DNR catches fish in the spring, marks them, and later recaptures them. While studies indicate the walleye population on Mille Lacs is increasing, some year classes remain below normal or average.
"It’s good news that anglers will be able to harvest walleye again this winter," said Tom Landwehr, DNR commissioner. "We’re also encouraged to see evidence that our conservative approach to Mille Lacs is paying off to the point that we’re seeing population increases on this renowned fishing lake."
According to the results of the 2018 population estimate, the abundance of walleye 14 inches and longer in the lake was 727,000 fish. This is up significantly from the population estimates in 2013 and 2014, both of which were around 250,000 fish.
The fall gill net assessment also showed that the total pounds of mature walleye sampled increased significantly from 18.9 pounds per net last year to 27.7 pounds per net this year, mostly due to an increase in mature females. Because of this result, the DNR selected a regulation that allows anglers to keep walleye from 21-23 inches, which focuses the harvest on mature female fish.
The DNR believes the population of mature female walleye can sustain harvest because their numbers are at sufficient levels to ensure good production of fry (baby walleye) in the spring.
2013 fish still strong, but stronger year classes neededWhile hopeful for a continued increase, the DNR is taking a cautious approach to interpreting the results of the population estimates. The 2013 year class (or fish hatched that year) continues to dominate the population, accounting for about 40 percent of the fish caught, but year classes hatched since 2013 show mixed results.
The 2014 and 2015 year classes remain below normal. The 2016 year class, which is now 13-15 inches in length, appears close to average compared to the last 15 years. This is significant because if it survives it will only be the second average-or-above year class since 2008. The 2017 year class, now between 9 and 12 inches in length, was well represented in the gill nets, but it’s too early to tell whether these fish will comprise an above average year class.
"Over time we want to let anglers keep more fish, but it is critical that population assessments continue to show surviving and self-sustaining year classes of walleye," said Brad Parsons, DNR fisheries chief. "We’ve seen promising year classes in past years fail to survive to older ages. Opening up additional harvest too fast or too soon could jeopardize the population increases we’re seeing."
The fall assessment also examines food abundance for walleye and walleye health. Perch and tullibee are the primary food source for Mille Lacs’ walleye. Perch from 0 to 2 years old were caught in low numbers, and the number of young-of-year tullibee caught also was low. Walleye condition or "plumpness" reflects these results and remained lower than recent averages.
Low forage levels usually mean the walleye bite is good because there is less food available for fish to eat, making an angler’s bait all the more attractive.
"We expect the walleye bite to be quite good on Mille Lacs this winter, which means ice anglers may experience a lot of fishing action out on the lake," Parsons said.
Complete winter regulation information for Mille Lacs is available on the DNR website at mndnr.gov/millelacslake.