Gunderson

A targeted survey of nearshore fish species in Gunderson Lake was conducted on August 17-18, 2021, by Index of Biological Integrity (IBI) Program staff. Sampling sites were evenly spaced around the lake, and each was sampled by backpack electrofishing and seining with a 50-foot or 15-foot seine, where possible. Backpack electrofishing was completed at 10 sampling stations, but one station was sampled from the boat due to site conditions. Similarly, a 50-foot seine was used to sample three stations, a 15-foot seine was used at two stations, and site conditions prevented the use of seines at five stations. Nearshore sampling captured 13 species of fish including four species that are intolerant of disturbance (Banded Killifish, Blackchin Shiner, Blacknose Shiner, Iowa Darter) and no species that are tolerant of disturbance. The nearshore data were combined with trap net and gill net data from an August 2020 survey to describe the fish community and provide a Fish-based IBI (FIBI) score. The FIBI uses fish community data to measure a lake's health, and the types of fish species present can help identify any stressors that may be negatively affecting the lake environment. In Minnesota lakes, certain fish species cannot survive without clean water and a healthy habitat (Blackchin Shiner, Iowa Darter, and Rock Bass), while other species are tolerant of degraded conditions (Green Sunfish). The FIBI score, composed of several fish community diversity and composition metrics, indicates the overall health of a lake by comparing it to what is expected for a healthy lake. For additional information on the FIBI, search for "lake index of biological integrity" on the mndnr.gov website. Results from this survey indicate that the fish community in Gunderson Lake is healthy as indicated by an FIBI score above the impairment threshold for aquatic life use determined for similar lakes. These results will be considered when the biological health of the lake is assessed during the Big Fork River Watershed assessment process, which will be completed in coordination with MN Pollution Control Agency.

Gunderson Lake is a 146-acre lake located 7 miles north of Talmoon, MN off state highway 6 in the Chippewa National Forest. The lake is moderately developed and has relatively clear water. There is a state-owned public access on the northeast shore. Previous water chemistry sampling indicated moderate hardness and fertility. Aquatic vegetation is relatively abundant. Gunderson Lake outlets to the Big Fork River through an unnamed tributary. The initial lake management plan was drafted in 2013. Northern Pike were identified as the primary management species and Black Crappie were considered a secondary management species. A standard lake survey was conducted in August 2020 to assess the status of the fish community. Gunderson Lake has generally produced high numbers of Northern Pike with poor size structure. The 2020 catch rate declined from previous surveys but was typical for lakes with similar habitat. Size structure remained poor; pike ranged from 14.9 to 29.0 inches with an average length of 20.6 inches. Only 28% of pike exceeded 21 inches. Pike were not aged in this survey, but previous surveys indicated frequent recruitment and slow growth. Net catches for Black Crappie have been variable, but generally low in recent surveys. In 2020 the gill-net catch was typical for the lake, but too few crappie were sampled to draw meaningful conclusions about recruitment, size structure or growth. Sampled crappie ranged from 7.0 to 11.0 inches. The Bluegill population can generally be described as having moderate to high numbers, poor size structure and slow growth. The 2020 trap-net catch was average compared to similar lakes. Sampled Bluegill ranged from 3.2 to 7.4 inches with an average length of 4.7 inches. Only 15% of Bluegill exceeded 6 inches. Ages 2 through 8 were represented, indicating frequent recruitment. Ages 3 and 4 made up the majority of the sample with few fish exceeding age 5. Growth was slow but typical for the lake. Fish averaged 5.4 inches after 5 years of growth. Poor size structure likely limits the popularity of the Bluegill fishery. Largemouth Bass are relatively abundant with modest size structure. Night electrofishing for bass was conducted in June 2020. This was the first time this sampling gear was used on Gunderson Lake. The electrofishing catch rate of 85/hour is considered relatively high compared to similar lakes in the area. Sampled bass ranged from 4.8 to 18.4 inches with an average length of 9.8 inches. Recruitment appeared good from recent years; ages 2 through 11 were represented with ages 2 through 4 making up 70% of the sample. Largemouth Bass averaged 12.4 inches after 5 years of growth. Gunderson Lake has good habitat for bass and likely provides fair angling opportunities. Gill-net catches of Yellow Perch have been highly variable, but have trended lower in recent surveys. The 2020 catch rate remained low at 3.8/net. While the reasons are unclear, the decline in perch numbers mirrors statewide trends. Perch have generally been too small to be of interest to anglers but can be an important prey species for predators like Northern Pike and Largemouth Bass. Walleye have been sampled in three of the five previous surveys, but always in low numbers. Three Walleye were sampled in 2020 for a gill-net catch of 0.5/net, which is average for the lake. Sampled Walleye ranged from 19.3 to 22.0 inches, and were aged at 4, 6 and 15 years. Lakes like Gunderson rarely support strong Walleye populations. A low-density population may persist through natural reproduction or migration from the Big Fork River. Other species sampled included Pumpkinseed, Hybrid Sunfish 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.

