Lake information report

Name: Shetek

Nearest Town: Currie Primary County: Murray Survey Date: 08/09/2010 Inventory Number: 51004600

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Public Access Information

Lake Characteristics

Fish Sampled for the 2010 Survey Year

Length of Selected Species (Trapnet, Gillnet) Sampled for the 2010 Survey Year

Fish Stocking Activity

Fish Stocked by Species for the Last Ten Years

Fish Consumption Guidelines

These fish consumption guidelines help people make choices about which fish to eat and how often. Following the guidelin es 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

General Population

DOWID - MN DNR, Divion 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.

Dioxin
Mercury
PCBS - Polychlorinated biphenyls
PFOS - Perfluorooctane sulfanate

Status of the Fishery (as of 08/09/2010)

Covering 3,596 acres, Lake Shetek is the largest lake in the Windom Area. It has a shoreline length of 31.7 miles and a maximum depth of ten feet. The immediate shoreline is covered primarily by woodland areas, and the majority of the surrounding watershed is cultivated. The watershed-to-lake ratio is 23 to 1 indicating a large impact of the surrounding landuse to the lake. Shoalwater areas are dominated by sand and gravel substrate. As with most lakes in the Windom Area, aquatic vegetation is considered sparse. Lake Shetek is a class 41 lake based on the above features, which is characteristic of southern Minnesota lakes. Lake Shetek is managed primarily for walleye while providing secondary populations of black crappie, yellow perch, and northern pike. A population assessment was conducted 9 August, 2010 to assess the fish community.

During the winter of 2009-2010 oxygen levels dropped to 1.6 parts per million (ppm) in the north half of Shetek and 1.0 ppm in the south half of the lake by the middle of February, 2010. Fish experience stress due to oxygen deprivation at or below 5.0 ppm with conditions becoming critical at 2.0 ppm. Many dead fish were observed after the ice went off the lake. Trap nets were set in the north and south basins in April of 2010 to assess the severity of the winterkill. Primary management species such as walleye, black crappie, yellow perch, and northern pike did not experience noticeable negative effects from the winterkill as they were all present in good numbers in the trap nets. The August 2010 population assessment set out to determine the true impacts, if any, of the winterkill.

The walleye catch rate during 2010 was 15.0 fish/gill net, which was near the upper expected range. The long-term average gill net catch rate since 1983 is 14.3 fish/gill net; the current catch rate exceeds the long-term average as well as exceeding the management goal of maintaining more than 12 walleye/gill net. In addition, the trap net catch rate was 7.3 fish/trap net which is over 4 times the upper expected range of 1.7 walleye/trap net. Trap nets usually are not a good indication of walleye abundance, but when gill net and trap net catch rates are high, as was seen in 2010, the population abundance is usually high as well. The average length of walleye was 13 inches and fish ranged in length from 10 to 22 inches. The size structure of the population favored smaller fish. The overall condition was fair and indicated that the walleye may have been experiencing some foraging stress. With a winterkill during 2009-2010, it is possible that the forage base (minnows) for walleye was thinned out, leading to competition for remaining food. The outlook remains good for the walleye population in Lake Shetek, minnow species usually rebound quickly which should allow for additional growth and an increase in the condition of the walleye. In 2010, 6 age groups of walleye were present representing the 2009, 2008, 2007, 2006, 2005, and 1998 year classes. The growth of walleye was fair with fish reaching 13 to 15 inches between ages 4 and 5. A follow-up population assessment will be conducted during the summer of 2011 to monitor the walleye population and assess growth, overall condition, stocking plan (fry every 2 of 3 years with next blank year in 2012), and abundance of walleye. The walleye population appears primed to make a comeback in Lake Shetek as the catch rates are high and in a few years the population will consist of larger fish.

The black crappie catch rates were 14.8 fish/trap net and 7.8 fish/gill net. The 2010 trap net catch rate was higher than the upper expected value of 12.3 fish/trap net, and the gill net catch rate was within the expected range of 0.8 to 11.1 fish/gill net. The average length of black crappie was 7.5 inches with a range of 3 to 11 inches. The size structure of the black crappie indicated a population that has a balanced size structure with 33% of the black crappie larger than 8 inches and 12% larger than 10 inches. The overall condition of the black crappie was excellent indicating a population of black crappie that is foraging successfully. The black crappie population currently meets the management goal of maintaining a catch rate within the expected range. Lake Shetek appears primed to have a good black crappie population with many fish larger than 8 inches and some 10 inch plus fish. The next several years should hold an opportunity for good black crappie fishing.

