Lake information report

Name: BASSWOOD

Public Access Information

Fishing Regulations:

Lake Characteristics

Fish Sampled up to the 2005 Survey Year

Length of Selected Species Sampled for All Gear for the 2005 Survey Year

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 08/01/2005)

Basswood Lake is in Ecological Lake Class 2, which consists of 15 lakes in northeast Minnesota that are very large and deep, have very irregular shoreline shapes, and have clear and soft (unmineralized) water. The east end of Basswood Lake (including the portion in Ontario) is deeper, clearer, retains oxygen to a greater depth, and has harder (more mineralized) water than the west end of the lake (Pipestone and Jackfish Bays). In general, the east end of Basswood Lake is oligotrophic and the west end is mesotrophic.

The differences in water quality between the east and west ends of Basswood Lake are largely due to the water source of the major inlets. The east end is fed from Knife Lake to the east and the Moose Lake drainage to the south, and the west end is fed by the Kawishiwi River and Range River to the south and west. Bottom substrates along the shoreline of Basswood Lake are largely ledge rock, boulder, and rubble interspersed with sand.

The 2005 fish population assessment on Basswood Lake, as with previous assessments in 1996, 1985, and 1977, was done in midsummer and consisted of standard gillnets set in and above the thermocline on the Minnesota portion of the lake. With the exception of one gillnet set just north of Washington Island, gillnets were not set in the no-motor portion of Basswood Lake north of Washington Island on the east end of the lake up around U.S. Point and west to Goose Narrows on the west end of the lake. A 1961 joint fisheries investigation with Ontario was done a month earlier, in late June, and used Minnesota and Ontario gillnets set in the entire lake. Data from Minnesota gillnets set in locations comparable to subsequent assessments were extracted from the 1961 investigation for the purpose of comparison.

Fish populations in 2005, as in previous investigations, were dominated by walleye and northern pike, followed by cisco, white sucker, and yellow perch. Good numbers of smallmouth bass are also known to be present in Basswood Lake, and are often targeted by anglers. Bass are "net shy" and difficult to catch in proportion to their abundance with standard sampling nets. Only three smallmouth were captured in the 2005 assessment, all on the east end of the lake; the largest was 15.6".

Walleye numbers in 2005 (15.1/gillnet) were in the fourth quartile for this lake class and were similar to the median walleye catch of 13.1/gillnet in all investigations on this lake. Walleye numbers in the east end of the lake (19.4/gillnet) were higher than in the west end (10.1/gillnet), largely due to a very strong 2001 year class that comprised 63 percent of the east end walleye catch. Walleye ages averaged 3.77 years on the east end of the lake and 3.38 years on the west end.

Walleye sizes in 2005 averaged 14.1" (1.0 lb) in the east end of the lake, which was at the median for this lake class, and 12.1" (0.7 lb) on the west end of the lake, which was in the first quartile for this lake class. The largest walleye (26.2") was caught on the west end of the lake. Growth of walleye captured in 2005 was somewhat slower than normal (in the second quartile by area standards) on the east end of the lake and slower than normal (in the first quartile) in the west end.

Northern pike numbers in 2005 (4.6/gillnet) were in the fourth quartile for this lake class and were similar to the median pike catch of 3.9/gillnet in all investigations on this lake. Pike catches have been remarkable consistent over time, with a range of 3.6-4.6/gillnet. More pike were captured in the east end of the lake in 2005 (5.8/gillnet) than in the west end (3.3/gillnet). Pike sizes in the east end of the lake averaged 22.9" (2.9 lb), and pike sizes in the west end of the lake averaged 22.6" (2.7 lb); both of these were near the first quartile for this lake class. The largest pike captured in 2005 (from the east end) was 38.6". Growth of pike from both ends of the lake was somewhat faster than normal (in the third quartile by area standards).

Cisco numbers in 2005 (4.7/gillnet) were in the second quartile for this lake class and were at the median value for all investigations on this lake. Cisco numbers were similar on each end of the lake, but cisco sizes were larger on the east end of the lake (average of 10.7") than on the west end (average of 9.4"). The largest cisco (caught on the east end) was 17.7". Cisco are probably more abundant in Basswood Lake than indicated by these shallow water gillnet sets that sampled water in and above the thermocline. This is especially true of the east end of the lake, where there is abundant well-oxygenated water below the thermocline that was not sampled by our netting regime.

Cisco samples collected from the east end of Basswood Lake in 2005 were submitted to David Etnier of the University of Tennessee for identification. Dr. Etnier reports that there are likely two species of cisco present in Basswood Lake (Coregonus artedi and C. zenithicus), and possibly a third species (C. nipigon). He is requesting more cisco samples for analysis.

White sucker numbers in 2005 (4.8/gillnet) were in the fourth quartile for this lake class and were at the median value for all investigations on this lake. More sucker were captured in the east end of the lake (6.1/gillnet) than in the west end (3.3/gillnet). Sucker sizes averaged 16.4" (1.9 lb), which was at the median value for this lake class.

Yellow perch numbers in 2005 (5.9/gillnet) were in the third quartile for this lake class and were at the median value for all investigations on this lake. Fewer perch were captured in the east end of the lake (2.4/gillnet) than on the west end (10.0/gillnet). Perch sizes averaged 7.0" (0.17 lb), which was near the median for this lake class and was similar to the average size of 7.1" in all investigations on this lake. The largest perch (12.4") was caught on the west end of the lake. Most of the perch on the west end (64 percent) were from a strong 2002 year class. Perch growth was normal by area standards.

Some of the game fish examined in 2005 were infected with neascus. One of the smallmouth bass had bass tapeworm larvae in its viscera. A few of the cisco had triaenophorus cysts in their muscle tissue, and a few of the perch had yellow grubs under their skin. All of these parasites are common and are native to the area. They cannot infect humans, are often removed by filleting fish, and are killed at temperatures used to cook fish.

Abundant crayfish populations were first observed in the 1985 investigation, when many crayfish (about 300/net) were entangled in the east end gillnets. They were identified as native crayfish at the time (Orconectes virilis and O. immunis) by Ely (later Tower) Area Fisheries staff, but it is likely they were the non-native species Orconectes propinquus (northern clearwater crayfish) or O. rusticus (rusty crayfish). These species have been present in Newfound and Sucker Lakes (just upstream of Prairie Portage) since the 1980's. In 2005, the east end crew counted 221 O. propinquus/gillnet. They also counted 25 rusty crayfish, all in the net nearest Prairie Portage. The west end crew in 2005 counted 58 crayfish (O. propinquus and O. rusticus)/gillnet, but did not separately count these species.

For more information on this lake, contact: Area Fisheries Supervisor 650 Hwy 169 Tower, MN 55790 Phone: (218) 753-2580 Internet: Tower Fisheries E-Mail: Tower.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 B3001,B3009,B3012,C5046 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