Name: Winnibigoshish

Nearest Town: Bena Primary County: Cass

Survey Date: 06/25/2012 Inventory Number: 11014700

Public Access Information

Ownership	Type	Description
US Forest Service	Earthen
US Forest Service	Concrete
US Forest Service	Concrete
US Forest Service	Concrete
US Forest Service	Concrete
US Forest Service	Concrete
US Forest Service	Concrete
US Forest Service	Concrete

Fishing Regulations:

Special and/or Experimental Fishing Regulations exist on this lake. Please refer to our online Minnesota Fishing Regulations.

Fish Health:
Disease:	Viral Hemorrhagic Septicemia (VHS)	Date Tested:	9/30/2009	Result:	Negative
Source:	MNDNR
Disease:	Heterosporis sp.	Date Tested:	9/29/2009	Result:	Positive
Source:	MNDNR

Lake Characteristics

Lake Area (acres): 56471.4 Littoral Area (acres): 18904 Maximum Depth (ft): 69.8 Water Clarity (ft): 9.4 (4.1-19.5)

Dominant Bottom Substrate: N/A Abundance of Aquatic Plants: N/A Maximum Depth of Plant Growth (ft): N/A

Fish Sampled for the 2012 Survey Year

Species	Gear Used	Number of fish per net		Average Fish Weight (lbs)	Normal Range (lbs)
		Caught	Normal Range
Black Crappie	Gill net	0.04	0.1 - 0.7	0.24	0.2 - 0.5
Brown Bullhead	Gill net	0.13	0.1 - 0.6	1.49	0.6 - 1.2
Lake Whitefish	Gill net	0.04	0.0 - 0.2	2.09	0.3 - 4.4
Northern Pike	Gill net	10.26	0.9 - 4.3	2.37	2.4 - 4.3
Rock Bass	Gill net	0.09	0.1 - 1.1	0.83	0.3 - 0.6
Shorthead Redhorse	Gill net	0.26	0.1 - 0.9	2.18	0.9 - 2.5
Tullibee (cisco)	Gill net	16.04	4.9 - 17.6	0.58	0.4 - 0.5
Walleye	Gill net	9.61	3.3 - 14.8	1.39	0.9 - 1.5
White Sucker	Gill net	3.91	0.8 - 2.4	1.95	1.6 - 2.1
Yellow Perch	Gill net	57.52	9.9 - 57.1	0.18	0.2 - 0.3

Length of Selected Species (Trapnet, Gillnet) Sampled for the 2012 Survey Year

Species	Number of fish caught in each category (inches)
	0-5	6-8	9-11	12-14	15-19	20-24	25-29	30+	Total
black crappie	0	1	0	0	0	0	0	0	1
brown bullhead	0	0	0	3	0	0	0	0	3
lake whitefish	0	0	0	0	1	0	0	0	1
northern pike	0	0	0	4	80	113	30	9	236
rock bass	0	0	2	0	0	0	0	0	2
shorthead redhorse	0	0	1	0	4	1	0	0	6
tullibee (cisco)	0	90	72	205	2	0	0	0	369
walleye	0	3	32	82	82	20	2	0	221
white sucker	0	1	5	21	60	3	0	0	90
yellow perch	324	868	131	0	0	0	0	0	1323

Fish Stocking Activity

Fish Stocked by Species for the Last Ten Years

Stocking Fish Sizes
Fry - Newly hatched fish that are ready to be stocked usually called "swim-ups". Walleye fry are 1/3 of an inch or around 8 mm.
Fingerling - Fingerlings are one to six months old and can range from a size of one to twelve inches depending on the species. Walleye fingerlings range from three to eight inches each fall.
Yearling - Yearling fish are at least one year old. A one-year-old fish can range from three to twenty inches depending on the species. Walleye yearlings average from six to twelve inches.
Adult - Adult fish are fish that have reached maturity. Depending on the species, maturity can be reached at two years of age. Walleye reach maturity between the ages of four and six 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 06/25/2012)

Assessment of Lake Winnibigoshish is completed annually to track changes in abundance and growth of fish species, and physical and chemical characteristics of the lake. The assessment season typically starts with seining and gill netting in late June to early July. The goal of seining is to sample young game and non-game species (including minnows) and to track growth of age-0 walleye and yellow perch (perch). Gill netting is conducted from late June through July to sample game and non-game species age 1 and older. Abundance, growth rates, maturity, presence of parasites etc. is determined from these data. Trawling is conducted in August to continue tracking growth rates of age-0 walleye and perch. Trawling gives us the first clue to abundance of age-0 walleye and perch for that year. Temperature and dissolved oxygen profiles are taken from June through August and water chemistry analysis is done in August to track changes in the system that may affect the ability of some species to prosper or exist in the lake. Plankton sampling was included in standard sampling for 2012. Five samples were taken on eight dates for a total of 40 samples. These samples were taken to determine baseline planktonic species composition.

Walleye; Walleye were sampled at a historic high rate of 9.6 per net. Walleye sampled varied from 8.3 to 26.7 inches with a mean length of 16.3 inches and mean weight of 1.4 pounds. The walleye population appeared to be healthy with most age classes sampled between age 1 and 16. Year-class strength was computed for walleye between age 2 and 7. Two average year classes (2005, and 2007), three strong year classes (2006 and 2009, and 2010), and one weak year class (2008) were sampled. Mean back calculated growth was similar to the Lake Winnibigoshish and statewide average for all ages, attaining 16.7 inches after five growing seasons.

The mean trawl catch rate of 35.6 walleye per hour was lower than average, however, low catch rates may not result in low abundance of that year class. For example, the trawl catch rate of 20.5 young of the year walleye per hour in 2005 resulted in an above average year class. An important factor in year-class strength is growth of those fish during their first year. Young of the year walleye growth was above average in 2012, reaching a mean length of 5.0 inches by mid-August. Fast growth of age 0 walleye often results in a strong year class.

