Union

Union is a small-sized lake (93 acres) located southwest of the City of South Haven in Wright County. Union has 1.5 miles of shoreline and a maximum depth of 35 feet. A state-owned public access with a cement boat ramp and a very small amount of parking is present on the south shore. Water clarity is typically fair to moderate and submergent vegetation is often sparse to moderate in abundance at Union. A spring trap netting survey was conducted during May 2022. Trap nets were used to target Bluegill and Black crappie. Spring trap net data should not be compared to historical summer trap net data, as summer nets often do a poor job of representatively sampling Bluegill. High numbers of Bluegill were collected and fish were 3 to 8 inches long, averaging 6 inches. Approximately 38% of the sample was 7 inches or longer, indicating that a good proportion of the fish sampled were keeper-sized. Bluegill were age-2 to age-11 with ten year classes being present. Moderate numbers of Black Crappie were collected, averaging almost 8 inches in length. The longest crappie collected was just over 12 inches in length. Black Crappie were age-1 to age-11 with ten year classes being present. Moderate numbers of Pumpkinseed Sunfish were captured, averaging just over 5 inches in length. The longest Pumpkinseed Sunfish collected was just over 7 inches long. Pumpkinseed Sunfish were age-3 to age-8 with six year classes being present. People can have significant impacts on lakes and the fish populations they support. Over harvest, lakeshore development, removal of shoreline vegetation, and introductions of invasive species can all adversely affect fish populations. Aquatic invasive species (AIS) are typically moved from infested to non-infested waters by anglers, boaters and lakeshore owners, and can adversely impact lakes and fish populations. To avoid spreading AIS, lake users are required to remove all aquatic plants and animals from their watercraft and drain all lake water from their boat and bait buckets before leaving the lake. If you suspect an infestation of an invasive species in this lake, save a specimen and report it to a local DNR office. Additional information on all of these topics can be found on the DNR website (www.dnr.state.mn.us) or by contacting the Hutchinson Area Fisheries office.

Union is a small-sized lake (93 acres) located southwest of the City of South Haven in Wright County. Union has 1.5 miles of shoreline and a maximum depth of 35 feet. A state-owned public access with a cement boat ramp and a very small amount of parking is present on the south shore. Water clarity is typically fair to moderate and submergent vegetation is often sparse to moderate in abundance at Union. A spring trap netting survey was conducted during May 2022. Trap nets were used to target Bluegill and Black crappie. Spring trap net data should not be compared to historical summer trap net data, as summer nets often do a poor job of representatively sampling Bluegill. High numbers of Bluegill were collected and fish were 3 to 8 inches long, averaging 6 inches. Approximately 38% of the sample was 7 inches or longer, indicating that a good proportion of the fish sampled were keeper-sized. Bluegill were age-2 to age-11 with ten year classes being present. Moderate numbers of Black Crappie were collected, averaging almost 8 inches in length. The longest crappie collected was just over 12 inches in length. Black Crappie were age-1 to age-11 with ten year classes being present. Moderate numbers of Pumpkinseed Sunfish were captured, averaging just over 5 inches in length. The longest Pumpkinseed Sunfish collected was just over 7 inches long. Pumpkinseed Sunfish were age-3 to age-8 with six year classes being present. People can have significant impacts on lakes and the fish populations they support. Over harvest, lakeshore development, removal of shoreline vegetation, and introductions of invasive species can all adversely affect fish populations. Aquatic invasive species (AIS) are typically moved from infested to non-infested waters by anglers, boaters and lakeshore owners, and can adversely impact lakes and fish populations. To avoid spreading AIS, lake users are required to remove all aquatic plants and animals from their watercraft and drain all lake water from their boat and bait buckets before leaving the lake. If you suspect an infestation of an invasive species in this lake, save a specimen and report it to a local DNR office. Additional information on all of these topics can be found on the DNR website (www.dnr.state.mn.us) or by contacting the Hutchinson Area Fisheries office.

