North Twin

North Twin Lake is a small, relatively clear lake in central Itasca County near Marble, Minnesota. The lakeshore has moderate levels of municipal and residential development. North Twin supports a relatively diverse aquatic plant community. Unfortunately, three exotic, invasive plants are present. Exotic aquatic plants are detrimental to the native aquatic plant community and often interfere with recreation. Eurasian water milfoil is present but appears to be limited in distribution at this time. Purple loosestrife and flowering rush are more widespread around the lake and appear to have displaced some other native, emergent plant species. Anglers should take care to remove all plant materials from boats, motors, trailers, and other gear. Despite the invasion by exotic plants and moderate levels of shoreline disturbance, North Twin Lake supports adequate fish habitat for a variety of species. The lake is connected to the Swan River via the outlet to South Twin Lake. This connectivity has resulted in a diverse fish community that offers anglers good opportunity for a variety of fish species. The lake is managed for northern pike, largemouth bass, and panfish. A population assessment was conducted in August of 2008 to assess the status and characteristics of the fish community. Bluegill were the most common fish in both the trap nets and the gill nets. The trap net catch rate was within the expect range in comparison to similar lakes and was similar to previous assessments conducted on North Twin. North Twin Lake has a history of producing relatively small bluegill and small average size may limit the popularity of the fishery. In 2008, the size structure was poor, as most individuals did not exceed 7 inches. Lakes with characteristics similar to North Twin rarely produce fast growing bluegill and growth of bluegill from North Twin was average, with individuals typically obtaining 6 inches in seven years. The 2001 year-class appeared relatively strong and may provide some quality fishing as individuals from that year-class averaged nearly seven inches at the time of capture. Northern pike were the second most common fish in the gill net. The gill net catch rate was within the expected range for this type of lake. Size structure was relatively poor as most individuals were did not exceed 21 inches. A few large individuals remain present, however, as one fish exceeding 36 inches was sampled. Growth was near the statewide average and individuals typically exceeded 21 inches in 5 years. Only 15% of the sampled individuals exceeded age 5, suggesting high angler exploitation of older, larger fish. Anglers should consider releasing northern pike exceeding 24 inches to increase the number of large fish in the lake. Black crappie were captured in relatively high numbers from the gill net. Size structure was poor as few individuals exceeded the quality size of 8 inches. Black crappie gill net catches have historically been high in North Twin. Growth was near the statewide average and individuals typically exceeded 8 inches at age 5. Only 4% of individuals exceeded age 5, however. Reproduction and recruitment of black crappies is often variable and one or two year-classes may dominate a fishery resulting in inconsistent angler success. In North Twin, recruitment appeared inconsistent, as the 2005 year-class comprised 73% of the sample. Poor recruitment of black crappie prior to 2005, high angler exploitation of older, larger individuals, or a combination of the factors appears to have resulted in the poor size and age structure. If the 2005 year-class continues to dominate the fishery, good angling opportunity may exist in the near future. Largemouth bass were sampled with nighttime boat electrofishing in June. Electrofishing resulted in a catch of 67/hour, indicating relatively high abundance. Size structure was favorable and most fish were of a quality size. Growth was near the statewide average and individuals typically exceeded 12 inches by age 5. Given the lakes characteristics, relative abundance, and favorable size structure, excellent angling opportunities should exist for this species. Yellow perch are an important prey species in many lakes. Yellow perch catches have been low from North Twin in most assessments. In 2008, the gill net catch remained quite low. High predator density may limit the yellow perch population. Walleye were captured at a rate of 0.7/gill net, indicating low abundance. Despite frequent stocking efforts until 1990, walleye catches remained low in comparison to similar lakes. A lack of spawning substrate, limited prey base, and an abundance of competing predators greatly limit walleye in North Twin Lake. Other species present include bigmouth buffalo, bowfin, black bullhead, brown bullhead, pumpkinseed sunfish, rock bass, shorthead redhorse, silver redhorse, white sucker, and yellow bullhead. 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.

North Twin Lake is 250 acres with a maximum depth of 42 ft and is located near Marble, MN. Several shallow bays contain extensive aquatic vegetation and phosphorous levels indicate moderate productivity. The lake is managed primarily for largemouth bass, northern pike, and panfish.Standard survey nets do not sample largemouth bass effectively, therefore shoreline electrofishing was conducted on May 21 to gather additional information. Electrofishing catch rate was 9.0/h which is similar to the catch rate of 7.0/h for similar lakes in Itasca County. Although the sample size was too small to calculate size structure indices; size was good with fish up to 19 inches sampled. Growth was similar to the statewide average with fish reaching preferred length of 15 inches in 6 years.Northern pike gill-net catch was 9.5/set which is within the expected range for similar lakes. Size structure was poor with no fish larger than preferred length of 28 inches. Growth was similar to statewide averages and fish reach quality length of 21 inches in 5 years. Anglers can help to increase the size structure of northern pike by releasing fish over 24 inches. These fish have survived the early years of high predation and mortality, and are most likely to become the 10-12 pound fish of the future.Black crappie gill-net abundance was 5.3/set which is higher than the expected range for similar lakes. Size structure was moderate with a few fish greater than 10 inches. Growth was similar to the statewide average with fish attaining preferred length of 10 inches in 6 years. Bluegill trap net abundance was 13.2/set which is within the expected range for similar lakes. Size structure was poor with few fish greater than 8 inches. Growth was similar to lake class averages, but much slower than statewide averages. Bluegill in North Twin Lake reach quality length of 6 inches in 6 years.Yellow perch gill-net abundance was 1.8/set which is below the first quartile range of 3.4/set. Other fish sampled include pumpkinseed sunfish, rock bass, silver redhorse, shorthead redhorse, river redhorse, bowfin, tulibee, white sucker and yellow bullhead. Flowering rush is an exotic emergent plant which is very abundant in North Twin Lake. This exotic species resembles native hardstem bulrush, but is not round in cross section, rather the stems are roughly square in cross section. Flowering rush is very difficult to control by chemical or mechanical means. Flowering rush is an invasive species which crowds out native species and forms dense stands which limit recreation such as swimming or boating. Flowering rush becomes easily established in shoreline areas which are disturbed. Lakeshore owners should not disturb native vegetation such as hardstem bulrush or cattails. Leaving native species in place will prevent or slow the spread of this exotic species. Lakeshore owners should consider lessening the extend of beaches or cleared shorelines to prevent flowering rush from becoming established. An example of the invasive nature of flowering rush can be found at the swimming beach at the public access.Lakeshore owners affect fish populations not only through fishing, but also through land use practices. It is important to leave a 30 to 50 ft buffer of native vegetation along the shoreline to prevent lawn wastes and sediments from entering the lake. In addition, if fertilizers must be used, lakeshore owners should use a brand containing no phosphorus. Nonfunctioning septic systems can also lead to water quality problems. Good water quality and fish populations are the direct result of good land use practices.

All species seem to be in good numbers and meet median levels. The northern cisco population is high and during seining, many minnows were caught. Very few young-of-the-year were caught but some were seen along shoreline.

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

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

North Twin has a maximum depth of 42 feet, per Minnesota DNR data.

The most recent Minnesota DNR survey data for the main sport fish in North Twin is from 2008. Surveys this old should be treated with some caution — fish populations change over time.

Yes — North Twin has confirmed Eurasian watermilfoil and flowering rush. Clean, drain, and dry your equipment to avoid spreading invasives to other waters.