Lake information report

Name: Mille Lacs

Public Access Information

Fishing Regulations:

Lake Characteristics

Fish Sampled for the 2012 Survey Year

Length of Selected Species (Trapnet, Gillnet) Sampled for the 2012 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 09/01/2012)

The Mille Lacs Lake game fish community is primarily composed of walleye, yellow perch, northern pike, muskellunge, and smallmouth bass. Other game fish include largemouth bass, bluegill, pumpkinseed and black crappie. Common minnow species include spottail shiner and mimic shiner. Invasive animal species include common carp, zebra mussel, Chinese mystery-snail, banded mystery-snail, and spiny water flea. Curlyleaf pondweed and Eurasian watermilfoil are well established in the lake.

Creel Survey Fishing effort for the 2011-2012 winter season was 1.63 million angler-hours (ang-hrs), about 7% below average. Open water 2012 fishing effort was 1.42 million ang-hrs, which is average. Walleye harvest declined slightly from 2011 levels to 173,900 lbs. Total kill was 310,000 lb, a 35% increase over 2011. Anglers released an additional 1,875,000 lb of walleye, which was almost a 125% increase over 2011. Most of the harvested walleye were age 3 and age 4.

Anglers harvested 6,800 lb of northern pike, and released 102,000 lb. Total kill for pike was 11,000 lb.

Yellow perch harvest was 34,800 lb. Tullibee harvest was 3,250 lb, Anglers caught 66,500 smallmouth bass in 2012, which was the highest ever observed for Mille Lacs Lake.

Fall Assessment Walleye catch per effort (CPE) in the inshore gillnets was 4.8 fish/net and 10.7 lb/net, the lowest ever observed. In offshore nets, walleye CPE was 9.9 fish/net and 25.4 lb/net, which are also the lowest observed. The CPE of walleye longer than 20 inches increased slightly in the offshore nets, and remains at a moderate level of five per net. In the inshore nets, CPE of larger walleye decreased for the second consecutive year to about 2 per net, which is well below peak values of close to 5 per net from 2000-2006. As observed in recent years, the 2000, 2001, 2004, 2009 and now the 2010 year classes are poorly represented in the gill nets, while 2005 through 2008 appear average. Early indications from electro-fishing suggest that the 2011 year may be low and the 2012 year class has the potential to be above average. The proportion of mature walleyes that were male in inshore gill nets decreased to the second lowest observed at 37%. The catch-per-effort of mature males in both the inshore and offshore nets decreased to the lowest levels observed. The number of mature female walleye in the inshore nets decreased in 2012, and is approaching the lowest level observed. Mature females increased slightly in the offshore nets where their numbers continue to remain relatively stable since these nets were first utilized in 1998. Walleye growth was below average for female walleye and the lowest observed for larger males. Growth was average for males ages 1-3. Walleye condition was below average at all sizes, and was the lowest observed for walleye greater than 20 inches.

Northern pike declined in the inshore nets for a second consecutive year to a CPE of 1.2 fish/net. Similarly, the northern pike catch in the 16 specialized northern pike gill nets declined for the second consecutive year to a CPE of 6.1 fish/net. Northern pike catch in the inshore nets went from a historical high in 2010 to below average in 2012. The specialized pike nets that were first set in 2007 went from the highest observed CPE in 2010 to the lowest observed in 2011 and again declined in 2012. The median weight of northern pike was below median at 4.4 lbs. Inshore nets sampled 10 year classes of northern pike, with an unusual observation of ten age 0 fish, which were all caught in a single net. Large pike (>28 inches) had generally been increasing since special regulations were implemented in 1998. In 2012, large pike numbers decreased by almost 50% and were well below average. Approximately 30% of the northern pike caught in the inshore nets were over 28 inches in length. Mature female pike weight in the inshore nets decreased 67%, from the 2010 historical high of 310 lbs to 102 lbs in 2012, which is the lowest weight observed since 2000. While gill net indices suggested a decrease in abundance, current population modeling suggests population biomass was still between 230,000 and 330,000 lbs, which is considerably higher than the average biomass from 1985-1997 of 147,000 lbs. Mark-recapture population estimates are planned for the spring of 2013, for both walleye and northern pike. These independent population estimates should help resolve some of the discrepancies observed between the gill net indices which, indicate sharp declines for these species, and the more robust model outputs that suggest the population decreases are more muted or non-existent.