A standard survey was conducted at Union Lake the week of July 24, 2017 to monitor the fish population. The 2013 lake management plan lists Bluegill and Largemouth Bass as primary management species while Northern Pike and Black Crappie are listed as secondary species. In 2017, a total of 15 species, plus Hybrid Sunfish, were sampled in the gill nets, trap nets, or by electrofishing. Catch rates were compared to other similar lakes across the state. Dissolved oxygen levels dropped below 2 mg/L at a depth of 10 feet on 7/24/17, indicating that deepwater portions of the lake were not suitable for fish to use this time of the year; maximum depth on Union Lake is 35 feet. The water clarity was fair, with a secchi disk reading of 6.8 feet due to a bog stain. Curlyleaf Pondweed, a non-native invasive aquatic plant, was abundant (surface mats) around much of the lake's shoal areas in mid-May. This type of submergent vegetation typically dies back in early July. Boat parking is limited on this small lake. Trap nets sampled high numbers (706) of Bluegill for a catch rate of 78.4/net which was above what might be expected for this type of lake. The 2012 catch rate was similar at 57.4/net. Historic catch rates from 1972 to 2017 (n=14) ranged from 13.9 to 146.0/net, with an average of 56.7. Catches indicated an upward trend since the 1997 assessment. In 2017, trap netted Bluegill were 3.2 to 8.4 inches long with an average of 5.7. Approximately 30% of the trap net catch was 7 inches or longer, indicating that a quality population was present. Size distributions indicated that multiple ages were present, likely indicating consistent reproduction most years. Bluegill anglers should expect plenty of action on this classis bass/panfish lake. Spring night-time electrofishing sampled moderate numbers (47) of Largemouth Bass for a catch rate of 51.5/hour, which was the highest ever recorded at Union Lake. Historical catch rates from 1992 to 2017 (n=6) ranged from 2.0 to 51.5/hour with an average of 23.1. Electrofished Largemouth Bass were 3.3 to 20.1 inches long with an average of 11.1. Approximately 21% of the electrofishing sample was 15 inches or longer. Trap nets sampled high numbers (21) of Largemouth Bass for a catch rate of 2.3/net, which was well above what might be expected for this type of lake. The size distributions indicated that multiple ages were present and that a quality population was present. Bass could expect good action from small and medium sized fish, plus the outside chance at a trophy as well. Gill nets sampled moderate numbers (26) of Northern Pike for a catch rate of 6.5/net, which was within what might be expected for this type of lake. The 2012 catch rate was 10.0/net. Historical catch rates from 1972 to 2017 (n=14) were variable ranging from 0.0 to 17.0/net with an average of 4.8. Gill netted Northern Pike were 18.7 to 32.5 inches long with an average of 23.7. Approximately 44% of the gill net sample was 24 inches or longer. Trap nets sampled fish up to 34.7 inches in length, indicating that quality sized fish were present. Size distributions indicated that multiple ages were present. Northern Pike were last stocked in 1992, indicating that the current population was the result of natural reproduction. Pike anglers should expect good action and a rare chance for a big fish as well. Trap nets sampled moderate numbers (101) of Black Crappie for a catch rate of 11.2/net, which was within what might be expected for this lake type. The 2012 catch rate was 15.0/net. Historic catch rates from 1972 to 2017 (n=14) were variable ranging from 0.0 to 42.3/net with an average of 11.6. Trap netted Black Crappie were 3.8 to 11.3 inches long with an average of 7.6. Approximately 59% of the trap net sampled was 8 inches or longer. Gill nets also sampled moderate numbers (42) of Black Crappie for a catch rate of 10.5/net, which was within what might be expected for this lake type. The 2012 gill net catch rate was 5.7/net. Historic gill net catch rates (n=14) were variable, ranging from 0.0 to 42.0/net with an average of 7.3. In 2017, gill