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Whitefish (Bardon) Lake - Fishery Survey Report Douglas County, Wisconsin, 2014-2015

WBIC Code: 2694000

Scott Toshner Fisheries Biologist

Wisconsin Department of Natural Resources Northern District – Brule

April, 2017

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Executive Summary

The fisheries of Whitefish (Bardon) Lake (Douglas County) were surveyed during 2014-2015.

Walleye abundance has increased by one third when comparing average density from 1988 to 2009 {2.0

fish/acre (SD = 1.0, N = 5)} to 2014 (3.2 fish/acre) and is now above the state walleye management

objective of 3.0 adults/acre. Walleye abundance in Whitefish Lake was also above the Bayfield and

Douglas County naturally reproducing lakes average of 3.0 adults/acre (SD = 2.0, N = 66) from 1991 to

2013. Recruitment of walleye was sustained entirely by natural reproduction since stocking was

discontinued after 1993. Northern pike were present in low abundance. Largemouth and smallmouth

bass abundances were considered normal and size structures large when comparing to similar lakes.

Bluegills have increased in abundance in Whitefish Lake and are increasingly being targeted by anglers.

Management recommendations include; 1) Continue annual fall electrofishing to evaluate walleye

year class strength. Complete adult walleye population estimates every 6 years along with gathering

data on northern pike abundance and length metrics, smallmouth and largemouth bass abundance and

length metrics and panfish community metrics through SE II electrofishing surveys. 2) Implement an 18

inch minimum length for smallmouth bass with a 1 fish/day bag limit and a no minimum length limit for

largemouth bass with a daily bag limit of 5 fish/day. These regulations will protect the high quality

smallmouth bass fishery while providing a harvest opportunity for largemouth bass. Retain all other

angling regulations for other species. 3) Continue to partner with interested anglers and the Whitefish

Lake Association to follow the adopted lake management plan and disseminate data.

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Introduction

Whitefish Lake, also known as Bardon Lake, is an 832-acre seepage lake with very clear, soft water and

excellent water clarity. It has been designated as an “Outstanding Resource Water” under Natural Resources

Administrative Code 102 and is the deepest inland lake in Douglas County, with a maximum depth of 102 feet

and a mean depth of 30 feet. The mean summer secchi disk depth (TSI) value on Whitefish Lake between 1995

and 2015 was 30.5 (SD = 2.9, N = 149). Average summer chlorophyll-a and total phosphorus TSI values were

41.8 (SD = 4.5, N = 62) and 39.5 (SD = 4.1, N = 69) respectively, over the same time period. Trophic state

index (TSI) values were calculated for water clarity (secchi disk measurements), chlorophyll-a, and total

phosphorus values on Whitefish Lake from 1995 to 2015. TSI is an index for evaluating the trophic state or

nutrient condition of lakes and represents a continuum ranging from very clear, nutrient poor water (low TSI’s)

to extremely productive, nutrient rich water (high TSI’s). Overall, data from Whitefish Lake indicates that it is

slightly mesotrophic when considering chlorophyll-a and total phosphorus values and oligotrophic when

considering secchi disk TSI values. Linear regression of TSI values indicate no significant trend in secchi disk

TSI values (r2 = 0.0003, p = 0.84). While both chlorophyll-a TSI (positive) and total phosphorus TSI (negative)

had significant trends (chlorophyll-a TSI, r2 = 0.42, p < 0.0005; total phosphorus TSI, r2 = 0.15, p = 0.001).

As a result of limited nutrient availability characteristic of oligotrophic lakes, density of aquatic

vegetation is low to moderate in Whitefish Lake. Aquatic plant diversity in Whitefish Lake is also relatively

average for northern Wisconsin Lakes (Toshner 2004). A “Sensitive Area Designation Survey” of Whitefish

Lake in 2003 identified a total of twenty different aquatic plant species occurring within sensitive areas, and no

exotic species (Toshner 2004).

