Fish Lake is an 888-acre eutrophic (fertile) lake located in central Otter Tail County approximately five miles northeast of Fergus Falls, MN. Fish Lake is part of the Otter Tail River Watershed. There are two intermittent inlets and one outlet. The immediate watershed is composed primarily of agricultural land interspersed with hardwood woodlots. The maximum depth of Fish Lake is 19 feet; however, the majority of Fish Lake is less than 15 feet in depth. The secchi disk reading during the 2015 lake survey was 7.7 feet. Previous secchi disk readings have ranged from 3.0 to 6.4 feet. Periodic plankton/algae blooms during the summer months can influence secchi disk readings.
The majority of the shoreline on Fish Lake remains undeveloped. The development that exists (homes and cabins) is located primarily along the north shoreline. The undeveloped shoreline is composed of mixed hardwoods. A DNR owned public water access is located along the north shoreline off of County Road 1. The shoal water substrates consist primarily of sand and silt. Large stands of hardstem bulrush are scattered along various shorelines of the lake. Common cattails are also prevalent along several areas of shoreline. Emergent aquatic plants such as hardstem 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 an important nursery area for all species of fish. Because of their ecological value, emergent plants may not be removed without a DNR permit.
Fish Lake is a popular angling lake because of its proximity to Fergus Falls. Walleye, Northern Pike, Largemouth bass, Black crappie, and Bluegill are the most sought after game-fish species in Fish Lake.
Walleye is a primary management specie in this lake. Walleyes ranged in length from 11.0 to 26.0 inches with an average length and weight of 14.7 inches and 1.2 pounds. The 2012 year class is very strong and should provide good Walleye angling for several years. Walleyes exhibit fast growth with an average length of 14.4 inches at four years of age.
Northern Pike abundance and size structure has historically fluctuated. Northern Pike ranged in length from 14.3 to 24.6 inches with average length and weight of 20.2 inches and 1.6 pounds. Northern Pike attain an average length of 21.7 inches at four years of age.
Data from a spring electrofishing assessment indicates that a balanced Largemouth Bass population exists. Bass reproduction appears to be consistently good. Largemouth Bass ranged in length from 6.6 to 18.9 inches with an average length and weight of 11.7 inches and 1.0 pound. Bass attain an average length of 12.9 inches at four years of age.
Data from a spring trapnetting assessment indicates that Black Crappies are very abundant. The 2010 and 2011 year classes appear to be very strong and should provide good crappie angling for several years. Seventy-two percent of the crappies were 10.0 inches or greater in length. Black crappies attain an average length of 10.9 inches at five years of age.
Anglers can help maintain the quality of angling 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.