South Twin

South Twin is a 179 acre lake located just south of Marble, MN. Access can be obtained via North Twin Lake through the channel on the north side. The 2001 lake management plan indicated largemouth bass and northern pike were primary species for management while black crappie were secondary species. In 2008, the black crappie gill-net catch rate was 2.8/net while the trap-net catch rate was 0.3/net. The gill-net catch was above average while the trap-net catch was below average. The catches for both gears were the lowest ever recorded for the lake. Fish sampled in gill nets ranged from 5.3 to 10.4 inches and averaged 6.9 inches while trap-net fish had a similar size distribution. Five year-classes from age 2 to age 7 were sampled. Two and three year old fish were the most prevalent, representing 74% of the sample. Growth was slower than that reported other class 31 lakes. Bluegill trap-net catch rates were 5.1 fish/net. The catch in 2008 was near the lake class 1st quartile value of 6.1/net and towards the lower end of previous catches. The fish ranged from 3.1 to 7.6 inches and averaged 5.2 inches. Six year-classes were identified ranging from 3 to 8 years old. The 2005 year class represented 43% of the sample. Growth was slow compared to the average for class 31 lakes. Largemouth bass were sampled with spring night electrofishing in 2008. Electrofishing catch rates increased substantially from 1999 to 2008. In 2008, 99 largemouth bass were captured for a catch rate of 99.0 fish/hr compared to just 9.0 fish/hr in 1999. The fish ranged from 3.2 to 16.8 inches and averaged 9.6 inches. The population appeared to have fairly consistent recruitment for the last six years. Eight year-classes were identified with the 2005 and 2006 year-classes representing 43 and 34% of the sample, respectively. The South Twin bass population appears to be another example of a lake in the area responding well to recent weather patterns. Northern pike gill-net catch rates have trended up in all assessments since 1958 and were the highest on record in 2008. The catch of 15.7 fish/gill net was well above average. The sampled fish ranged from 10.8 and 27.4 inches and averaged 17.6 inches. Seven age-classes were sampled from one to eight years old. Recruitment appears to be consistent and high in recent years. Two and three year old fish represented 33 and 34% of the sample, respectively. Growth was similar to statewide averages for all ages. Although tullibee and white sucker catches were good for this lake class, only three yellow perch were sampled. It appears the combination of the abundant northern pike spawning habitat, lack of yellow perch, and an unknown amount of harvest of 20 inch and longer northern pike are limiting northern pike size structure. Other species observed during the population assessment included bowfin, pumpkinseed sunfish, rock bass, shorthead redhorse sucker, white sucker, walleye, yellow bullhead, and yellow perch. In order to maintain or improve fish and wildlife populations, water quality and habitat must be protected. People often associate water quality problems with large-scale agricultural, forestry, urban development or industrial practices in the watershed. In reality, the impact of land use decisions on one lake lot may be relatively small, yet, the cumulative impact of those decisions on many lake lots can result in a significant decline in water quality and habitat. For example, removing shoreline and aquatic vegetation, fertilizing lawns, mowing to the edge of the water, installing beach sand blankets, failing septic systems and uncontrolled run-off, all contribute excess nutrients and sediment which degrade water quality and habitat. Understanding these cumulative impacts and taking steps to avoid or minimize them will help to insure our quality fisheries can be enjoyed by future generations.

South Twin Lake is located near the town of Marble, MN and is approximately 10 miles northeast of Grand Rapids, MN. South Twin Lake is connected to North Twin Lake by a small channel which is navigable by a small boat. There is no public access on South Twin Lake, however, there is a public access on North Twin Lake. South Twin Lake is 179 acres with a fish community dominated by largemouth bass, panfish, and northern pike. Largemouth bass were sampled by electrofishing on May 21st which resulted in a catch rate of 9.0/h. As a comparison, the average catch rate for largemouth bass in the Grand Rapids area was 13.6/h. Size structure was moderate with a few larger fish between 16 and 18 inches. Bluegill catch rate in trap nets was 10.6/set which is within the expected range for similar lakes. Size structure was poor with no fish greater than 8 inches. Bluegill often grow much slower than most people think. In fact it takes 9 years for bluegill in South Twin lake to reach 7 inches. Because it takes so long to replace a "keeper" bluegill, anglers should consider releasing a portion of their catch. Black crappie catch in gill nets was 4.3/set which is higher than the expected range for similar lakes. Black crappie catch in trap nets was similar to the expected range. Size structure in gill nets was moderate to poor with few fish approaching 10 inches. Northern pike were abundant with a gill-net catch of 11.1/set which is higher than the expected range for similar lakes. Size structure was generally poor with no fish exceeding 28 inches. Although south Twin is not managed for walleye, a single walleye was sampled. The presence of walleye is likely due to limited natural reproduction, or immigration from the Swan River.South Twin Lake is connected to the Swan River and as such riverine species such as shorthead redhorse and silver redhorse were sampled. Other species sampled include black bullhead, yellow bullhead, pumpkinseed sunfish, tullibee, bigmouth buffalo, bowfin, yellow perch, and rock bass.Flowering rush is an exotic emergent plant which is very abundant in North Twin Lake and is present to a lesser extent in South Twin Lake. This exotic species resembles native hardstem bulrush, but is not round in cross section, rather the stems are roughly triangular 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 extent of beaches or clear 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 on North Twin Lake.Lakeshore owners may 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.

Northern cisco population has declined considerably since 1971 from 54% to 2% in 1986. Black crappie population was recorded at 40% in 1977 compared to 3% in 1986. Northern pike population appears to have increased slightly from past net catches. 1986 population assessment shows the first time that walleye have been caught in South Twin Lake.

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

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

South Twin has a maximum depth of 40 feet, per Minnesota DNR data.

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

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