Whitefish Lake has no tributaries or natural surface water inlets or outlets, with water levels being

maintained as a result of the water table. Water levels declined by approximately 2 to 3 vertical feet during the

drought which occurred from 2006 to 2011. Water levels where near normal during the 2014 survey.

Topographically, the lake consists of two deep basins connected by a narrows section. Littoral substrates are

over ninety-five percent sand (Weiher 1967), but some soft detrital sediments overlay sand in areas of greater

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depths outward of two to five feet. The shoreline of Whitefish Lake is highly developed, with over 85 cottages

and permanent homes. The upland shoreline area is dominated by oak (Quercus sp.), aspen (Populus sp.), jack

pine (Pinus banksiana) and red pine (P. resinosa). Adequate public access consists of a boat landing with

parking located at the southwest end of the lake off of Whitefish Lake Road.

Whitefish Lake has a history of fish stocking dating back to 1934 (Table 2). Prior to 1949, only walleye

(Sander vitreus) and largemouth bass (Micropterus salmoides) were stocked. From 1949 to 1952, smallmouth

bass (M. dolomieui) and northern pike (Esox lucius) were stocked in addition to walleye and largemouth bass.

In 1958, Kamloops strain rainbow trout (Oncorhynchus mykiss) were introduced, and continuing through 1977

the lake was managed for salmonids in addition to warm water fish. During that time period it was stocked

mostly with rainbow trout and brown trout (Salmo trutta), but also with brook trout (Salvelinus fontinalis) from

1962 - 1965, lake trout (S. namaycush) in 1964, and coho salmon (O. kisutch) in 1970-71. The main factors

contributing to the initiation of this two-story management plan were Whitefish Lake’s cold water temperatures,

the large numbers of cisco (Coregonus artedii) present, and the abundant volume of deep water (Schram 1979).

Although minor numbers of trout have been sampled during fishery surveys in 1959, 1961, 1967, and 1977, no

evidence of natural reproduction has been found to occur to date for any salmonids stocked in Whitefish Lake.

After a variety of fishery surveys were performed in 1977, recommendations were to stock walleye in

order to diversify the fishery and provide additional predation on bluegill (Schram 1979). Since 1978,

Whitefish Lake has continued to be managed as a two-story fishery for both warm and coldwater fish species,

with management primarily directed towards walleye, largemouth and smallmouth bass, northern pike, brown

trout and rainbow trout, and panfish species; including, bluegill (Lepomis macrochirus), black crappie (Pomoxis

nigromaculatus), and yellow perch (Perca flavescens). Trout stocking was to be done every third year under

this management plan (Kampa 1988). Almost 397,000 walleye fingerlings were stocked from 1978 – 1993;

however, walleye stocking was discontinued after 1993 because natural reproduction was sufficiently

maintaining the fishery (it was also thought they were drastically reducing abundance of panfish populations).

Although it was recommended by Kampa (1988) that yearling rainbow trout be stocked every third year

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because there was evidence of some year-to-year carry-over, stocking of rainbows was discontinued after 1991

in hopes that brown trout would survive better because of less stringent habitat requirements (Sand 1991).

Brown trout continued to be stocked approximately every third year until 2009 when all trout stocking was

discontinued after gill net and hydroacoustic surveys completed in 2006 and 2007 found healthy populations of

cisco (Hrabik 2007). Limiting predation and competition with cisco (native species) with brown trout (non-

native species) was thought to be prudent in preserving and protecting cisco populations.

Other fish species documented as present from past surveys of Whitefish Lake include: pumpkinseed (L.

gibbosus), green sunfish (L. cyanellus), warmouth (L. gulosus), rock bass (Ambloplites rupestris), yellow

bullhead (Ictalurus natalis), black bullhead (I. melas), channel catfish (I. punctatus), white sucker (Catostomus

commersoni), shorthead redhorse (Moxostoma macrolepidotum), banded killifish (Fundulus diaphanus), johnny

darter (Etheostoma nigrum). Iowa darter (E. exile), creek chub (Semotilus atromaculatus), bluntnose minnow

(Pimephales notatus), fathead minnow (P. promelas), golden shiner (Notemigonus crysoleucas), common

shiner (Notropis cornutus), spottail shiner (N. hudsonius), mimic shiner (N. volucellus) and blacknose shiner (N.

heterolepis).

