effects of minimum and slot length limit ...table 14. comparison of growth rates and length...
TRANSCRIPT
EFFECTS OF MINIMUM AND SLOT LENGTH LIMIT REGULATIONS
FOR LARGEMOUTH BASS ON THE LARGEMOUTH BASS AND
BLUEGILL FISHERIES IN FOUR LAKES IN WISCONSIN
by
Marty E. Lundquist
A Thesis
submitted in partial fulfillment of the
requirements for the degree of
MASTER OF SCIENCE
in
Natural Resources (Fisheries)
College of Natural Resources
uNiv~K~i~1 ur WISCONSIN
Stevens Point, Wisconsin
June, 1990
APPROVED BY THE GRADUATE COMMITTEE OF:
Dr. Daniel w. Coble, Committee Chairman Professor of Fisheries
Professor of Biology
Dr. Richard v. Frie Professor of Fisheries
ii
ABSTRACT
Effects of length limit regulations for largemouth bass
(Micropterus salmoides) on the bass and bluegill (Lepomis
macrochirus) fisheries in four lakes in southeast Wisconsin
were studied from 1980 to 1989. In 1982 a slot length limit
of 305-406mm (12-16 inches) was established on Beulah and
Rockland lakes, and a minimum length limit of 406mm was
introduced on Pretty and Browns lakes. Angling effort for
largemouth bass and bluegills did not change, and some of
the expected, desired changes occurred for both largemouth
bass and bluegills. The regulations reduced the harvest
rate of protected largemouth bass while the harvest rate of
legal bass decreased in one lake and increased in three
lakes. Electrofishing catch per effort of larger largemouth
bass increased in three lakes, and mean length of protected
bass increased in the other, but angler catch rate did not
change and relative weight of largemouth bass decreased in
three lakes. Relative weight of Wuegills ano mean length
of harvested bluegills increased. Bluegill electrofishing
catch per unit effort increased in two lakes but not the
other two, and no change was detected in angler catch rate,
or growth rate.
iii
ACKNOWLEDGEMENTS
This study was supported by the Wisconsin Department of
Natural Resources, and the Wisconsin Cooperative Fishery
Research Unit, University of Wisconsin, Stevens Point.
I express my appreciation and special thanks to Dr.
Daniel Coble, my committe chairman, for is support,
patience, and careful editing of this manuscript. I thank
committee members Drs. Fred Copes and Richard Frie for their
advice and review of this manuscript. I also express thanks
to Dr. Bill Le Grande and Jay Harvey for sharing their
knowledge of computers, and Dr. Robert Rogers for his advice on
statistical analysis.
I am gratefully to Doug Welch and Rick Dueffenbach for
scheduling the electrofishing, and creel surveys, and to all
DNR personnel who helped conduct the field work. I am also
grateful to the work study students who pressed scales.
I would like to thank Dorothy Snyder for all her help
during this project.
My deepest appreciation goes to my parents for their
support of my decisions and during my trials and
tribulations as a college student aqd for introducing me to
nature at a young age.
iv
ABSTRACT .....
ACKNOWLEDGEMENTS.
LIST OF TABLES ..
LIST OF FIGURES.
LIST OF APPENDICES ..
INTRODUCTION .....
TABLE OF CONTENTS
.iii
. . i V
. . • vii
. . . xi
. xvii
. . . . . 1
METHODS AND MATERIALS . . . . . . . . . . • . . . . . . . . 5 Sampling . . . . . . . . . . . . . . . . . 5 Creel Survey. . . . . . . . . . . . . . ... 7 Length Frequency, Mean Length and, Catch Per Unit
Effort From Electrofishing. . . . . . . ... 9 Proportional Stock Density . . . . . . . . . .. 10 Relative Weight. . . . . . . . . . . . . . . 13 Age, Growth, and Mortality. . . . . . . . . .. 14 Population Estimates, Standing Stock, and
Exploitation. . ..... . 15
RESULTS AND DISCUSSION. . . . . . 1 7
Creel Survey. . . . . . . . . . . . . . 17 Fishing Pressure. . . . . . . . . . . . 17 Harvest Rate, Mean Length Harvested, and
Catch Rate . . . . . . . . .... 17 Largemouth Bass. . . . . . . . . . 1 7 Bluegills. . . . . . . . . . . . ... 31
Length Frequency, Catch Per Unit Effort, and Mean Length From Electrofishing Samples. . ... 37 Iiargemouth Bass • • . . . . . . • . . . . . 31 Bluegills . . . . . . . . . . . . . . . . . 50
Proportional Stock Density . . ....... 59 Largemouth Bass . . . . . . . . .... 59 Bluegills. . . . . . . . . . . . . 63
Relative Weight. . . . . . . . . . . . . .... 65 Largemouth Bass . . . . . . . . .. 65 Bluegills . . . . . . . . . . . . . . . .... 69
Growth . . . . . . . . . . . . . . . . . 73 Largemouth Bass . . . . . . . . .... 73 Bluegills . . . . . . • . . .. 79
Mortality. . . . . . . . . . . . . . . . .... 81 Largemouth Bass . . • . . . . . . . . . .. 81 Bluegills. . . . ....... 88
Population Estimates and Exploitation of Largemouth Bass in Rockland Lake ............. 88
V
CONCLUSION ....
LITERATURE CITED.
APPENDICES ..
vi
• • 97
. .101
. .104
LIST OF TABLES
Table 1. Fish sampling methods in the four lakes with effort in hours for the electroshocker and hours/week for the creel survey. . . . . . .6
Table 2. Minimum stock and quality size {mm) for largemouth bass, bluegills, pumpkinseeds, warmouth, green sunfish, and yellow perch ... 11
Table 3. Estimated angling effort {hours/hectare) of largemouth bass, bluegills, and all species in 1980, 1982, 1984, 1986, and 1988 and results of regression analysis of estimated angling effort versus time in Beulah, Rockland, Pretty, and Browns lakes. + = positively significant, - = negatively significant, and o = not significant at the 0.05 level of significance ........... 18
Table 4. Estimated mean harvest rate {number/hectare) of largemouth bass of protected, unprotected, and of all sizes in Beulah, Rockland, Pretty, and Browns lakes compared between 1980 and 1982-1988 {and between 1980 and 1982-1986 for Rockland Lake) with a Chi-square test {Li 1969; p.458). +=positively significant, -= negatively significant, and o = not significant at the 0.05 level of significance ........ .
Table 5. Estimated total number harvested, harvest rate {number/hectare), and percent of each size group of largemouth bass harvested in
• • • 2 2
1980, 1982, 1984, 1986, and 1988 ........ 25
Table 6. Estimated mean length {mm) and catch rate {number/hectare) of largemouth bass in 1980, 1982, 1984, 1986, and 1988 and results of regression analysis of estimated mean length harvested and catch rate versus time in Beulah, Rockland, Pretty, and Browns lakes. +=positively significant, - = negatively significant, o = not significant at the 0.05 level of significance ............. 29
vii
LIST OF TABLES (continued)
Table 7. Estimated harvest and catch rates (number/hectare) and mean length (mm) of bluegills in 1980, 1982, 1984, 1986, and 1988, and results of regression analysis of estimated harvest and catch rates, and mean length harvested versus time in Beulah, Rockland, Pretty, and Browns lakes. + = positively significant, - = negatively significant, o = not significant at the 0.05 level of significance ............. 36
Table 8. Catch per unit effort (CUE) and mean length of largemouth bass from electrofishing in spring in the four lakes, 1980 - 1989, and results of regression analysis of CUE and mean length versus time. +=positively significant, - = negatively significant, and o = not significant at the 0.10 level of significance. Mean in table computed from values in appendix G .............. 40
Table 9. Catch per unit effort (CUE) and mean length of bluegills from electrofishing in spring in the four lakes, 1980 - 1989, and results of regression analysis of CUE and mean length versus time. +=positively significant, - = negatively significant, and o = not significant at the 0.10 level of significance. Mean in table computed from values in appendix H .............. 55
Table 10. Proportional Stock Density (PSD %) of largemouth bass and bluegills in 1980 to 1989 rrom the four lakes. Number in parentheses represents number of fish of stock size .... 62
Table 11. Comparison of mean relative weights of largemouth bass from spring electrofishing samples between 1988 andi 1980-1982 and 1983-1985 for lakes Beulah, Rockland, and Pretty and between 1988-1989 and 1980-1982 and 1983-1985 for Browns Lake with at-test (Zar 1974; p.105). The asterisk(*) indicates a significant difference at the 0.05 level of significance; t values computed from values in appendices I, J ..•........ 68
viii
LIST OF TABLES (continued)
Table 12. Comparison of mean relative weights of bluegills from spring electrofishing samples between 1988 and 1980-1982 and 1983-1985 for lakes Beulah, Rockland, and Pretty and between 1988-1989 and 1980-1982 and 1983-1985 for Browns Lake with at-test (Zar 1974; p.105). The asterisk(*) indicates a significant difference at the 0.05 level of significance; t values computed from values in appendices L, M ........... 70
Table 13. Comparison of growth rates and length increments of largemouth bass of various age groups in all lakes from 1979 to 1988. F values computed from values in appendix o, (Steele and Torrie 1960). +=positively significant, - = negatively significant, o = not significant at the 0.05 level of significance .................. 74
Table 14. Comparison of growth rates and length increments of bluegills of various age groups in all lakes from 1979 to 1988. F values computed from values in appendix s, (Steele and Torrie 1960). +=positively significant, - = negatively significant, o = not significant at the 0.05 level of significance. . . . . . . . . . . . . .. . 80
Table 15. Total annual and instantaneous mortality (A and Z), and survival (S) of largemouth bass, bluegills, and pumpkinseeds (Browns Lake only) for 1980-1982, 1983-1985, and 1988 f1988-r9&9 in Browns I:mket, r is ·t;he correlation coefficient. Rates calculated from data from spring electrofishing samples .. 84
Table 16. Comparison of total annual mortality of largemouth bass from spring electrofishing samples between 1988 and 1980-1982 and 1983-1985 for lakes, Beulah, Rockland, and Pretty and between 1988-1989 and 1980-1982 and 1983-1985 for Browns Lake with at-test (Zar 1974; p.228). The asterisk(*) indicates a significant difference at the 0.05 level of significance; t values computed from values in appendix w .............. 85
ix
LIST OF TABLES (continued)
Table 17. Comparison of total annual mortality of bluegills from spring electrofishing samples between 1988 and 1980-1982 and 1983-1985 for lakes, Beulah, Rockland, and Pretty and between 1988-1989 and 1980-1982 and 1983-1985 for Browns Lake with at-test (Zar 1974; p.228). The asterisk(*) indicates a significant difference at the 0.05 level of significance; t values computed from values in appendix w .............. 89
Table 18. Schnabel population estimate (number/hectare), 95% confidence interval (CI), estimated standing stock, and mean individual weight of largemouth bass in Rockland Lake in Springs 1980-1988. Estimated exploitation rate (u) for 1980, 1982, 1984, 1986, and 1988 ...... 93
