Ice-out Winterkill Assessments


Ice-out assessments are used to assess the extent of winterkill in lakes that experienced low dissolved oxygen levels during the previous winter. These lakes are identified by conducting dissolved oxygen tests throughout the winter and observing dead fish after ice-out. Often times, the public notices evidence of winterkill before we do and we encourage anyone to report large numbers of dead fish to our office by phone (320-234-2550) or email.

Typically, the assessments consist of 5 trap nets set overnight. Captured fish are identified, counted, and released. Length and weight measurements are not taken. Dead fish observed while on the lake, live fish caught in the trap nets, and dissolved oxygen (DO) readings during the winter are all summarized and used to assess the extent of winterkill at the lake. These assessments are not made available through Lakefinder but will be posted here soon after they are completed.

Note: Walleye ponds are not usually sampled since they are often stocked regardless of whether or not winterkill occurred.

 

Otter Lake (McLeod Co)

Low DO readings were recorded on Otter Lake as early as 1/7/13. The levels rebounded a bit through most of February but by 2/28/13, DO was measured at less than 1 ppm throughout the basin. Immediately following ice-out, dead fish were observed and large numbers of gulls, pelicans, and cormorants were present and feeding on dead fish throughout the lake. Trap nets were set on 4/25/13 and a count of dead fish along the shoreline revealed hundreds of common carp and dozens of channel catfish. No dead walleyes or other gamefish were observed at that time. On 4/26/13, the trap nets caught a total of 8 northern pike, 1 walleye, 3 black crappies, 1 white crappie, 4 yellow perch, 2 buffalo, 1,000+ bullheads, 15 common carp, and 23 white suckers. Overall, Otter Lake likely experienced a moderate winterkill.

 

Silver Lake (Sibley Co, near Arlington)

DO levels at Silver Lake near Arlington declined from 8.6 ppm on 1/15/13 to 3.2 ppm on 2/14/13. Considering how long the winter lasted, there is a good chance the DO continued to decline in the following weeks. On 4/29/13, trap nets were set and a count of dead fish revealed hundreds of black crappies, walleyes, and bullheads, dozens of sunfish, and a few white suckers common carp. On 4/30/13, trap nets yielded 1,000+ bullheads and nothing more. Overall, Silver Lake likely experienced a severe winterkill.

 

Preston Lake (Renville Co)

DO levels at Preston Lake decreased from 6.9 ppm on 1/4/13 to 1.3 ppm on 3/20/13. Trap nets were set on 4/30/13 and a count of the dead fish revealed more than a thousand dead common carp, white sucker, and yellow perch, hundreds of black crappie, walleyes, and channel catfish, and dozens of northern pike and bluegills. On 5/1/13, a total of 13 white suckers, 1 northern pike, 4 common carp, 4 yellow perch, 2 walleye, and 160+ bullheads were sampled. Overall, nets were light and Preston Lake likely experienced a moderate winterkill.

 

Round Lake (Meeker Co)

Several reports of dead and crowded fish at an open water area near a culvert on Round lake were made in mid to late March. DO levels were sampled on 3/20/13 and revealed extremely low DO levels of less than 1 ppm throughout the lake. Following ice-out, dead fish were abundant throughout the lake. Trap nets were set on 5/1/13 and a count of dead fish revealed hundreds of dead northern pike, yellow perch and bullheads, and dozens of bluegills and black crappies. On 5/2/13, a total of 22 northern pike, 1,000+ bullheads, 1 yellow perch, and 1 golden shiner were sampled. Overall, Round Lake likely experienced a moderate winterkill.

 

Thompson Lake (Meeker Co)

Although aerators were operating throughout the season, low DO levels of 1.2 ppm were recorded on 3/8/13. Trap nets were set on 5/1/13 and a count of dead fish revealed hundreds of dead bluegills and yellow perch, and a few walleyes, common carp, and bullheads. On 5/2/13, a total of 1,000+ bullheads, 800+ yellow perch, 65 common carp, and 1 black crappie were sampled. Overall, Thompson Lake likely experienced a moderate winterkill.

 

Peterson Lake (Meeker Co)

Low DO levels were recorded on Peterson Lake as early as 2/4/13 and continued to decline through the winter. Only 1.8 ppm were recorded on 2/21/13. Trap nets were set on 5/2/13 and a count of dead fish revealed hundreds of dead common carp, bluegills, and black crappies, and dozens of northern pike, largemouth bass, and bullheads. On 5/3/13, a total of 3 common carp, 5 northern pike, 85 black crappies, 4 yellow perch, and 51 bullheads were sampled. Overall, Peterson Lake likely experienced a moderate winterkill.

