Jack

A targeted survey of nearshore fish species in Jack Lake which is located wholly within the Leech Lake Band of Ojibwe Nation, was conducted August 20-21, 2024, by Index of Biological Integrity (IBI) Program staff. Sampling sites were evenly spaced around the lake, and each was sampled by backpack electrofishing and seining with a 50-foot or 15-foot seine, where possible. Backpack electrofishing was completed at ten sampling stations. Similarly, a 50-foot seine was used to sample four stations, and a 15-foot seine was used at three stations. Three stations were not seined due to soft mucky substrate and dense wild rice, water lilies, and/or chara that prevented wading. Nearshore sampling captured 17 species of fish including 7 species that are intolerant of disturbance (i.e., Banded Killifish, Blackchin Shiner, Blacknose Shiner, Iowa Darter, Least Darter, Northern Sunfish, and Rock Bass) and no species that are tolerant of disturbance. A concurrent summer trap net survey was also conducted by IBI Program staff. Nine trap nets were set along the shoreline in locations that encompassed multiple habitat types. Trap net sampling captured eight species of fish, including one that is intolerant of disturbance (i.e., Rock Bass). Bluegill comprised a majority of the catch by number, whereas Northern Pike and Bluegill comprised a majority by biomass. The trap net catch was light overall. The nearshore and trap net were combined with gill net data from a June 2018 survey to describe the fish community and provide a fish-based IBI (FIBI) score. The FIBI uses fish community data to measure a lake's health, and the types of fish species present can help identify any stressors that may be negatively affecting the lake environment. In Minnesota lakes, certain fish species cannot survive without clean water and a healthy habitat (e.g., Blackchin Shiner, Least Darter, and Cisco), while other species are tolerant of degraded conditions (e.g., Green Sunfish and Common Carp). The FIBI score, composed of several fish community diversity and composition metrics, indicates the overall health of a lake by comparing it to what is expected for a healthy lake. For additional information on the FIBI, search for "lake index of biological integrity" on the mndnr.gov website. Results from this survey provide evidence that the fish community in Jack Lake is healthy as indicated by an FIBI score that exceeds the MNDNR FIBI exceptional use threshold determined for similar lakes. These results are similar to previous findings regarding the biological health of Jack Lake. You can help protect the fish community in Jack Lake by reducing runoff, maintaining natural shorelines, and preventing the spread of invasive species. Jack Lake has a beautiful shoreline with a large amount of natural shoreline and abundant wild rice, bulrush, water lilies, and chara. In addition to the FIBI survey work, temperature and dissolved oxygen measurements were collected in the deepest basins in Jack Lake to evaluate the quantity and quality of cold, oxygenated water (i.e., oxythermal habitat) available to Cisco, also known as Tullibee, the most sensitive coldwater species present in this lake. During the summer, Cisco require a layer of oxythermal habitat that contains water temperatures below 21.2 degrees C (70.2 degrees F) and dissolved oxygen concentrations above 3.0 mg/L. Based on the profile from the deepest basin, the water temperature decreased to below 21.2 degrees C (70.2 degrees F) at 18.0 feet and the dissolved oxygen concentration decreased to 3.0 mg/L at 28.3 feet at the time of sampling. The thickness of this layer of water in the water column was 10.3 feet, indicating that oxythermal habitat was present for Cisco. Further, the temperature at which dissolved oxygen decreased to 3.0 mg/L (i.e., TDO3, a single variable to characterize oxythermal habitat) was 11.3 degrees C (52.3 degrees F). TDO3 values cooler than/warmer than 21.2 degrees C (70.2 degrees F) indicate that oxythermal conditions were suitable for Cisco at the time of the survey. This is the first Minnesota Department of Natural Resources temperature and dissolved oxygen survey completed on Jack Lake during the late summer period of maximum oxythermal stress. When inadequate oxythermal habitat is available, Cisco are squeezed into unfavorable, warmer water conditions and experience higher levels of stress.

