Fisheries Lake Survey

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Name: Loon

Nearest Town: Jackson
Primary County: Jackson
Survey Date: 06/18/2012
Inventory Number: 32002000
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Public Access Information

Ownership Type Description
County Concrete
DNR Concrete

Lake Characteristics

Lake Area (acres): 706.97
Littoral Area (acres): 706.97
Maximum Depth (ft): 7
Water Clarity (ft): 1.2 (1-1.4)

Dominant Bottom Substrate: N/A
Abundance of Aquatic Plants: N/A
Maximum Depth of Plant Growth (ft): N/A

Did you know? The annual budget for the Section of Fisheries is approximately $17 million, which is funded primarily by fishing license and stamp fees and by a federal excise tax on fishing and boating equipment.

Fish Sampled for the 2012 Survey Year


Gear Used

Number of fish per net

Average Fish Weight (lbs)

Normal Range (lbs)


Normal Range

Bigmouth Buffalo Trap net 1.08 0.2 - 1.0 5.83 2.6 - 5.8
Gill net 2.25 0.8 - 7.0 2.60 N/A
Black Bullhead Trap net 9.58 11.5 - 132.6 0.81 0.2 - 0.4
Gill net 22.50 30.3 - 150.6 0.53 0.2 - 0.4
Black Crappie Trap net 4.08 1.2 - 20.5 0.36 0.2 - 0.5
Gill net 1.25 1.4 - 13.8 0.09 0.2 - 0.4
Bluegill Trap net 1.83 1.2 - 20.0 0.55 0.1 - 0.4
Channel Catfish Trap net 0.17 N/A 5.07 N/A
Gill net 5.00 N/A 2.04 N/A
Common Carp Trap net 0.42 1.0 - 5.5 7.21 1.4 - 4.6
Freshwater Drum Trap net 1.08 0.2 - 3.3 1.08 0.3 - 1.0
Gill net 6.50 0.5 - 8.3 0.25 0.4 - 1.7
Green Sunfish Trap net 0.17 0.2 - 1.9 0.09 0.1 - 0.2
Northern Pike Trap net 0.25 N/A 3.17 N/A
Gill net 1.00 1.1 - 8.0 2.98 1.8 - 3.4
Shortnose Gar Trap net 0.75 N/A 1.41 N/A
Gill net 0.50 N/A 2.54 N/A
Walleye Trap net 0.83 0.5 - 3.0 1.00 0.8 - 2.3
Gill net 11.75 2.3 - 18.1 2.01 1.0 - 2.3
White Bass Trap net 0.17 0.2 - 0.7 0.83 0.2 - 0.6
White Crappie Trap net 0.33 0.3 - 6.0 0.07 0.3 - 0.6
Gill net 0.50 0.5 - 8.4 0.09 0.2 - 0.3
White Sucker Trap net 0.58 0.3 - 2.6 1.69 1.0 - 2.0
Gill net 4.50 0.8 - 6.5 1.79 0.9 - 2.0
Yellow Bullhead Trap net 0.25 0.5 - 2.5 0.60 0.3 - 0.7
Gill net 0.25 0.5 - 3.5 0.37 0.3 - 0.7
Yellow Perch Trap net 0.17 0.3 - 3.8 0.22 0.1 - 0.3
Gill net 4.50 2.7 - 25.0 0.30 0.1 - 0.3
Normal Ranges represent typical catches for lakes with similar physical and chemical characteristics.

Length of Selected Species (Trapnet, Gillnet) Sampled for the 2012 Survey Year

Species Number of fish caught in each category (inches)
0-5 6-8 9-11 12-14 15-19 20-24 25-29 30+ Total
bigmouth buffalo 0 5 1 1 7 4 3 0 22
black bullhead 0 36 131 32 1 0 0 0 205
black crappie 25 9 18 2 0 0 0 0 54
bluegill 2 14 4 0 0 0 0 0 22
channel catfish 0 0 7 0 6 9 0 0 22
common carp 0 0 0 0 0 2 3 0 5
freshwater drum 12 18 0 1 4 2 0 0 39
green sunfish 2 0 0 0 0 0 0 0 2
northern pike 0 0 0 0 0 5 2 0 7
shortnose gar 0 0 0 0 3 7 1 0 11
walleye 0 5 6 3 36 4 0 0 57
white bass 0 1 0 1 0 0 0 0 2
white crappie 5 1 0 0 0 0 0 0 6
white sucker 0 0 1 9 15 0 0 0 25
yellow bullhead 0 1 3 0 0 0 0 0 4
yellow perch 2 12 6 0 0 0 0 0 20