 

Dunns Lake (Meeker Co)

A low DO reading of 2.1 ppm was recorded at Dunns Lake on 3/20/13. Trap nets were set on 5/2/13 and no dead fish were observed. On 5/3/13, a total of 6 northern pike, 24 walleyes, 16 largemouth bass, 7 black crappies, 80 bluegills, 18 common carp, 2 bullheads, 76 yellow perch, and 1 white sucker were sampled. Although low DO levels were recorded, Dunns Lake likely experienced little to no winterkill.

 

Winsted Lake (McLeod Co)

The aerator on Winsted Lake was shut off temporarily in early February and DO levels below 3.0 ppm were recorded on 2/19/13. After the aerator was back in operation, DO levels rebounded and levels of 4.9 ppm were recorded on 3/8/13. Trap nets were set on 5/6/13 and no dead fish were observed. On 5/7/13, a total of 18 bluegills, 5 yellow perch, 5 northern pike, 3 largemouth bass, 1 white sucker, 3 bigmouth buffalo, 220 black crappie, 21 common carp, and 170 bullheads were sampled. Overall, Winsted Lake likely experienced little to no winterkill.

 

Arville Lake (Meeker Co)

DO levels of less than 1 ppm were recorded on 1/15/13 at Arville Lake and unlimited fishing was allowed until the season closed. Trap nets were set on 5/6/13 and a count of dead fish revealed hundreds of dead common carp, and dozens of white suckers, northern pike, black crappies, bluegills, bowfin, channel catfish, and largemouth bass. On 5/7/13, a total of 19 northern pike, 8 walleyes, 2 largemouth bass, 2 black crappies, 2 yellow perch, 1 white sucker, 1 common carp, and 1,000+ bullheads were sampled. Overall, Arville Lake likely experienced a moderate winterkill.

 

Hook Lake (McLeod Co)

The lowest DO level recorded in Hook Lake was 6.7 ppm on 2/21/13. No tests were conducted later than that but given the lake's history, it's possible DO levels approached or fell below stressful thresholds. Trap nets were set on 5/7/13 and no dead fish were observed. On 5/8/13, a total of 4 largemouth bass, 26 northern pike, 90 black crappies, 12 walleyes, 2 yellow perch, 1 bluegill, 17 common carp, 23 golden shiners, and 140 bullheads were sampled. Overall, Hook Lake likely experienced little to no winterkill.

 

Echo Lake (McLeod Co)

Extremely low DO levels of less than 1 ppm were recorded on Echo Lake on 2/21/13. Trap nets were set on 5/7/13 and hundreds of dead carp and a few northern pike were counted along the shoreline. On 5/8/13, a total of 7 northern pike, 26 black crappies, 31 common carp, and 800+ bullheads were sampled. Since Echo Lake is connected to Hook Lake, it is possible some of these fish migrated from Hook following ice-out. Overall, Echo Lake likely experienced a moderate to severe winterkill.

 

High Island Lake (Sibley Co)

Low DO levels recorded on High Island approached 3 ppm on 3/20/13. Trap nets were set on 5/8/13 and no dead fish were observed. On 5/9/13, a total of 21 walleyes, 32 black crappies, 6 white suckers, 7 green sunfish, 5 yellow perch, 20 common carp, and 5,000+ bullheads were sampled. The walleyes averaged 9 inches long and are likely from the 2011 stocked year-class. Overall, High Island Lake likely experienced little to no winterkill.

 

Hoff Lake (Meeker Co)

Extremely low DO levels of less than 1 ppm were recorded in Hoff Lake on 3/20/13. Trap nets were set on 5/8/13 and only a single dead largemouth bass was observed along shore. On 5/9/13, a total of 100 black crappies, 3 largemouth bass, 2 northern pike, 56 bluegills, 52 yellow perch, 3 golden shiners, 6 bowfin, 2 bigmouth buffalo, 16 common carp, and 1,000+ bullheads were sampled. Overall, Hoff Lake likely experienced little to no winterkill.

 

Long Lake (Meeker Co, near Grove City)

Extremely low DO levels of less than 1 ppm were recorded in Long Lake on 3/20/13. Trap nets were set on 5/9/13 and a count of dead fish revealed hundreds of dead carp, dozens of largemouth bass, and a few yellow perch and white suckers. The majority of the dead fish were seen along the northeast shoreline. On 5/10/13, a total of 10 northern pike, 70 white suckers, 3 yellow perch, and 450+ bullheads were sampled in 4 nets. The fifth net was collapsed and open and did not fish well. Overall, Long Lake likely experienced a moderate winterkill.

 

Updated May 28, 2013