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2005-2010 Leech Lake
Action Plan
Cormorant Management

What is the status of the Leech Lake cormorant population?
 The nesting population of double-crested cormorants on Leech Lake has grown from 73 nesting pairs in 1998 to 2,524 nesting pairs in 2004.
 The nesting colony is located on Little Pelican Island, which is owned and managed by the Leech Lake Band. All control activities on Little Pelican Island must be with consent of the Band.
 The lake is also a migratory stopover by cormorants heading north to Canada in the spring and south to the Gulf Coast in the fall.

What is the status of cormorants in Minnesota?
 Under Minnesota law the cormorant is an unprotected species, but under tribal and federal law it is a bird protected by the Migratory Bird Treaty Act.
 The first statewide population survey of double-crested cormorants was conducted in 2004.
 Minnesota has a total of 35 nesting colonies that support a statewide population of about 16,100 nesting pairs.
 The 2,524 nesting pairs on Leech Lake represent 15% of the statewide cormorant population.

What are the concerns with the significant increase in cormorants?
 There is mounting circumstantial evidence that cormorants may be having a major negative effect on important sportfish populations on Leech Lake, namely walleye and yellow perch.
 The expanding cormorant population is reducing the nesting habitat available for the rare Common Tern on Little Pelican Island; Leech Lake supports one of only four nesting colonies of this tern in Minnesota.

What actions are being proposed?
The Leech Lake Tribe, the U.S. Department of Agriculture (USDA), the U.S. Fish and Wildlife Service (USFWS) and the Minnesota Department of Natural Resources (DNR) are working together to address cormorant concerns on Leech Lake. The agencies are developing a science-based, aggressive plan to reduce the size of the cormorant colony to a level that will not have significant negative effects on game fish or common terns. Key elements of the plan include the following:
 Cooperating agencies have established a preliminary target population range for cormorants of 250-750 nesting pairs. This will result in a population control program that will reduce the current population of 70-90%. This number will be evaluated through the Environmental Assessment (EA) process described below and as information from field research, long-term fish population assessments and tern colony monitoring becomes available.
 The cooperating agencies have begun preparing an EA to evaluate the appropriate level of population reduction and feasible measures for controlling cormorants on Leech Lake beginning in 2005. Various lethal and non-lethal control measures are being evaluated and could include harassment of migrants, removal of adults, egg oiling, habitat manipulation and various nesting deterrents. The EA will be published this winter (2005) for public comment.
 The Leech Lake Band received a grant from the USFWS to assess the diet of nesting cormorants and to evaluate their impact on select fish species in Leech Lake. This study, which was initiated in 2004 and is being conducted in cooperation with the DNR, will help advance our approach to managing the Leech Lake cormorant population.
 In the fall of 2004, 198 adult cormorants were collected to examine their stomach contents; the analysis is pending.

2005-2010 Leech Lake Action Plan
Habitat Protection

What is happening to Leech Lake fish and wildlife habitat?
Natural shoreline supports the fish, wildlife and water quality that make Leech Lake one of the most-visited lakes in the state. Unfortunately, changes in land use are rapidly altering the lake’s shoreline, impacting water quality and destroying important habitat. Undeveloped shoreline is being developed and cabins are being enlarged or renovated. Aquatic vegetation removal, beach creation, land clearing, and the construction of docks, harbors and moorings have had a cumulative negative impact on important fish habitat and have decreased lakebed stability.

How is this habitat being protected?
The Department of Natural Resources (DNR) is working throughout the state to protect fish and wildlife habitat on Minnesota lakes through annual fish and wildlife sampling, environmental review, educational efforts, regulations enforcement and habitat acquisition. Leech Lake has been the subject of other special initiatives to improve and preserve habitat as well.

