Three Island

Three Island Lake is a 235-acre lake located 5 miles east of Marcell, MN. The lake is moderately developed and has very clear water with a Secchi disk reading of 23 ft. Three Island Lake is deep with a maximum depth of 66 ft and is accessible by a portage trail from Crooked Lake. Previous water chemistry indicated low fertility which impacts the fishery through slow growth and reduced abundance. Primary fish species include smallmouth and largemouth bass, northern pike and panfish. Smallmouth and largemouth bass were sampled by night electrofishing in early June. Three Island Lake historically has a high density smallmouth bass population with quality fish. The catch rate in 2012 was 121.9/hour and was similar to past assessments which varied from 65 to 120/hour. Size structure was good with fish up to 20 inches sampled. Growth was slow with fish averaging 13.5 inches by age six compared to 20.5 inches at age six for the statewide average. Although growth was slow, fish up to age 12 were sampled. Despite slow growth, smallmouth in Three Island Lake live long enough to attain a large size. Anglers can help maintain the quality smallmouth bass population by releasing larger fish because it can take 10 years or longer to grow a 20 inch fish. Largemouth bass were less abundant and had an electrofishing catch rate of 4.5/hour and was similar to past assessments. Size structure was good with fish up to 17 inches sampled. Growth was also slow with fish averaging 13.5 inches at age six compared to 15.1 inches for the statewide average. The northern pike gill net catch rate was 3.0/net and was at the lower end of the expected range for similar lakes. Northern pike were not sampled in the first two assessments in 1968 and 1974 and catch rates in assessments since then have varied from 4.0 to 8.6/gill net. Size structure in 2012 was moderate with fish up to 30 inches sampled. Previous assessments had sampled fish up to 39 inches. Growth was faster than the statewide average to age seven and slower than the average to age nine. The bluegill catch rate was 4.7/trap net and was lower than the expected range for similar lakes. Catch rates in past assessments have been variable from 3.0 to 37.5/trap net. Size structure was poor with only two fish sampled larger than 8 inches. Size structure has also been poor in past assessments, likely due to the low fertility of the lake. Three walleye were sampled for a catch rate of 0.5/gill net which was below the expected range. Walleye catch rates have generally been low and walleye were not sampled in the first two assessments in 1968 and 1974. Walleye have not been stocked and the population is maintained through natural reproduction. Yellow perch are an important prey species for walleye and their low catch rates likely limits the walleye population. Yellow perch catch rates have been less than 1/gill net in all assessments except in 1982 when the catch rate was 10.8/net. Only one yellow perch was sampled by trap nets in 2012. Low yellow perch catch rates likely limits the population of walleye and northern pike. Three Island Lake has a fairly simple fish community and white sucker was the only other species sampled. Because Three Island Lake is a small, deep and fairly sterile, net catches are generally light. In 2012, six gill nets sampled a total of 45 fish and trap nets sampled 52 fish.

Three Island Lake is primarily a smallmouth bass lake. Bluegill and northern pike are also abundant. The 1997 smallmouth bass night electrofishing catch rate (107.1/hour) was greater than the 1993 catch rate (39.8/hour) and the 1995 catch rate (93.2/hour). The mean length of electrofished bass was 9.8 inches, ranging from 3.9 to 20.5 inches. The smallmouth bass gill net catch rate (3.0/set) exceeded the expected range for lakes of this type. The mean length of gill net sampled smallmouth was 13.4 inches, ranging from 8.9 to 18.9 inches. Trap nets also sampled smallmouth, again with a catch rate (1.4/set) greater than the expected range. The mean length of these bass was 8.0 inches, ranging from 5.6 to 18.3 inches. Growth rates of smallmouth bass are below the statewide mean (<85%)for all ages except age 1, where they are near the statewide mean. The northern pike gill net catch rate (4.0/set) was within the expected range. The mean weight (4.5 pounds) exceeded the expected range. The mean length of sampled pike was 27.4 inches, ranging from 20.3 to 38.7 inches. The bluegill trapnet catch rate (28.7/set) was within the expected range. Sampled bluegill had a mean length of 4.2 inches, ranging from 3.0 to 7.2 inches. Other species sampled in the lake include: golden shiner, largemouth bass, walleye, white sucker, and yellow perch. Three Island Lake is a good smallmouth bass fishery. Anglers can do their part to ensure continued good fishing in the lake by practicing catch and release.

Smallmouth bass dominate the fish population, as evidenced by a high gill net CPUE, and SCUBA observations. The gill net CPUE was 3.6/lift, which is well above the third quartile (1.0/lift) for Schupp's lake class #23. The population structure includes a high number of large fish. The gill net proportional stock density (PSD) is very high at 89, and the relative stock density (RSD-14) is high at 61 (n=18). Growth is slower than the statewide average, especially for age IV+ fish. Ages I-VI, and VIII were sampled.Northern pike were sampled in the gill net with a CPUE of 4.6/lift, which is very close to the mean of 4.5/lift for lake class #23. While the CPUE approximates the lake class mean, the pounds per set is nearly double at 20.4 pounds/lift. Further indication of a quality northern pike fishery is a gill net PSD of 70 and a RSD-28 of 35. Growth exceeds the statewide average at all ages sampled: ages II-VI represented.The walleye gill net catch was 1.2/lift, which falls within the first (0.89) and third (4.75) quartile for lake class #23. All 6 walleye sampled were age I; mean length at annulus formation was 6.9 inches. There is no record of walleye stocking in Three Island, and walleye do not appear to be a major part of the fishery.Bluegill were captured in low numbers with a trap net CPUE of 3.0, compared with the lake class median of 17.2. This is well below the first quartile (9.83) for lake class #23, and is a dramatic decrease from 24.3/trap net sampled in the 1982 survey. Ages III and IV comprise the entire sampled. No bluegills were observed while SCUBA diving, which is normally expected.

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

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

Three Island has a maximum depth of 66 feet, per Minnesota DNR data.

The most recent Minnesota DNR survey data for the main sport fish in Three Island is from 2012. Surveys this old should be treated with some caution — fish populations change over time.

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