For the record, the largest Shovelnose Sturgeon taken in Minnesota weighed 5 lbs., 9 oz. and was caught:

    Where: Mississippi River near Red Wing, Goodhue County
    When: 6/4/07
    Statistics: 36" length, 11 7/8" girth

Fish Stocking Activity

Fish Stocked by Species for the Last Ten Years

Year Species Size Number Pounds
2015 Walleye fingerlings 4,566 397.0
  Walleye fry 370,660 3.2
  Yellow Perch adults 1,241 208.0
2014 walleye fry 369,524 3.4
  walleye fingerlings 10,285 407.0
2013 Walleye fry 370,225 4.0
2011 Northern Pike fingerlings 7,446 64.5
  Walleye fry 369,256 3.2
2010 Walleye fry 369,256 3.2
2009 Walleye fry 368,602 3.5
2007 Northern Pike fingerlings 509 6.6
  Walleye1 fingerlings 15,561 1,476.0

Stocking Notes
1 - indicates fish purchased and stocked by private citizens and sporting groups.
2 - indicates fish purchased by the DNR for stocking.

Stocking Fish Sizes
Fry - Newly hatched fish that are ready to be stocked usually called "swim-ups". Walleye fry are 1/3 of an inch or around 8 mm.
Fingerling - Fingerlings are one to six months old and can range from a size of one to twelve inches depending on the species. Walleye fingerlings range from three to eight inches each fall.
Yearling - Yearling fish are at least one year old. A one-year-old fish can range from three to twenty inches depending on the species. Walleye yearlings average from six to twelve inches.
Adult - Adult fish are fish that have reached maturity. Depending on the species, maturity can be reached at two years of age. Walleye reach maturity between the ages of four and six years.

Fish Consumption Guidelines

These fish consumption guidelines help people make choices about which fish to eat and how often. Following the guidelines enables people to reduce their exposure to contaminants while still enjoying the many benefits from fish.

Pregnant Women, Women who may become pregnant and Children under age 15

County, DOWID
Species Meal Advice Contaminants
Unrestricted 1 meal/week 1 meal/month Do not eat
Jackson Co., 32002000
Carp All sizes        
Crappie All sizes        
Walleye   All sizes     Mercury

General Population

County, DOWID
Species Meal Advice Contaminants
Unrestricted 1 meal/week 1 meal/month Do not eat
Jackson Co., 32002000
Carp All sizes        
Crappie All sizes        
Walleye All sizes        

DOWID - MN DNR, Division of Waters' lake ID number.

Contaminants listed were measured at levels that trigger advice to limit consumption.

Listing of consumption guidelines do not imply the fish are legal to keep, MN DNR fishing regulations should be consulted.

PCBS - Polychlorinated biphenyls
PFOS - Perfluorooctane sulfanate

Status of the Fishery (as of 06/18/2012)


Loon Lake is a 738-acre class 43 lake with a maximum depth of 7 feet and 6.24 miles of shoreline 10 miles south of Lakefield, MN near the Iowa-Minnesota Border. The surrounding land use of Loon Lake is largely agricultural. Historically, Loon Lake was susceptible to regularly occurring winterkill situations. In 1982, an aeration system was installed in an attempt to remedy the low dissolved oxygen in the winter months in order to sustain a fishable walleye population. Dissolved oxygen readings during most winters since 1982 have not been low enough to cause extensive winterkill. While this helped the fish population, problems still exist in the way of water quality. In 2002, the MN PCA conducted water quality assessments on several southwestern MN lakes and found total phosphorus levels in Loon Lake that were nearly 5 times higher than the upper normal range for the Western Corn Belt Plains Ecoregion. Loon Lake has a watershed-to-lake ratio of 27 to 1 (27 acres of land for every 1 acre of water); this large catchment area for the lake might partially explain some of the poor water quality values. Loon Lake is managed for walleye, yellow perch, and northern pike. A population assessment was conducted during the week of June 18, 2012 using 4 gill nets and 12 trap nets as well as shoreline seining and backpack electrofishing (nearshore sampling) to determine the health of the fish community by sampling as many species of fish as possible (generally more species present equals a better index score).