Shoreland Rules and Habitat Protection. Governor Pawlenty launched a Clean Water Initiative in 2003 designed to increase the level of attention being directed to Minnesota’s lake and stream resources. At the center of this initiative is the North Central Lakes Pilot Project. Cass County is one of the five counties participating in this project, which has made reviewing and revising shoreland management rules a high-priority objective for 2005. Because Leech is one of the biggest lakes in the project area and has had a watershed-level management program for more than a decade, many of the shoreland rule proposals have immediate relevance to the lake, especially with regard to its intra-lake zoning initiative (a lake classification system that would allow for varied development/protection criteria based on the different kinds of shoreline and in-lake habitat in question).

Control of Exotic Species. Ecological monitoring on Leech Lake turned up three new exotic species in 2004: Eurasian water milfoil, curly leaf pondweed and the Chinese mystery snail. The DNR quickly responded to the finding of Eurasian water milfoil this past summer by hiring a contractor to aggressively treat the five harbors where milfoil was found, and will continue to monitor the lake for these and other exotic species that could impair native habitat or upset native diversity in the lake. Increased public awareness is critical to preventing the spread of these or other harmful exotic species.

How is habitat protection part of the DNR strategy for Leech Lake?
Habitat protection is one component of a multi-faceted approach to improving the walleye sport fishery on Leech Lake over the next five years. A strong walleye population is dependant on adequate locations for spawning, which makes habitat protection a key component of maintaining a healthy walleye fishery on Leech Lake. Other important elements of the plan include a stepped-up cormorant control program, experimental angling regulations and walleye stocking.

Where do we go from here?
The DNR is committed to working with the many stakeholders on Leech Lake, the Leech Lake Association, the Tri-County Leech Lake Watershed Project, the Leech Lake Foundation, the Leech Lake Band, the U.S. Forest Service and local units of government to protect habitat on the lake. In coming years, our focus will be on acquiring critical shoreline habitat; monitoring exotics and surveying aquatic vegetation on the lake; developing and implementing the lake management plan spearheaded by the Leech Lake Association; and pursuing new shoreland rule recommendations that will help preserve habitat on Leech and other area lakes. Toward that end, the DNR is pursing three primary objectives in 2005:
 In conjunction with the Leech Lake Watershed Foundation, the DNR is working to ensure the state land at Ah Gwah Ching, including 0.42 miles of shoreline and 60 acres of woodlands and bluff, remains in state ownership as an aquatic management area.
 DNR staff will continue to work with Cass County to incorporate intra-lake zoning as part of the review/revision of shoreland rules, a change that would provide needed protection to sensitive areas on Leech Lake that are not developed.
 DNR staff will continue to map aquatic vegetation in the fourth of a five-year study of habitat distribution on the lake. We will also continue to monitor the lake for Eurasian water milfoil and aggressively treat areas as needed.

Significant Accomplishments to Date
 Summer 2002 to present. The DNR implemented a five-year aquatic vegetation mapping project of the current distribution of habitat types, which will provide a baseline for future monitoring.
 1983 to present. Annual fish sampling, as part of Minnesota’s Large Lake Program, provides up-to-date information on the various fish species in Leech Lake. Such monitoring can also provide clues to the status of critical aquatic habitat in the lake.
 June 2003. The DNR acquired 30 acres and 1,200 feet of wild shoreline near Five Mile Point, a known muskie spawning area.
 April 2001. The U.S. Forest Service, with help from Leech Lake Watershed Foundation and the DNR, acquired Cedar Springs Resort, protecting 167 acres and 0.37 miles of sensitive shoreline.
 October 2003. Six acres of wetlands on Pumphouse and Shingobee Bays were gifted to the Leech Lake Watershed Foundation.

For more information or to submit public comments, please contact the Walker Area Fisheries Office
07316 State Highway 371 NW, Walker MN, 56484; (218) 547-1683; harlan.fierstine@dnr.state.mn.us

2005-2010 Leech Lake Action Plan
Experimental
Regulation Proposal

What is being proposed?
Possession limit of four (4) walleye and all walleye from 18 inches to 28 inches must be immediately returned to the water. Only one (1) walleye over 28 inches is allowed in a possession limit.