Fishing regulations for walleye have changed over time in Whitefish Lake. Until 1989 these changes

had been in concurrence with statewide bag and length limit changes. This included a minimum length of 13

inches from 1966 through 1974 and a change back to no minimum length for walleye from 1974 through 1989.

In 1990, the length limit for walleye was again changed to the present statewide minimum length of 15 inches.

Beginning in 2015 the walleye regulation changed to a minimum length limit of 15 inches and a no harvest slot

length limit of 20 to 24 inches with 1 fish over 24 inches allowed and a daily bag limit of 3 fish. Northern pike,

bass, and panfish regulations on Whitefish Lake have followed the statewide bag and length limits in place at

the time.

Recent management has included fall electrofishing surveys nearly every year since 1991 to assess year-

class strength of young-of-the-year (YOY) and yearling walleye. The last comprehensive fisheries surveys

conducted by Wisconsin DNR personnel took place in 1988, 1991, 2005 and 2009 with adult walleye

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population estimates performed those years using methods as outlined by Hennessey (2002) for treaty

assessment work. Creel surveys to assess fishing pressure and harvest were also performed in those years with

the exception of 2009. In addition, the Great Lakes Indian Fish and Wildlife Commission (GLIFWC)

performed a walleye population estimate in 2001.

The objective of the 2014-2015 survey of Whitefish Lake was to determine the present status of walleye,

largemouth and smallmouth bass populations, along with sport and tribal use of these species. More

specifically, we were interested in determining abundance, growth, size structure and harvest of walleye and

bass. In addition, we hoped to determine some population parameters for panfish in Whitefish Lake.

Methods

Whitefish Lake was sampled during 2014-2015 following the Wisconsin Department of Natural

Resources comprehensive treat assessment protocol (Hennessey 2002). This sampling included spring fyke

netting and electroshocking to estimate walleye, bass (both largemouth and smallmouth) and northern pike

abundance and fall electroshocking to estimate year class strength of walleye young-of-the-year (YOY), and a

creel survey (both open water and ice fishing).

Walleye were captured for marking in the spring shortly after ice out with fyke nets. Each fish was

measured (total length; inches and tenths) and fin-clipped. Adult (mature) walleyes were defined as all fish for

which sex could be determined and all fish 15 in or longer. Sexable adult walleye and walleye ≥ 15 inches were

given a primary fin clip. Walleyes of unknown sex less than 15 inches in length were classified as juveniles

(immature) and were marked with a secondary fin clip. Marking effort was based on a goal of marking 10% of

the anticipated spawning population estimate. To estimate adult abundance, walleyes were recaptured 1-2 days

after netting. Because the interval between marking and recapture was short, electrofishing of the entire

shoreline was conducted to ensure equal vulnerability of marked and unmarked walleyes to capture. All

walleyes in the recapture run were measured and examined for marks. Population estimates were calculated

with the Chapman modification of the Petersen Estimator using the equation:

)1()1)(1(

+++

=R

CMN

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where N is the population estimate, M is the total number of marked fish in the lake, C is the total number of

fish captured in the recapture sample, and R is the total number of marked fish captured. The Chapman

Modification method is used because simple Petersen Estimates tend to overestimate population sizes when R is

relatively small (Ricker 1975). Abundance and variance were estimated for walleye that were ≥ 15 in and

sexable.