Table 19. Estimated and predicted densities (number/hectare) of largemouth bass ( 200mm) in Rockland Lake compared with a paired t-test (Sokal and Rohlf 1981). Estimated densities based on Chapman-modified Schnable population estimates (Ricker 1975). Predicted densities based on the regression equation, log Y = 1.2274 log X -0.5489 (Hall 1986), where Y is the predicted density and Xis the spring electrofishing catch per unit effort (CUE) .......... 95
Table 20. Summary of results of largemouth bass: results of regression analysis, t-tests and Chi-square -tests --0£ data from _cr_ee_i surveys and electrofishing for largemouth bass for the period 1980 through 1988. "P~o." and "Unpro." indicates largemouth bass of protected and unprotected sizes respectively. "Pre." is pre-regulation years (1980-1982), "Post." represents the time period 1983-1985. # = an interpretation of the data. +=positively significant, - = negatively significant, o = not significant. . . . . . . . . . . .98
Table 21. Summary of results of bluegill: Results of regression analysis, and t-tests of data from creel surveys and spring electrofishing for bluegills for the period 1980 through 1988. "Pre." is pre-regulation years (1980-1982), "Post." represents the time period 1983-1985. #=an interpretation of the data. + = positively significant, - = negatively significant, and o = not significant ...... 99
X
LIST OF FIGURES
Figure 1. Angling effort (hours/hectare) for largemouth bass (LMB) and bluegills (BLG) in Beulah and Rockland lakes in 1980, 1982, 1984, 1986, and 1988. . . . . . . . . . . 19
Figure 2. Angling effort (hours/hectare) for largemouth bass (LMB) and bluegills (BLG) in Pretty and Browns lakes in 1980, 1982, 1984, 1986, and 1988 ................ 20
Figure 3. Harvest composition (number/hectare) of three size groups of largemouth bass from Pretty Lake in 1980, 1982, 1984, 1986, and 1988. . . . . . . . . . . . . . . . . . . 23
Figure 4. Harvest composition (number/hectare) of three size groups of largemouth bass from Browns Lake in 1980, 1982, 1984, 1986, and 1988. . . . . . . . . . . . . . . . . . . 24
Figure 5. Harvest composition (number/hectare) of four size groups of largemouth bass from Beulah Lake in 1980, 1982, 1984, 1986, and 1988 ... 26
Figure 6. Harvest composition (number/hectare) of four size groups of largemouth bass from Rockland Lake in 1980, 1982, 1984, 1986, and 1988. . . 27
Figure 7. Regression of mean length (mm) of harvested largemouth bass from Browns Lake in 1980, 1982, 1984, 1986, and 1988, with regression equation, F value, correlation coefficient (R), and sample size (N). "Sign." indicates a si-gn--i--f'icant r-elation a--t the -0-.05 level of significance ................. 30
Figure 8. Estimated numbers of largemouth bass caught and harvested per hectare, and total angling effort (hours/hectare) in Beulah Lake in 1980, 1982, 1984, 1986, and 1988 ....... 32
Figure 9. Estimated numbers of largemouth bass caught and harvested per hectare, and total angling effort (hours/hectare) in Rockland Lake in 1980, 1982, 1984, 1986, and 1988 ....... 33
xi
LIST OF FIGURES (continued)
Figure 10. Estimated numbers of largemouth bass caught and harvested per hectare, and total angling effort (hours/hectare) in Pretty Lake in 1980, 1982, 1984, 1986, and 1988 ......• 34
Figure 11. Estimated numbers of largemouth bass caught and harvested per hectare, and total angling effort (hours/hectare) in Browns Lake in 1980, 1982, 1984, 1986, and 1988 ....... 35
Figure 12. Regression of mean length (mm) of harvested bluegills from Beulah and Rockland lakes in 1980, 1982, 1984, 1986, and 1988, with regression equation, F value, correlation coefficient (R), and sample size (N). "Sign." indicates a significant relation at the 0.05 level of significance ........ 38
Figure 13. Regression of mean length (mm) of harvested bluegills from Browns Lake in 1980, 1982, 1984, 1986, and 1988, with regression equation, F value, correlation coefficient (R), and sample size (N). "Sign." indicates a significant relation at the 0.05 level of significance. . • . . . ......... 39
Figure 14. Spring electrofishing catch per unit effort of largemouth bass in 10-mm length groups, sample (N), and Proportional Stock Density (PSD) from Beulah Lake in 1980 to 1988. Slot length limit represented by dashed vertical lines. . . . . . . . . . . . .. 41
Figure 15. Regression o£ sptl~ el~ctrmishing: catch per unit effort of largemouth bass longer than 305mm from Beulah and Rockland lakes in 1980 to 1988, with the regression equation, F value, correlation coefficient (R), and sample size (N) for each lake. "Sign." indicates a significant relation at the 0.10 level of significance ........ 42
Figure 16. Spring electrofishing catch per unit effort of largemouth bass in 10-mm length groups, sample (N), and Proportional Stock Density (PSD) from Rockland Lake in 1980 to 1988. Slot length limit represented by dashed vertical lines ................ 44
xii
LIST OF FIGURES (continued)
Figure 17. A: Regression of mean length (mm) of largemouth bass longer than 305mm from spring electrofishing samples from Rockland Lake in 1980 to 1988. B: Regression of mean length (mm) of protected largemouth bass from spring electrofishing samples from Pretty Lake in 1980 to 1988, with the regression equation, F value, correlation coefficient (R), and sample size (N) for each lake. 11 Sign. 11 indicates a significant relation at the 0.10 level of significance .. 45
Figure 18. Spring electrofishing catch per unit effort of largemouth bass in 10-mm length groups, sample (N), and Proportional Stock Density (PSD) from Pretty Lake in 1980 to 1988. Minimum length limit represented by dashed vertical line. . . . . . . . . . ..... 46
Figure 19. A: Spring electrofishing catch per unit effort of protected largemouth bass from Browns Lake in 1980 to 1989. B: Spring electrofishing catch per unit effort of unprotected largemouth bass from Browns Lake in 1980 to 1989, with the regression equation, F value, correlation coefficient (R), and sample size (N) for each lake. 11 Sign. 11 indicates a significant relation at the 0.10 level of significance ........ 47
Figure 20. Spring electrofishing catch per unit effort of largemouth bass in 10-mm length groups, sample (N), and Proportional Stock Density LPSD) from BroRns Lake in 1980_ to 19_8_9 _._ Minimum length limit represented by dashed vertical line ................. 48
Figure 21. Spring electrofishing catch per unit effort of bluegills in 10-mm length groups, sample (N), and Proportional Stock Density (PSD) from Beulah Lake in 1980 to 1988. Quality size is represented by the solid vertical 1 ine. . . . . . . . .
Figure 22. Spring electrofishing catch per unit effort of bluegills in 10-mm length groups, sample (N), and Proportional Stock Density (PSD) from Rockland Lake in 1980 to 1988. Quality size is represented by the solid vertical
. 51
line . .................... 52
xiii
LIST OF FIGURES (continued)
Figure 23. Spring electrofishing catch per unit effort of bluegills in 10-mm length groups, sample (N), and Proportional Stock Density (PSD) from Pretty Lake in 1980 to 1988. Quality size is represented by the solid vertical 1 ine. . . . . . . . .
Figure 24. Spring electrofishing catch per unit effort of bluegills in 10-mm length groups, sample (N), and Proportional Stock Density (PSD) from Browns Lake in 1980 to 1988. Quality size is represented by the solid vertical 1 ine. . . . . . . . .
Figure 25. Spring electrofishing catch per unit effort of all bluegills from Beulah Lake in 1980 to 1988, and from Browns Lake in 1980 to 1989, with the regression equation, F value, correlation coefficient (R), and sample size (N) for each lake. "Sign." indicates a significant relation at the 0.10 level of
. 53
. 54
significance ................. 56
Figure 26. Spring electrofishing mean length (mm) of all bluegill from Browns Lake in 1980 to 1989, with the regression equation, F value, correlation coefficient (R), and sample size (N) for each lake. "Sign." indicates a significant relation at the 0.10 level of significance .......... 57
Figure 27. Proportional Stock Density (PSD %) of largemouth bass and bluegills from Beulah and Rockland lakes in 1980 to 1988. Points
- -- ------ - - --- - -
are connected in chronological order. Solid squares represent 1980 and 1988 values .... 60
Figure 28. Proportional Stock Density (PSD %) of largemouth bass and bluegills from Pretty in 1980 to 1988, and Browns Lake in 1980 to 1989. Points are connected in chronological order. Solid squares represent 1980 and 1988 or 1989 values. . . . . . . . . . . .61
Figure 29. Relative weight of largemouth bass from 1981-1982, 1983-1985, and 1988 in 10-mm length groups in Beulah and Rockland lakes .. 66
xiv
LIST OF FIGURES (continued)
Figure 30. Relative weight of largemouth bass from 1981-1982, 1983-1985, and 1988 (1988-1989 in Browns Lake) in 10-mm length groups in Pretty and Browns lakes ............ 67
Figure 31. Relative weight of bluegills from 1981-1982, 1983-1985, and 1988 in 10-mm length groups in Beulah and Rockland lakes ......... 71
Figure 32. Relative weight of bluegills from 1981-1982, 1983-1985, and 1988 (1988-1989 in Browns Lake) in 10-mm length groups in Pretty and Browns lakes ........... .
Figure 33. Regressions of instantaneous growth rate by age group of largemouth bass in Beulah Lake from 1979 to 1988. Figure is a representation of table 8, minus age groups 8-9, 9-10. Values used to calculate
. 72
regressions are in appendix o •...••.•• 75
Figure 34. Total length (mm) at age of years 1980-1982, 1983-1985, and 1988 of largemouth bass in Beulah and Rockland lakes; and the southeastern Wisconsin average (Druckenmiller 1972) ....•........ 77
Figure 35. Total length (mm) at age of years 1980-1982, 1983-1985, and 1988 (1988-1989 in Browns Lake) of largemouth bass in Pretty and Browns lakes; and the southeastern Wisconsin average (Druckenmiller 1972) .... 78
------,.p,c-,i---,-,gr-tture J6. 'Potal length (mm} at age of years 1%&-l %2, 1983-1985, and 1988 of bluegills in Beulah and Rockland lakes; and the southeastern Wisconsin average (Druckenmiller 1972) .... 82
Figure 37. Total length (mm) at age of years 1980-1982, 1983-1985, and 1988 (1988-1989 in Browns Lake) of bluegills in Pretty and Browns lakes; and the southeastern Wisconsin average (Druckenmiller 1972) ......... 83
xv
Figure 38. Catch curve from spring electrofishing samples from 1980-1982, 1983-1985, and 1988 for largemouth bass in Beulah and Rockland lakes. Natural logarithm of numbers caught versus age .............. .
