Mille Lacs Lake: Building a sustainable future

For an important update on the 2015 fishing season, see the tabs below.

View Mille Lacs: A System Under Change
View a presentation that explains what's happening at Mille Lacs Lake and what steps DNR is taking to restore the lake's renowned walleye fishery.

Improving Mille Lacs Lake's walleye fishery as expediently as possible with as little negative impact to the local community as possible is the state's primary goal.

The situation will not turn around for several years. It will take time – as well as careful management, monitoring and analysis – for enough smaller walleyes to grow into the larger walleyes that anglers prefer to catch and that can contribute to future reproduction.

Even so, Mille Lacs remains a quality sport fishery. In addition to high numbers of large walleye, excellent quality fishing exists for northern pike, smallmouth bass and muskellunge.

Time and experience have proven that Mille Lacs is a resilient multi-species fishery for the anglers of Minnesota and tourists beyond our borders. A combination of regulations friendly to small walleye and cooperation among all users now will build and enhance the long-term sustainability of the fishery.

 

2015 Fishing Season

Fishing 2015 FAQ

Changes & Impacts

Lake FAQ

Newsletter

Strong catch, warm weather push Mille Lacs walleye fishery toward state quota

The DNR announced on July 21 that the previous week’s creel survey on estimated walleye harvests, releases and kill on Mille Lacs Lake during the first two weeks of July showed drastic increases that could result in the state reaching its limit by July 29.
During the first seven months of the monitoring period (December 2014 – June 2015) walleye harvest rates were at or below predicted levels, based on tight regulations adopted for the open-water season. Based upon those results, total harvest was expected to be below the State’s 28,600-pound limit for this twelve-month period and the DNR’s June 30 creel study showed the state was within 15,300 pounds of reaching the annual quota.
Despite the ongoing challenges with the walleye population, other fishing on the lake remains strong and near record highs. DNR Commissioner Tom Landwehr stressed that anglers should take advantage of the continuation of liberal northern pike and smallmouth bass regulations on the lake.

Collaboration

The DNR has met with the Minnesota tribes who harvest on Mille Lacs, as well as the executive administrator of the Great Lakes Indian Fish and Wildlife Commission on the situation and shared fisheries data with them. There is mutual concern to respond to the increased harvest and take steps necessary to protect the walleye population.
Earlier this year, the DNR also met with Mille Lacs Lake business owners and anglers to discuss the struggling walleye population and the risks of going over the lower quota. The DNR, Department of Employment and Economic Development, and Explore Minnesota Tourism will continue working with area resorts and businesses to gather their input, assess the impact of fishing conditions on area businesses, and work with the community as a decision is made on the continuation of the fishing season.

The future

Despite this year’s low walleye population, DNR fishery surveys have shown this year that there may be good news on the horizon. Biologists are seeing a large population of young walleyes hatched in 2013. Walleyes in that group are currently 10-to 13-inches long. It is important to protect those fish so they can contribute to future angling success and walleye production.

2015 regulations

For Mille Lacs Lake fishing regulations, see fishing regulations at Mille Lacs Lake for the 2015 season.

Click a question to view or hide the answer

What's the status of the state's allocation of the walleye quota?

As of July 15th, when the last angler survey was conducted, the state was within just 3,000 pounds of reaching the State's 28,600-pound limit for this twelve-month period. Based upon prior surveys, total harvest had been expected to be below the quota. The DNR's June 30 creel study showed the state was within 15,300 pounds of reaching the quota at that time.

 

How soon could the state exceed its allocation?

Last week's creel survey on estimated walleye harvests, releases, and kill during the first two weeks of July showed drastic increases that could result in the state reaching its limit by July 29. Gov. Mark Dayton has directed the DNR to wait until after the next creel survey which will cover the period from July 16 to July 31, to see if the most recent numbers are an aberration. After the next creel report is received, the commissioner will take the necessary actions.

 

Does that mean walleye fishing will be closed?