Walleye were first stocked into Loon Lake in 1979 (as fry) when walleye management was started on Loon Lake. Since 1979, a combination of walleye fry, fingerling, and adults have been stocked into Loon Lake. Walleye fry are now stocked 3 of every 4 years, after a lake management change in 2009. The spring of 2012 was the first non-stocked year of the 4 year walleye stocking rotation started in 2009, and was a great year to assess the walleye population during a non-stocked year to determine if any natural reproduction exists. The gill net catch rate in 2012 was 11.8 fish per net, which was the second highest catch rate observed since 1997 (18.3 per gill net) but still within the normal range of 2.3 to 18.1 fish per gill net for lake class 43. The Loon Lake walleye gill net catch rate has only exceeded the normal range one time in 1997 with a catch rate of 18.3 fish per gill net, which was nearly identical to the upper normal range of 18.1 fish per gill net. Also, the walleye catch rate has never been less than the low end of the normal range of 2.3 fish per gill net with the lowest observed gill net catch rate equal to 3.0 in 1983. Therefore, the walleye population in Loon Lake appears to be stable regardless of the rate at which walleye are stocked into the lake. However, the current management plan does have a benefit to the size structure of the walleye in the lake, as reflected in the 2012 sample. The mean length of walleye in the gill nets and trap nets was 17 and 13 inches, respectively, with walleye ranging in length from 6 to 24 inches in both gears. Growth of walleye was excellent with walleye reaching 15 inches by the end of age 2 and 18 inches by the end of age 3 with 8 different year classes present in the sample. The size structure of walleye in the sample indicated a population that is dominated by fish greater than 15 inches. The health of the walleye in the sample was good as well. Given a high prevalence of walleye in the sample across multiple year classes, coupled with the good size structure and good overall health of the fish in the sample, the walleye population appears to be doing well. Loon Lake may be one of the more stable populations of stocked walleye in the Windom Fisheries Management Area. The outlook for the walleye population is good and average numbers of healthy fish should be expected to be found in the lake.


Yellow perch are a secondary management species in Loon Lake. The historical yellow perch catch in gill nets shows a decline from highs in the 1980's (2.2 to 2.7 fish per trap net in 1988 and 1983, respectively), to lows in the late 1990's and 2000's (between 0 and 0.8 fish per trap net from 1997 to 2012). The 2012 catch rate of 4.5 fish per gill net is within the normal range of 2.7 to 25.0, albeit the low end of the range, and below the long-term catch rate of 8.7 fish per gill net indicating a population that is lower than expected for Loon Lake. The current catch rate shows some improvement, but careful analysis of the yellow perch population again in 2016 should help to assess whether 2012 is a true increase or simply a temporary increase. Yellow perch in the 2012 sample ranged in length from 5.5 to 10.5 inches. The bright spot of the yellow perch population was the good size structure of the population with 20% of the fish being 10 inches or bigger. The yellow perch in the sample were healthy indicating the fish are finding enough food. Future improvements in the abundance of yellow perch may be directly related to a reduction in the number of predators in the lake. Loon Lake has walleye, black crappie, bluegill, channel catfish, northern pike, and shortnose gar all of which will prey upon the yellow perch population. A reduction in the number or abundance of predators in Loon Lake may increase yellow perch abundance. Future stocking may be needed to help boost the population to levels where they can successfully reproduce if increased abundance does not naturally occur. Fishing for yellow perch will be hit-or-miss over the next 2 to 4 years depending on natural reproduction success.