Figure 39. Catch curve from spring electrofishing samples from 1980-1982, 1983-1985, and 1988 (1988-1989 in Browns Lake) for largemouth
. 86
bass in Pretty and Browns lakes. Natural logarithm of numbers caught versus age .... 87
Figure 40. Catch curve from spring electrofishing samples from 1980-1982, 1983-1985, and 1988 for bluegills in Beulah and Rockland lakes. Natural logarithm of numbers caught versus age . . . . . . . . . . . . . . . . . . . . 9 O
Figure 41. Catch curve from spring electrofishing samples from 1980-1982, 1983-1985, and 1988 (1988-1989 in Browns Lake) for bluegills in Pretty and Browns lakes. Natural logarithm of numbers caught versus age. . . . . . . 91
Figure 42. Regression of population estimates from spring electrofishing samples in Rockland Lake from 1980 to 1988, with the regression equation, F value, correlation coefficient (R), and sample size (N). F value computed from values in appendix X, (Steel and Torrie 1960). "Not sign." indicates no significant relation at the 0.05 level of significance .. 92
xvi
LIST OF APPENDICES
Appendix A. Common and scientific names of species caught by electrofishing (E), and angling (A) during spring 1988 to spring 1989 in the four study lakes ....•....... 104
Appendix B. Location of the four study lakes in three counties in southeast Wisconsin. . . . .105
Appendix C. Hydrographic maps of Beulah, Rockland, Pretty, and Browns ........ . .. 106
Appendix D. Length - frequency distributions of largemouth bass in electrofishing samples in spring and fall of 1988 in all lakes and spring of 1989 in Browns Lake. . .... 111
Appendix E. Length-frequency distributions of bluegills, pumpkinseeds, yellow perch, green sunfish, and warmouth in electrofishing samples in spring and fall of 1988 in all lakes and spring of 1989 in Browns Lake ....••..•...... 113
Appendix F. Bluegill and prey weighted Proportional Stock Densities (PSD %) from 1980 to 1985 and 1988 (1988-1989 in Browns Lake) in the study lakes. Prey weighted PSD was not calculated when number of stock size fish or prey species was less than 30 because Novinger and Legler (1978) suggested 30 as a minimum number of fish to determine PSD .. 117
Appendix G. Length frequency distributions of largemouthba-s-s in spring-e:1:--eclr-ofishing samples in 1980 to 1988 (1980 to 1989 in Browns Lake) from the study lakes. These data are plotted in figures 14, 16, 18, and 20 as number per hour ............ 118
Appendix H. Length frequency distributions of bluegills in spring electrofishing samples in 1980 to 1988 (1980 to 1989 in Browns Lake) from the study lakes. Subsample size is the number of fish measured to determine length distribution of the entire sample (total). These data are plotted in figures 21-24 as number per hour •.............. 126
xvii
LIST OF APPENDICES (continued)
Appendix I. Mean Relative Weight (Wr%) of largemouth bass in 10-mm length groups from 1981-1982 and 1988 (1988-1989 in Browns Lake) from spring electrofishing samples in the study lakes. Sample means compared with at-test (Sokal and Rohlf 1981; section 9.4). All statistical tests were at the 0.05 level of significance. 1980-1982 data from Mayers (1988) ................... 130
Appendix J. Mean Relative Weight (Wr%) of largemouth bass in 10-mm length groups from 1983-1985 and 1988 (1988-1989 in Browns Lake) from spring electrofishing samples in the study lakes. Sample means compared with at-test (Sokal and Rohlf 1981; section 9.4). All statistical tests were at the 0.05 level of significance. 1983-1985 data from Mayers ( 1988). . . . . . . . . . . . . . . . . . . 138
Appendix K. The Wr regression equation of largemouth bass (> 100mm) from Pretty Lake in 1988 and at-test of the significance of the slope (Sokal and Rohlf 1981; p.473). The period exhibited a significant negative slope at the 0.05 level of significance. Wr values are from appendix r, J and are plotted in figure 30 .................. 146
Appendix L. Mean Relative Weight (Wr%) of bluegills in 10-mm length groups from 1981-1982 and 1988 (1988-1989 in Browns Lake) from ~ing elest1?wishing samples in the swdy lakes. Sample means compared with at-test (Sokal and Rohlf 1981; section 9.4). All statistical tests were at the 0.05 level of significance. 1980-1982 data from Mayers (1988). . . . . . . . . . . . . . . . . 147
Appendix M. Mean Relative Weight (Wr%) of bluegills in 10-mm length groups from 1983-1985 and 1988 (1988-1989 in Browns Lake) from spring electrofishing samples in the study lakes. Sample means compared with at-test (Sokal and Rohlf 1981; section 9.4). All statistical tests were at the 0.05 level of significance. 1983-1985 data from Mayers (1988) ................... 151
xviii
LIST OF APPENDICES (continued)
Appendix N. The Wr regression equation of bluegill (> 80mm) from Beulah Lake and at-test of the significance of the slopes (Sokal and Rohlf 1981; p.473). All three periods exhibited a significantly negative slope at the 0.05 level of significance. Wr values are from appendix L, Mand are plotted in figure 31. 1981-1982, and 1983-1985 data from Mayers (1988) ............. 155
Appendix o. Instantaneous growth (G) and length increments (mm) of largemouth bass in the study lakes. Values determined from last two annuli on scales for all years except 1986, in which the first and second annuli from the scale edge were used. Number in parenthesis represents sample size for instantaneous growth and length increments. 156
Appendix P. Comparison of instantaneous growth rates of largemouth bass, bluegills, and pumpkinseeds (Browns Lake) of various age groups in all lakes between 1988 and pre-regulation (1979-1981) years, with a t-test (Zar 1974; p.105). The asterisk(*) indicates a significant difference at the 0.05 level of significance; t values computed from values in appendix o, s. .160
Appendix Q. Total length (mm) at age of largemouth bass and bluegills in the four study lakes, and pumpkinseeds (Browns Lake) for 1979-1981, 1982-1985, and 1988 (1988-1989 for Browns Lake) -time petiods; and the southeastarn Wisconsin average (Druckenmiller 1972). 1980-1982, and 1983-1985 from Prendergast (1984) and Mayer (1988) respectively. . 163
Appendix R. Back calculated total lengths (mm) of largemouth bass in some lakes ........ 164
Appendix S. Instantaneous growth (G) and length increments (mm) of bluegills in the study lakes, and pumpkinseeds (Browns Lake). Values determined from last two annuli on scales for all years except 1986, in which the first and second annuli from the scale edge was used. Number in parenthesis represents sample size for instantaneous growth and length increments ........ 165
xix
LIST OF APPENDICES (continued)
Appendix T. Comparison of instantaneous growth rates and length increments of pumpkinseeds of various age groups in Browns Lake from 1979 to 1988. F values computed from values in appendix s, (Steel and Torrie 1960). + = positively significant, - = negatively significant, and o = not significant at the 0.05 level of significance. . . . . 170
Appendix u. Comparison between length at age in 1988 of largemouth bass, bluegills, and pumpkinseed (Browns Lake), with the southeast Wisconsin average (Druckenmiller 1972) with a paired t-test (Zar 1974; p.121). All statistical tests were at the 0.05 level of significance. Where significant changes occurred, the southeast Wisconsin average had the larger value. . . . . . . . . . 171
Appendix v. Back calculated total lengths (mm) of bluegills in some lakes. . . . . . . 1 72
Appendix W. Number of largemouth bass, bluegills, and pumpkinseeds (Browns Lake) in each age class from 1980-1982, 1983-1985, and 1988 (1988-1989 in Browns Lake) from spring electrofishing samples, and the regression equations used for the catch curves shown in figures 38-41 .............. 173
Appendix x. Estimated population density (number/hectare) of largemouth bass from electrofishing in spring in Rockland Lake, 1980-198_9_, and results of regre_s__s_ion analysis of estimated population density versus time. "No" indicates not significant at the 0.05 level of significance ................ 176
Appendix Y. Results of regression analysis from spring electrofishing samples of largemouth and bluegills in the four study lakes. "Pro." and "Unpro." indicates protected and unprotected size largemouth bass respectively. +=positively significant, - = negatively significant, and o = not significant at the 0.05 level of significance. Duplicate of relative abundance and mean length by electrofishing tests in table 20 ......•....... 177
xx
1
INTRODUCTION
The Wisconsin Cooperative Fishery Research Unit and the
Wisconsin Department of Natural Resources began this study
to determine what effect length limit regulations on
largemouth bass (Micropterus salmoides) would have on the
largemouth bass and bluegill (Lepomis macrochirus) fisheries
of four lakes in southeast Wisconsin. The goal of the study
was to improve the bass and bluegill fishing in the four
lakes. It was thought that overharvest of largemouth bass
had resulted in too little predation on panfish: bluegill,
pumpkinseed, yellow perch, black crappie, warmouth, and
green sunfish (Appendix A). All four lakes were considered
out-of-balance before length limit regulations were imposed
(Michaelis 1982). It was believed that the regulations
would improve the bass fishery through protection of certain
sizes of largemouth bass and result in larger bluegills
because of increased predation by the greater numbers of
bass.
Data described below were collected from 1980 to 1989.
The fishing season for largemouth bass extended from the
first Saturday in May to March first, and the possession
limit was 5. From 1980 to 1982 there was no length limit on
largemouth bass. On May 1, 1982, length limit regulations
were added: a 305-406mm (12-16 inch) slot length limit was
placed on largemouth bass in two lakes, and a 406mm minimum
length limit was imposed on two lakes. Largemouth bass of
2
lengths within the slot in the two lakes, or shorter than
406mm in the other two lakes, were to be released alive
immediately. Bass of other sizes could be harvested. If
anglers abide by the regulations, high minimum length limits
protect large fish and also small fish, which is valuable if
recruitment is low or irregular. Slot length limits protect
large fish, but allow small fish to be harvested, which may
be appropriate if recruitment is consistently high.
Michaelis (1982) described the fisheries before
regulations were imposed. Prendergast (1984) and Mayers
(1988) described the fisheries one and three years,
respectively, after regulations were imposed. Objectives of
my portion of the study were to describe changes in the
fisheries in lakes Beulah, and Rockland (slot length limit
lakes) and Pretty and Browns (minimum length limit lakes)
through 1988 for the first three lakes and through spring
1989 for Browns Lake.
Electrofishing and fyke nets were used to sample the
--------i-f~i~s~h ~latiens, an4 ~r~l 54H'v~ys were used w assess
angling. Characteristics used to describe the largemouth
bass and panfish (mostly bluegill) fisheries were: 1,
length frequency, catch per unit effort, and mean length; 2,
Proportional Stock Density (Anderson 1976); 3, Relative
Weight (Wege and Anderson 1978); 4, growth rate; and 5,
total annual mortality rate from the electrofishing
sampling; and 6, fishing pressure (hours/hectare), catch
rate, and harvest rate (number/hectare) from the creel
3
surveys. Also population density (number/hectare} was
calculated for largemouth bass in Rockland Lake for every
year 1980-1988, and exploitation rate was calculated for
every other year.
Lake Beulah (338 ha} is in Walworth County, Lake Pretty
(26 ha} is in Waukesha County, Rockland (16 ha) and Browns
(160 ha) are in Racine County (Appendices B, C}. Rockland,
Pretty and Browns are hardwater seepage lakes; Rockland and
Browns have an outlet; Pretty has none. Lake Beulah was
originally five lakes that were made into one by the damming
of the outlet stream in 1840. Beulah is also a hardwater
lake. Shoreline development is greater on Pretty and Browns
lakes, intermediate on Beulah, and Rockland Lake is mostly
undeveloped.
Aquatic vegetation occurred in all lakes, but was spare
in Pretty Lake. Vegetation was most abundant in Browns
Lake, where plants grew to the surface throughout the lake
in summer except for an approximate 3 hectare area
_____(__Mi_chael i.s l 982). Aquatic weed harvesting machines worked
throughout the summers on Browns and Beulah lakes.
Browns Lake was chemically treated in September of
1971, to remove carp and stunted panfish (Schumacher and
Rebicek 1977). In 1987 and 1988, 180,687 panfish and 961
bullheads (Ictalurus sp.) weighing a total of 5,313
kilograms were caught by fyke nets and seine and removed
from Browns Lake and transferred to Lac La Belle in Waukesha
County. In May 1977, and 1978, panfish were removed from
4
Pretty Lake. Michaelis (1982) gave a more complete
description of the lakes and their past management.
Harvest regulations for species other than largemouth
bass were no closed season and a possession limit of 50
panfish in aggregate for all lakes. The fishing season for
northern pike extended from the first Saturday in May to
March 1 for all four lakes, with five being the bag limit on
Pretty Lake, and a bag limit of two on the other three
lakes.
5
METHODS AND MATERIALS
SAMPLING
Fish were captured in 1988 and 1989 by electrofishing
and angling (Table 1). Electrofishing was conducted with a
boat-mounted boom electroshocker (Novotny and Priegel 1974).
Lakes Beulah and Browns were electrofished on two nights in
spring and fall, 1988. Rockland Lake was also electrofished
in 1988 two nights in fall, but four nights in spring so
that a multiple census population estimate of largemouth
bass could be calculated. Pretty Lake was electrofished two
nights in 1988 in spring, but not in fall because of low
water. The only electrofishing in 1989 was in spring, in
Browns Lake.
One complete circuit of the shoreline was electrofished
on Browns and Rockland lakes each night. Because of its
size, only the shoreline of the southwest portion of Lake
Beulah was el:eet~~fishee {Appendix C). In ~ty Lake, twe
circuits of the lake were completed each night, one along
the shoreline, and another along the weed line at a depth of
about 2 meters.
Captured fish were held in a holding tank. Largemouth
bass (Appendix D), northern pike, and walleye were measured
to the nearest 2.54mm (one-tenth of an inch), weighed to the
nearest 14.17 grams (half ounce), scale samples were
collected, and the fish, released. Panfish were netted
Table 1. Fish sampling methods in the four lakes with effort in hours for the electroshocker and hours~week for the creel survey.
----------------------------------~--------------------------------------------------------------------
YEAR GEAR
BEULAH
TOTAL D4TES EFFORT SAMPLED
ROCKLAND
TOTAL DATES EFFORT SAMPLED
PRETTY
TOTAL DATES EFFORT SAMPLED
BROWNS
TOTAL DATES EFFORT SAMPLED
----------------------------------~-------------------------------------------------------------------19a8 ELECTROFISHING 3.6 18, 25 MAY 3.4
CREEL SURVEY 24 2~ MAY- 20 31 AUG.
ELECTROFISHING 3.5 5, 12 OCT, 1.6
1989 ELECTROFISHING
16, 19, 26 2.6 MAY;l JUNE
7 MAY- 16 11 SEPT.
3, 10 OCT.
31 MAY 2 JUNE
28 HAY-31 AUG.
5.2 17, 24 MAY
20 7 MAY-11 SEPT.
4.8 4, 11 OCT.
4.9 18, 22, 23 MAY
7
from the holding tank without regard to size and placed in a
19-liter jug containing 10 percent formalin. Panfish were
added until the jugs were full, and they constituted a
subsample (Appendix E). The rest of the panfish were
counted by species and released. Panfish in the jugs were
later measured, weighed, and a scale sample was collected.
Prendergast (1984) considered samples from the spring
electrofishing of 1982 to form part of the pre-regulation
data because they were obtained 12 days after regulations
were imposed. All electrofishing samples after spring,
1982, form post-regulation data.
CREEL SURVEY
Creel surveys were conducted on the lakes in 1988 as
well as 1980, 1982, 1984, and 1986. Rockland and Browns
lakes were surveyed in 1988 from 7 May (the opening of bass
season) through 11 September. Beulah and Pretty lakes were
surveyed from 28 May through 31 August. All weekends,
holidays, and three weekdays selected at random, were
censused in two periods: 0600-1400 hours and 1400-2200
hours. The early and late periods were randomly selected
for each survey day.
One creel clerk worked on Rockland and Browns lakes.
The creel clerk surveyed each lake 20 hours per week, half
of each survey day on each lake. I surveyed Beulah and
Pretty lakes. Beulah was surveyed for 24 hours each week, 8
8
hours on one weekday, 4 hours on each of the other weekdays,
and 4 hours on both weekend days. Pretty Lake was surveyed
16 hours a week, 4 hours on each of two weekdays, and 4
hours on each of both weekend days.
