Long

A temperature-dissolved oxygen (TDO) profile was collected on 8/4/2025, to measure the amount of thermal habitat available for Tullibee. Adequate oxy-thermal habitat for Tullibee survival was observed from a depth of 13 feet to approximately 106 feet. In some years, a TDO3 (temperature at 3 mg/l dissolved oxygen) value cannot be calculated as the dissolved oxygen does not fall below 3ppm. This year the TDO3 was calculated at 18.5, 9.0, and 5.6 degrees C across multiple depths. TDO data indicates sufficient Tullibee habitat in each year since monitoring began (2007), although a significant summer kill was observed in 2009 when the poorest TDO values were observed as water temperatures peaked in mid-September. The lake provides "good" habitat compared to other lakes in the Aitkin management area that are monitored for Tullibee habitat. Because the management area is located near the southern edge of Minnesota's Tullibee range, TDO profiles should continue to be recorded to monitor the availability of cold-water habitat.

A spring trap net assessment was conducted between 4/15/2025 and 4/18/2025 on Long Lake to assess the adult Walleye population. Historical gill net assessments have resulted in low Walleye catch rates (range = 0.2 to 1.2 per net, average = 0.6 per net), despite high density annual fingerling stocking (2.5 pounds per littoral acre). Low gill net catch rates are likely due to the morphology of the lake that is not favorable for gill netting (e.g. deep and fast breaking shorelines). Therefore, 30 trap net sets were deployed in 13 locations over three days during the Walleye spawn to get a better representation of the adult population. A variety of habitats were sampled, but mainly near the 4 small inlets and one outlet of Long Lake. Water temperatures ranged from 36.5 to 41.4 degrees Fahrenheit. All Walleye were marked on the lower caudal fin with a hole punch, and length, sex, spawning condition and recaptures were recorded. Northern Pike length and sex were also recorded. All other bycatch was immediately released. A total of 106 Walleye were captured during the sampling period, resulting in a catch rate of 3.5 per trap net. Population estimate analyses were not carried out due to a low sample of recaptures (R=1). Walleye ranged from 16.2 to 28.9 inches and averaged 20.9 inches. About 72 percent (n=76) of the sample were male and 28 percent (n= 30) were female. Males ranged from 16.2 to 24.8 inches and averaged 19.5 inches, while females ranged from 20.1 to 28.9 inches and averaged 24.7 inches. All males were ripe during the sample period while 63 percent (n = 19) of females were green, 33 percent (n = 10) were ripe, and 3 percent (n =1) were spent. The still high number of green and low number of spent females suggest that our sampling was likely just before the peak of spawning. A total of 122 Northern Pike were also captured, resulting in a catch rate of 4.1 per trap net. Pike ranged from 9.2 to 31.3 inches and averaged 18.0 inches. Forty-eight percent (n=59) of the sample were female, 43 percent (n = 52) were male, and 9 percent (n = 11) were unknown. Males ranged from 13.0 to 24.9 inches and averaged 18.3 inches. Females ranged from 15.0 to 31.2 inches and averaged 21.4 inches. Unknown sexes ranged from 9.25 to 24.0 inches and averaged 15.8 inches. Around 90 percent (n = 53) of females were ripe during the sampling period with 6 percent (n = 4) spent, 2 percent (n = 1) green, and 2 percent unknown spawning condition (n = 1). With only 1 Walleye recapture, a total catch nearly as high as pike and well over what would be expected with the low gill net catch rate in 2024 (0.2/net), we can be confident that gill net catches are not representative of Walleyes in Long Lake. Spring trap net surveys will be conducted periodically to be sure our stocking program is continuing to produce catchable fish in Long Lake.

A targeted survey (16 trap nets) was conducted on Long Lake the week of 10/14/2024 to assess the status of the Splake fishery. In 2018, as an attempt to increase angling opportunity for trout, an experimental Splake stocking program was implemented at Long Lake. Splake prefer deep cold-water habitat, and it was anticipated the abundant Tullibee population would provide them an adequate prey source. The 2024 targeted survey resulted in zero Splake captured. A few anglers have reported catching or observing Splake while targeting other species, but no Splake fishery has developed. In 2024, the decision was made to terminate Splake stocking due to their apparent low survival and lack of contribution to the fishery.

Based on Minnesota DNR survey data, anglers target Largemouth Bass, Black Crappie, Rock Bass, Walleye, and Pumpkinseed in Long. See the full species list above for catch rates, size structure, and quality scores.

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

Long has a maximum depth of 116 feet and a mean depth of 30 feet, per Minnesota DNR data.

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

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