Jack Lake is a 142-acre lake with 2.50 miles of shoreline and a maximum depth of 110 feet located southeast of Walker, Minnesota. A county-owned public access is located on the west shore. The Minnesota Department of Natural Resources (MNDNR) has classified Minnesota lakes into 43 different classes based on physical, chemical, and other characteristics. Jack Lake is in Lake Class 23; lakes in this class are generally very deep and very clear. Other area lakes in this class include Baby, Mule, Grave, and Ponto. Jack Lake is connected to Leech Lake through an unnavigable wetland. Jack Lake is entirely within the Chippewa National Forest and Leech Lake Indian Reservation. A majority of the shoreline is publicly owned and undeveloped. The lake is primarily managed for Northern Pike, Largemouth Bass, and Bluegill and secondarily for Black Crappie and Tullibee (Cisco). Jack Lake has a moderate population of Northern Pike (6.7 fish per net) with an average length and weight of 22.2 inches and 2.4 pounds. Northern Pike ranged from 17 to 29 inches. Bluegill are abundant, but small in size with most fish below 6 inches; lengths ranged from 3 to 8.0 inches. Few Largemouth Bass were sampled as no electrofishing was conducted. Bass ranged in length from 7 to 19 inches, with an average length and weight of 14.1 inches and 1.9 pounds. Other species sampled included Black Crappie, Bowfin (Dogfish), Tullibee (Cisco), Hybrid Sunfish, Walleye, Yellow Bullhead, and Yellow Perch, Rock Bass, and Pumpkinseed. People can have significant impacts on lakes and the fish populations they support. Harvest, lakeshore development, removal of shoreline vegetation, and introductions of invasive species can all adversely affect fish populations. Currently, no aquatic invasive species (AIS) have been identified in Jack Lake. AIS are moved from infested to non-infested waters by anglers, boaters, and lakeshore owners and can adversely impact lakes and fish populations. To avoid spreading AIS, lake users are required to remove all aquatic plants or animals from their watercraft and drain all water from their boat before leaving the access. If you suspect an infestation of an invasive species in this lake, save a specimen and report it to a local natural resource office. Additional information on all of these topics can be found on the DNR website (www.dnr.state.mn.us) or by contacting the Walker Area Fisheries office.

Jack Lake is a 142-acre lake located near Walker, Minnesota that has 2.50 miles of shoreline and a maximum depth of 110 feet. There is a county-owned public access on the west shore. The Minnesota Department of Natural Resources (MNDNR) has classified Minnesota lakes into 43 different classes based on physical, chemical, and other characteristics. Jack Lake is in Lake Class 23; lakes in the class are generally very deep and very clear. Jack Lake has a good population of northern pike, ranging from 16 to 29 inches. The abundance of northern pike caught compared favorably to other lakes in this class. Jack Lake has an abundant population of bluegill. Average length of these fish was about 6 inches, though bluegill about 8 inches were sampled. Pumpkinseed sunfish and rock bass numbers compared well with numbers found in other lakes of this class. Other species present included black crappie, bowfin (dogfish), brown bullhead, burbot (eelpout), cisco (tullibee), hybrid sunfish, largemouth bass, walleye, yellow bullhead and yellow perch. Anglers can help maintain or improve the quality of fishing by practicing selective harvest. Selective harvest allows for the harvest of smaller fish for table fare, but encourages release of medium- to large-sized fish. Releasing these fish can help maintain balance in the fish community in Jack Lake and provide anglers the opportunity to catch more and larger fish in the future. Shoreline areas on the land and into the shallow water provide essential habitat for fish and wildlife that live in or near Minnesotas lakes. Overdeveloped shorelines cant support the fish, wildlife, and clean water that are associated with natural undeveloped lakes. Shoreline habitat consists of aquatic plants, woody plants and natural lake bottom soils. Plants in the water and at the waters edge provide habitat, prevent erosion and absorb excess nutrients. Shrubs, trees, and woody debris such as fallen trees or limbs provide good habitat both above and below the water and should be left in place. By leaving a buffer strip of natural vegetation along the shoreline, property owners can reduce erosion, help maintain water quality, and provide habitat and travel corridors for wildlife.

Based on Minnesota DNR survey data, anglers target Northern Pike, Walleye, Black Crappie, Hybrid Sunfish, and Rock Bass in Jack. See the full species list above for catch rates, size structure, and quality scores.

We don't have a confirmed public access point on record for Jack. Check the DNR LakeFinder page for current access details before you go.

Jack has a maximum depth of 110 feet, per Minnesota DNR data.

The most recent Minnesota DNR survey data for the main sport fish in Jack is from 2024.

No invasive species are on record for Jack in Minnesota DNR data. Always clean, drain, and dry your equipment to help keep it that way.