Why is this regulation being proposed?
The Leech Lake walleye population is well below the long-term goal with regard to overall abundance and size distribution. Subsequently, walleye fishing on Leech Lake has been difficult during the last three years. In combination with predation by a rapidly expanding double-crested cormorant population since 2000, high angler harvest in the late 1990s likely contributed to a decline in the Leech Lake walleye population. Walleye recruitment has been poor since 1997. Given poor recruitment over the past seven years, DNR biologists believe increased protection of the brood stock is warranted until additional year classes are mature (see graphs). A variety of regulation options were considered but deemed either too restrictive or not restrictive enough. Any experimental regulation for Leech Lake must protect the current brood stock for the long-term health of the walleye fishery.

How will this regulation be evaluated?
If enacted, the proposed regulation would be implemented on the walleye opener in 2005 and evaluated for a period of five years. Annual walleye sampling, which is part of the large lake monitoring program on Leech Lake, will allow continual evaluation of changes in the walleye population, specifically walleye abundance and changes in walleye biology that indicate population health. Angler surveys are scheduled for 2005 and 2010.

How is this regulation part of an overall DNR strategy for Leech Lake?
This regulation proposal is one component of a multi-faceted approach to improving the walleye fishery on Leech Lake over the next five years. The proposed changes will protect walleye brood stock, which is essential to the long-term health of the Leech Lake walleye fishery. Other important elements of the plan include a stepped-up cormorant control program, walleye stocking and an increased focus on habitat protection.

What are the DNR’s walleye management goals for Leech Lake?
1) The standing stock of mature female walleye is maintained at 1.25 to 1.75 pounds per acre. (See graph on back.)
2) The number of walleye sampled in experimental gill nets increases from less than 5.0 walleye per net in 2004 to the historical average of 7.4 walleye per net. (See graph on back.)
3) The catch rate of age-1 walleye in DNR trawl samples increases from less than 10 age-1 walleye per hour to at least the historical average of 45 age-1 walleye per hour. (See graph on back.)
4) The sizes of walleye sampled in experimental gill nets includes fish of all sizes, with at least 50% of walleye sampled measuring less than 15.0 inches in length. (See graph on back.)
5) Two good walleye year classes are established within the next five years.

2005-2010 Leech Lake Action Plan
Stocking

What is being proposed?
The Minnesota Department of Natural Resources (DNR) will be stocking Leech Lake with 5.0 million marked walleye fry for three consecutive years beginning in the spring of 2005. The fish will be marked with oxytetracycline (OTC), which is an antibiotic that leaves an identifiable mark on fish bones. By marking fish, the DNR can identify them as a stocked fish when they are captured later.

Why is this being proposed?
The objective of this stocking proposal is to estimate the natural fry production in Leech Lake and determine the optimal level of mature female spawners needed to provide consistent natural reproduction. Recent recruitment of walleye in the lake has been poor.

How will the stocking effort be evaluated?
Walleye fingerlings will be sampled using shoreline seining, trawling and electrofishing for three consecutive years beginning in the summer of 2005. These fish will be examined for the OTC mark. Once all samples are examined for marks, an estimate of natural walleye fry production will be made.

How is stocking part of an overall DNR strategy for Leech Lake?
This experimental stocking is one component of a multi-faceted approach to improving the walleye sport fishery on Leech Lake over the next five years. The marked, stocked fish will help the DNR determine what the optimal level of walleye brood stock is for Leech Lake (as measured by mature female biomass) so future management objectives can target maintaining that level. Other important elements of the plan include a stepped-up cormorant control program, experimental angling regulations and an increased focus on habitat protection.

What management concerns were addressed in the stocking plan?
Source of walleye eggs. It is critical that any walleye stocking conducted on Leech Lake not jeopardize the genetic integrity of this fishery. Leech Lake walleye have evolved in this system over thousands of years. DNR fisheries staff has worked with the University of Minnesota to identify the best genetic match, with the lowest level of associated risk. The Boy River spawning run (Woman Lake) has been identified as the closest genetic match.