Instantaneous counts of boat and shore anglers were
obtained every other hour, including immediately when a
clerk arrived at a lake and immediately before the clerk
left a lake. Clerks counted from one or two vantage points
on Rockland, Pretty, and Browns lakes, and while traversing
a transect entirely across Lake Beulah.
Anglers were interviewed from a boat between
instantaneous counts or on shore at the completion of their
trip. About 50% of the interviews were from completed
trips. Information recorded included: mode of fishing (boat
or shore), number in party, time spent fishing, species
sought (if more than one, the percent applied to each
species was recorded), and the number of each species caught
and released. When a creel clerk found an angler with an
illegal bass, th~ fish was released, but counteo as a
harvested fish because it was assumed the angler would have
kept the fish if not stopped by the clerk.
Creeled fish, with the permission of the angler, were
counted, measured, weighed, and a scale sample was collected
from largemouth bass. When time did not allow for measuring
all fish, a sample of panfish was selected without regard to
size.
Estimated catch and harvest rates were calculated by
9
dividing catch (number of fish released or kept) or harvest
(number of fish kept) from interviews by total effort from
instantaneous counts (Hoey and Redmond 1974).
Because Beulah and Pretty lakes were not surveyed for
the whole month of May, estimates of fishing pressure,
catch, and h~rvest for the surveyed period, 28 May - 31 May,
were extrapolated to cover the period 7 May - 27 May, by the
proportion:
Est. for the last 4 days in May for Browns and Rockland lakes
Est. for entire month of May in Browns and Rockland lakes
=
Est. for the last 4 days in May for Beulah and Pretty lakes
Unknown estimate for entire month of May for Beulah and Pretty lakes
LENGTH FREQUENCY, MEAN LENGTH AND, CATCH PER UNIT EFFORT
FROM ELECTROFISHING
I evaluated changes in size composition of the
1--a-rgemo-uth bass and bluegill populations by comparing length
frequencies from spring electrofishing samples from 1980 to
1988 (1989 in Browns Lake). I also assessed changes in size
by linear regressions (Steel and Torrie 1960) of mean length
of each species in spring electrofishing samples versus time
for the course of the study. I calculated regressions
separately for all largemouth bass and for largemouth bass
longer than 300mm for the slot length limit lakes (Beulah
and Rockland) and for protected bass, those shorter than
400mm, from the minimum length limit lakes.
10
Similarly, I evaluated changes in relative abundance
for each species from linear regressions of catch per unit
effort in spring electrofishing samples versus time. I
calculated regressions separately for bass longer than 300mm
in the slot length limit lakes and for both protected(<
400mm) and unprotected (>400mm) largemouth bass in the
minimum length limit lakes.
The regulations were stated in inches: 12 - 16 inch
slot and 16 inch minimum length. Because their metric
equivalents did not coincide with 10-mm size groups, I
considered 300mm equivalent to 12 inches and 400mm
equivalent to 16 inches.
PROPORTIONAL STOCK DENSITY
Proportional Stock Density (PSD) is the percentage of
quality sized fish in a stock (Anderson 1976) and is defined
as:
number of fish> minimum quality size PSD = X 100
number of fish~ minimum stock size
I used the quality and stock sizes (Table 2) defined by
Anderson and Gutreuter (1983).
Proportional Stock Density has been used to evaluate
community and population structure (Anderson and Weithman
1978). PSD ranges for largemouth bass of 40 to 60 percent
11
Table 2. Minimum stock and quality size (mm) for largemouth bass, bluegills, pumpkinseeds, warmouth, green sunfish, and yellow perch.
SPECIES Stock - size Quality - size
Largemouth bass 200 300
Bluegill 80 150
Pumpkineed 80 150
Warmouth 80 150
Green sunfish 80 150
Yellow perch 130 200
12
have been considered satisfactory (Reynolds and Babb 1978),
and PSD's of 20 to 40 percent have been considered
satisfactory for bluegills (Novinger and Legler 1978) when
angling for largemouth bass and bluegills is important.
I calculated PSD for largemouth bass and bluegills and
also a prey community PSD by weighting the PSD of each prey
species by its relative abundance (Anderson and Weithman
1978). Because the weighted PSD's were so similar to
bluegill PSD's (Appendix F), I used bluegill PSD 1 s for all
analyses. I calculated largemouth bass, bluegill and
weighted PSD's only if there were at least 30 fish longer
than stock size in a sample, as recommended by Novinger and
Legler (1978). I did not calculate weighted PSD's for
predators because largemouth bass were virtually the only
predator caught.
Community structure can be evaluated by plotting prey
PSD as a function of predator PSD in a tic-tac-toe graph
(Anderson 1976; Anderson and Weithman 1978). Parallel lines
e-:freeommended PSD ranges result in a eenter panel which is
the recommended area for a balanced fish community.
13
RELATIVE WEIGHT
I used a Relative Weight (Wr) index developed by Wege
and Anderson (1978) to evaluate weight-length relations of
largemouth bass longer than 100mm and bluegills longer than
80mm. Wr compares the actual weight (W) of a fish to a
standard weight (Ws) for a fish of the same length and
species: Wr = W/Ws x 100. Mean Relative Weight, standard
deviation, and 95% confidence intervals were calculated for
every 10-mm length group of largemouth bass and bluegills
captured during spring electrofishing. Regression equations
used to calculate standard weights were: largemouth bass,
log weight (g) = -5.316 + 3.191 log length (mm) (Wege and
Anderson 1978); and bluegills, log weight (g) = -5.374 +
3.316 log length (mm) (Hillman 1982).
Wege and Anderson (1978) considered a Wr of 95 - 100%
as satisfactory for largemouth bass in late summer and early
fall, and Legler (1977) considered 95 - 100% to be
satisfactory for bluegills. Hillman (1982), Michaelis
(1982), Prendergast (1984), and Mayers (1988) judged these
ranges too narrow for diverse fish communities, concluding
that Wr's of 90 - 105% were satisfactory for largemouth bass
and bluegills. I agree with their assessment that 90 - 105%
is a satisfactory range of Wr values for largemouth bass and
bluegills in diverse fish communities.
14
AGE, GROWTH, AND MORTALITY
Scales from largemouth bass and bluegills were used to
determine age and growth statistics in all lakes. If there
were more than 12 scales in a 10-mm length group, 10 were
selected randomly from the group; otherwise, all scales were
read.
I cleaned scales by scrubbing with a toothbrush, then
pressed them on an acetate slide with a hand roller press.
I used a tri-simplex projector to magnify the image of the
scales 30X, and a digitizer to record measurements from the
focus to each annulus and to the scale edge along the
anterior scale radius. The most legible scale image of
several on a slide was measured. Back calculations from
scales were obtained by the program developed by Frie
(1982).
I estimated instantaneous growth rate (G) from back
calculated lengths at annulus formation using the
length-weight relationship (ln weight= ln u + v ln length)
of a functional regression (Ricker 1975). Then I calculated
regressions of instantaneous growth rates for each age
versus time from 1979 to 1988. To detect changes in
instantaneous growth rate, I compared slopes of the
regressions of instantaneous growth rates for each age
(Steel and Torrie 1960), and I also compared instantaneous
growth rates with at-test (Zar 1974) for each age group
between the pre-regulation and the 1986 to 1988 time
periods.
15
My back calculated lengths at age were determined from
scales from fish from combined electrofishing samples from
fall and the following spring. All fish captured in fall
were assumed to have formed an annulus; hence, their length
at age was comparable to length at age of fish captured the
following spring. I also compared length at age for
largemouth bass and bluegills with the southeast Wisconsin
average (Druckenmiller 1972) with at-test (Zar 1974).
Total annual and instantaneous mortality (A and Z) and
survival (S) rates were calculated from catch curves (Ricker
1975).
POPULATION ESTIMATES, STANDING STOCK, AND EXPLOITATION
I used Chapman's modification of the Schnabel formula
(Ricker 1975; equation 3.17) to estimate the size of the
largemouth bass population in Rockland Lake. I calculated
population estimates for fish larger than the minimum size,
130mm, that both Mayers (19M) and I thought. was hl'le size
effectively captured by electrofishing. I also calculated
populations estimates for fish larger than the minimum size
harvested by most anglers, i.e. 200mm. Largemouth bass were
marked by clips of the caudal fin on four nights of
electrofishing in a 2 week period every spring from 1980 to
1988. Electrofishing was used for both marking and
recapture of fish. Approximate confidence limits (95%) were
estimated by treating R (recatures) as a Poisson variable
(Ricker 1975; p.97).
16
The exploitation rate of largemouth bass in Rockland
Lake in 1980, 1982, 1984, 1986, and 1988 was calculated by
division of the estimated harvest (from creel surveys) by
the population estimates (Ricker 1975; p.264). Separate
exploitation rates were calculated from population estimates
based on minimum length of fish harvested by anglers and
from minimum length of fish in electrofishing samples.
Hall (1986) found a positive linear relation between
electrofishing catch per hour of largemouth bass and the
estimated number of largemouth bass longer than 199mm in 12
Ohio lakes. I used Hall's regression equation, log 10
(number per hectare)= 1.2274 log 10 (electrofishing catch
per hour) - 0.5489, to calculate predicted densities of
largemouth bass longer than 199mm ir. Rockland Lake. Then I
used a paired t-test (Zar 1974; p.121) to assess the
difference between my estimated densities (from Schnabel
population estimates) and the predicted densities (from
Hall's equation) of largemouth bass longer than 199mm.
17
RESULTS AND DISCUSSION
CREEL SURVEY
Fishing Pressure
The length limits probably did not affect fishing
pressure. Angling effort (hrs/ha) did not change for
largemouth bass and bluegills in any lake (Table 3). Effort
varied considerably from year to year making significant
trends impossible to identify (Figures 1, 2). Effort for
all species combined decreased in Browns Lake (Table 3). I
do not know if this decrease was related to abundance of
species other than largemouth bass and bluegills or to
anglers' perceptions of chances for successful fishing
trips.
HARVEST RATE, MEAN LENGTH HARVESTED, AND CATCH RATE
Largemouth bass
The length limits affected the harvest of largemouth
bass, as one might predict. I would expect harvest rate to
decrease after imposition of the length limit regulations in
the minimum length limit lakes because of the release of
large numbers of protected largemouth bass. In the slot
length limit lakes, the harvest rate should decrease for
Table 3. Estimated anfling effort (hours/hectare) for largemouth bass, bluegills, and all species in 1980, 1982, 1984, 1986, and 1988 and results of regression analysis of estimated angling effort versus time in Beulah, Rockland, Pretty and Browns lakes. +=positively significant, - = negatively significant, and o = not significant at the 0.05 level of significance.
---------------------------------------------------------~-----------------
SPECIES
LARGEMOUTH BASS
BLUEGILLS
ALL SPECIES
LAKE
BEULAH ROCKLAND PRETTY BROWNS
BEULAH ROCKLAND PRETTY BROWNS
BEULAH ROCKLAND PRETTY BROWNS
EFFORT (HRS/HECT}
YEAR 1980 1982 1984 1986 1988
78 163
27 117
42 125
39 26
151 348 107 187
64 102 110
68
131 209
83 45
215 370 227 141
64 98 34 80
78 171
53 31
148 279 117 127
55 123
58 84
81 165
81 56
141 277 142 120
59 111 19 54
24 166
24 18
84 277
50 75
F VALUE SIGNIFICANT
8.17 1.01 0.28 3.65
0.37 0.13 0.12 0.01
3.01 6.23 0.94
35.91
0 0 0 0
0 0 0 0
0 0 0
I--'
00
/""'-140 <( J: 120 ......__,
(/) 100
a: / J: 80 . '-.../
r 60 a: f2 40 LL
19
BEU.LA·H · LAKE ..
,_
Q
~ LMB
·0 - BLG
UJ 20+-----+-----+-----+---~f-----,ClJl------4 1980 1982 1984 :1986 · · 1988.
YEAR
ROCKLAND LAKE
,-._ 220 ~ LMB <( 0
I 200
~ .0- BLG
' 180 (J) Gl
----□ a
~ I '_,I 140
l-a: 120
0 LL 100 LL w 80
1980 1982 1984 1986 1988
YEAR
Figure 1. Angling effort (hours/hectare) for largemouth bass (LMB) and bluegills (BLG) in Beulah and Rockland lakes in 1980, 1982, 1984, 1986, and 1988.
I"" 120
<I: I :1..-00
.........
en 80
0: :r: 60 '-,I
I- 40 0: 0 20 LL LL w 0
I"" 120
<I: J: 100
.........
(J) 80
--er-I 60 -._,I
I- 40 a: 0 20 LL LL w 0
20
PRETTY LAKE
□
1980 1982~ 1984 1986
YEAR
BROWNS· ·LAKE.