Northern pike catch per unit effort and size structure indices (CPUE: the number of northern pike

caught/net lift) were calculated from the spring netting survey in 2009. Northern pike were not counted or

measured in the 2014 fyke netting survey. Largemouth and smallmouth bass encountered during fyke netting

and subsequent electroshocking runs (adult and total walleye) were marked. Bass ≥ 12.0 in were given the

same primary (adult) fin-clip given to walleye for that lake. Bass 8.0-11.9 in were given the secondary

(juvenile) fin-clip for the lake. For comparison purposes catch per unit effort (CPUE: the number of largemouth

or smallmouth bass caught/mile of electroshocking ≥ 8 inches) and size structure indices were calculated from

the second electroshocking survey. Comparison of bass abundance and size structure utilized the bass lakes

classification tool (Hansen and Hansen 2016, unpublished) for which Whitefish Lake is classed as “cool clear”

for largemouth bass and “deep cool large” for smallmouth bass. Panfish catch per unit effort (CPUE: the

number of panfish caught/mile of shoreline) and size structure indices were calculated from the second

electrofishing surveys which occurred in May of 2009 and June of 2014. These surveys contained three ½ mile

index stations in 2009 and two ½ mile of index stations in 2014 in which all fish encountered were collected.

Walleye age and growth were determined from dorsal spine cross sections viewed microscopically at

100X (Margenau 1982). Age and growth of other fish species were determined by viewing acetate scale

impressions under a 30X microfilm projector. Growth rates for all species were compared to an 18 county

regional mean (Northern Region) using the Fisheries and Habitat database. Size structure quality of species

sampled was determined using the indices proportional (PSD) and relative (RSD) stock densities (Anderson and

Gutreuter 1983). The PSD and RSD value for a species is the number of fish of a specified length and longer

divided by the number of fish of stock length or longer, the result multiplied by 100 (Appendix Table 1).

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Changes in population size structure were determined using Kolmogorov-Smirnov tests. Changes in mean

length were determined using a regression model.

A random stratified roving access design was used for creel surveys (Beard et al. 1997; Rasmussen et al.

1998). The survey was stratified by month and day-type (weekend / holiday or weekday), and the creel clerk

conducted interviews at random within these strata. The survey was conducted on all weekends and holidays,

and a randomly chosen two or three weekdays each week. Only completed-trip interview information was used

in the analysis. The clerk recorded effort, catch, harvest, and targeted species from anglers completing their

fishing trip. The clerk also measured the total length of harvested fish and examined them for fin-clips.

Results

Total survey effort in 2014 included 46 fyke net lifts targeting spawning gamefish. Three

electroshocking surveys of the entire shoreline totaling 6.5 hours in spring (first and second recapture surveys)

and 2.6 hours in fall (walleye recruitment survey) were conducted.

Walleye. Adult walleye abundance (≥ 15 in and sexable fish) was 2,626 (CV = 22%; 3.2 adults/acre) in 2014.

Adult walleye density has increased since 2005 (Figure 1). Density estimates from 1988 to 2014 averaged 2.2

fish/acre (SD = 1.0, N = 6). Adult walleye density in 2014 was the highest of all surveys conducted.

Length frequency of walleye captured in fyke nets in 1988, 1991, 2001, 2005, 2009 and 2014 suggests

significant shifts in size structure between all years, except 1988 and 2014 (Table 2; Figure 2). Mean length for

sexable walleye was not significantly different among years and ranged from 15.0 to 16.6 inches (t-statistic =

1.64, p = 0.18; Table 3). Proportional stock density (PSD) values ranged from 42 (1991) to 93 (2001). RSD-20

values ranged narrowly from 0 (2001) to 8 (2014), indicating the proportion of walleye over 20 in has been low

for all survey years (Table 3).

Age of adult walleye sampled during the 2014 survey ranged from III to XIV. Male and female walleye

first reached maturity at III and IV, respectively. Age IV walleye accounted for 39% of the adult stock. Age

distribution data indicate fairly consistent naturally reproduced year classes (Figure 3). Growth rates for both

sexes were dimorphic with males reaching 15 inches between ages IV and V and females prior to age IV in the

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2014 survey. Male walleye growth rates in 1988 and 1991 were predominately below Northern District

averages, especially for age VIII and younger. While male walleye growth rates were near or above Northern

District average in 2005, 2009 and 2014 up to age X (Figure 4). Female walleye grew slower than Northern

District averages with a few exceptions in 1991 and 2014 (Figure 5).

