Bear Island

Temperature and dissolved oxygen measurements were collected from the deepest basin in Bear Island Lake on July 31st, 2025. This was done 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. 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 data collected from the deepest basin (maximum sampled depth was 55.8 feet), the water temperature decreased to 21.2 degrees C (70.2 degrees F) at 14.8 feet and the dissolved oxygen concentration decreased to 3.0 mg/L at 42.6 feet at the time of sampling. This layer in the water column was 27.8 feet, indicating oxythermal habitat for Cisco was present. Further, the temperature at which dissolved oxygen decreased to 3.0 mg/L (i.e., TDO3, a single variable to characterize oxythermal habitat) was 10.6 degrees C (51.1 degrees F). TDO3 values cooler than 21.2 degrees C (70.2 degrees F) indicate that oxythermal conditions were suitable for Cisco at the time of the survey. Data collected by the Minnesota Department of Natural Resources during the period of maximum oxythermal stress (July 26th to Aug 24th) in 2021, 2023, 2024 also indicated suitable oxythermal habitat in all years surveyed, with the least favorable conditions recorded in 2024 when the suitable oxythermal habitat layer was 11.2 feet thick. When adequate oxythermal habitat is not available, Cisco are squeezed into unfavorable, warmer water conditions and experience higher levels of stress.

Bear Island Lake is a 2,351-acre lake that is ten miles southwest of Ely. There are three public accesses with boat ramps on the lake. Bear Island Lake is up to 62 feet deep and has shoreline substrates that are mostly rubble, boulder, and gravel. The lake has brown, bog-stained water with roughly 7 feet of visibility. Aquatic vegetation is sparse along most of the shoreline. Bear Island Lake was thermally stratified on August 7, 2023, with a surface temperature of 73 F and a temperature of 44 F near the bottom. Adequate oxygen levels for warmwater fish species were retained to a depth of 45 feet where the water temperature was 45 F. Walleye were sampled at a rate of 7.9 fish/gill net, which was slightly above average for the lake. Walleye sampled in gill nets averaged 14.3 inches in length, and 35% of the fish were over 16.0 inches. Walleye ages ranged from 1 to 21 and indicated consistent recruitment. Walleye fry are stocked into Bear Island Lake in odd years, but ages indicated that natural reproduction is also occurring in the lake. Northern pike were sampled at a rate of 3.9 fish/gill net, which was slightly higher than average for Bear Island Lake. The average length was 23.8 inches, which was larger than the historical average for the lake. The largest pike sampled in 2023 was 37.2 inches long. Bluegill were sampled at a rate of 10.7 fish/trap net, which was higher than the historical average for the lake. The average bluegill was 6.4 inches long, and 28% of the catch was 7.0 inches or larger. The largest bluegill was 9.5 inches in length, and bluegill ages ranged from 2 to 10. Black crappie were sampled at a rate of 1.3 fish/trap net, which was similar to the historical average for the lake. Black crappie averaged 7.7 inches in length, and the largest individual was 8.5 inches. Black crappie ages ranged from 2 to 7. Both smallmouth and largemouth bass are present in Bear Island Lake, although the gill nets and trap nets are inefficient at catching them. In this survey, 12 smallmouth bass and 3 largemouth bass were sampled. Smallmouth bass averaged 13.5 inches in length and the largest individual was 17.2 inches. Largemouth bass averaged 14.3 inches in length and the largest individual was 19.3 inches. Additional species sampled in 2023 included cisco, hybrid sunfish, rock bass, white sucker, and yellow perch.

Bear Island Lake is located 10 miles southwest of Ely. There are three public accesses, two of which have concrete ramps, the other is gravel. This 2,351 acre lake contains four inlets and one outlet, the Bear Island River, which flows out of the far east finger of the lake and over an old dam. Bear Island has a maximum depth of 62 feet and brown water. On August 16, 2021 Bear Island was thermally stratified with a surface temperature of 69 F and a bottom temperature of 49 F. Oxygen levels were adequate for gamefish to a depth of 44 feet where the water temperature was 50 F. Shoal-water substrates consist of mostly rubble, boulder, and gravel. Aquatic vegetation grows to a depth of 7 feet and is sparse along most of the shoreline. This was a targeted survey looking mainly at the walleye population. The overall gillnet catch rate for all fish combined was 15.9 fish/net which was tied with two other surveys for the lowest catch rate on record for Bear Island. Total yield was 19.7 lbs/net which was below average compared to past surveys on the lake. Fish species sampled were walleye, rock bass, northern pike, smallmouth bass, white sucker, yellow perch, cisco, black crappie, bluegill, and pumpkinseed. Fifty-two walleye were sampled in gill nets for a catch rate of 4.3 fish/net which was below average compared to other similar lakes and the lowest catch rate since the 1993 survey (3.3 fish/net). Walleye have been stocked in Bear Island dating back to 1941. Since 1993 walleye fry have been stocked at the rate of 900,000 fry every other year. Sizes ranged from 9 to 27 inches with an average of nearly 15 inches. Nearly 29% of the gillnetted fish were larger than 16 inches. Growth was slow compared to other walleye lakes in the area. The average fish took six years to reach 15 inches long. Ages ranged from 1 to 9 years old with only the 2014 year class missing representation. The 2018 and 2015 year classes were quite strong with 60% of the fish coming from those two year classes. Fifty-eight percent of the catch came from stocked years.

Based on Minnesota DNR survey data, anglers target Rock Bass, Northern Pike, Walleye, Smallmouth Bass, and Bluegill in Bear Island. See the full species list above for catch rates, size structure, and quality scores.

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

Bear Island has a maximum depth of 62 feet, per Minnesota DNR data.

The most recent Minnesota DNR survey data for the main sport fish in Bear Island is from 2023.

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