Lake information report

Name: Independence

Nearest Town: Maple Plain Primary County: Hennepin Survey Date: 07/26/2010 Inventory Number: 27017600

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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 07/26/2010)

Lake Independence is an 844-acre lake located in western Hennepin County in the city of Maple Plain. Baker Park Reserve (Three Rivers Park District) borders the southeast portion of the lake and provides a two-lane concrete boat access. Lake Independence offers a diverse sportfish community consisting of black crappie, bluegill, largemouth bass, muskellunge, pumpkinseed, northern pike, walleye, and yellow perch. Since 1999, management plan goals include stocking walleye at 2.0 lb/littoral acre (850 lb) in odd-numbered years while stocking 1000 muskellunge in even-numbered years. A population assessment was conducted, starting in late July 2010, to determine the species composition and abundance of fish in the lake.

Water quality in Lake Independence has been declining in recent years. Three Rivers Park District has been monitoring the water quality and nutrient loading within the lake. Watershed development and the numerous hobby farms within the watershed are suspected to be the source of nutrient input into Lake Independence. Dissolved oxygen levels fell below 2 ppm at 16 ft in 2010, despite the lake's maximum depth of 58 feet.

Walleye abundance (5.1/gill net) is moderately high compared to other similar lakes in the state. However, gill-net catch is below the long-term average (past 7 assessments) of 10.7/net, and is the lowest on record since 1984. Average length and weight were 15.5 inches and 1.95 pounds, with the longest measuring 29.1 inches. Thirty percent were 15 inches or longer, 25% were 20 inches or longer, and 16% were 25 inches or longer. The walleye population is supported by the strong 2007 year class that comprised 50% of the catch. The next strongest year class was in 2009 which comprised 18% of the catch. These 1 and 3 year old fish dominated the sample and should grow into desirable sizes in next 2 to 3 years. Walleye averaged 15 inches by age 4 and 21 inches by age 5.

Black crappie abundance is lower than some of the previous assessments; however, catch was still moderately high in gill nets (14.5/net) and moderate in trap nets (9.1/net) compared to other similar lakes in the state. Mean length and weight of black crappie from both gear types was 7.8 inches and 0.24 pounds. Thirty-four percent were 8 inches or longer and the longest measured 9.5 inches. Ages ranged from 1 through 6. The largest year class was 2004, which comprised 53% of the sample. Black crappie averaged 8 inches by age 4.

Bluegill abundance is high (66.2/trap net) and size is moderate (mean = 0.17 pounds) compared with other similar lakes in the state. Trap net catch is near the long-term average (49.5/net over previous 7 assessments), although is less than half that observed in the last assessment in 2007 (134.6/trap net). Mean length of bluegill in trap nets was 6.0 inches. Sixty-nine percent were 6 inches or longer and the longest measured 7.1 inches. Ages ranged from 2 to 6. The largest year class was 2008, which comprised 42% of the sample. Bluegill averaged 6 inches by age 4.

Northern pike abundance has historically been low in Lake Independence, averaging 2.2/gill net over the previous 7 assessments. In 2010, 1.3/gill net were sampled, which is considered low compared to other similar lakes in the state. Alternatively, size structure is good. Ninety-four percent were 21 inches or longer, 50% were 28 inches or longer, and 19% were 34 inches or longer. Ages 2 through 9 were represented, with the 2007 year class (44%) being the most abundant. Northern pike reached 21 inches by age 3 and 28 inches by age 4.

Nine largemouth bass were collected during the assessment; however, passive sampling gears, such as trap nets and gill nets, are not effective methods for collecting largemouth bass. The data presented for this species is not indicative of relative abundance. Electrofishing is the typical method for largemouth bass assessments but was not conducted during this survey. Mean size was 12.3 inches and 1.2 pounds with the largest reaching 16.1 inches and 2.7 lbs. Fifty-six percent were 12 inches and longer and 22% were 15 inches and longer.

Yellow perch are abundant. Gill net catch was high (39.3/net) compared to other similar lakes in the state. Yellow perch gill net catch has historically remained relatively stable. Current yellow perch numbers are similar to the mean over the previous 7 assessments (40.2/gill net). Mean length and weight were 6.9 inches and 0.14 pounds. Ten percent were 8 inches or longer and the longest measured 9.1 inches. Ages 2 through 6 were represented, with the 2007 year class (56%) being the most abundant. Yellow perch reached 8 inches by age 5.

Spring ice-out trap netting is used to index adult muskellunge abundance but this was not conducted in this assessment, so the data presented for this species is not indicative of relative abundance. However, 7 muskellunge were sampled ranging from 22.6 to 47.6 inches. Lake Independence is a popular muskellunge fishery in the western metro area.

In an assessment of the shallow, nearshore fish community, backpack electrofishing and seining were conducted at two different times throughout the summer. The most abundant species observed were bluegill and bluntnose minnow. Additionally, black bullhead, yellow bullhead, green sunfish, largemouth bass, pumpkinseed, yellow perch, black crappie, hybrid sunfish, walleye, golden shiner, spotfin shiner, fathead minnow, Iowa darter, and Johnny darter were observed. An Index of Biotic Integrity (IBI) was estimated based on all fish sampled in this assessment. The absence of sensitive species contributed to low IBI scores of 68.1 and 83.8, indicating water quality and habitat may be impaired.

Other species sampled in low abundance were common carp and white sucker.

For more information on this lake, contact: Area Fisheries Supervisor 7050 E Hwy 101, Suite 100 Shakopee, MN 55379 Phone: (952) 496-4141 Internet: West Metro Fisheries E-Mail: MetroWest.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 B0031 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