Union

Union Lake is a 403 acre lake located in Rice County near the town of Little Chicago. A county-owned earthen access is located on the northeast side of the lake off Rice County Highway 46. Union Lake has a maximum depth of 10 feet and is placed in Lake Class 43, which includes other Waterville Area Lakes such as Circle Lake (Rice County), Crystal Lake (Blue Earth County), Gorman Lake (Le Sueur County), and Pickeral Lake (Freeborn County). Union Lake is managed as a "boom and bust" fishery primarily for Black Crappie, Bluegill, Northern Pike, and Yellow Perch and secondarily for Walleye. The management plan calls for Black Crappie and Bluegill adults and Walleye fry to be stocked following evidence of a winterkill. It also allows for the removal of Walleye, Northern Pike, or Yellow Perch as needed for management purposes. Recent stocking events are limited to Walleye fry in 2014 and 2015. Low dissolved oxygen levels during the winter of 2013-2014 and the results of the subsequent spring trap net assessment suggest the lake experienced a strong winterkill. Union Lake was surveyed the week of July 20, 2015 as part of a regular monitoring program conducted by the Minnesota DNR. This survey was intended to assess the fish community by deploying five gill nets and nine trap nets, as well as recording water quality parameters. Black Crappie No Black Crappies were sampled for the second consecutive survey since 2005. Since 1984 (n=4), trap net catch rates have varied from 0/net in 2005 and 2015 to 24.7/net in 1984 with an average of 6.5/net. Winterkill events appear to have eliminated the Black Crappie population from Union Lake and have surprisingly not rebounded like other game species in the lake. Stocking Black Crappie adults should be considered in order to reintroduce the species to Union Lake. Bluegill A total of 73 Bluegills were sampled with trap nets for a catch rate of 8.1/net, indicating moderate to high numbers were present. Since 1984 (n=4), catch rates have varied from 0/net in 1984 to 60.7/net in 2005 with an average of 18.6/net. Lengths ranged from 3.2 to 4.6 inches with an average of 3.8 inches. An additional 12 Bluegills ranging from 3.6 to 7.9 inches were sampled with gill nets for a catch rate of 2.4/net. Fish from both gears were 0 or 1 year old with the exception of one 8 year old fish. Overall, the Bluegill population in Union Lake is in a state of recovery from the 2013-2014 winterkill and is dominated by small, young fish. Northern Pike Northern Pike were sampled at an extremely high rate in 2015. A total of 140 fish were sampled with gill nets for a catch rate of 28.0/net, indicating high numbers were present. Since 1984 (n=4), catch rates have varied from 9.0/net in 1995 to 28.0/net in 2015 with an average of 16.2/net. Lengths ranged from 13.4 to 27.0 inches with an average of 19.2 inches. An additional 4 fish ranging from 14.7 to 22.3 inches were sampled with trap nets. Fish from both gears were 1 or 2 years old, with 1 year old fish making up 91% of the sample. Northern Pike numbers remain high in Union Lake despite frequent winterkills. Yellow Perch A total of 216 Yellow Perch were sampled with gill nets for a catch rate of 43.2/net, which was the highest ever recorded in Union Lake and indicated high numbers were present. Catch rates have increased every survey since sampling began in 1984 (n=4) with an average of 17.4/net. Lengths ranged from 5.3 to 9.8 inches with an average of 7.1 inches. An additional 54 Yellow Perch ranging from 5.6 to 7.9 inches were sampled with trap nets for a catch rate of 6.0/net. Fish from both gears ranged from 1 to 3 years old with three year-classes present. Two year old fish made up over 64% of the sample. Despite high Northern Pike numbers, Yellow Perch have continued to increase in abundance in Union Lake but small size structure limits the fishery. Walleye Only eight Walleyes were sampled with gill nets for a catch rate of 1.6/net, indicating low numbers were present. Since 1984 (n=4), catch rates have varied from 0/net in 1984 and 1995 to 4.0/net in 2005 with an average of 1.4/net. Lengths ranged from 12.2 to 13.7 inches with an average of 12.9 inches. An additional four Walleyes ranging from 5.7 to 12.9 inches were sampled with trap nets. Fish from both gears were 0 or 1 year old and coincide with fry stocking in 2014 and 2015. Despite regular fry stocking, the Walleye population remains low in Union Lake providing limited fishing opportunity. Black Bullhead A total of 336 Black Bullheads were sampled with gill nets for a catch rate of 67.2/net, which was the lowest ever recorded and indicated low to moderate numbers were present. Since 1984 (n=4), catch rates have varied from 67.2/net in 2015 to 284.0/net in 2005 with an average of 176.6/net. Lengths ranged from 4.3 to 10.7 inches with an average of 6.5 inches. An additional 63 Black Bullheads were sampled with trap nets. Despite the decrease in abundance, Black Bullheads continue to thrive in Union Lake where winterkills are common. Common Carp Common Carp numbers remained high in 2015. A total of 226 were sampled with gill nets for a catch rate of 45.2/net, indicating high numbers were present. Since 1984 (n=4), catch rates have varied from 27.8/net in 1995 to 56.7/net in 1984 with an average of 43.3/net. Sizes were small with over 95% less than 5.5 inches. Common Carp were also the most abundant fish sampled with trap nets with a catch rate of 44.8/net. Fish up to 27.8 inches were caught but the mean length was just 6.6 inches. Common Carp are able to repopulate Union Lake quickly following winterkill and remain a dominant member of the lake's fish community. Other Species Other species sampled in 2015 include Bigmouth Buffalo, Green Sunfish, hybrid sunfish, Tadpole Madtom, and White Sucker. Water Quality Parameters Water quality parameter measurements included secchi depth, water temperature, and dissolved oxygen readings. At the time of this survey, secchi depth was 1.9 feet, indicating poor water clarity. Water temperatures and dissolved oxygen readings throughout the water column ranged from 77.2 degrees Fahrenheit and 9.9 ppm at the surface to 76.3 degrees Fahrenheit and 6.0 ppm at 9 feet. Anglers can play an important role in maintaining or improving a fish population by practicing selective harvest. Selective harvest allows for the harvest of smaller fish for consumption, while encouraging the release of medium to large fish that may contribute to natural recruitment. This practice helps maintain balance in the fish community and provides anglers the opportunity to catch more and larger fish in the future. Additionally, smaller fish often taste better and have fewer contaminants than larger, older fish from the same water body. Shoreline property owners also play an important role in the overall health of an aquatic ecosystem, including the fish population. Natural shorelines, including vegetation, woody debris, and bottom substrates, provide valuable habitat for fish and wildlife, help maintain water quality, and reduce bank erosion. By leaving natural shorelines unaltered or restoring them to natural conditions, shoreline property owners are doing their part to maintain or improve a healthy ecosystem in the lake and protect the resource for future generations. -Sky Wigen, Fisheries Specialist

