(L-R) Tom Jones and Eric Jensen of the DNR prepare to release walleye fry in Mille Lacs Lake.
Nine months after increasing its management efforts on Mille Lacs Lake, the Minnesota Department of Natural Resources recently released 10 million walleye fry into the lake as part of a major research project.
The mosquito-sized baby walleye were released over several days starting May 5 at various locations around the lake. Given a special chemical marker, the fry can be differentiated from wild walleye by fisheries biologists. When biologists survey the lake’s young fish this fall, they will be able to compare the number of wild walleye to the stocked ones.
This comparison will provide an estimate of the wild fry hatched in the lake this spring. Mille Lacs currently has enough spawning walleye, but if natural production ever dropped to a level where stocking became necessary, the information from the study will also help DNR determine an appropriate stocking rate.
Last August, the DNR committed to the stocking plan and study as a part of a long-term project aimed at improving the Mille Lacs Lake walleye population while building a closer working relationship with the Mille Lacs community.
“The walleye fry release marks another milestone in our efforts to ensure the long-term health of Mille Lacs Lake,” said Commissioner Tom Landwehr. “Mille Lacs is in many ways a world-class fishery, and we are committed to making it better.”
In addition to better understanding walleye population dynamics, Landwehr said the DNR is using regulations to help build the lake’s walleye population. The state instituted catch-and-release regulations earlier this year aimed at protecting young walleye so they could grow older and reach spawning age.
The walleye fry project started earlier this spring when DNR biologists collected 160 quarts of walleye eggs from Mille Lacs Lake and fertilized them. The fry were hatched at a St. Paul facility and marked with oxytetracycline, a common antibiotic that places a mark on the fish’s ear bone. Biologists will catch them along with wild walleye this fall, look for the hatchery mark, and learn more about the lake’s walleye reproduction.
In addition to releasing walleye fry into the lake, the DNR is conducting a major study to better estimate how walleye survive after being caught by anglers and released. Data from the “hooking mortality” study will aid the agency in setting future walleye regulations. The DNR has also studied what predator fish eat to better understand the predator-prey relationships in the lake. Future work may also include a more detailed look at the food web of the lake, including potential effects of invasive species on the production of key prey fish including tullibee (cisco) and yellow perch.
Here are other significant management steps the agency has undertaken in the last nine months:
Created a new advisory committee: The DNR created a 17-member Mille Lacs Lake Advisory Committee to help guide future management decisions. The committee has met eight times since last October and has covered topics such as walleye population monitoring, fisheries treaty management, creel surveys, hooking mortality, stocking, and fishing regulations. The Committee is now working to identify new issues the DNR should consider.
Proposed a new fisheries facility: The DNR is hoping the Legislature will approve a $3.5 million bonding project this session, proposed by Gov. Mark Dayton, to build a new fisheries management facility on the lake. In addition to a cool-water hatchery, the facility will accommodate educational, research, visitor and interpretive functions, and serve as a location for public meetings. Lawmakers have until May 22 to approve the proposal.
New staff: Staffing assignments have been adjusted to focus exclusively on Mille Lacs, including a new outreach specialist and a new Mille Lacs project leader. These staff will provide more capacity for monitoring, foster better communication with local stakeholders, help with various expanded efforts, and assist the community with outreach and marketing efforts.
Promoting other fishing and outdoor recreation: The DNR is promoting the other great fishing in the lake, including northern pike, smallmouth bass and muskellunge, and the many recreational resources in the region. In an ongoing partnership with Explore Minnesota Tourism, the DNR is collaborating on the Do the Lake outreach campaign to draw more visitors to the lake.
Increased transparency of quota setting: The DNR has increased the transparency of the quota-setting process by inviting both DNR and band members of the fisheries technical committee to report on the process at an advisory committee meeting. A long-standing policy of inviting key legislators will continue and will be encouraged as well.
Learn more about the DNR’s efforts to improve Mille Lacs Lake at www.mndnr.gov/millelacslake.
DNR fisheries Eric Jensen of DNR releases walleye fry into Mille Lacs Lake.