Plan highlights management strategies for walleye lakes of special concern

The Walleye Lakes of Concern Management Plan was created for Clear and Katherine Lakes in Oneida County as well as Anvil and Laura Lakes in Vilas County. In a joint effort, the Department of Natural Resources (DNR), the Lac du Flambeau Band of Lake Superior Chippewa Indians and the Great Lakes Indian Fish and Wildlife Commission (GLIFWC) put together a plan to address walleye declines in four specific lakes in the Northwoods.

Over the past two decades, the plan states, a number of lakes in the north have experienced declines in walleye recruitment. This has brought about a variety of management techniques including increased stocking of large fingerlings, habitat restoration projects, more research projects and tighter conservation regulations being put into place. These have been balanced with the wish to still provide fishing opportunities for anglers. 

Some walleye populations have started to respond favorably to these efforts. Others, however, have continued to decline. The plan was put together to address these walleye populations and highlights the idea that as waterbodies and fisheries experience changes, management strategies, too, must change. 

Historically, the four lakes pinpointed in this plan have had self-sustaining walleye populations. There had been natural reproductions and recruitment was strong, creating good quality walleye fisheries. 

The management plan identified walleye management objectives aimed at creating sustainable fisheries and looks at management techniques needed to achieve stated objectives. There is also a plan for public outreach and a process delineated to inform stakeholders of timelines and measures of success. It also identifies metrics such as lake-specific habitat, aquatic plant management and aquatic invasive species (AIS) on these lakes. The two main objectives of the plan are to “increase and maintain current adult walleye densities,” and to “increase walleye recruitment.”

Increasing and maintaining adult densities will be either compared against the observed historic range when reproduction and recruitment were creating self-sustaining populations or will look to create a fishery with adult walleye densities of at least three fish per acre, as identified in the 1988 report, which set this as a metric at which a walleye population could be said to be healthy and self-sustaining.

Increasing walleye recruitment would be measured by one of three criteria. The first criteria to be met would be for that recruitment to increase from the historic levels that sustained the population in the past. The second criteria which could be met would be an electrofishing catch rate of at least 15 age-0 walleye per mile at least once every three years. Third would be a minimum of five fish per mile every three years of age-1 walleye through either natural recruitment or a combination of natural and stocked recruitment.

Strategies

One of the strategies outlined in the plan is a proposed harvest reduction strategy. This is the same regulation as will apply to the Minocqua Chain when it reopens for walleye harvest. The experimental regulation will include one fish over 18 inches with a no harvest slot between 22 and 28 inches. The daily bag limit is one fish. 

“This an aggressive harvest strategy that sends a clear message to anglers that harvest opportunities are very limited in waters where applied,” the plan states. On lakes where an 18-inch size limit, even with a daily bag limit of three fish, has appeared to be effective at reducing angler harvest, according to creel surveys. 

This aggressive harvest strategy will significantly protect adult walleye populations on these lakes. The plan states this regulation, if in place already on Clear, Katherine, Anvil and Laura Lakes would have protected 14%, 38%, 31% and 0% of harvested walleye, respectively, on these four lakes.

The Lac du Flambeau Tribe, too, has recognized the need to limit harvest on these lakes. In 2021, they began reducing harvest, taking less than 50% of the walleye available for harvest on those lakes.

Stocking is another strategy outlined in the plan. The main goal is stated as “to produce year-classes large enough to increase the spawning populations of walleye when they mature, and for these walleye to naturally reproduce.” Evaluation of stocking strategies are part of the ongoing plan with adjustments to be made to meet the goals. 

The differences between stocking small and large fingerlings are addressed in the plan as well. Large fingerlings are more expensive to produce, but are more effective in lakes with abundant predators and under other specific conditions. Large fingerlings have a higher survival rate, according to recent research.

Recently there has been concern raised over the sex ratio of fish coming out of hatcheries. These stocked fish have had an extremely female-dominated sex ratio, which is currently being investigated. Results from that investigation will be used in future stocking considerations.

Evaluation

Evaluation of the plan is also included in the plan itself. The initial evaluation is set for the year 2027. However, partners will meet annually to review performance measures of populations on these lakes, the plan states. Walleye populations will be monitored annually for the life of the plan. It also calls for at lest one adult walleye population assessment to be completed on each lake within the first five years. Angler harvest will also be monitored through creel surveys as part of the plan as will tribal harvest. 

Measures of success are also delineated in the plan. Those will include increases and age-0 walleye recruitment, which would indicate stocked small-fingerlings were surviving and/or natural recruitment had increased.

Another measure of success would be an increase in age-1 walleye recruitment. This would also indicate stocked small-fingerlings were surviving and/or natural recruitment had increased. 

The third measure is stated as finding increases in walleye numbers and increased presence of young adults in the population. This would point toward successful recruitment.

Lake specific data

The plan also includes lake specific data for each of the four lakes involved in the plan. As well as historic management strategies. Data such as abundance and density numbers, sex ratios, size structure and year class distribution are available for each lake. Juvenile recruitment history and harvest monitoring are also listed. Regulations and regulation changes for each lake are highlighted as is tribal spearing regulations and stocking information. 

Those interested in reading the entire plan can do so by visiting the DNR website dnr.wi.gov and inputting the search words “walleye management plan” into the search box. Here, visitors can also view the newly updated walleye management plan for all of the state’s waters.

Beckie Gaskill may be reached via email at [email protected].