19a0·· 1982' 1984 · 1986
YEAR·
..)f(... LMB
.0- BLG
1988.
..)f(... LMB
.a- BLG
1988"
Figure 2. Angling effort (hours/hectare) for largemouth bass (LMB) and bluegills (BLG) in Pretty and Browns lakes in 1980, 1982, 1984, 1986, and 1988.
21
fish within the slot, but the harvest rate for bass of all
sizes could decrease or not depending on the harvest of fish
smaller than the slot.
The harvest rate decreased in the minimum length limit
lakes (Pretty, Browns) for fish of protected sizes (<
400mm), and therefore for all largemouth bass (Table 4;
Figures 3, 4). The pattern of harvest in Browns Lake was as
one might expect: bass of legal size continued to be
harvested from 1982 to 1988 and the illegal harvest was
small (Figure 4; Table 5). In Pretty Lake there appeared to
be a substantial illegal harvest in 1982 and 1984, and no
largemouth bass were observed in the creel in 1988. Still,
the harvest of largemouth bass decreased (Table 4).
Novinger (1987) found a decrease in largemouth bass harvest
rates after a 381mm length limit was imposed for bass in the
James River and Long Creek arms of Table Rock Reservoir,
Missouri.
In both Pretty and Browns lakes the harvest rate of
------t-l=e-ng=al bass increased after the regulations were imposed
(Table 4), a suggestion that the regulations effected an
increase in survival of largemouth bass to larger sizes.
In the slot length limit lakes, the harvest rates of
protected largemouth bass (about 300-399mm) decreased in
Lake Beulah after imposition of the regulations, but not in
Rockland Lake if data for 1988 are included in the analysis
(Table 4; Figures 5, 6). There appeared to be a substantial
illegal harvest of protected bass in 1988 in Rockland Lake
22
Table 4. Estimated mean harvest rate (number/hectare) of largemouth bass of protected sizes and of all sizes in Beulah, Rockland, Pretty, and Browns lakes compare.a between 1980 and 1982-1988 (and between 1980 and 1982-1986 for Rockland Lake) with a Chi-square test (Li 1969; p.458). +=positively significant, - = negatively significant, and o = not significant at the 0.05 level of significance.
GROUP MEAN HARVEST CHI-SQUARE LAKE 1980 1982-1988 VALUE SIGNIFICANT -------------------------------------------------------------BEULAH PROTECTED 423.0 87.5 266.1
ALL 1217.0 1633.S 142.5 +
ROCKLAND PROTECTED 48.0 39.8 1.4 0 PROTECTEDa 48.0 17.3 19.6
ALL 323.0 219.5 33.2
PRETTY PROTECTED 84.0 29.7 35.1 ALL 112.0 74.7 12.4
BROWNS PROTECTED 1686.0 112.8 1468.0 ALL 1777.0 302.8 1223.0
-------------------------------------------------------------a MEAN HARVEST OF LARGEMOUTH BASS FROM 1982-1986
w a: 5 ~ 1-u w I. 4
' O· W 3 1-(J) w > a: 2
<l: :t a: 1 llJ ca 3 0-+---2 1980 1982
RRETTY LAKE
·: :I
. ~Ii~ 1984 1986
YEAR 1988
m·)40·0 W Mb\
~ 200-399rnrn
II <200rnm
Figure 3. Harvest composition (numbers/hectare) of three size groups of largemouth bass from Pretty Lake in 1980, 1982, 1984, 1986, and 1988.
N w
LU $ROWNS LAKE I
a: 12. I <{ r-u LU 10 :r: ........
O· 8 w Ill >400tnrn 1--en 6 ~ 200-399rnrn w > ■ (200tnM a: <! 4 :r: h: 2 LU o:l ~ :J 0 2 1980 1982 1984 1986 1988
YEAR Figure 4. Harvest composition (numbers/hectare) of three size groups of largemouth bass from Browns Lake in 1980, 1982, 1984, 1986, and 1988.
N ~
25
Table 5. Estimated total number harvested, harvest rate (number/hectare), and percent of each size group of largemouth bass harvested in 1980, 1982, 1984, 1986, and 1988.
-----------------------------------------------------------------------------------------SIZE &ROUP NUNBER HARVESTED
1980 1982 1984 1986 1988
(200 31 483 205 123 12 200-299 670 2113 1411 1164 326 300-399 423 36 181 61 72 )400 93 72 96 107 72
TOTAL 1217 2704 1893 1455 482
(200 116 18 10 13 200-299 143 170 121 72 229 300-399 48 9 33 10 107 )400 16 39 5 40
TOTAL 323 197 193 99 389
HARVEST RATE
1980 1982 1984 1986 1988
BEULAH
0.1 1.4 0.6 0.4 o.o 2.0 6.3 4.2 3.4 1.0 1.3 0.1 o.s 0.2 0.2 0.3 0.2 0.3 0.3 0.2
3.7 8.0 5.6 4.3 1.4
ROCKLAND
7.3 1.1 0.6 0.8 8.9 10.6 7.6 4.5 14.3 3.0 0.6 2.1 0.6 6.7 1.0 2.4 0.3 2.5
20.2 12.3 12.1 6.1 24.3
PREJTY
PERCENT
1980 1982 1984 1986 1988
2 18 11 8 2 55 78 75 80 68 34 I 10 4 IS 8 3 s 7 15
99 100 101 99 100
36 9 10 3 44 86 63 74 59 15. s 17 10 28 s 20 s 10
100 100 100 99 100
----------------------------------------------------------------------------------------------------------------(200 28 17 I.I 0.7 25 25 200-399 56 17 55 2.2 0.7 2.1 so 25 75 )400 28 34 18 83 I.I I. 3 0.7 1 .8 25 50 25 100
TOTAL 112 68 73 83 0 4.3 2.6 2.8 1.8 o.o 100 100 100 100 0
BROWNS ---------------------------------------------------------------------------------------------------------------(200 21 33 38 0.1 0.2 0.2 1 17 13 200-399 1665 60 109 48 54 10.4 0.4 0.7 0.3 0.3 94 31 27 16 17 >400 91 99 291 209 270 0.6 0.6 1.8 1.3 1.7 5 52 73 71 83
TOTAL 1777 192 400 295 324 11. 1 1.2 2.5 1.8 2.0 100 100 100 100 100
w a: ~ r () w I :<.... 0 w r (/) w > 0: <l'. :c 0: w co ~ :J z
8
7
6
5
4
3
2
1
0 1980 1982
B[EULAH LAKE
i984 1986
YEAR 1988
m }40011\M
~ 300-399rnrn
~ 200-299mm
II <200l!nn
Figures~ Harvest composition (numbers/hectare) of four size groups of largemouth bass from Beuiah Lake in 1980, 1982, 1984, 1986, and 1988.
N 0)
liJ a: 25 <! ~ 0 w
20 :c
' 0 w 15 f-U) w > 10 a: <! J: a: 5 UJ O'..)
2 0 :J
2
R9CKLAND LAKE
1980 1982 1984
YEAR 1986 1988
m >4001nrii
~ 300-399rnm
~ 200-299mrn
■ (20011\tn
Figure 6. Harvest composition (numbers/hectare) of four size groups of largemouth bass from Rockland Lake in 1980, 1982, 1984, 1986, and 1988.
N -...J
28
(Table 5; Figure 6). If data for 1988 are omitted, the
harvest rate of protected largemouth bass decreased in
Rockland Lake too after imposition of the regulations. The
harvest rate of all sizes of largemouth bass decreased in
Rockland (data for 1988 omitted), but it increased in Lake
Beulah because of the harvest of fish smaller than the slot
(Table 4, Figure 5).
The harvest rate of legal bass after imposition of the
length limit regulation, increased in Lake Beulah and
decreased in Rockland Lake (Table 4). This difference in
harvest rates was caused by differences in numbers of bass
harvested that were shorter than the slot from 1982 to 1988
(Figures 5, 6).
Mean lengths of harvested largemouth bass followed a
pattern similar to harvest rates. One might expect mean
length of largemouth bass harvested to increase in the
minimum length lakes, but mean length would not necessarily
change in slot limit lakes because of the harvest of bass --
shorter than 305mm. The mean length of harvested largemouth
bass increased in Browns Lake, but not in Pretty Lake (Table
6; Figure 7), perhaps because the illegal harvest in 1982
and 1984 and lack of data for 1988 (Figure 3). Mean length
of harvested bass did not change in the slot length limit
lakes.
Results for catch rates were not as expected. I would
expect catch rates to increase after imposition of the
length limit regulations because of repeated recapture of
29
Table 6. Estimated mean length (mm) and catch rate (number/hectare) of largemouth bass in 1980, 1982, 1984, 1986, and 1988 and results of regression analysis of estimated mean length harvested and catch rate versus time in Beulah, Rockland, Pretty, and Browns lakes. +=positively significant, - = negatively significant, o = not significant at the 0.05 level of significance.
------------------------------------------------------------------YEAR
LAKE 1980 1982 1984 1986 1988 F VALUE SIGNIFICANT ------------------------------------------------------------------BEULAH
HEAN LENGTH 298.0 242.0 257.0 259.6 302.0 0.07 0 CATCH RATE 28.8 25.8 30.4 22.2 23.8 1.99 0
ROCKLAND HEAN LENGTH 245.0 252.0 307.0 276.6 303.3 4.80 0 CATCH RATE 73.3 40.9 58.4 36.3 42.5 2.62 0
PRETTY MEAN LENGTH 330.0 325.0 344.0 454.4 o.o 4.53 0 CATCH RATE 12.4 37.3 45.2 51.6 19.2 0.22 0
BROWNS HEAN LENGTH· 330.0 356.0 410.0 395.0 439.9 22.32 + CATCH RATE 18.8 13.7 13.2 26.7 17.1 0.25 0
::C 440
I- 420 C, 2 400 w _J 380
2 360 <{
340 w 2 320
1979
0
V 12.888 R - 0.88 -
30
BROWNS LAKE
1981 1983 1985 1987 1989
YEAR 25167.86 F 22.32 SIGN
N - 472 -
Figure 7. Regression of mean length {mm) of harvested largemouth bass from Browns Lake in 1980, 1982, 1984, 1986, and 1988, with regression equation, F value, correlation coefficient {R), and sample size {N). "Sign." indicates a significant relation at the 0.05 level of significance.
31
released protected largemouth bass. However, catch rates
did not change (Table 6; Figures 8-11). The lack of
increase in catch rates is inconsistent both with the data
for harvest rates presented above and with spring
electrofishing results, presented in the next section, in
which catch per unit effort of largemouth bass increased
after imposition of the regulations in 3 of the 4 lakes.
Novinger (1987) found that catch rates increased
significantly for largemouth bass after imposition of a
381mm minimum length limit in the James River arm, but not
in the Long Creek arm of Table Rock Reservoir, Missouri.
Angler catches of piscivorous fish may by variable
(e.g. Figures 8-11) and may be influenced by factors other
than abundance of the predators, e.g. prey availability
(Kempinger et al. 1975), weather and environmental
conditions. I do not know if other influences prevented
increases in the catch rates.
___Bluegills
Both catch and harvest rates of bluegills did not
change from 1980 to 1988 in any lake (Table 7). Apparently
any changes in the largemouth bass populations brought about
by the length limit regulations were insufficient to change
the rate at which anglers caught or caught and kept
bluegills.
In contrast, the mean length of bluegills harvested
35,
Lu 30 a: ~ r- 25 ()
W 20 :r:
' a: 15 w ca 10 2 :J 2 5
BEULAH LAKE I
.......... )I<
250
200 w. ct,...:---------.
150 ~ -+- CAUGkr CJ LU -~ HARiJEST£D :t
100 , -- EFFORT
a: :c
50
0~-~------+----_.----~-----~-~0 1980 1982 1984 1986 1988
YEAR . -
Figure 8. Estimated numbers of largemouth bass caught and harvested per hectare, and total angling effort (hours/hecbare) in Beulah Lake in 1980, 1982, 1984, 1986, and 1988.
w N
RO~KLAND LAKE I
80 · 400
350
300 W a: .... ·--------,
258 <( -+-- CAUGHT ~ . u 200 W -~ HARVESTED
:t:. 150 , -- EFFORT
a: 100 :C
50
0-1---+------+------+-----;-----;--~0 1980 1982 1984 1986 1988
YEAR Figure 9. Estimated numbers of largemouth bass caught and harvested per hectare, and total angling effort (hours/hectare) in Rockland Lake in 1980, 1982, 1984, 1986, and 1988.
w w
60
W 50
0: <{ r- 40 0 w I 30
' 0: W 20 ca ~ :J 10 2
I I
I I
I I
~
I I
I I
I
•
y I
"'··············· ,,
PRETTY LAKE
~ ,,, ,,.