Yes, if the state has been determined to have exceeded its harvest allotment, a federal court decision legally requires state officials to suspend fishing for walleyes on the lake for the remainder of the season, which closes Nov. 30.

 

How could this happen so quickly? Didn't the DNR estimate that the current regulation would allow anglers to continue this summer with a one-fish limit?

Records show that this was only the second time in 30 years that Mille Lacs walleye catch rates in July were higher than the second half of June. This dramatic spike is believed to be due to unusual circumstances - including the high catch rates over the 4th of July and warm water temperatures (the third highest on record).

 

It's been warm this summer too. Is that affecting the quota?

Yes. In July, water temperatures in Mille Lacs hit their third highest on historical record. Warm water greatly increases walleye mortality on fish that had to be released because they did not fall within the harvest slot. The so-called "hooking mortality" of walleyes that die after being released counts toward the state quota.

 

Is this trend impacting large, breeding-size walleye?

Yes. When more big walleye die, the quota is reached more quickly. The quota is calculated in pounds and bigger fish are heavier than smaller fish.

 

Why didn't the DNR see this coming?

During the first seven months of the monitoring period (December 2014 - June 2015) walleye harvest rates were at or below predicted levels, based on tight regulations adopted for the open-water season. Based upon those results, total harvest was expected to be below the State's 28,600-pound limit for this twelve-month period and the DNR's June 30th creel study showed the state was within 15,300 pounds of reaching the annual quota. Dayton has directed the DNR to wait until after the next creel survey which will cover the period from July 16 to July 31, to see if the most recent numbers are an aberration. During that time, officials at the DNR, the Office of Tourism, and the Department of Employment and Economic Development will meet with resort owners and other affected stakeholders on Mille Lacs to discuss the situation and seek recommendations.

 

Why is the quota so low this year?

Since 2008, not enough young walleye are surviving to maturity and replenishing the Lake Mille Lacs population. As a result, Mille Lacs walleye numbers are currently at a 30-year low. In response, the state instituted more restrictive walleye regulations this year in order to protect young walleyes so they could grow older. In fact, this year Lake Mille Lacs' 2015 walleye safe harvest level was deliberately reduced from 60,000 to 40,000 pounds so that more fish could potentially survive and spawn to improve the walleye population. Under this year's quota, state anglers can harvest up to 28,600 pounds of walleye, and the eight Chippewa bands with 1837 Treaty harvest rights can harvest up to 11,400 pounds of walleye. Anglers are able to keep one walleye that is 19- to 21-inches long, or longer than 28 inches.

 

Is there hope for the fishery to recover?

Despite this year's low walleye population, DNR fishery surveys have shown this year that there may be good news on the horizon. Biologists are seeing a large population of young walleyes hatched in 2013. Walleyes in that group are currently 10- to 13- inches long. It is important to protect those fish so they can contribute to future angling success and walleye production.

 

Mille Lacs is not the same lake it used to be. Unprecedented changes are causing unexpected impacts. Learn more about how the lake is changing by clicking each item in the list below.

Clearer Water

More Predators

Aquatic Invaders

Food Competition&

Fewer Tullibee

Water clarity

Water clarity has nearly doubled since the mid-1980s. Improvement began about 25 years after the implementation of the federal Clean Water Act in the early 1970s. Zebra mussels were first discovered in Mille Lacs in 2006. They did not exist in great numbers until 2011, which corresponds with a sharp upward trend in water clarity during the past three years. Improved water clarity has been linked to movement of young of the year walleye off-shore at smaller sizes and also may have benefited sight-feeding fish that prey on walleye and perch.

Bedrock

Underwater photo of Mille Lacs Lake bedrock after zebra mussels.
Underwater photo of Mille Lacs Lake bedrock before zebra mussels.

Boulders

Underwater photo of Mille Lacs Lake boulders after zebra mussels.
Underwater photo of Mille Lacs Lake boulders before zebra mussels.