Yellow perch CPE declined in the inshore gillnets to the lowest observed since 1989 at 19 fish/net and 5.7 lb/net. Gill net CPE of perch larger than 9 in had remained stable for the last five years, but dropped by about 50% to around 7 fish/net in 2012. In the offshore nets, perch CPE also declined by about 50% to a CPE of 17.9 fish/net and 6.3 lb/net.

Tullibee CPE declined sharply by about 88% to 0.2 fish/net and 0.2 lb/net in the inshore nets and increased about 30% to a relatively high level of 20.1 fish/net and 21.8 lb/net in the offshore nets. Sixty-six percent of the tullibee caught in the gill nets were four years old, with no other strong year classes apparent in the population. The difference in magnitude between the inshore and offshore catches, in 2012, may reflect a diminished population that is no longer over-flowing into the less desirable habitat of the near shore region, or it may represent a behavioral shift due to other environmental factors.

Other species were also caught in standard gill nets, generally in low numbers. Burbot continue to exhibit declining numbers, and are now only occasionally observed in the assessment nets. Rock bass increased slightly to above average levels in 2012. Smallmouth bass catch remained at 1.0 fish/net in 2012, the third highest level observed in the inshore gill nets. Trends over the last decade show an increasing smallmouth bass population in the lake.

The forage gill nets showed weak numbers of tullibee and yellow perch at all ages. Age 1 and age 2 tullibee were at moderate levels. Age 0 spottail shiners were relatively high, while age 1+ spottails were moderate to low. Bluntnose minnows were absent in the four panel forage gill nets and observed at trace levels in the six panel nets. The CPE of YOY and age 1 yellow perch in the trawl were among the lowest observed, however, it appears that aquatic invasive species may be interfering with trawl catches, particularly in the Wealthwood area. The size of YOY perch caught in the trawl was the highest ever observed at 3.2 inches, however, the size of YOY perch observed while fall electrofishing was much closer to typical expected average length at 2.8 inches. Reduced forage levels help explain the low condition observed in fall walleyes and suggest an increased propensity for a strong walleye bite for recreational anglers until forage stocks are replenished in early summer. While this was not reflected in the fall angler catch rates, which were low, it was realized in the winter 2012-13 fishing season, which experienced very high angler catch rates of primarily large walleye.

Invasive Species Zebra mussel density increased slightly to 1270/ft2, which was about 1.3 times higher than in 2011, and represents the lowest amount of increase since zebra mussels were first observed in 2005. Veliger (larval zebra mussels) densities generally increased from 2011 levels, particularly from May through July. The 2012 peak levels were the second highest observed in the five years we have been performing veliger counts.

Spiny water flea (Bythotrephes) was observed during each sampling period from May through September with the exception of the May samples. Peak density occurred in September and was 6.1 Bythotrephes per sample. Cursory spot checks of fish stomachs show that age 1+ tullibee and age 1+ yellow perch were consuming spiny water flea. The peak level of spiny water flea observed in 2012 was less than the peak levels observed the previous two years.

More detailed reports are available at http://www.dnr.state.mn.us/areas/fisheries/aitkin/index.html

For more information on this lake, contact: Area Fisheries Supervisor PO Box 138 1200 Minnesota Ave S Aitkin, MN 56431 Phone: (218) 927-7503 Internet: Aitkin Fisheries E-Mail: Aitkin.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 B0212 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