Periodically, good numbers of northern pike develop in Union Lake. A "boom and bust" northern pike fishery periodically develops following winter kill and some panfishing may be created at times. Commercial species such as carp, buffalo, bullhead, and sucker thrive in these conditions.

THE NORTHERN POPULATION IS VERY STRONG AVERAGING 16.66 FISH PER NET, WITH A 3.57 LB AVG. II AND III YR CLASSES DOMINATE THE FOUR SAMPLED. A MODERATE BLACK CRAPPIE POPUALTION HAS DEVELOPED FROM STOCKING; TWO YEAR CLASSES ARE PRESENT WITH 2 YR OLDS DOMINATING. THERE IS A SMALL WHITE CRAPPIE POPULATION PRESENT MADE UP OF TWO AND THREE YEAR OLDS. FEW PERCH WERE SAMPLED, WHICH PROBABLY RE- FLECTS THE HIGH PREDATOR POPUALTION PRESENT. BLACK BULLHEADS ARE VERY ABUNDANT AND APPEAR TO BE OF ONE YEAR CLASS, AVERAGING 12 FISH/LB. SMALL CARP ARE ABUNDANT AND PROBABLY OF ONE YEAR CLASS. OTHER FISH (BUFFALO,WHITE SUCKER,GREEN SUNFISH) WERE SAMPLED IN SMALL NUMBERS.

Based on Minnesota DNR survey data, anglers target Yellow Perch, Hybrid Sunfish, Black Crappie, Northern Pike, and White Crappie in Union. 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 Union. Check the DNR LakeFinder page for current access details before you go.

Union has a maximum depth of 10 feet, per Minnesota DNR data.

The most recent Minnesota DNR survey data for the main sport fish in Union is from 2015. Surveys this old should be treated with some caution — fish populations change over time.

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