Click each photo above to see underwater photos taken before and after zebra mussels infested Mille Lacs Lake. Note the difference in water clarity.

A northern pike

A northern pike

Increased predation

Northern pike and smallmouth bass populations have risen significantly since the early 1990s. In 2013, the northern pike population increased to the highest level ever observed. The 2013 smallmouth bass population was the second-highest ever recorded. Smallmouth bass populations have been on the increase throughout Minnesota and Canada.


Invasive impacts

Once devoid of aquatic invasive species, Mille Lacs now contains zebra mussels, spiny water fleas, and Eurasian watermilfoil. While it's unknown exactly what implications these infestations are having, it's suspected the increase in milfoil is providing more ambush cover for northern pike. Also, water-filtering mussels are contributing to water clarity that allow more aquatic vegetation to grow at deeper depths and in more dense stands.


Underwater photo of native Mille Lacs Lake mussel after zebra mussels.
Underwater photo of native Mille Lacs Lake mussel before zebra mussels.

Before zebra mussels infested Mille Lacs Lake, cadis fly, snails and other native organisms co-existed with native mussels (left). Now, zebra mussels attach themselves to native mussels, displacing those symbiotic organisms. Native mussels, now with restricted feeding openings and competing with zebra mussels for the same microscopic food, eventually starve to death (right).

The aquatic food chain

The aquatic food chain

More competition for zooplankton

First detected in 2009, spiny water flea numbers have fluctuated but show no signs of declining. Spiny water fleas may be having a negative impact on the native zooplankton community by directly competing with small fish for food and altering the historic aquatic food chain.

Tulibee, also called cisco, have been a preferred food source for Mille Lacs Lake walleye.

A tullibee or cisco

Changes in key forage species

The most prominent change is a decline in tullibee, likely the result of warmer water temperatures. A decline in tullibee is likely negatively affecting walleye in Mille Lacs, especially larger walleye, as walleye grow significantly faster when they are able to feed on this species because it is higher in calories than other prey species, including yellow perch.

 

Click a question to view or hide the answer

What is happening at Lake Mille Lacs?

The aquatic system is undergoing significant change, including a declining walleye population. The vast majority of walleye that hatch do not survive to their second autumn in the lake. The DNR has initiated unprecedented actions in response to this unprecedented change. The agency wants to increase the walleye population as quickly as possible with minimal impact to the local community.

Why is this happening?

While state and tribal fisheries management has played a role in the decline, the persistent problem of promising walleye year classes that disappear year after year is also linked to system change. Changes include increased water clarity that benefits sight-feeding fish; the introduction of zebra mussels, Eurasian watermilfoil and spiny water fleas; significantly higher populations of smallmouth bass and northern pike that may prey on walleye; a changing zooplankton community that may be altering the aquatic food chain; and declines in certain forage species, including tullibee.

What is the DNR doing?

As part of a multi-pronged approach, the DNR will convene a blue-ribbon panel of national fisheries experts to review past and current management practices. These experts reviewed the DNR's work and offered recommendations. The agency will also contract nationally recognized fisheries expertise to do an intensive review the state's fish tagging and fish population estimates. These reviews, plus new and more intensive field studies, are part of a systematic approach to improve walleye fishing.

What will this mean to anglers?

The agency will continue to implement regulations that protect young walleye. The lake has not produced a strong year class since 2008. That year class and upcoming year classes need to be protected to ensure there is adequate spawning stock in the future. Currently, there is adequate spawning stock, more than enough egg production and abundant fry production.

Anything else planned?

Details still are being finalized but DNR will explore new and innovative ways to engage citizen input on future management decisions; consider any feasible methods to manage aquatic invasive species; continue discussion and cooperation with tribal natural resource managers; and support a new Mille Lacs tourism marketing initiative with Explore Minnesota Tourism.

Hooked On Mille Lacs

A regularly issued newsletter from the Aitkin Area Fisheries Office that focuses on Mille Lacs Lake.