I
250
200
w a:;-:------
150 ~ ..,.._ CAUGHT u W -~ HARVESTED :c
100 , _._ EFFORT
tt: :r:
50
...... -~ ..................... ·"' ..................... -~. 0~-+-----+----~----+--··_···_···~···~·-·~···~··~-~0
1980 1982 1984 1986 1988
YEAR Figure 10. Estimated numbers of largemouth bass caught and harvested per hectare, and total angling effort (hours/hectare) in Pretty Lake in 1980, 1982, 1984, 1986, and 1988.
30
UJ 25 a: <( 1-u 20 w J:
'15 a: w ca 10 2 :)
2 5
•
)K ·,,
'• ., ·, ·•. •. . ·,
·• .. ·, ·,,
•, ..
BRIOWNS LAKE I
I+_. I '
I ', I \.
I '\ I ' I '\
I '\
' \
.. ······*········· ,.u •• •••••••••• ••• , •••••••• ~ ••••••••••••••••• ••·••,fl'\ ~-·····
200
1s0w a: ;-. -------, <( 1-
100~ J:·
' a: 50 :C
-+- CAUGHT
-~ HARVESTRD
->- EFFORT
0~-~-----+------t-----t------r--~0 1980 1982 1984 1986 1988
YEAR Figure 11. Estimated numbers of largemouth bass caught and harvested per hectare, and total angling effort (hours/hectare) in Browns Lake in 1980, 1982, 1984, 1986, and 1988.
w l11
36
Table 7. Estimated harvest and catch rates (number/hour), and mean length (mm) of bluegill harvested in 1980, 1982, 1984, 1986, and 1988 and results of regression analysis of estimated harvest and catch rates, and mean length harvested versus time in Beulah, Rockland, Pretty, and Browns lakes. +=positively significant, - = negatively significant, o = not significant at the 0.05 level of significance.
YEAR LAKE 1980 1982 1984 1986 1988 F VALUE SIGNIFICANT
BEULAH HARVEST RATE HEAN LENGTH CATCH RATE
ROCKLAND HARVEST RATE HEAN LENGTH CATCH RATE
PRETTY HARVEST RATE ·HEAN LENGTH CATCH RATE
BROWNS HARVEST RATE HEAN LENGTH C~TCR RATE
74.1 189.1 97.7 145.8 35.5 155.0 166.0 165.0 166.4 182.6 132.3 318.6 201.0 283.7 62.4
210.6 291.3 311.2 238.8 145.7 152.0 163.0 164.0 166.9 179.8 459.5 548.8 637.8 512.4 311.3
45.0 259.8 137.9 168.5 56.3 143.0 147.0 156.0 150.9 170.9 146.0 583.7 278.4 387.5 100.3
37.0 80.1 65.7 43.9 9.5 132.0 140.0 147.0 142.7 154.2 160.4 224.5 198.2 215.7 49.5
0.34 11.10 0.22
0.71 24.97 0.70
0.05 9.56 0.17
1.17 13.44 1.0S
0 + 0
0 + 0
0 0 0
0 + 0
37
increased in three of the lakes and also appeared to improve
in the fourth (Table 7; Figures 12, 13). This consistency
suggests that the change in mean length of harvested
bluegills was real rather than due to chance.
LENGTH FREQUENCY, CATCH PER UNIT EFFORT, AND MEAN LENGTH
FROM ELECTROFISHING SAMPLES
Largemouth Bass
The length limits appeared to affect the largemouth
bass populations. In three of the lakes the relative
abundance of larger bass increased after imposition of the
length limit regulations, and in the fourth lake the mean
length of the smaller, protected largemouth bass increased
(Table 8).
The length limit probably increased the number of
la-Eger largemottth bass in Beulah Lake. Although an increase
in catch per unit effort of bass longer than 305mm was not
readily apparent in the length frequency (Figure 14), it was
significant (Table 8; Figure 15). The electrofishing CUE of
largemouth bass longer than 305mm increased from 1980 to
1988. This increase in relative abundance of the larger
bass, however, did not increase the mean length of the fish
longer than 305mm, nor of all largemouth bass (Table 8;
Figure 14).
Numbers of larger largemouth bass also increased in
38
BEULAH LAKE I 195
I-CJ 185
0
2 w 175 _J
165 2 <! 155 w ~ 145
1979 1981 1983 1985 1987 1989
YEAR V - 2.78X - 5348.52 R - 0. 79
F - 11.10 SIGN N - 8525
I 100 IC, 2 w ....J
175
170
165
Z- 160
<( 155 w
ROCKLAND LAKE 0
0
~ 150-----------------1979 1981 1983 1985 1987 1989
V - 2.98X R - 0. 89
5737.26 YEAR
F - 24.97 SIGN N - 3634
Figure 12. Regression of mean length (mm} of harvested bluegills from Beulah and Rockland lakes in 1980, 1982, 1984, 1986, and 198.8, with regression equation, F value, correlation coefficient.(R}, and sample size (N). "Sign." indicates a significant relation at the 0.05 level of significance.
I J-C, 2 w ...J
2 <! w 2
39
BROWNS .LAKE 155
150
145
140
135 0-
130 1979 1981 1983 1985 1987 1989
V = 2.368 - 4529.14 R = 0.82
YEAR F 13.44 SIGN N - 4421
Figure 13. Regression of mean length (mm) of harvested bluegills from Browns Lake in 1980, 1982, 1984, 1986, and 1988, with regression equation, F value, correlation coefficient (R), and sample size (N). "Sign." indicates a significant relation at the 0.05 level of significance.
Table 8. Catch per unit effort (CUE) and mean length of largemouth bass from electrofishing in spring in the four lakes, 1980 - 1989, and results of regression analysis of CUE and mean length versus time. +=positively significant, - = negatively significant, and o = not significant at the 0.10 level of significance. Means in table computed from values in appendix G.
-----------------------------------------------------------------------------------------------------------------------------LENGTH YEAR
LAKE GROUP (mm) 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 F VALUE SIGNIFICANT -----------------------------------------------------------------------------------------------------------------------------BEULAH
CUE >300 2.00 3.10 3.30 1.80 4.30 7.80 6.90 5.50 7.50 15. 72 + HEAN LENGTH >300 390.38 344.91 3S7.8S 3S7.S6 367.S6 377. 32 3S4 .11 3S3.09 3S4,54 0.94 0 HEAN LENGTH ALL 221.45 231.57 214.76 214 .14 227.45 243.85 235.18 237.87 215.63 0.57 0
ROCKLAND CUE >300 5.00 5.40 4.10 7.10 7.60 3.90 13. 20 8.40 18.20 8.43 + HEAN LENGTH >300 386.33 424.10 371.33 341.60 373.11 390.07 3S6.48 344.65 348.80 4.68 HEAN LENGTH ALL 225.81 240.44 238.19 235.36 234.19 226.14 249.10 244.02 237.28 1.46 0
PRETTY CUE <400 67.50 74. 40 27.50 24.50 34.30 42.20 45.80 52.70 46.90 0.48 0 CUE >400 0.00 1.90 1.60 0.70 1. 70 0.80 0.80 1. 20 0.40 0.15 0 HEAN LENGTH <400 216.55 213.51 223.02 201.8S 202.93 217.45 221.48 23L 43 237. 71 3.85 +
BROWNS CUE <400 S2.10 21. 30 14. 50 10. 40 7.00 9.40 37.10 S2.70 52.30 83,30 3.53 + CUE >400 1.10 2.50 5.70 4.40 3.50 5.30 4.30 5.10 3.50 6.10 4.53 + HEAN LENGTH <400 286.55 279.90 298.33 227.84 267.71 281.80 205.09 235.38 251.45 265.30 2.20 0
41
I
11 ·1 1986 : _.111 II 11, ....... _____ :
PSD=27 N=230
15
15
192
15 143
32
158
14 173 .. _
Figure 14. Spring electrofishing catch per unit effort of largemouth bass in 10-mm length groups, sample (N), and Proportional Stock Density (PSD) from Beulah Lake in 1980 to 1988. Slot length limit represented by dashed vertical lines.
42
a: BEULAH LAKE :::, 8 C·
0 7 -c:::•
:r: 6 <::>
' 5
a: 4 w 3
~ co 2 2
:::, 1
2 1979 1981 1983 1985 1987 1989
YEAR V - 0.71X - 1397.34 F - 15.72 SIGN - -R --
0: 20 :::, 016 :t ,12
a: 8 -W ca 4
2 :J 0
0.69
2 1979
N - 180 -
ROCKLAND LAKE
1981 1983 1985 1987
YEAR V - 1.28X - 2531.42 R - 0.55
F - 8.43 SIGN N - 317
1989
Figure 15. Regression of spring electrofishing catch per unit effort of largemouth bass longer than 305mm from Beulah and Rockland lakes in 1980 to 1988, with the regression equation, F value, correlation coefficient (R), and sample size (N) for each lake. "SIGN." indicates a significant relation at the 0.10 level of significance.
43
Rockland Lake after imposition of the length limit (Table 8;
Figure 15) -- an increase that was evident in numbers of
fish in the slot (Figure 16). Electrofishing CUE of fish
longer than 305mm increased significantly (Table 8). The
mean length of largemouth bass longer than 305mm decreased
(Table 8; Figure 17), because of variation in numbers of
bass of various lengths within the slot (Figure 16).
The regulation did not increase the numbers of larger
largemouth bass in Pretty Lake, nor the numbers of smaller,
protected bass (Table 8; Figure 18). Catch per unit effort
of neither group increased. Yet the mean length of the
protected bass increased (Table 8; Figure 17), a suggestion
that anglers released fish that they would have kept before
the length limit regulation.
The length limits appeared to increase the number of
both larger and smaller largemouth bass in Browns Lake
(Table 8; Figure 19). Catch per unit effort of both groups
increased from 1980 to 1989. The increase in relative
abundance of the prot-e-Gt-ed largemouth bass was evident in
the length frequency (Figure 20), which also showed evidence
of strong year classes of largemouth bass increasing in
length in successive years. This apparent variation in year
class strength may account for the lack of a significant
increase in mean length of the protected fish (Table 8).
Increased numbers of largemouth bass after imposition of
minimum length limit regulations has been found in other
studies (Ager 1988; Anderson 1976).
44
II 1988. : PSD=Ll-6
II I ' 1 N=266 - _111 ·h .. _ .. l ••-~11h1 .. _.1 ___ ---
1
1 o ! I 1987 : 27 5 1-11 I 'I I 215 o ---- J 11111 II ••··· __ .__ _ · ,
[Y ; ~ + I I 1986 : 21
~ ~ i ... h1o1.111ll11 li.1 .. , .. 1 ••• ~ - ---- 265 er: 1S - ! I
~ 1 of I 1985 : ~ ~ _ .I 1rnl1m1.J ______ l. z ·1 o 1984 : CJ z
5 I I I :
0 I _.11ll1i1l1 .•••• ~--D ■ ___ !_ 1983
I
11 228 2.7
218
41 I U1 5T LL O 1 _.1l •.. ___ .1h ....• !n.1 .. _ _ ___ ] 79
~ 1~! W 40 _J w 30 CJ 20 .. z 10 er: 0 o_ 20 U1
15 10
5
1982
.,111 ...• 1111., ...... - - -- -
1980
12
206
8
465
27
330 0 ~l"'t-H~~~~~I\A!-l'IHSi'l'I' ~-~F;"i-lH-1 ++I l-+-1 l-+'l"'i9"l-ll"i-1--1 ++I l-l-11-ti-+I ++I 1-+-fl I
60 160 260 360 460 560
LENGTH ( mm) Figure 16. Spring electrofishing catch per unit effort of largemouth bass in 10-mm length groups, sample (N), and Proportional Stock Density (PSD) from Rockland Lake in 1980 to 1988. Slot length limit represented by dashed vertical lines.
45
::c 440 ROCKLAND LAKE
t-CJ 420 ~ UJ 400 ...J
2 380
<{ 360 w
2 340 1979. 1981 1983 1985 1987
YEAR V - -6.16X + 12595.47 R - 0. 40
F - 4.68 SIGN N - 317
::c PRETTY LAKE 240
t- -0
C·
CJ 2
230
w ...J 220
_z. <I: 210
w 0
2 0 200
1979 1981 1983 1985 1987
YEAR
A
1989
B
1989
V = 2.67X - 5069.25 R = 0.36
F = 3.85 SIGN N = 1040
Figure 17. A: Regression of mean length (mm) of largemouth bass longer than 305mm from spring electrofishing samples from Rockland Lake in 1980 to 1988. B: Regression of mean length (mm) of protected largemouth bass from spring electrofish.ing samples from Pretty Lake in 1980 to 1988, with the regression equation, F value, correlation coefficient (R), and sample size (N) for each lake. "Sign." indicates a significant relation at the 0.10 level of significance.