The yellow perch catch rates were 4.0 fish/gill net and 3.7 fish/trap net. The 2010 gill net catch rate was within the expected range of 3.0 to 22.5 fish/gill net, and the trap net catch rate was higher than the expected catch rate of 2.6 fish/trap net and higher than the long-term average catch rate of 3.4 fish/trap net in Lake Shetek. Yellow perch population abundance and size structure are best assessed with the gill net catch as yellow perch are most effectively caught with gill nets. The average length of yellow perch in the gill nets was 8 inches and yellow perch ranged from 7.5 to 12 inches. The size structure of the yellow perch indicated that the population was balanced and did not favor smaller or larger fish. The overall condition of the yellow perch was good and indicated that the yellow perch were foraging successfully. The yellow perch population currently meets the management goal of maintaining a catch rate within the expected range. While the population abundance is near the lower end of the expected range, the size of yellow perch is good with 55% of the fish larger than 8 inches. Fishing for yellow perch in Lake Shetek should be productive over the next couple years with the majority of the fish being larger than 8 inches with some 10 inch or larger.

The 2010 northern pike catch rates were 0.2 fish/gill net and 0.3 fish/trap net. The 2010 gill net catch rate was lower than the 25% quartile of 1.2 fish/gill net for lake class 41. The average length of all northern pike was 26 inches and fish ranged from 20 to 35 inches. The size structure indicated a population of northern pike that was dominated by larger fish with 80% of the fish being larger than 21 inches and 20% being larger than 35 inches. While the average weight of northern pike was excellent at nearly 4 pounds per northern pike caught, which exceeded the expected range of 1.5 to 3 pounds, the overall condition was relatively low indicating a population of northern pike that may be experiencing some stress. The northern pike population metrics indicate that the current management goal of maintaining a catch rate within the expected catch range has not been met. The catch rate for northern pike has only been within the expected range of 1 to 8 fish/gill net) during one year, back in 1983. Northern pike are stocked every year in Lake Shetek, but it appears an increased stocking rate may be needed. Stocking is only effective if habitat and resources are available to support the fish, northern pike may be experiencing some habitat and resource scarcity in Lake Shetek. Habitat improvements in Lake Shetek will go a long way in improving the conditions for northern pike, without habitat improvements the pike abundance in Lake Shetek will remain low.

Channel catfish numbers were the lowest they have been since 2006. The winterkill of 2009-2010 may have reduced their abundance slightly. It would also appear the significant winterkill of 2009-2010 had little impact to common carp or bigmouth buffalo as their catch rates were within or above the expected range. Black bullhead numbers continue to remain at low levels. Since 2006 only 8 black bullhead have been sampled in trap nets.

Other species caught in 2010 were bigmouth buffalo, black bullhead, bluegill, brown bullhead, channel catfish, common carp, green sunfish, orangespotted sunfish, quillback, white crappie, white sucker, and yellow bullhead. Of the species listed above, bigmouth buffalo, channel catfish, and white sucker all had catch rates above their expected catch rates indicating good population abundances. It appears at second glance that the bigmouth buffalo population may not have experienced as much of a decline due to the winterkill as we first thought. The average size of the buffalo may have decreased slightly indicating the loss of large fish, but the numbers have increased since 2009. Brown bullhead, common carp, quillback, and white crappie all had catch rates within their respective expected catch ranges. Black bullhead, bluegill, green sunfish, orangespotted sunfish, and yellow bullhead all had catch rates lower than their respective expected catch ranges. Of those species with a catch rate lower than the expected catch range, it is possible that the time of year (late summer) may have negatively influenced catch rate due to high water temperatures, or changing weather patterns. The overall condition of all the species listed above was good and indicated good foraging conditions. The exceptions were bigmouth buffalo and common carp, both of which were in fair condition and may have suggested some kind of foraging stress.

To maintain a healthy fish community in Lake Shetek, we need to promote Best Management Practices (BMPs) within the watershed to help reduce nutrients entering the lake. High nutrients and sediments in a lake can cause algae blooms and reduce water clarity and may alter the food chain in a lake causing foraging stress and reduced overall condition of the fish. Improved conditions in the surrounding watershed will lead to improve water quality and habitat within the lake.

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 E-Mail: Windom.Fisheries@state.mn.us	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 B0292 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 Internet: www.dnr.state.mn.us E-Mail: info.dnr@state.mn.us	Turn in Poachers (TIP):     Toll-free: (800) 652-9093