Long (Main Bay)

A targeted survey of nearshore fish species in Long Lake was conducted beginning on August 26th, 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, where possible. Backpack electrofishing was completed at all ten sampling stations. Similarly, a 50-foot seine was used to sample two stations, a 15-foot seine was used at five stations, and site conditions prevented the use of seines at three stations. Nearshore sampling captured 16 species of fish including four species that are intolerant of disturbance (i.e., Blackchin Shiner, Iowa Darter, Northern Sunfish, and Rock Bass) and no species that are tolerant of disturbance. A concurrent summer trap net survey was conducted on August 26th - 29th, 2024 by IBI Program Staff. Nine trap nets were set along the shoreline and in shallow offshore locations that encompassed multiple habitat types. Bluegill comprised a majority of the trap net catch by number, and Bowfin and Bluegill comprised a majority of the catch by biomass. The total catch of fish was light and the number of Black Crappie sampled per net was below the 25% quartile for similar Lake Class 25 lakes, and the number of Bluegill sampled per net was below the 50% quartile for similar Lake Class 25 lakes. A concurrent summer gill net net survey was conducted on August 26th - 29th, 2024 by IBI Program Staff. Nine gill nets were set in offshore locations that encompassed deeper littoral habitat. Black Crappie and Bluegill comprised a majority of the gill net catch by number, and Northern Pike and Black Crappie comprised a majority of the catch by biomass. The number of Black Crappie sampled per net (17.1/net) was well above the 75% quartile for similar Lake Class 27 lakes (2.7/net) and the average length was 5.4 inches, with 9% over 7 inches. The nearshore, trap net, and gill net survey data from August 26th, 2024 were combined 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., Iowa Darter, Northern Sunfish, and Rock Bass), while other species are tolerant of degraded conditions (e.g., Black Bullhead, Fathead Minnow, and Green Sunfish). 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. Data from this survey indicates Long Lake is in good health as indicated by an FIBI score above the impairment threshold for aquatic life use determined for similar lakes. These results are similar to previous findings which indicated that Long Lake is fully supporting aquatic life. Data from this survey will contribute biological information about the health of the fish community to the Mississippi River - Grand Rapids Watershed assessment process in coordination with MN Pollution Control Agency.

Long Lake is located approximately 16 miles southeast of Bigfork, MN, within the Mississippi River watershed. Other similar lakes in this area include: Balsam, Grave and North Star. The 331 acre lake has 177 littoral acres (less than 15 feet), a 34 foot maximum depth and is moderately developed along the 8.9 mile shoreline. There is a state owned public access located on the south central shore. Secchi disk transparency, a standard measure of water clarity, has averaged 7.9 feet over seven surveys and has ranged from 6.0 - 10.1 feet. The West Fork of the Prairie River flows through the lake. The lake outlet was modified in 2015 by the DNR Stream Habitat Program in order to enhance fish passage. The water level control structure was removed and a rock weir was installed. The rock weir was further modified in 2017 to lower the lake level. The 2007 Lake Management Plan (LMP) lists Northern Pike and Black Crappie as primary management species due to habitat suitability and angler interest. The lake is also well suited for Bluegill and Largemouth Bass and these were listed as secondary species. The LMP goals were to: 1) maintain a Northern Pike population that is characterized by a gill net catch rate of 5.0/net with 40% longer than 21 inches and 5% longer than 28 inches and 2) maintain a Black Crappie population that is characterized by a trap net catch rate of 5.0/net. A standard survey was conducted in late June 2017 to assess the status and characteristics of the fish community using nine gill nets and eight trap nets. A night electrofishing survey was conducted on May 24, 2017 to obtain additional information on the Largemouth Bass and Black Crappie populations. In general, the Northern Pike population is average in abundance, has poor size distribution and average growth rates. The Northern Pike gill net catch rate decreased slightly from 7.1/net in 2007 to 5.7/net, but remains within the range typical of lakes with similar habitats. The Northern Pike gill net catch rate ranged from 2.9 - 13.6/net in the five surveys prior to 2007. Management goals were met for gill net catch rate but not size structure. Northern Pike from gill nets ranged from 13.1 - 29.9 inches and averaged 20.4 inches. Size structure was poor as 45% exceeded 21 inches and 2% exceeded 28 inches. Growth rates were similar to the statewide average with an average length of 20.3 inches at age-4. Eight consecutive age classes (ages 1 - 8) were represented in the sample. The Black Crappie population has poor size structure and slow growth rates. Black Crappie were captured at a rate of 3.1/trap net, which was within the typical range for similar lakes, but did not meet the management goal. Electrofishing sampled Black Crappie at a rate of 28.4/hr on-time. Black Crappie from electrofishing ranged from 4.9 - 9.8 inches with an average of 8.0 inches, while those from trap nets ranged from 4.6 - 11.5 inches and averaged 6.8 inches. Black Crappie growth rates were slower than those from similar lakes with an average length of 7.5 inches at age-4. Three consecutive age classes (ages 3 - 5) were represented in the sample. The Bluegill population can be described as average in abundance, with moderate size structure and average growth rates. The Bluegill trap net catch rate increased slightly from 14.0/net in 2007 to 18.5/net but remained within the typical range for similar lakes. Bluegill trap net catch rates have been within this range in all surveys since 1976. Bluegill from trap nets ranged from 3.1 - 9.1 inches with an average of 5.8 inches. Size structure was moderate as 49% exceeded six inches and 10% exceeded eight inches. Bluegill growth rates were typical of similar lakes with an average length of 6.3 inches at age-6. Eight consecutive age classes (ages 2 - 9) were represented in the sample. The Largemouth Bass population had good size structure and average growth rates. The Largemouth Bass electrofishing catch rate decreased from 30.4/hr in 2007 to 14.4/hr. Largemouth Bass ranged from 7.5 - 19.0 inches, with an average of 13.6 inches. Size structure was similar to 2007 with 68% of the sample exceeding 12 inches and 41% exceeding 15 inches. Growth rates remained similar to the statewide average with an average length of 12.7 inches at age-4. Six consecutive age classes (ages 2 -7) were represented in the sample. One Walleye was sampled in this survey which measured 18.5 inches. Walleye gill net catch rates have been low in all surveys and have varied from 0 - 1.1/net. Walleye were stocked intermittently from 1946 - 1967 and regularly from 1985 - 1991. Walleye stocking was discontinued in 1992 because it did not succeed in increasing the population. However, with the modification of the lake outlet, fish are better able to move throughout the Prairie River system. Other species sampled include: Brown Bullhead, Golden Shiner, Pumpkinseed Sunfish, White Sucker and Yellow Bullhead.