Ct:: I
"' Ct:: w m 2 ::J z (.9 z I C/1
LL 0 Ct: 1-u w _j
w -- -- TI
z Ct: I)_
C/1
46
PSD=34 N=126
36 154
24 122 17
159
30
110
13
73 29
92
LENGTH (mm) . Figure 18. Spring electrofishing catch per unit effort of largemouth bass in 10-mm length groups, sample (N), and Proportional Stock Density (PSD) from Pretty Lake in 1980 to 1988. Minimum length limit represented by dashed vertical line.
47
a: 100 BROWNS LAKE
::, 0 80 ::c
' 60
0
a: 40 w ca 20
2 ~
·C- C>
::> 0 1979
2 1981 1983 1985 1987
YEAR V - 4.67X - 9242.63 R - 0.31
F - 3.53 SIGN N - 1873
a: :J 0 ::c
' a: w ca 2 ::> 2
BROWNS LAKE 7
6
5
4
3 0
2
1 1979 1981 1983 1985 1987
V = 0.31X - 603.23 R = 0.36
YEAR F = 4.53 SIGN N = 251
A
1989
B
0
1989
Figure 19. A: Spring electrofishing catch per unit effort of protected largemouth bass from Browns Lake in 1980 to 1989. B: Spring electrofishing catch per unit effort of unprotected largemouth bass from Browns Lake in 1980 to 1989, with the regression equation, F value, correlation coefficient (R), and sample size (N) for each lake. "Sign." indicates a significant relation at the 0.10 level of significance.
a:: I
.'-.... a:: w rn 2 :J z (.9
z :r: U1
LL 0 a:: fu w _J
w l
0. z.
~l (11;
48
1989 1 PSD=55
11 1111 I N = 44 1 ... 11111,11 II 1111 tlJlltl., .. ,,, ..
. ~ I
1111988 I :25
•• 11L11HIH I 111 ........ L .. ····· .291 I I 1987 I 51
_ . .11l lllhhll1,lu ... , . .l.. .... ... /IO 1
1986 48
... ,11111111.111.... .. .. .............. 242
2 o I - - ■ ----
2
1985
1984
79 68
61 . 71
o I - I ■ --n--. ••-•---•---!law ■■
1983 : 2 . n Lu -·- ._ ----•-
I I - --··•-R ■ l&I.■■ •
4
02I 111 -
1982
- ---· 042!
.• 1111l11h11 ... _ •• .l&al.1. -·
1981
90 124
75 gg
46 137
4 1980 68
~ f.,,,,,, --~~. ~~ullh~ ...... --~~ 50 150 250 350 450 550
LENGTH (mm) Figure 20. Spring electrofishing catch per unit effort of largemouth bass in 10-mm length groups, sample (N), and Proportional Stock Density (PSD) from Browns Lake in 1980 to 1989. Minimum length limit represented by dashed vertical line.
49
A good deal of variation from year to year was apparent
in the catch per unit effort and mean length data (Figures
14-20). This variability could be responsible for the
inconsistency in results, i.e., increases in catch per unit
effort only or mean length only in various lakes. Catch per
unit effort and mean length are independent. It would be
possible to have large catches in one year and small in
another while mean length was increasing. In this
circumstance a significant increase might be found for mean
length but not for catch per unit effort. It would also be
possible to get increasing catches from year to year without
exceptionally large variation while the variance of lengths
was sufficiently high to prevent detection of a significant
increased in mean length.
All of the significant changes were in the direction
(positive slope for regressions) expected from the length
limit regulations except the decrease in mean length for
bass longer than 305mm in Rockland Lake, which appeared to
be caused by variation in numbe£s of fish of va£i~us lengths
in the slot (Figure 16). This correspondence of results
with what was expected, indicates that the changes were
related to the length limit regulations and not to random
variation.
50
Bluegills
None of the changes expected of bluegills were evident
in the spring electrofishing samples (Figures 21-24). With
increased predation by largemouth bass, one might expect
catch per unit effort of bluegills to decrease and lengths
to increase (Anderson 1976). The only changes in relative
abundance of bluegills were increases in lakes Beulah and
Browns (Table 9; Figure 25). The only change in size was a
decrease in mean length in Browns Lake (Table 9; Figure 26).
The lack of expected changes in the bluegill
electrofishing samples suggests that the increased abundance
or size of largemouth bass was insufficient to cause changes
in the bluegill populations. Yet there were changes
(improvements) in the bluegill populations. Not only mean
length harvested (presented above), but also condition
(presented below), of bluegills increased. These changes
are to be expected from increased densities of largemouth
bass, whieh: 1, are theoretically filqrected from the length
limit regulations, and 2, were indicated by the decreased
harvest rates of largemouth bass (creel survey section) and
the increased catch per unit effort or mean length of
largemouth bass from electrofishing samples (Table 8).
Inconsistencies or discrepancies in various measures of
the bluegill populations could have been influenced by
normal variations in abundance and distribution and by gear
bias. Catch rates of bluegills were somewhat inconsistent.
------
51
~~1 2~.
100 75 50
er::: '"" c-
I L.J
"- C' ! ..
er:: ·1 DU
LLI l ~-). I]] '·,u '-·' .. 2. 25 =:i z 0
.... "0 IU T I
C) ,51 I -'-
z I so.:. I 25~ U1 o' -- .., ..L
LL
~~! 0 er::: I-· 0 u 501 w _J 25 w n C) 50. z- 2§t er::: 01 [)_ 7r:z U1 5~i 25
0 ....
50l 25 0
0 200
LENGTH ( mm) Figure 21. Spring electrofishing catch per unit effort of bluegills in 10-mm length groups, sample (N), and Proportional Stock Density (PSD) from Beulah Lake in 1980 to 1988. Quality size is represented by the solid vertical line.
5:1
Ct::: 5:1
I .......... 5:1 Ct:::· w; rn
5:1 2 ::)·
Z'
100~1 (_9·
Z'. 50 I'
0 C/1
LL
5:1 0 Ct::: I-
1 DOI u w 50 _J
w G_ ~ --
(.9
5~1 z Ct::: [L 1001 C/1
50
0 0
52
1988 PSD=21 I · N=760
_1111111 D ■ mll ■ --s--1987. -· - - 34
_me~all-m ■ D-~~544 1986" --- 16
383 ma&!._ Iii Im- -- __
1985 35
- - . I 11 II II Im Ii 11n_1025
1984 10
_.mmllmlla----~041 1983 13
598
1982 10
_ ..... 1 •. ---- 2~1 1981 17
I a 566 ---■ llllnr; __ _
1980 16
50 100 150 200 LENG-TH- (mmr
Figure 22. Spring electrofishing catch per unit effort of bluegills in 10-mm length groups, sample (N), and Proportional Stock Density (PSD) from Rockland Lake in 1980 to 1988. Quality size is represented by the solid vertical line.
100
oI
er:::
i oo I D
=r= ........... 1 oo T er::: w 01 II)
> 1 oo 1 ..,,::_
=J -.7 ni u ..a: .. __
C) 1 oo I z ----- o. I
2001 [.11
LL 100 0 c:r::: 0 f-·-·· 2001 u w 100 _J
Lt.J 0
CJ 2001 z 100+ er::: ol [)_
- 1/l 200-
100
o. 0
1985
1984
1qo~ ...... o.._.,
825 8
918 .~ ...... -·--t---t- .. ! --4----+---f
1 00 7DD LENGTH ( mm)
Figure 23 .. Spring electrofishing catch per unit effort of bluegills in 10-mm length groups, sample (N), and Proportional Stock Density (PSD) from Pretty Lake in 1980 to 1988. Quality size is represented by the solid vertical line.
LL 0 CY fu . ---w, _J wl
I I
(.9i I
Zi -· CY o_ C/l
2001 100
0 , o~ I 2001 100
0
, oo I 2n·8I 100
zoBJ , oo I 208
100
54
1989 PSD=4
__ 11 Ill ■ • ___ _ N~ 1460 1988 . \2
_ m ii 11111 . -_ _ 1142
1987 - 1
__ a alll •- ___ 1820 1986 2
_1.111.__ 1300 --· ··---- ..
allll ■ •a•--... -l983-- - ·-- ··-- .
_a ■ • ■ lla_
1982 __ .1h. __ 1981
_.1111. __ _ 1980
2
943
3
1163
4
883
2
125
1 1071
2
894 0 +-+--+-+--+--+-+-+--t-L+J-+ ............ '-+-'--~-...-..-
0 50 100 150 200
. LENGTH (mm). Figure 24. Spring electrofishing catch per unit effort of bluegills in 10-mm length groups, sample (N), and Proportional Stock Density (PSD) from Browns Lake in 1980 to 1989. Quality size is represented by the solid vertical .
Table 9. Catch per unit effort (CUE) and mean length of bluegill from electrofishing in spring in the four lakes, 1980 - 1989, and results of regression analysis of CUE and mean length versus time. +=positively significant, - = negatively significant, and o = not significant at the 0.10 level of significance. Means in table computed from value in appendix H.
LAKE
BEULAH CUE HEAN LENGTH
ROCKLAND CUE HEAN LENGTH
PRETTY CUE HEAN LENGTH
BROWNS CUE HEAN LENGTH
LENGTH GROUP
ALL ALL
ALL ALL
ALL ALL
ALL ALL
1980 1981 1982 1983
189.80 280.00 316 .60 218.60 129.85 142.89 138.47 125.00
294.80 205.90 3lit.90 206.20 122.77 127.76 106.25 112.00
573.80 546.90 615.20 572. 40 117. 76 119.66 117. 09 121.00
319.30 396.70 416. 70 284.80 112. 48 117. 38 113.33 112. 00
YEAR 1984 1985 1986 1987 1988 1989 F VALUE SIGNIFICANT
222.20 409.70 427.90 486.50 365.80 9.40 + 136.00 137.00 123.43 127.23 132.98 1.06 0
281.40 284.70 60.80 112. 30 223.50 2.67 0 113.00 121.00 111.81 128.97 120.28 0.05 0
536.90 426.70 550.00 519.40 664.40 o.oo 0 117. 00 110.00 108.60 107.55 128.29 o. 71 0
204.00 523.90 463.30 650.00 439.20 561.50 4.91 + 103.00 104.00 101.90 104.77 104. 64 89.53 21.20
Ul U'l
0:: 500 :::J .Q 450
~ 400
'-,,.350
0:: 300
W 250 al 2 200 0
:::J 150 2 1.979 1981
56
BEULAH LAKE
1983 1985 1987
YEAR V - 28.958 - 57119.29 R - 0. 57
F - 9.40 SIGN N - 9373
a: I :::,
0 J:
700
600
......_500
0: 400 ---w-
aJ 300
2
BROWNS LAKE
0
1989
::) 200-+-----+---+----+---+--~---+----+--------2 1979 1981 1983 1985. 1987 1989
V - 27.278 - 53687.17 R - 0.38
YEAR F = 4.91 SIGN N = 9908
Figure 25. Spring electrofishing catch per unit effort of all bluegills from Beulah Lake in 1980 to 1988, and from Browns Lake in 1980 to 1989, with the regression equation, F value, correlation coefficient (R), and sample size (N) for each lake. "Sign." indicates a significant relation at the 0.10 level of significance.
:r:: I-C, z w ...I
z <( w 2
57
BROWNS LAKE 120
0
110
100
90 0
80 1979 1981 1983 1985 1987 1989
YEAR V -2.23X + 4530.29 F 21.20 SIGN R 0.73 N 3740
Figure 26. Spring electrofishing mean length (mm) of all bluegills from Browns Lake in 1980 to 1989, with the regression equation, F value, correlation coefficient (R), and sample size (N) for each lake graph. "Sign." indicates a significant relation at the 0.10 level of significance.
58
Angling catch (and harvest) rates did not change in any lake
(Table 7), and electrofishing catch per unit effort did not
change in two lakes but increased in the other two (Table
9). Catches of fish are notoriously unpredictable, being
influenced not only by fish abundance and the gear used, but
also by temperature, currents, and a variety of weather
related and other environmental conditions. I suspect that
increased predation by largemouth bass resulting from the
length limit regulations was not sufficient to overcome the
inherent variability in the catch data so that consistent,
expected trends were evident.
Data on mean lengths of bluegills were contradictory.
Mean lengths of bluegills harvested by angling increased
(Table 7), whereas mean lengths of bluegills caught by
electrofishing did not -- and mean length decreased in one
lake (Table 9). These two methods of capture differ in the
portions of the length distribution of a population of
bluegills that they sample. Electrorishing samples contain
a larger proportion of smaller fish than samples (catches)
from angling (Goedde 1980; Michaelis 1982). Mean length of
bluegills harvested by anglers in the study lakes was greater
than mean length of bluegills caught by electrofishing for
every year that a creel survey was conducted (Tables 7, 9).