Developing a robust research design for stocked fish. Fish population data suggest that the current level of brood stock is sufficient to naturally repopulate the lake. This stocking study will help determine the optimum number of mature female walleye needed to sustain the fishery. The regulation proposal also ensures that is the case for the coming years. From this study we hope to determine why young walleye are not being produced in the main lake in sufficient numbers, and to take corrective action once the reasons are identified. The current research design includes stocking marked walleye for three years and conducting mark-recapture studies over the course of the next five years to determine optimal female biomass for the lake. Opportunities to integrate the stocking evaluation with the cormorant diet study will also be explored.

For more information or to submit public comments, please contact the Walker Area Fisheries Office
07316 State Highway 371 NW, Walker MN, 56484; (218) 547-1683; harlan.fierstine@dnr.state.mn.us

2005-2010 Leech Lake Action Plan
Summary

The Minnesota Department of Natural Resources (DNR) is proposing a five-year action plan for improving the walleye sport fishery on Leech Lake. Key elements of the plan include experimental angling regulations to protect walleye broodstock; stepped up cormorant population control measures; a 3-year walleye stocking evaluation; and increased focus on long-term habitat protection. The DNR is committed to working with the Leech Lake Band, the Leech Lake Association, the Tri-County Leech Lake Watershed Project, the Walker Area Chamber of Commerce, local resorts and businesses, anglers and numerous other partners to achieve our common goals of good fishing and a healthy economy.

Experimental Fishing Regulations
 Walleye Regulation Proposal - Possession limit of four (4) walleye and all walleye from 18 inches to 28 inches must be immediately returned to the water. Only one (1) walleye over 28 inches is allowed in a possession limit.
 The objective of this regulation is to protect walleye brood stock until additional year classes reach maturity.
 If enacted, the new regulations would be implemented in May 2005 and evaluated for a period of five years.
Cormorant Management
 The DNR, the Leech Lake Band, the US Fish and Wildlife Service, and the US Department of Agriculture are cooperating on the preparation of an Environmental Assessment (EA) to evaluate the appropriate level of population reduction and feasible measures for controlling cormorants on Leech Lake beginning in 2005. Various lethal and non-lethal control measures are being evaluated. The EA will be published early this winter for public comment.
 Cooperating agencies have established a preliminary target population range for cormorants of 250 - 750 nesting pairs. This will result in a population control program that will reduce the current population from 70 - 90% from 2004 levels.
 The Leech Lake Band received a grant from the USFWS to assess the diet of nesting cormorants and to evaluate their impact on select fish species in Leech Lake. This study, being conducted in cooperation with the DNR, will help advance our approach to managing the Leech Lake cormorant population.
Walleye Stocking
 Five million walleye fry will be stocked in Leech Lake for three consecutive years beginning in 2005. Walleye fry will be marked with a chemical called oxytetracyclene (OTC), which is an antibiotic that leaves an identifiable mark on fish bones. By marking fish, the DNR can identify them as a stocked fish when they are captured later.
 The objective of the stocking evaluation is to estimate the natural fry production in Leech Lake and determine the optimal level of mature female spawners needed to provide consistent natural reproduction.
 Walleye eggs will be obtained from the Boy River spawning run (Woman Lake spawning stock). DNA analysis of tissue samples concluded that this source of eggs is the closest genetic match to Leech Lake with the lowest risk of genetic contamination.
Habitat Protection
 The Governor’s Water Initiative will provide a unique opportunity to examine how our precious water resources are managed in Minnesota. Cass County, with Leech Lake as its centerpiece, will be front and center in the Central Lake Pilot Study, which includes a review of the State’s shoreland rules.
 DNR staff will continue to map aquatic vegetation in the fourth year of a five-year study of habitat distribution on the lake. We will also continue to monitor the lake for Eurasian water milfoil and aggressively treat areas as needed.
 DNR staff will work with the Tri-County Leech Lake Watershed Project, the Leech Lake Foundation, the Leech Lake Association and other project partners to purchase critical habitat areas in and around Leech Lake. Preserving the shoreline and adjacent blufflands at the Ah Gwah Ching treatment center as an Aquatic Management Area is a high priority for the DNR.