North Star Lake is a class 25 lake located just south of Marcell, MN. The lake has one public access and moderate shoreline development. The 2010 lake management plan indicates Muskellunge, Northern Pike, and Walleye as the primary species of management with Largemouth bass as secondary species. A special protected slot length limit was implemented in 2003 that requires all Northern Pike from 24 to 36 inches to be released and only one fish over 36 inches can be in possession.
Muskellunge are not sampled well with our standard summer assessment gear. However, one Muskellunge from the trap nets was sampled that was 38.6 inches. Spring special assessments are used to more effectively sample the Muskellunge population.
The Northern Pike gill-net catch was 2.4 fish/net, up from the last two assessments. Gill-net catch rates have ranged from a low of 1.4 fish/net in 1949 to a high of 5.2 fish/net in 1979. Fish ranged from 18.3 to 36.9 inches and had a mean length of 26.5 inches. The length distributions resulted in PSD, RSD-P, and RSD-M values of 72, 38, and 14, respectively. Eight age-classes were identified from cliethra and scales ranging from age 3 to age 10. Age-3 and 4 fish each represented 28% of the sample. Northern Pike averaged 24.3 inches by age 4 which was above the statewide average of 20.5.
The Walleye gill-net catch rate of 3.3 fish/net did not attain the aggressive management goal of 5.0 fish/net. However, the catch was near the lake mean and above the lake class median. Gill-net catch rates have ranged from 2.3 to 5.2 since Walleye stocking began in 1972. In 2014, the sampled fish ranged from 9.5 to 28.0 inches and had a mean length of 18.1 inches. Size structure had PSD, RSD-P, and RSD-M values of 82, 37, and 5, respectively.
Walleye age and growth information was determined from scale, opercle and otolith analysis. Eleven year-classes were identified with fish from 2 to 12 years old present. No one age-class dominated the sample. Walleye have been stocked annually since 2000. The last three assessments evaluated a period of frequent stocking and found higher (2005 & 2009) or similar (2014) gill-net catch rates to 2001, but slower growth. Although growth was still within the normal range, age-4 fish averaged 14.1 inches. In addition to more fish competing for food, a few of the summer growing seasons prior to these assessments were short and cooler, potentially affecting the growth rates observed.
Largemouth Bass catch rates ranged from 15.4 to 51.8/hr (on-time) in the three samples from 2001 to 2009. In 2014, 58 Largemouth Bass were caught for a rate of 23.4/hr on-time. The sampled fish ranged from 3.7 to 17.1 inches and had a mean length of 9.6 inches. Scale analysis indicated nine age-classes from 2 to 10 years old. Age-3 and 4 fish represented 33 and 31% of the sample. Mean back-calculated length-at-ages were within 15% of the statewide mean but generally slower.
Black Crappie have never been sampled in high numbers in North Star Lake but the catches have not been uncharacteristically low for this lake class. In 2014, the gill-net and the trap-net catches were 0.3 fish/net. The fish sampled ranged from 4.5 to 12.2 inches. Age and growth information was not collected in this assessment.
The Bluegill catch rates have ranged from a low of 2.3 fish/trap net in 1976 to an all-time high of 27.7 fish/trap net in 1975. In 2014, the trap-net catch was 22.5 fish/net. The catch was above the lake class median of 17.3 fish/net for the fourth time. Bluegill ranged from 3.0 to 7.7 inches with a mean length of 4.8 inches. Age and growth information was not collected in this assessment.
Yellow Perch gill-net catch rates have fluctuated from a low of 2.0 fish/net in 1996 to a high of 30.9 fish/net in 1984. In general, the population has been sampled in low numbers except for the 1984 and 2009 assessments. In 2014, the catch was 7.7 fish/gill net; the third highest catch on record. Age and growth information was not collected in this assessment.
Tullibee can be difficult to catch because they frequently live over deep water, an area the standard sampling gear was not designed to sample. However, they are important to fish communities as a prey source for many predator species, especially Muskellunge, Northern Pike and Walleye. Tullibee gill-net catch rates have been as low as 0.3 fish/net and as high as 14.5 fish/net with no apparent trend in abundance. In the previous three assessments, the Tullibee catch was 8.2, 0.9, and 3.9 fish/gill net. The Tullibee catch rates were highly variable which is not uncommon. The 2014 catch was equal to the 3rd quartile value of 6.5 fish/gill net. The fish ranged from 7.1 to 13.8 inches and had a mean length of 10.0 inches. Although age information was not collected, it appears there were at least two year-classes based on the length distribution.
Other species observed during the population assessment included Pumpkinseed Sunfish, Rock Bass, Smallmouth Bass, and Yellow Bullhead.
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 water's edge, 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.