Gunderson Lake is a 146-acre lake located 7 miles north of Talmoon, MN off Highway 6. The lake is moderately developed and had moderate clarity with a Secchi disk reading of 11 ft. Gunderson Lake has a maximum depth of 36 ft and is accessible by a concrete access on the northeast shore. Previous water chemistry sampling indicated moderate hardness and fertility. Gunderson Lake outlets to the Bigfork River through an unnamed tributary. Primary fish species include northern pike, largemouth bass, and panfish. The northern pike gill net catch rate was 15.8/net and was higher than the expected range for similar lakes. Northern pike catch rates have generally been high in most assessments varying from 6.7 to 24.0/gill net. Size structure in 2012 was poor with few fish over 24 inches sampled. High gill net catches generally correspond to poor size structure. Despite high abundance, a 37 inch fish was sampled in 2012 and large fish have been sampled in past assessments. Fish up to age eight were sampled and growth was slow, but within 15% of the statewide average. Northern pike averaged 24.7 inches by age 7. The bluegill catch rate was 8.8/trap net and was towards the low end of the expected range for similar lakes. Catch rates in past assessments have been much higher varying from 15.0 to 102.5/net. Size structure was poor with no fish eight inches or larger sampled. Fish up to nine inches have been sampled in past assessments indicating size structure may have declined. Growth was slightly slower than the lake class average with fish only averaging 7.2 inches by age eight. Since bluegill rarely live beyond age 10 it will be difficult to improve size structure unless growth rates improve. Black crappie gill net and trap net catches were 2.2 and 0.7/net. The gill net catch was slightly higher than the expected range and trap net catch was towards the low end of the expected range. Catch rates in past assessments have been highly variable, varying from 0 to 10.8/gill net and 3.3 to 23.5/trap net. Size structure was good with fish up to 11 inches sampled. Ageing data indicated inconsistent recruitment with two missing year classes and growth that was similar to the lake class average with fish averaging 9.9 inches by age five. The yellow perch catch rate was 1.7/gill net and was lower than the expected range for similar lakes. Catch rates in past assessments were higher and varied from 14.3 to 134.8/net. Size structure was poor and no fish 9 inches or larger were sampled. Size structure has also been poor in past assessments. Although yellow perch are too small to interest most anglers they are an important prey species for northern pike. Three walleye were sampled for a catch rate of 0.5/gill net which was below the first quartile of 1.3/net. Walleye have not been sampled in all assessments and catch rates have varied from 0 to 1.5/gill net. The walleye sampled were large and varied from 19.9 to 22.4 inches and were relatively old fish, aged at 9, 17, and 18 years old. Because walleye have not been stocked in many years and many year classes are missing, the fish may have migrated from the Bigfork River. Largemouth bass were also sampled in the 2012 assessment. Largemouth bass are not sampled well by gill nets or trap nets and net catches do not accurately reflect abundance. Gill nets sampled 11 fish for a catch rate of 1.8/net and trap nets sampled six fish for a catch rate of 0.7/net. Gunderson Lake has the ability to produce larger fish and fish up to 18 inches were sampled. Other species sampled include pumpkinseed sunfish and yellow bullhead. Water levels appear to be much higher than normal and lakeshore residents mentioned the outlet channel is blocked by several beaver dams. High water has accelerated shoreline erosion, killed numerous trees and blocked fish migration from the Bigfork River. An open channel between the lake and the river may improve the fish community of Gunderson Lake.

Based on Minnesota DNR survey data, anglers target Largemouth Bass, Black Crappie, Northern Pike, Walleye, and Hybrid Sunfish in Gunderson. See the full species list above for catch rates, size structure, and quality scores.

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

Gunderson has a maximum depth of 41 feet and a mean depth of 17.6 feet, per Minnesota DNR data.

The most recent Minnesota DNR survey data for the main sport fish in Gunderson is from 2020.

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