Long lake is a 330-acre lake in ecological lake class 25 in northern Itasca County. A population assessment was conducted on Long Lake to determine the status of the fish community. The assessment included night-time boat electrofishing for largemouth bass in mid-June and gill and trap netting to assess other species in early July. Black crappies were sampled in relatively good numbers when compared to similar lakes. Size distribution was balanced with approximately 50% of the catch exceeding 8 inches. Few individuals exceeding 10 inches were captured, however, and growth was relatively slow. Size distribution and catch rate were similar to previous surveys. Bluegills were captured in average numbers compared to similar lakes. Size structure was moderate as approximately 36% of the catch exceeded 6 inches and growth was average. Northern pike were captured in above average numbers when compared to similar lakes. Northern pike catches have varied since the initial survey in 1949 when the catch was relatively low. The pike catch increased from 1976 through 1989, when an exceptionally high catch was observed. Since that time, catch rates have declined and are currently within the expected range for the lake type. High pike densities often result in relatively poor size structures. Size structure in Long Lake appears to have changed inversely to abundance as the size structure was relatively poor between 1976 and 1997. The current assessment indicates a modest improvement in the size structure as the proportion of individuals exceeding 21 and 28 inches were the highest observed since the 1949 survey. Growth was about average for pike in Minnesota. The current size structure indicates moderate angling opportunity for quality-sized individuals and at least some opportunity to catch pike exceeding 28 inches. Walleye were relatively rare in the sample. Walleye have consistently occurred in low numbers in Long Lake. Prior to 1991, walleye stocking was attempted but failed to produce an improved fishery and was subsequently discontinued. Size structure was favorable with 60% exceeding 18 inches. Largemouth bass were relatively abundant in the night electrofishing catch. The length distribution was favorable as most individuals exceeded 12 inches and individuals exceeding 15 inches were common. Given the good abundance and favorable size structure, good angling opportunities exist for this species. Yellow perch, brown and yellow bullhead, golden shiner, rock bass, white sucker, and pumpkinseed were sampled in relatively low abundance. The protection of water quality and habitat is critical in maintaining or improving fish and wildlife populations. Unfortunately, human activities often negatively impact our lakes. Fertilized turf-grass lawns and failing septic systems along with the removal of shoreline and aquatic vegetation, mowing to the shore, and installing sand blanket beaches result in destabilized shorelines, uncontrolled erosion, and increased run-off, contributing excess nutrients and sediment to the lake and degrading water quality and habitat. By understanding the cumulative impacts of our actions and taking steps to avoid or minimize them, we can help insure our quality water resources can be enjoyed well into the future. Anglers can further help insure quality fishing by practicing selective harvest and catch and release.

Based on Minnesota DNR survey data, anglers target Northern Pike, Largemouth Bass, Black Crappie, Walleye, and Bluegill in Long (Main Bay). See the full species list above for catch rates, size structure, and quality scores.

Minnesota DNR records list public access for Long (Main Bay). Check the DNR LakeFinder page for the launch type and directions before you go.

Long (Main Bay) has a maximum depth of 34 feet, per Minnesota DNR data.

The most recent Minnesota DNR survey data for the main sport fish in Long (Main Bay) is from 2024.

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