State of the Lakes State of the Lakes 
2005 2005 
A summary of current sampling A summary of current sampling 
around the Winnebago system around the Winnebago system 

Spring Walleye Sampling Spring Walleye Sampling

0 
100 
200 
300 
400 
500 
600 
700 
800 
900 
Number Captured 
10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 
Length (inches) 
Walleye Length Frequency 
Winnebago System - Spring 2005 
Females (n=816) 
Males (n=6156)

0.00% 
5.00% 
10.00% 
15.00% 
20.00% 
25.00% 
30.00% 
35.00% 
40.00% 
45.00% 
Yearclass 
2002 2001 2000 1999 1998 1997 1996 1995 1994 1993 1992 1991 1990 
Percent of Spawning Stock 
Spawning Stock Age Compostion 
Wolf River - 2004 
% Males in 2004 Pop. 
% Females in 2004 Pop.

0.00% 
5.00% 
10.00% 
15.00% 
20.00% 
25.00% 
30.00% 
35.00% 
Percent of Spawning Stock 
2003 2002 2001 2000 1999 1998 1997 1996 1995 1994 1993 1992 1991 1990 
Yearclass 
Spawning Stock Yearclass Composition 
Wolf River Spawning Assessment - 2005 
% Males in 2005 Population 
% Females in 2005 Population

Mean Walleye Length at Age 
Winnebago System - 2005 
0
5 
10 
15 
20 
25 
30 
II III IV V VI VII VIII IX X XI XII XIII XIV XV 
Age (completed summers) Length (inches) 
Male (n=260) 
Female (n=261)

Mean Walleye Length at Age 
Winnebago System - 2004 
0
5 
10 
15 
20 
25 
30 
I II III IV V VI VII VIII VIX X XI XII XIII XIV XV 
Age (completed summers) 
Length (inches) 
Female (n = 215) 
Male (n = 197) 
Fingerling and Yearling (n=588)

Sauger Rehabilitation Project Sauger Rehabilitation Project

Sauger Reef Construction Sauger Reef Construction 
• 6 new sauger spawning 6 new sauger spawning 
reefs constructed in Feb. reefs constructed in Feb. 
2005 2005 
• Total reefs placed in the Total reefs placed in the 
NE corner of the lake to NE corner of the lake to 
date is 13 date is 13 
• 6 more are planned for 6 more are planned for 
this Feb. this Feb.

Sauger Stocking Project Sauger Stocking Project 
• Temperatures confounded Temperatures confounded 
spawning efforts spawning efforts 
• Rapid rise hastens maturity Rapid rise hastens maturity 
in some fish in some fish

Lake Winnebago Sub-surface Water Temperatures 2001-2005 
30.0 
35.0 
40.0 
45.0 
50.0 
55.0 
60.0 
65.0 
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 1 2 3 4 5 6 7 
Apr Apr Apr Apr Apr Apr Apr Apr Apr Apr Apr Apr Apr Apr Apr May May May May 
Date Water Temperature ( 0F) 
2001 
2002 
2003 
2004 
2005 
Stars are when at least 8 oz. 
of eggs were taken

Sauger Stocking Project Sauger Stocking Project 
• Temperatures confounded Temperatures confounded 
spawning efforts spawning efforts 
• Rapid rise hastens maturity in Rapid rise hastens maturity in 
some fish some fish 
• Nets pulled after 5 nights – too Nets pulled after 5 nights – too 
few ripe females for the effort few ripe females for the effort 
• Collected only 20 oz. of eggs Collected only 20 oz. of eggs 
• Only 66,000 fry stocked Only 66,000 fry stocked 
• No pond-reared fry survived for No pond-reared fry survived for 
stocking as fall fingerlings stocking as fall fingerlings

Fishing Tournament Monitoring Fishing Tournament Monitoring 
• Collected data at: Collected data at: 
• Mercury Marine Natl. Mercury Marine Natl. 
Walleye Tournament Walleye Tournament 
• Otter St. Fishing Club Otter St. Fishing Club 
• Masters Walleye Masters Walleye 
Circuit Circuit 
• Waupaca Bass Club Waupaca Bass Club 
Muscular Dystrophy Muscular Dystrophy 
Open Open