Relative abundance of age-0 walleye in Whitefish Lake in 2015 was 17.1 fish/mile for fall

electrofishing. The average walleye age-0/mile was 34.6 (SD = 36.3, N = 21) for surveys completed from 1986

to 2015 by both WDNR and GLIFWC. However, age-0 relative abundance has been highly variable from 1986

to 2015 with a range of 2.5 fish/mile to 140.0 fish/mile (Figure 6). Mean relative abundance of YOY walleye

for naturally reproducing walleye lakes surveyed by WDNR in Bayfield and Douglas Counties from 1986 to

2015 was 21.0 fish/mile (SD = 42.4, N = 376).

Smallmouth and Largemouth Bass. In 2014, smallmouth bass represented 55% and largemouth bass

45% of the total number of bass surveyed (N = 58). Largemouth and smallmouth bass abundance has increased

since 1991. However, when compared to lakes in the same class, smallmouth bass abundance was within the

33rd to 66th percentile (“normal”) and largemouth bass abundance was within the 10th to 33rd percentile (“low”;

Figure 7). Smallmouth bass PSD and RSD-14 values were 80 (> 90th percentile “very high”) and 43 and the

longest fish was 18.2 inches for the 2014 survey. Largemouth bass PSD and RSD-15 values were 88 (>90th

percentile “very high”) and 42 and the longest fish was 19.2 inches for the 2014 survey.

Northern Pike. Northern pike were not measured or counted during the 2014 spring netting survey.

However, data from 1991, 2005 and 2009 indicated a low density northern pike population. Ten northern pike

were sampled in 1991; the longest fish was 28.3 inches. Thirty eight northern pike were sampled in the 2005

survey; the longest fish was 34.3 inches. Ten northern pike were sampled in the 2009 survey; the longest fish

was 44.5 inches.

Panfish. Yellow perch were the most abundant panfish species sampled in the 2009 and 2014 spring

electrofishing surveys. Yellow perch relative abundance was 158 fish/mile in 2009 and 130 fish/mile in 2014.

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The average length of yellow perch was 2.5 and 3.3 inches in 2009 and 2014, respectively. The longest yellow

perch sampled was in 2014 and was 5.1 inches.

Bluegill relative abundance was 0 and 35 fish/mile in 2009 and 2014, respectively. The longest bluegill

caught in 2014 was 7.4 inches. Rock bass were the only other panfish species encountered and were low in

abundance (1.3 and 11.0 fish/mile for 2009 and 2014, respectively).

Sport and Tribal Fishery. Anglers fished an estimated 7,742 hours (9.3 hrs/acre) during the 2014-2015

(hereafter referred to as 2014) season in Whitefish Lake, which is below the average of 24.5 (SD = 14.3, N =

62) hrs/acre for Bayfield and Douglas County walleye lakes (WDNR unpublished data, Brule field office) and

below the Northern Wisconsin Region (22 counties) average of 32.2 (SD = 24.2, N = 562) hrs/acre from 1990

to 2015. Fishing pressure increased on Whitefish Lake in 2014 when compared to the 1991 creel survey (7.5

hrs/acre). Open water anglers accounted for 84% of all fishing effort in 2014. Directed effort for gamefish (i.e.

effort targeted toward a specific gamefish) was highest for walleye (57%). The most sought after panfish

species was bluegill, with 7% of the directed effort.

Walleye were the most heavily exploited gamefish in Whitefish Lake. An estimated 3,449 walleye were

caught in the open water and ice season of 2014 of which 31% (1,059) were harvested. The open water season

accounted for 99.8% of the total walleye harvest, which was higher than 1993 (70%). Average length of angler

harvested walleye was 17.2 in (SD = 1.7, N = 222). Projected total harvest by anglers was higher in 2014

(1,059) when compared to 1991 (394). Angler exploitation, calculated by dividing the estimated number of

marked walleye harvested by the total number of marked walleye, was 14% in 2014.