Yellow perch; Perch are an important species both for anglers and as a prey item for predators. The catch of perch in assessment nets reached a historic low catch rate (at the time) in 2005 largely due to poor year classes in 2000 and 2002. A strong 2003 year class moved through the system resulting in higher assessment catch rates through 2007. Gill net catch rates then declined through 2011 to a new historic low of 43.6 per net that year.

Perch were captured at a rate of 57.5 per net in 2012. Perch sampled varied from 5.0 to 11.5 inches with a mean length of 7.1 inches and mean weight of 0.2 pounds. Age classes 2 through 8 and were sampled by the gill nets. An index of year class strength was computed for ages 3 through 7. The 2005, 2008 and 2009 year classes were average, and the 2006 and 2007 year classes were weak. The previously strong 2003 and average 2004 year classes were not well represented in the catch. Natural mortality of perch increases at age 9 and few individuals live past age 10. The catch of perch in 2012 was primarily represented by younger individuals with 87% of the catch made up of age 3 through age 5 fish. Growth was relatively slow through age 2, then increased to average from age 3 to age 8. Perch grew to an average length of 9 inches at age 6.

Relative health of the perch population can be described by the percent of perch longer than nine inches in the gill net catch. The catch of large perch declined to 6% in the early 1990's driven by high angler harvest. Changes in the perch population of Lake Winnibigoshish and other lakes prompted a statewide change in the perch bag limit to 20 daily and 40 in possession in 2001. Several strong year classes were produced during the same time period and the assessment catch of perch longer than nine inches increased to 30% in 2004. In 2005, the proportion of large perch sampled in near-shore gill nets declined for the first time since 1998. The proportion of perch longer than nine inches was about 17% in 2005 and 2006, then declined to 9.8% in 2007 as young perch were recruited to the fishery. Many small fish remain in the population and 10% of the perch sampled in 2012 were longer than nine inches.

The microsporidian parasite heterosporis has been documented in Lake Winnibigoshish yellow perch. No evidence of heterosporis was observed in perch during the 2012 population assessment, however, anglers report the presence of heterosporis in a few perch each year.

The catch rate for age-0 perch of 10,720 per hour of trawling was average. Growth of age-0 perch was slower than average with a mean length of 1.7 inches in mid August. No correlation is evident between trawl catch rates or growth of age-0 perch and year-class strength.

Northern pike; Catch rates of northern pike (pike) showed an increasing trend from 1999 through 2005 and exceeded the third quartile (9.6 per net) in five years between 2002 and 2009. The pike catch rate decreased to 7.3 per gill net in 2010 from 10.0 in 2009 then rose to 8.5 in 2011 and was the third highest observed in 2012 at 10.3 per net. Pike sampled in 2012 varied from 13.9 to 34.1 inches with a mean length of 21.6 inches. All age classes from 1 to 8 were sampled by gill net. The 2009 and 2010 year classes were most abundant and contributed 64% of the catch. Growth rates were similar to the statewide mean through all ages.

Size structure of the pike population has been improving for the last three years. That trend continued in 2012 and extended to the largest fish in the system. Mean length and the number of pike longer than 30 inches was similar to those from 2011 and higher than in any assessments since 2000. Increased size structure can be attributed to several causes. Cisco abundance has increased (cisco are preferred prey that provides more energy than other similar size prey), which may lead to faster growth rates. Reduced abundance of pike may also be beneficial to the pike population since increased pike density can cause more competition for food and space which may lead to decrease growth. The recent increase in catch rate may resut in slower pike growth in the future. Anglers can help maintain the pike size structure by releasing most pike longer than 25 inches.

Cisco; Cisco are a primary prey for muskellunge, pike and walleye. Growth rates of these species can be reduced if cisco are not present in the system. The gill net catch of 16.0 cisco per net in 2012 was nearly identical to the catch of 16.4 per net in 2011. Cisco sampled varied from 6.9 to 16.4 inches with a mean length of 11.3 inches. Cisco catch rates were lower than average for 5 of the last 10 years. This is likely due to warmer than average summer and fall water temperatures that may affect reproduction and cause occasional summer kills. Summer water temperatures were warm during the summer of 2012. This resulted in a moderate summer kill of cisco. Any effect on the cisco population should be short term if average temperatures are experienced in the near future.

Water Quality; Seven temperature and dissolved oxygen profiles were taken between June 25 and August 20, 2012. Dissolved oxygen stratification was evident between July 2 and July 27. No evidence of thermal stratification was found in 2012. Thermal and dissolved oxygen stratification may result during periods of high air temperatures and low wind. When wind speeds increase to moderate levels (15 mph) the entire water column appears to mix.

Invasive Aquatic Species; Species that have been introduced through human activities to a location where they don't naturally occur are termed "invasive". Some invasive species are not necessarily harmful, but others cause ecological or economic problems. Several invasive species have been introduced to Lake Winnibigoshish. Three species of snail: banded mystery, Chinese mystery, and faucet have become established since 2000. Both species of mystery snail appear to have no negative effect at this time. The faucet snail carries a trematode parasite that can kill several species of ducks if ingested. Thousands of ducks were killed by these parasites during the falls of 2007 and 2008. Emerald shiners (often used as bait) are not native and were first sampled in 2005. Juvenile zebra mussel (veliger), were discovered while sampling for plankton in 2012. No adults were found during the summer of 2012. Each of these invasive species were likely introduced through human activities.

For more information on this lake, contact: Area Fisheries Supervisor 1201 East Hwy 2 Grand Rapids, MN 55744 Phone: (218) 327-4430 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 B0010 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