Walleye Tournament Sex and Maturity 
Lake Winnebago - 2005 
Female, 501, 22.45% 
Imm. Female, 1345, 
60.26% 
Male, 386, 17.29%

0 
50 
100 
150 
200 
250 
300 
350 
Number 
14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 
Length (inches) 
Sexed Walleye Tournament Length Frequency 
Mercury, Otter St. and MWC Tournaments - 2005 
2005 - imm Female examined (n=1345) Total 
2005 - m Female examined (n=501) Total 
2005 - m Male examined (n=386) Total

0 
1000 
2000 
3000 
4000 
5000 
6000 
7000 
Number Mercury Marine Natl. Otter Street Masters Walleye Circuit Totals 
Initial Tournament Mortality 
2005 Winnebago System Summer Walleye Tournaments 
Total # brought in 
# Dead 
# Released

Estimated Walleye Exploitation Rates 
Winnebago System 
0.00% 
5.00% 
10.00% 
15.00% 
20.00% 
25.00% 
30.00% 
35.00% 
40.00% 
1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 % Exploitation 
@25% 
@ 50% 
@75% 
"Safe" Exploitation Rate

Winnebago System Walleye Population Estimates 
Fish 15" and Larger 
0 
200,000 
400,000 
600,000 
800,000 
1,000,000 
1,200,000 
1,400,000 
1,600,000 
1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 
Est. Number 
100% Recap Reporting 
50% Recap Reporting 
Linear (100% Recap Reporting)

0 
50 
100 
150 
200 
250 
Number 
13 13.5 14 14.5 15 15.5 16 16.5 17 17.5 18 18.5 19 19.5 20 20.5 21 21.5 
Length (inches) 
Largemouth Bass Tournament Length Frequency 
Winnebago System - 2005 
Largemouth Bass (n=897)

0
5 
10 
15 
20 
25 
30 
Number 
13 13.5 14 14.5 15 15.5 16 16.5 17 17.5 18 18.5 19 19.5 20 20.5 21 21.5 
Length (inches) 
Smallmouth Bass Tournament Length Frequency 
Winnebago System - 2005
Smallmouth Bass (n=140)

Summer/Fall Assessment Trawling Summer/Fall Assessment Trawling

20.57 
6.34 
55.02 
29.41 
135.46 
71.47 
23.22 
2.91 
42.44 
76.61 
377.41 
28.96 
7.26 
85.76 
30.74 
87.07 
36.72 
173.04 
49.07 
74.91 
0.00 
50.00 
100.00 
150.00 
200.00 
250.00 
300.00 
350.00 
400.00 
Mean Number per Trawl Cast 
'86 '87 '88 '89 '90 '91 '92 '93 '94 '95 '96 '97 '98 '99 '00 '01 '02 '03 '04 '05 
Drum Yearclass Strength 
Lake Winnebago 1986 - 2005 
YOY - DRUM

20.57 
6.34 
55.02 
29.41
135.46 
71.47
23.22 
2.91 
42.44 
76.61
377.41
28.96 
7.26 
85.76 
30.74 
87.07 
36.72
173.04
49.07 
74.91 
0.00 
50.00 
100.00 
150.00 
200.00 
250.00 
300.00 
350.00 
400.00 
Mean Number per Trawl Cast '86 '87 '88 '89 '90 '91 '92 '93 '94 '95 '96 '97 '98 '99 '00 '01 '02 '03 '04 '05 
White Bass Yearclass Strength 
Lake Winnebago 1986 - 2005 
YOY - W. BASS

0.02 0.02 0.00 0.04 
0.28 
2.76 
0.89 
0.02 0.12 0.02 0.26 
0.04 0.13 0.15 0.07 
4.70 
1.50 
3.54 
9.07 
1.26 
0.00 
1.00 
2.00 
3.00 
4.00 
5.00 
6.00 
7.00 
8.00 
9.00 
10.00 
Mean Number per Trawl Cast '86 '87 '88 '89 '90 '91 '92 '93 '94 '95 '96 '97 '98 '99 '00 '01 '02 '03 '04 '05 
Yellow Perch Yearclass Strength 
Lake Winnebago 1986 - 2005 
YOY - Y. PERCH

