Fish Lake is a 175-acre lake located 2 miles southwest of the Town of Odin in Martin County. Fish Lake is shallow, having a maximum depth of 5.0 feet. Fish Lake has a history of low dissolved oxygen levels during the winter and therefore is aerated by the Watonwan Game and Fish Club with an Aire-O2 aeration system. Fish Lake is managed primarily for Northern Pike and secondarily for Walleye, Yellow Perch and Black Crappie. Northern Pike fingerlings are stocked one out of three years at a rate of 10 per littoral acre (2011, 2014, 2017). Walleye fingerlings are stocked one out of three years at a rate of one pound per littoral acre (2011, 2014, 2017). Yellow Perch and Black Crappie have not been stocked in recent history because they have maintained their populations through natural reproduction. A standard survey was conducted the week of July 6, 2015 to monitor fish populations using two gill nets and eight trap nets.
In 2015, Northern Pike were captured at a rate of 1.0 per gill net, which is within the expected range of catch rates for similar lakes in the area (0.0 to 2.0 per gill net), and at a rate of 2.5 per trap net, which is above the expected range of catch rates for similar lakes in the area (0.1 to 0.9 per trap net). The gill net and trap net catch rates were the highest observed Northern Pike catch rates at Fish Lake. Northern Pike were 16.1 to 32.4 inches long and averaged 25.5 inches. Although Northern Pike were not aged, nearly every inch group between 18.0 and 32.0 was present suggesting that the fingerling stockings have been successful or some degree of natural reproduction occurs in this system. With an average length of 25.5 inches, Fish Lake should provide a good angling opportunity for Northern Pike.
The 2015 Walleye catch rate of 5.0 per gill net decreased slightly from the 2009 catch rate of 7.0 per gill net, but was within the expected range of catch rates for similar lakes in the area (2.3 to 13.3 per gill net). Walleye were 10.8 to 25.8 inches long and averaged 12.8 inches. Ninety-five percent of the Walleye sampled were 10.0 to 13.5 inches, and were age-2 (2013 year class). The age-2 Walleyes averaged 12.0 inches, which means they are growing slow. An additional summer to grow should get these Walleyes to a length that is acceptable to anglers to harvest.
The catch rate of Yellow Perch in 2015 remained below the expected range of catch rates for similar lakes in the area (3.3 to 30.4 per gill net) at 1.0 per gill net. The two gill netted Yellow Perch were 5.8 and 6.0 inches in length. Not much of a Yellow Perch fishery exists in Fish Lake at this time.
In the past 15 years, catch rates of Black Crappie have decreased from 36.1 per trap net in 2000 to 14.2 per trap net in 2009 to 9.0 per trap net in 2015, but is within the expected range of catch rates for similar lakes in the area (0.7 to 15.3 per trap net). White Crappie were first sampled in Fish Lake in 2000, being captured at rates of 3.0, 13.0, and 3.0 per trap net in 2000, 2009, and 2015, respectively. The Black Crappie population may be adjusting to White Crappies being present as well. The two species can coexist, but competition for food and habitat may cause one of the species to occur at lower abundance than the other. Black Crappie were 3.8 to 16.7 inches long and averaged 7.3 inches. The majority of Black Crappie were less than 9.0 inches (94 percent); however, two of the Black Crappie sampled were approaching 17 inches in length. White Crappie were 6.5 to 11.3 inches long and averaged 8.1 inches. Fish Lake presents a unique opportunity to catch a trophy sized Black Crappie.
Channel Catfish were sampled for the first time in Fish Lake at a rate of 17.5 per gill net, which is well above the expected range of catch rates for similar lakes in the area (0.0 to 3.0 per gill net). Channel Catfish were 6.9 to 20.3 inches and averaged 10.7 inches. Channel Catfish likely got into Fish Lake from Cedar Lake which is connected and has historically had a stable Channel Catfish population. Channel Catfish will provide an additional angling opportunity on Fish Lake.
Black Bullhead catch rates remained low in Fish Lake, as they were captured at a rate of 0.6 per trap net, which is below the expected range of catch rates for similar lakes in the area (11.5 to 132.6 per trap net). Historically, Black Bullhead catch rates have ranged from 0.2 per trap net in 2009 to 576.5 per trap net in 1995. Black Bullhead were 6.3 to 10.2 inches long and averaged 8.2 inches. Lack of Black Bullhead may be attributed to the Channel Catfish that have recently become established in Fish Lake, because they are a main prey item for Channel Catfish.
Abundance of Common Carp has decreased from 25.0 per gill net in 2000 to 10.5 per gill net in 2009 to 4.0 per gill net in 2015. Common Carp were 21.0 to 26.7 inches long and averaged 23.3 inches.
Bigmouth Buffalo were captured at a rate of 1.5 per gill net, which is low compared to similar lakes. They ranged in length from 16.4 to 24.0 inches.
Freshwater Drum were first sampled in Fish Lake in 2009 at a rate of 14.0 per gill net. The catch rate in 2015 was similar as they were sampled at a rate of 12.0 per gill net, which is still higher than the expected range of catch rates for similar lakes in the area (0.5 to 8.3 per gill net). Freshwater Drum were 6.3 to 10.2 inches long and averaged 8.2 inches.
Plants in the water and at the water's edge provide habitat, prevent erosion, and absorb excess nutrients. Shrubs, trees, and woody debris such as fallen trees or limbs provide good habitat both above and below the water and should be left in place. By leaving a buffer strip of natural vegetation along the shoreline, property owners can reduce erosion, help maintain or improve water quality, and provide habitat and travel corridors for wildlife.
Best management practices within the watershed (no-till farming, cover crops, buffer strips, targeted fertilizer application, reduced or metered tiling) would help reduce nutrients entering the lake. High nutrient and sediment input can cause algae blooms and reduce overall water quality. Any improvements in the watershed are likely to have positive impacts on the fishery.
Prepared by Jonah Dagel