Lake information report

Name: Bowstring

Public Access Information

Fishing Regulations:

Lake Characteristics

Fish Sampled for the 2008 Survey Year

Length of Selected Species (Trapnet, Gillnet) Sampled for the 2008 Survey Year

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

General Population

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

Contaminants listed were measured at levels high enough to warrant a recommendation 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 08/04/2008)

Bowstring Lake is a class 22 lake that outlets through Inger, MN. The lake has four public accesses, several resorts, and moderate shoreline development. The 2003 lake management plan indicates black crappie and walleye as the primary species of management with northern pike and yellow perch as secondary species.

The walleye gill-net catch rate (10.1 fish/net) exceeded the management goal of 8.1 fish/net. Previous assessment catch rates have ranged from 3.5 to 15.0 since 1957. The sampled fish ranged from 9.3 to 25.6 inches and had a mean length of 13.9 inches. Eight year classes were identified from scale and bony structure analysis with fish from two to nine years old. The 2005 and 2006 year classes represented 44 and 30% of the sample. Walleye were last stocked in Bowstring Lake in 1991, therefore, natural reproduction was responsible for all the walleye sampled in 2008. Growth was similar to statewide averages for all ages. Walleye averaged 15.4 inches after four years of growth.

The black crappie trap-net catch (0.7 fish/net) and gill-net catch (0.9 fish/net) were at or above their respective lake class medians. The fish from both gears ranged from 3.5 to 12.6 inches. Two size groups were obvious from the length frequency histogram; fish from 3.5 to 5.0 inches and fish from 10.5 to 12.5 inches. Although five year classes from age 1 to age 8 were documented, age-1 fish represented 83% of the sample. Growth was generally above statewide averages for all ages but still within 15% of the mean.

The northern pike gill-net catch was 5.8 fish/net. The 2008 catch was similar to the 2002 catch of 5.7 fish/net and near the lake class median of 5.0 fish/net. The last two assessments had the lowest catch rates on record and were distinctly lower than all other assessments dating back to 1957 (range was 8.3 to 15.8 fish/net). Spring water levels due to the snow melt can affect the success of northern pike reproduction. Lower northern pike catches may partially be explained by the generally mild winters the area experienced for approximately 10 years prior to 2007. In 2008, the sampled fish ranged from 12.9 to 32.2 inches and had a mean length of 20.1 inches. Eight year classes were identified from cliethra and scales ranging from age 1 to age 8. Three and four year old fish were the most common. Northern pike averaged 20.4 inches by age 4 which was near the statewide average of 20.5.

Yellow perch gill-net catch rates have fluctuated from a low of 14.4 fish/net in 2008 to a high of 59.0 fish/net in 1980. Although the 2008 catch was lower, it was still near the lake class median of 17.1 fish/net. The sampled fish ranged from 5.2 to 11.7 inches and had a mean length of 7.4 inches. The yellow perch population may not attract a lot of attention by anglers due to the lack of larger fish but it still provides an important function in the fish community as prey. Age and growth information was not collected in this assessment.

Tullibee are a species that can be difficult to sample but are also important to fish communities as a prey source. The gill-net catch rate was 0.6 fish/net in this assessment which is just above the 1st quartile for this lake class. Tullibee catch rates have been as low as 0.1 fish/net and as high as 4.8 fish/net with no apparent trend in abundance. The fish ranged from 8.2 to 17.1 inches and had a mean length of 12.8 inches.

Other species observed during the population assessment included bowfin, black bullhead, brown bullhead, largemouth bass, pumpkinseed sunfish, shorthead redhorse, silver redhorse, white sucker, and yellow bullhead.

In order to maintain or improve fish and wildlife populations, water quality and habitat must be protected. People often associate water quality problems with large-scale agricultural, forestry, urban development or industrial practices in the watershed. In reality, the impact of land use decisions on one lake lot may be relatively small, yet, the cumulative impact of those decisions on many lake lots can result in a significant decline in water quality and habitat. For example, removing shoreline and aquatic vegetation, fertilizing lawns, mowing to the edge of the water, installing beach sand blankets, failing septic systems and uncontrolled run-off, all contribute excess nutrients and sediment which degrade water quality and habitat. Understanding these cumulative impacts and taking steps to avoid or minimize them will help to insure our quality fisheries can be enjoyed by future generations.?

For more information on this lake, contact: Area Fisheries Supervisor 1201 East Hwy 2 Grand Rapids, MN 55744 Phone: (218) 327-4430 Internet: Grand Rapids Fisheries E-Mail: GrandRapids.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 B0458 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