Tribal harvest accounted for 51 walleye in 2014. Tribal harvest represented 5% of the combined total

harvest (sport angling plus tribal spearing) and tribal exploitation of the adult walleye population was 2%. Total

walleye exploitation (sport and tribal) was 16% in 2014 and 10% in 1991. Harvested walleye ranged from 12.4

to 26.4 inches. The mean length of tribally harvested walleye was 18.1 inches (SD = 3.3, N = 51) and 14%

were < 15 inches. Male and female walleye represented 16% and 27% of the total tribal harvest, respectively.

The remaining 57% were walleye of unknown sex.

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The second most sought after gamefish species by anglers was smallmouth bass with 20.3% of the

directed effort. In comparison, the directed effort for smallmouth bass was 15.8% in 1991. In 2014, an

estimated 1,142 smallmouth bass were caught, an estimated 165 of which were harvested. The mean length of

angler harvested smallmouth bass was 17.1 (SD = 1.7, N = 33) inches.

Northern pike and largemouth bass attracted low angler effort and had low estimated catch and harvest

on Whitefish Lake in 2014. Northern pike directed effort was 4.3% with an estimated catch and harvest of 57

and 11 fish. Largemouth bass directed effort was 8.5 % with and estimated catch and harvest of 155 and 13

fish. Even though low numbers were encountered by anglers the average size of harvest northern pike was high.

Average length of northern pike was 30.0 inches (SD = 3.5, N = 6) while the longest fish measured by the creel

clerk was 36.1 inches. One largemouth bass was measured by the creel clerk at 18.1 inches.

Bluegill was the most sought after panfish species by anglers in 2014 with 7.3% of the directed effort.

Angler estimated catch and harvest of bluegill has increased since 1991. Bluegill estimated catch and harvest

was 2,934 and 1,051 in 2014. In 1991, catch and harvest for bluegill was 38 and 7. Mean length of harvested

bluegill was 7.4 inches (SD = 0.8, N = 135) in 2014. The only other panfish with estimated harvest were rock

bass. Estimated harvest of rock bass was 84 fish in 2014. Black crappie and yellow perch were rarely sought

after by anglers in 2014.

Discussion

Whitefish Lake has supported, and continues to support a diverse fish community and popular sport

fisheries. Natural reproduction supports all species. Harvest management aimed at maintaining self-sustaining

stocks has been largely successful. The recent increase in walleye abundance could be related to shifting habitat

types and is in contrast to declining walleye abundance throughout the northwest section of the state.

Walleye abundance has increased by one third when comparing average density from 1988 to 2009 {2.0

fish/acre (SD = 1.0, N = 5)} to 2014 (3.2 fish/acre) and is now above the state walleye management objective of

3.0 adults/acre. Walleye abundance on Whitefish Lake was also above the Bayfield and Douglas County

naturally reproducing lakes average of 3.0 adults/acre (SD = 2.0, N = 66) from 1991 to 2013. Interestingly,

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the walleye abundance increase on Whitefish Lake was contrary to the decline of Bayfield and Douglas

Counties naturally reproducing walleye lakes. Walleye abundance on naturally reproducing walleye lakes in

Bayfield and Douglas Counties declined from 3.7 (SD = 2.2, N = 33) adults/acre from 1991 to 2001 to 2.3 (SD

= 1.3, N = 33) adults/acre from 2002 to 2013. A change in length indices and age composition suggests a shift

to smaller, younger fish which could be attributed to a large year class in 2011. Factors contributing to the

increase in adult walleye abundance may be related to increases in habitat due to an approximately 4 foot

increase in water level after the drought of the mid-2000’s and related large sporadic year class strength.

Exploitation levels below 35% are generally thought to be sustainable and are the exploitation levels that

are used to determine total allowable catch for the combined fishery of angler and tribal harvest for walleye in

the state of Wisconsin. Exploitation levels found on Whitefish Lake have remained below 35%. Recent

research using data from northern Wisconsin ceded territory walleye populations suggest sustainable walleye

exploitation of ~20% (Tsehaye et al. 2016). Walleye exploitation on Whitefish Lake remains below 20%.