1.29 2.69 7.70 7.46 
91.22 
256.84 
81.52 
43.80 
119.56 
47.74 
111.46
108.17
112.54
255.30
335.54
378.37 
297.04
504.65
304.59 
285.41 
0.00 
100.00 
200.00 
300.00 
400.00 
500.00 
600.00 
Mean Number per Trawl Cast '86 '87 '88 '89 '90 '91 '92 '93 '94 '95 '96 '97 '98 '99 '00 '01 '02 '03 '04 '05 
Trout Perch Yearclass Strength 
Lake Winnebago 1986 - 2005 
YOY - T.PERCH

1.90 
0.36 
7.65 
59.96 
70.37 
31.44 
1.09 0.43 0.19 0.04 0.07 0.00 0.00 0.28 
6.24 
2.78 
35.83 
2.20 1.91 
18.85 
0.00 
10.00 
20.00 
30.00 
40.00 
50.00 
60.00 
70.00 
80.00 
Mean Number per Trawl Cast '86 '87 '88 '89 '90 '91 '92 '93 '94 '95 '96 '97 '98 '99 '00 '01 '02 '03 '04 '05 
Gizzard Shad Yearclass Strength 
Lake Winnebago 1986 - 2005 
YOY - G. SHAD

1.29 2.69 7.70 7.46 
91.22 
256.84
81.52 
43.80
119.56
47.74
111.46
108.17
112.54
255.30
335.54
378.37
297.04
504.65
304.59
285.41 
0.00 
100.00 
200.00 
300.00 
400.00 
500.00 
600.00 
Mean Number per Trawl Cast '86 '87 '88 '89 '90 '91 '92 '93 '94 '95 '96 '97 '98 '99 '00 '01 '02 '03 '04 '05 
Emerald Shiner Yearclass Strength 
Lake Winnebago 1986 - 2005 
YOY - T.PERCH

0.12 0.00 0.13 0.02 
3.91 
7.42 
1.96 
4.54 
0.12 0.30 
41.07 
3.33 2.33 
0.26 0.26 
23.46 
2.15 
10.65 
14.17 
12.87 
0.00 
5.00 
10.00 
15.00 
20.00 
25.00 
30.00 
35.00 
40.00 
45.00 
Mean number per cast 
'86 '87 '88 '89 '90 '91 '92 '93 '94 '95 '96 '97 '98 '99 '00 '01 '02 '03 '04 '05 
Walleye Yearclass Strength 
Lake Winnebago 1986 - 2005 
YOY - WALLEYE

0
5 
10 
15 
20 
25 
30 
35 
40 
45 
Number per Trawl Cast 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 
YOY and Yearling Walleye Catch Rates 
Lake Winnebago - August Trawling 
YOY per Trawl 
Yearling per Trawl

0 
50 
100 
150 
200 
250 
Number Captured 
3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 
Length (inches) 
Walleye Length Frequency - Lake Winnebago 
August Trawling - 2005 
Aug. Trawling

Fall Shoreline Night Electrofishing Fall Shoreline Night Electrofishing

0 
10 
20 
30 
40 
50 
60 
70 
80 
Number captured 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 
Length (inches) 
Fall Walleye Shoreline Length Frequency 
Lake Winnebago and Butte des Morts - 2005

0
2
4
6
8 
10 
12 
14 
16 
18 
20 
Number Captured 4 4.2 4.4 4.6 4.8 5 5.2 5.4 5.6 5.8 6 6.2 6.4 6.6 6.8 7 7.2 7.4 7.6 7.8 8 8.2 8.4 8.6 8.8 
Length (inches) 
Fall YOY Length Frequency 
Lakes Winnebago and Butte des Morts - 2005


Mean Fall Walleye YOY Lengths and Weights 
0
1
2
3
4
5
6
7
8
9
1962 1965 1968 1971 1974 1977 1980 1983 1986 1989 1992 1995 1998 2001 2004 
Length (inches) 
0
0.5 
1
1.5 
2
2.5 
3 
Weight (ounces) 
Mean Length (inches) 
Mean Weight (ounces) 
Long-term mean weight 
Long-term mean length