Tonseth

Tonseth Lake is located in west-central Otter Tail County approximately eight miles southeast of Erhard, MN. Tonseth Lake is a 156-acre moderately fertile lake that is part of the Otter Tail River Watershed. Two small intermittent inlets are located along the north shoreline of the lake and an outlet to Kempfer Lake is located along the northwest shoreline. The inlets and outlet are not navigable. The immediate watershed is composed primarily of undeveloped mixed hardwoods. The maximum depth of Tonseth Lake is 27 feet; however, 50% of the lake is less than 15 feet in depth. The secchi disk reading during the 1999 lake survey was 13.7 feet which indicates excellent water clarity. Previous secchi disk readings have ranged from 7.0 to 18.5 feet. Periodic plankton/algae blooms throughout the summer months can influence secchi disk readings The Minnesota Department of Natural Resources (DNR) has classified Minnesota's lakes into 43 different lake classes based on physical and chemical characteristics of the lakes. Tonseth Lake is included in lake class 34 of this classification scheme. Tonseth Lake is located within the DNR's Fergus Falls Management Area. The majority of the shoreline of Tonseth Lake remains undeveloped. Homes and cottages are scattered around the lake but the shoreline is primarily composed of mixed hardwoods. As referenced in the 1994 lake survey, there are 21 homes/cottages located on Tonseth Lake. The same number of homes/cottages was referenced in the 1981 lake resurvey. Tonseth Lake does not have a designated public access; however, a DNR leased public access will be constructed in 2000 or 2001. The shoal water substrates consist primarily of sand and gravel with scattered areas of rubble. Large stands of hardstem bulrush are scattered along the shoreline of the lake. Common cattail is also prevalent in several of the lakes' bays. Emergent aquatic plants such as bulrush and cattail provide valuable fish and wildlife habitat, and are critical for maintaining good water quality. They protect shorelines and lake bottoms, and can actually absorb and break down polluting chemicals. Emergent plants provide spawning areas for fish such as northern pike, largemouth bass, and panfish. They also serve as important nursery areas for all species of fish. Because of their ecological value, emergent plants may not be removed without a DNR permit. To maintain the excellent water quality and angling that this lake has to offer, it is imperative to preserve the quality of the aquatic habitat. Tonseth Lake can be ecologically classified as a bass-panfish type of lake and this is reflected in the assemblage of the fish community. Largemouth bass, northern pike, bluegill, and black crappie are the dominant species in the fish community of Tonseth Lake. These species are abundant and also exhibit good size structures. The prolificacy of these species can be attributed to the abundance of suitable spawning habitat that is available. Data collected from a spring electrofishing assessment indicated that Tonseth Lake has a balanced largemouth bass population. Bass ranged in length from 5.2 to 18.9 inches with an average length and weight of 11.3 inches and 1.0 pounds. Bass reach an average length of 11.3 inches at four years of age. A creel survey conducted in 1986 indicated that angler catch rates for largemouth bass were excellent. The northern pike test-net catch rate increased from previous surveys and is within the normal range for lake class 34 lakes. The increase in pike abundance may be attributed to the recent high water level which has increased the accessability of northern pike to suitable spawning habitat (marsh areas). Northern pike ranged in length from 17.3 to 34.2 inches with an average length and weight of 23.2 inches and 2.9 pounds. Northern pike reach an average length of 19.3 inches at four years of age which is slower than average growth rates for pike in class 34 lakes in the Fergus Falls Management Area. Bluegill test-net catch rates have fluctuated in the recent series of lake surveys; however, the catch rate in this survey exceeded the upper limit of the normal range for lakes in class 34. Bluegill size distribution and growth rates have remained consistent over recent surveys. Twenty percent of the bluegills sampled were 7.0 inches or greater in length. Bluegills reach an average length of 6.4 inches at six years of age which is at the lower limit of the statewide normal range of growth for lake class 34. Catch data collected from a special spring trapnetting assessment indicated that black crappie are very abundant in Tonseth Lake. Black crappies ranged in length from 4.6 to 12.2 inches. Sixty-seven percent of the crappies sampled were 9.0 inches or greater in length. Several strong year classes (1995 and 1998) should provide consistently good crappie angling for several years. Crappies reach an average length of 9.5 inches at five years of age which is slower than average growth rates for crappies in class 34 lakes in the Fergus Falls Management Area. No fish species are presently stocked in Tonseth Lake; however, a walleye stocking plan will be initiated in 2000 or 2001 contingent upon development of the public access. The plan identifies a stocking regime of 78 pounds of walleye fingerlings on a biennial basis. This stocking plan may increase walleye angling opportunities for anglers of Tonseth Lake. To maintain the excellent fishing this lake presently has to offer, it is imperative to preserve the existing quality of the fish community. Anglers can maintain the quality of fishing by practicing selective harvest. Selective harvest encourages the release of medium to large-size fish while allowing the harvest of the more abundant smaller fish for table fare. Releasing the medium to large fish will ensure that the lake will have enough spawning age fish on an annual basis and will provide anglers with more opportunities to catch large fish in the future.

The population estimate of largemouth bass greater than 6.0 inches in length was 1,258 fish. This compares to the 1985 estimate of 1,216 largemouth bass.

The population estimate of largemouth bass greater than 6.0 inches in length was 1,258 fish. This compares to the 1985 estimate of 1,216 largemouth bass.

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

We don't have a confirmed public access point on record for Tonseth. Check the DNR LakeFinder page for current access details before you go.

Tonseth has a maximum depth of 27 feet and a mean depth of 15 feet, per Minnesota DNR data.

The most recent Minnesota DNR survey data for the main sport fish in Tonseth is from 1999. Surveys this old should be treated with some caution — fish populations change over time.

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