Northern pike have been stocked 11 times in Loon Lake from 1982 to 2007 as fry, fingerling, yearling, adults, or a combination of each. Since 2009, northern pike fingerlings have been stocked every other year. Seven northern pike were caught in gill nets and trap nets in 2012 with a gill net catch rate of 1 fish per net and a trap net catch rate of 0.3 fish per net. The northern pike gill net catch rate was lower than the normal range of 1.1 to 8.0 for lake class 43. Historically, the northern pike gill net catch rate has never exceeded 4.6 fish per net and it has only been within the normal range during 3 out of 9 surveys (in 1988, 1990, and 1993). Most likely, northern pike will always be at a low abundance in Loon Lake with some years of increased abundance when conditions are right. Conditions were right from 1988 to 1992 which were drought years and low water levels may have led to more aquatic vegetation abundance and increased abundance of northern pike. While the 2012 catch rate was low, the size structure of the fish in the sample was fair with fish ranging in length from 21.0 to 27.2 inches. The health of the northern pike in the sample was good, showing the fish are finding adequate food. Northern pike are creatures of habitat; when favorable habitat is present, including abundant aquatic vegetation, the northern pike population will do well and the population abundance will reflect that. Continued stocking will be needed to keep northern pike present in Loon Lake, but the future outlook for the population is promising as the size structure and health of the population are fair and good, respectively.


Nineteen other species were present in the netting and nearshore sampling in Loon Lake, all of which are not managed and maintain themselves without stocking from the DNR. Those species included bigmouth buffalo, black bullhead, black crappie, bluegill, bluntnose minnow, common carp, channel catfish, fathead minnow, freshwater drum, green sunfish, Iowa darter, johnny darter, largemouth bass, orangespotted sunfish, shortnose gar, white bass, white crappie, white sucker, and yellow bullhead. Including walleye, yellow perch, and northern pike (all discussed above), 22 total species were sampled in Loon Lake during 2012.


Twenty-two species of fish were present in Loon Lake in 2012. A lake that has 22 species of fish exhibits very high diversity, particularly for a class 43 lake in southwest Minnesota. An index of biotic integrity (IBI score) score (from 0 to 100) will be developed for Loon Lake based on the catch of fish in 2012, and future monitoring (every 4 years from 2016 on) will help to determine if conditions are getting better, or worse, for the fish in Loon Lake. A high diversity of fish will most likely lead to a higher IBI score (greater than 50) for Loon Lake relative to other southwest Minnesota lakes, indicating a relatively healthy fish community was present in Loon Lake in 2012. This is further evident by the second highest gill net catch rate observed for walleye in 2012, with a good size structure of fish and fish in good health condition. Yellow perch and northern pike were at lower abundances than expected, but with a large number of predators in Loon Lake it is expected that yellow perch will be heavily preyed upon and northern pike will be in competition for food. Additionally, the prevalence of bluegill in the 2012 sample was a surprise and a highlight in the 2012 fish community sample. The bluegill trap net catch rate has been increasing since 2001 and the 2012 catch rate is the highest on record even though the DNR has not stocked bluegill into the lake since 1982. The increase in the abundance of bluegill in Loon Lake may be a reflection of increased spawning habitat through improved water quality conditions in the lake. Future IBI sampling in addition to managed species monitoring in 2016 and beyond will help to determine if conditions are truly improving or if it merely appeared so in 2012. Best management practices in the surrounding watershed (i.e. treating and slowing agricultural and urban runoff) will greatly improve conditions for fish community in Loon Lake and lead to better water clarity as well.

Prepared by Nate Hodgins

For more information on this lake, contact:

Area Fisheries Supervisor
175 Co Rd 26
Windom, MN 56101-1868
Phone: (507) 831-2900
Internet: Windom Fisheries

Lake maps can be obtained from:

Minnesota Bookstore
660 Olive Street
St. Paul, MN 55155
(651) 297-3000 or (800) 657-3757
To order, use C0523 for the map-id.

For general DNR Information, contact:

DNR Information Center
500 Lafayette Road
St. Paul, MN 55155-4040
TDD: (651) 296-6157 or (888) MINNDNR

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