Smallmouth bass abundance on Whitefish Lake was considered normal when compared to lakes in the

same class. Smallmouth bass size structure was considered very high when compared to lakes in the same

class. Largemouth bass were considered low and very high in respect to abundance and size structure for lakes

in the same class, respectively.

Northern pike were not sampled during spring fyke netting in 2014. We recommend that in future

surveys northern pike caught in fyke nets are measured with sex determined if possible to provide abundance

and length metrics. Northern pike data were collected in 2014 through the creel survey. Although catch and

harvest estimates were low for northern pike, size structure was above average. Anglers targeted northern pike

infrequently (4% of directed effort) which may indicate that they are in low abundance in Whitefish Lake.

Yellow perch remain in relatively high abundance and are likely an important forage item for walleye

(Lyons and Magnuson 1987). Average size of yellow perch was low and may be an indication that many

yellow perch are consumed by predators including walleye. Continued strong recruitment of yellow perch may

aid in walleye growth and abundance.

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Bluegills have increased in abundance in Whitefish Lake and are increasingly being targeted by anglers.

This may be a result of increased littoral zone habitat when water levels increased after the drought and

inundated more complex habitats provided by grasses and shrubs that had grown during the drought. If littoral

zone habitat decreases as inundated terrestrial plants decompose a shift back to lower abundances in bluegill

populations could be expected.

Although not sampled in the 2014 survey ciscoes were sampled in 2006 and 2007 using gill nets and

hydroacoustic sampling (Hrabik unpublished). Those surveys indicate that cisco were naturally reproducing in

Whitefish Lake and were an important component of the lakes fishery. The densities of cisco were within

expected ranges for an oligotrophic lake.

Management recommendations include; 1) Continue annual fall electrofishing to evaluate walleye year

class strength. Complete adult walleye population estimates every 6 years along with gathering data on

northern pike abundance and length metrics, smallmouth and largemouth bass abundance and length metrics

and panfish community metrics through SE II electrofishing surveys. 2) Implement an 18 inch minimum length

for smallmouth bass with a 1 fish/day bag limit and no minimum length limit for largemouth bass with a daily

bag limit of 5 fish/day. These regulations will protect the high quality smallmouth bass fishery while providing

a harvest opportunity for largemouth bass. Retain all other angling regulations for other species. 3) Continue to

partner with interested anglers and the Whitefish Lake Association to follow the adopted lake management plan

and disseminate data.

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Acknowledgements

I would like to thank Fred and Sandy Anderson and all other volunteers for the Self-Help Lake Monitoring

Program that gathered the water quality data presented in this report. I would also like to thank the biologists

and technicians of the Wisconsin Department of Natural Resources who assisted with field collection of data as

well as the WDNR treaty assessment unit for data collection and data entry. Special thanks to Jeff Kampa who

provided a critical review of the manuscript.