netted fish were 4.3 to 12.1 inches long with an average of 8.1. Approximately 67% of the trap net sample was 8 inches or longer, and 21% were 10 inches or longer. Size distributions indicated that multiple ages were present and that a quality population existed. Crappie anglers often do well fishing the edge of the cattails in the spring. Gill nets sampled low numbers (3) of Walleye for a catch rate of 0.8/net, which was below what might be expected for this lake type. The 2012 catch rate was very similar at 0.7/net. Historic catch rates from 1972 to 2017 (n=14) were all low, ranging from 0.0 to 3.0/net with an average of 0.6. Walleye were only stocked by Minnesota DNR three times (1985, 1987, and 1989) during the last 45 years. Walleye sampled in this survey were likely the result of river immigrants during high water or illegal unpermitted stocking efforts; carryover natural reproduction to sustain the population since ceasing stocking is unlikely. In the early 1990's it was decided to manage Union as a bass/panfish type lake. In 2017, the gill netted Walleye were 21.9 to 26.1 inches long with an average of 23.9. Anglers targeting walleye are advised to try other nearby water such as Big Swan or Collinwood. Gill nets sampled low numbers (1) of Channel Catfish for a catch rate of 0.3/net, which was the highest ever recorded at Union Lake. This indicated that there was likely not a very good connection to Scott Lake and the Clearwater River system. All other historic catch rates (1972 to 2012) were 0.0/net. In 2017, the gill netted Channel Catfish was 19.3 inches long. The only other year that Channel Catfish were gill or trap netted was 1997 (4 fish in the trap nets). Channel Catfish were never stocked into Union Lake and likely are present from illegal unpermitted stocking efforts or from a short window of opportunity during high flows and a connection to the Clearwater River. Gill nets sampled low numbers (10) of Yellow Perch for a catch rate of 2.5/net, which was within what might be expected for this lake type. The 2012 catch rate was also low (1.0/net). Historic catch rates from 1972 to 2017 (n=14) were variable, ranging from 0.0 to 42.3/net with an average of 9.9. In 2017, Yellow Perch were 5.8 to 7.3 inches long with an average of 6.2. Gill nets did not sample Common Carp in 2017. Historic gill net catch rates (n=14) from 1972 to 2017 were all low, ranging from 0.0 to 0.3/net with an average of 0.0. Trap nets sampled low numbers (1) of Common Carp for a catch rate of 0.1/net, which was below the lake's normal range. Historic trap net catch rates (n=14) ranged from 0.0 to 2.0/net with an average of 0.5. The 2017 Common Carp was 14.1 inches long. Historic low catches could indicate a poor connection to Scott Lake and the Clearwater River system. Moderate to high numbers of Bluegill, over the years, were likely efficient predators on Common Carp eggs, further limiting their abundance in Union Lake. Gill nets sampled low numbers (8) of Black Bullhead for a catch rate of 2.0/net, which was below what might be expected for this type of lake. Historic catch rates from 1972 to 2017 (n=14) ranged from 0.0 to 34.5/net with an average of 6.0. Gill netted Black Bullhead were 7.8 to 12.7 inches long with an average of 11.6. Trap nets also sampled low numbers (1) of Black Bullhead in 2017. Trap nets sampled low numbers (14) of Yellow Bullhead for a catch rate of 1.6/net, which was within what might be expected for this lake type. Historic catch rates (n=14) ranged from 0.0 to 27.7/net with an average of 6.1. Gill nets also sampled low (5) numbers of Yellow Bullhead in 2017. Additional species sampled in the standard gear included Bowfin, Brown Bullhead, Golden Shiner, Hybrid Sunfish, Pumpkinseed Sunfish, and White Sucker.

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

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

Union has a maximum depth of 35 feet, per Minnesota DNR data.

The most recent Minnesota DNR survey data for the main sport fish in Union is from 2017. 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.