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References

Anderson, R. O., and S. J. Gutreuter. 1983. Length, weight, and associated structural indices. Pages 283-300 in L. Nielson and D. Johnson, editors. Fisheries Techniques. American Fisheries Society, Bethesda, Maryland. Beard, T. D., Jr., S. W. Hewett, Q. Yang, R. M. King, and S. J. Gilbert. 1997. Prediction of angler catch rates based on walleye population density. North American Journal of Fisheries Management 17: 621-627. Hansen, G. and J. Hansen. 2016. A proposed lake classification system for black bass. Unpublished. Hennessy, J. 2002. Ceded territory fishery assessment report. Wisconsin Department of Natural Resources. Administrative Report 55, Madison, Wisconsin. Hrabik T. R. 2007. Acoustic assessment of Whitefish Lake pelagic fish populations. Unpublished. Kampa, J. 1988. Whitefish Lake Survey - 1988. WDNR, Brule Office. Lyons J. and J. J. Magnuson. 1987. Effects of walleye predation on the population dynamics of small littoral- zone fishes in a northern Wisconsin lake. Transactions of the American Fisheries Society 116.1: 29-39. Margenau, T.L. 1982. Modified procedure for aging walleye by dorsal spine sections. Progressive Fish Culturist 44: 204. Rasmussen, P. W., M. D. Staggs, T. D. Beard, Jr., and S. P. Newman. 1998. Bias and confidence interval coverage of creel survey estimators evaluated by simulation. Transactions of the American Fisheries Society 127: 460-480. Ricker, W.E. 1975. Computation and interpretation of biological statistics of fish populations. Fisheries Research Board of Canada, Bulletin 191. Sand, C. 1991. Summary and Management Recommendations. Whitefish Lake File, WDNR, Brule Office. Schram, S. 1979. Basic Inventory Bardon Lake, Douglas County. WDNR, Brule Office. Toshner, P. J. 2004. 2003 Whitefish (Bardon) Lake, Douglas County, Sensitive Area Designation Survey and Management Guidelines. WDNR, Superior Office. Tsehaye I., Roth B. M., Sass G. G. 2016. Exploring optimal walleye exploitation rates for northern Wisconsin Ceded Territory lakes using a hierarchical Bayesian age-structured model. Canadian Journal of Fisheries and Aquatic Sciences, 73(9): 1413-1433. Weiher, W. 1967. Lake Survey – Bardon Lake, Douglas County. WDNR, Brule Office.

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Table 2. Kolmogorov-Smirnov test results for walleye length distribution comparisons from Whitefish Lake, Douglas County, Wisconsin.

Comparison D Statistic p Value1988 vs. 1991 0.2 < 0.00051991 vs. 2001 0.52 < 0.00052001 vs. 2005 0.39 < 0.00052005 vs. 2009 0.24 < 0.00052009 vs. 2014 0.25 < 0.00052014 vs. 1988 0.09 0.05

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Table 3. Mean length (inches) for walleye from Whitefish Lake, Douglas County, Wisconsin.

Figure 1. Estimated density and 95% confidence interval of adult walleye, 1986 - 2014, Whitefish Lake, Douglas County, Wisconsin.

Year Mean Length SD N PSD RSD - 201988 15.7 2.0 667 61.3% 3.9%1991 15.0 2.3 624 41.7% 3.4%2001 16.3 1.1 377 93.4% 0.3%2005 16.0 2.3 378 59.0% 4.0%2009 16.6 2.1 574 77.0% 5.4%2014 15.9 2.7 394 54.6% 7.9%

0

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Num

ber

of fi

sh/a

cre

Year

19

Figure 2. Walleye adult density by length, spring netting survey, Whitefish Lake, Douglas County, Wisconsin.

20

Figure 3. Percent distribution by age of walleye in Whitefish Lake, Douglas County, Wisconsin.

21

Figure 4. Length at age for male walleye, Whitefish Lake, Douglas County, WI.

Figure 5. Length at age for female walleye, Whitefish Lake, Douglas County, WI.

22

Figure 6. Relative abundance of age-0 walleye determined by fall electrofishing, Whitefish Lake, Douglas County, Wisconsin. Horizontal line represents the mean relative abundance of age-0 walleye for all years combined. No surveys occurred in 1987, 1989, 1993, 1994, 1996 and 2007-2010.

Figure 7. Relative abundance of smallmouth and largemouth bass determined by spring electrofishing, Whitefish Lake, Douglas County, Wisconsin. Horizontal lines represent the mean for lakes of the same class (Hansen and Hansen 2016, unpublished).

0

20

40

60

80

100

120

140

1986

1987

1988

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

2007

2008

2009

2010

2011

2012

2013

2014

2015

Num

ber

of fi

sh/m

ile

Year

0

2

4

6

8

10

12

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

2007

2008

2009

2010

2011

2012

2013

2014

Num

ber

of fi

sh/m

ile

Year

SMBSMB lake class avg.LMBLMB lake class avg.

23

Appendix Table 1. Proportional and relative stock density values. Species Stock Size (in) Quality Size (in) Preferred Size (in) Largemouth Bass 8 12 15 Smallmouth Bass 7 11 14 Walleye 10 15 20