After all the years of the length limit regulations, there
were still many small bluegills in the electrofishing
samples from all lakes (Figures 21-24). Any increased
predation by largemouth bass was insufficient to cause the
59
mean length of the part of the populations sampled by
electrofishing to increase. Yet the increase in mean length
of the part of the bluegill populations harvested by angling
suggests that the length limits were effective in increasing
predation by largemouth bass. It would seem a remarkable
coincidence for these increases to occur for reasons
unrelated to the regulations. I suspect that the increased
mean length of the harvested bluegills was caused by
increased predation by largemouth bass, but that the
increased predation was insufficient to increase the mean
length of the part of the bluegill population sampled by
electrofishing, that part of the population being more
directly influenced by recruitment of young fish.
PROPORTIONAL STOCK DENSITY
Largemouth Bass
The length limits had little or no effect on PSI> values
of largemouth bass (Figures 27, 28; Table 10) because of
annual variations in numbers of fish of both stock and
quality sizes (Figures 14, 16, 18, 20). The PSD of
largemouth bass fell in the recommended range of 40-60% only
in some years of the study in Rockland and Browns lakes
(Figures 27, 28; Table 10). In Beulah and Pretty lakes the
large number of fish of stock size relative to numbers of
quality size fish caused PSD values to be below the desired
range throughout the study (Figures 27, 28).
60
BEULAH. LA~E.
~ _Q
0 80
(J) 0..
....J
.J -60
(!l 40+----,1-----"----+------+---------t
UJ :> _J 20~---"'~------+-----1-----------,
Ci}
0-1------+---+----+---+---+---1---+----i---+---, 0 20 40 60 80 100
LARGEMO-UTH BASS PSD%
ROCKLAN .. D~ .. LAKE 100-----------.-----.------------,
~ Oa0 Cl) a.. _j 60 .
....J
CJ 40-+----------t-----+----------,
w ::) 1988 ....J 20-1-------~~-----+------+----------l ca
0~-~------+-----1,---------------t----1------1 0 20 40 60 80 100
LARGEMOUTH BASS PSD% Figure 27. Proportional Stock Density (PSD %) of largemouth bass and bluegills from Beulah and Rockland lakes in 1980 to 1988. Points are connected in chronological order. Solid squares represent 1980 and 1988 values.
61
PRETTY LAKE 100-----------,,------,----------
~ Q80
(J) a..
. 60, _J .J -C, 40 ~---------t------+------------, w :J
1988'
_J 20 +----------+---+------+----------!
ca 0 .J----+----=i1r-=9=8=0:<.........t---+----+---+---+---t---+-----J
I I
I i !
0 20 40 60· 80 100
100
~ 000 Cl) lL
'60 _J _J
CJ 40 w ::J _J 20 ca 4
0 :0
LARGEMOUTH BA·ss PSD%
BR'O\NN·s LAKE
-- __c ------l---- 1989 ~ ......... w
"' ,.. 1980
20 40 60 B0 100
LARGEMO.UTH BASS.PSD% Figure 28. Proportional Stock Density (PSD %) of largemouth bass and bluegills from Pretty Lake in 1980 to 1988, and Browns Lake in 1980 to 1989. Points are connected in chronological order. Solid squares represent 1980 and 1988 or 1989 values.
62
Table 10. Proportional Stock Density (PSD %) of largemouth bass and bluegills in 1980 to 1989 from the four lakes. Number in parentheses represents number of fish of stock size.
SPECIES · YEAR BEULAH ROCKLAND PRETTY BROWNS -----------------------------------------------------------------LARGEMOUTH 1980 11 (96) 27 (97) 22 (65) 68 (72) BASS 1981 14 (121) 8 (335) 6 (65) 46 (125)
·1952 32 (60) 12 (130) 29 (59) 75 (81) 1983 11 (93) 41 (116) 13 (40) 90 (82) 1984 15 (124) 27 (130) 30 (69) 71 (52) 1985 24 (127) 11 (122) 17 (107) 79 (62) 1986 20 (158) 21 (214) 24 (70) 48 (103) 1987 15 (159) 27 (157) 36 (91) 51 (220) 1988 27 (83) 46 (140) 34 (82) 25 (242) 1989 55 (350)
BLUEGILLS 1980 32 (158) 16 (286) 5 (506) 2 (314) 1981 52 (118) 11 (149) 5 (269) 1 (363) 1982 35 (174) 10 (174) 4 (324) 2 (303) 1983 23 (249) 13 (206) 16 (361) 4 (154) 1984 35 (216) 10 (342) 10 (354) 3 (230)
·1985 28 (206) 35 (254) 8 (421) 2 (319) 1986 19 (263) 16 (185) 10 (387) 2 (449) 1987 21 (295) 34 (182) 6 (444) 1 (479) 1988 31 (179) 21 (184) 29 (335) 2 (361) 1989 4 (315)
63
In Rockland Lake largemouth bass were in the desired
range of PSD in 1983, and 1988 (Table 10; Figure 27). The
PSD value in both years was the result of a large number of
fi-sh in the slot, i.e. of quality size (Figure 16).
Proportional stock density values were below the desired
range in all other years because of the many smaller bass.
If strong cohorts in the future continue to survive to enter
the slot length range, PSD would continue in the desired
range.
PSD values in Browns Lake were in the desired range in
1981, 1986, 1987, and 1989 (Table 10; Figure 28). In all
other years, they were above the recommended range because
of low numbers of fish of stock size, except for 1988, when
one or more strong cohorts of small bass were responsible
for a PSD of 25 (Figures 6, 15). This cohort(s) grew into
the quality size range in 1989 causing the improved PSD
value. I expect PSD to remain in the desired range if
largemouth bass are protected from harvest until they reach
406mm.
Bluegills
The length limits may have improved PSD of bluegills in
Rockland Lake, but seemed to have little effect in the other
lakes (Figure 27, 28; Table 10). In Rockland Lake the PSD
was below the recommended range of 20 to 40 percent in the
first five years of the study and in the recommended range
64
in 3 of the last 4 years (Table 10). Bluegill PSD in Lake
Beulah was in or above the recommended range in all years.
In Pretty and Browns lakes bluegill PSD was always below the
recommended range except for one year., 1988, in Pretty Lake
(Figure 28).
These results are consistent with the length frequency
data. With the exception of bluegill PSD in Rockland Lake,
improvements, with the length limit regulations, in bluegill
size composition were lacking in the spring electrofishing
samples.
The length limits were generally ineffective in
changing PSD values of both largemouth bass and bluegills to
the window of desirable PSD values in the tic-tac-toe
figures (Figure 27, 28). Only in the last year of sampling
in Rockland Lake did PSD for both species fall in the
recommended ranges. In contrast, Eder (1984) found that
five years after a 305-381mm slot length limit was imposed
on Watkins Mill Lake, Missouri, PSD values were in the
recommerta~a range ~or both large~6uth bass and bluegills.
In general, changes in the largemouth bass and bluegill
size compositions in this study were not measured suitably
by PSD values from spring electrofishing samples.
65
RELATIVE WEIGHT
Largemouth Bass
In general, relative weights (Wr) were in the
recommended range of 90 - 105 percent in all lakes in all
years (Figure 29, 30). However, in 1988 (1988-1989 for
Browns Lake) the mean relative weight of largemouth bass
from electrofishing samples was significantly lower than in
pre-regulation years for every lake except Beulah, and was
lower than the period 1983-1985 in all lakes except Rockland
(Table 11). With the possible exception of Pretty Lake,
these decreases cannot be explained on the basis of a
decline in abundance of bluegills small enough to be eaten
by largemouth bass. In spring electrofishing samples, catch
per unit effort of bluegills did not change from 1980 to
1988 (1988-1989 in Browns Lake), and PSD's did not increase
except in Pretty Lake in 1988 (Table 9; Figures 21-24; Table
10). These decreases in relative weights of largemouth bass
may have been caused by shortage of food for bass other than
bluegills. Relative abundance of largemouth bass increased
in three lakes (Table 8; Figures 15, 19), and Mayers (1988)
found that 86% of the food of largemouth bass in the lakes
in October 1984 was not bluegills. I have no measure of
other foods and do not know the importance of other foods
for bass in the other months. However, with the increased
abundance of largemouth bass, it is possible that there was
less food available per bass in 1988, 1989.
66
BEULAH·LAKE J- 120 ..... ,-.:...._ _________________ ___,
:t - 0
C) 110·
w $ 100
w > -J-<(
70
+
<>
0 0
+
+ +
<>
0 <>
<>
..J w a: 60+-+-+-+--+-+-+-4--t-+-+-+-+-++-t--+-+-+-4..-i-+-+-+--+-+--+-+-+-f-+-ll-+-,--.-+-+--+-+-,-+-f-+-I~
J:c C,
w s w > -I-<( ..J w a:
100
120
110 +
100
i 90+
80 +
70
150 200 250 . 300 350. 400 450 500 . 550
· 1981-1982
<>
- - .. -+
o+ +
-++
LENGTH (mm) + 1983- 0 1988
1985
ROCKLAND LAKE
0 -0 <> + oo. •<> - o<;>
-·-<> + <> 0 +
+
60+-+-t-t--H---H-+-+-+-+-+--+-+-+--t-+-lf-+-H-+-+++-+-+-+-1H--...+-+--+-+-+-+--H-+-<H-H
100 150 200
- 1981-1982
250 . . · 300 350 400 450 500
LENGTH (mm) + 1983-
1985 0 1988
550·
Figure 29. Relative weights of largemouth bass from 1981-1982, 1983-1985, and 1988 in 10-mm length groups in Beulah and Rockland lakes.
67
PRET·TY LAKE
<>
LU -
'-'
s 100 0 + <> + 0
0 + + -,..+++~ <> - e, +· + + • • ....01;:e+,o...._+ _ - +.- +
w 90 - - +- ~ ++ + • <> o· +
> .o <> e-o - -- 80 <>
f-0
0
<{ 70 ...J w
60 . . a: . 100 150 200 250 300 350· 400 450. 500 550
LENGTH (mm) - 1981- + 1983- 0 1~88
1982 1985
BROWNS LAKE f- 120-.-----------------------,. + J: o+
- + + C, 110 +
+
-w +
+ - + e o+-o.
+
$ 100 o e 0 00 ~ .,..o o+ • - o~o
0 Oo • • • .... <:> 0 -
ttl > ·+
- 80 f- +
<{ 70 ...J w
60
+
+ +
- +
0
a: 100 150 200 .. 250 300 350 400 450 500 550
- 1981-1982
LENGTH (mm) + 1983-
1985 0 1988-
1989
Figure 30. Relative weights of largemouth bass from 1981-1982, 1983-1985, and 1988 (1988-1989 in Browns Lake) in 10-rnm length groups in Pretty and Browns lakes.
68
Table 11. Comparison of mean relative weights of largemouth bass from spring electrofishing samples between 1988 and 1980-1982 and 1983-1985 for lakes Beulah, Rockland, and Pretty and between 1988-1989 and 1980-1982 and 1983-1985 for Browns Lake with a t-test (Zar 1974; p.105}. The asterisk(*} indicates a significant difference at the 0.05 level of significance; t values computed from values in append~ces I, J.
LAKE PERIODS TESTED CALCULATED df SIGNIFICANCE 1988 OR 1988-89 t
VERSUS ------------------------------------------------------BEULAH (1980-1982) -1.02 511
(1983-1985) -5.93 722 * ROCKLAND (1980-1982) -2.75 652 *
(1983-1985) 6.57 831 * PRETTY (1980-1982) -1.70 337 *
(1983-1985) -4.89 454 * BROWNS (1980-1982) -3.98 1030 * (1983-1985) -2.02 971 *
69
In Pretty Lake the high PSD value of largemouth bass in
1988 (Table 10) was accompanied by a significant decrease in
relative weight of largemouth bass with increasing length of
largemouth bass (Figure 30; Appendices I, J, K). The relative
shortage of bluegills of stock size that resulted in the
high PSD may also have meant a shortage of bluegills small
enough to be eaten by the bass in that year.
In Browns Lake, Wr tended to be higher than in the
other lakes (Figures 29, 30). Browns Lake had the highest
proportions of small bluegills, as indicated by PSD values
(Table 10).
Bluegills
The length limits on largemouth bass appeared to
improve the condition of bluegills. Mean relative weights
of bluegills in 1988 (1988-1989 in Browns Lake) increased
significantly in all lakes from pre-regulation y~ars and
also in all lakes from the period 1983-1985 (Table 12;
Figures 31, 32). In all lakes, relative weights in 1988
fell in the recommended range of 90 to 105 percent for a
majority of lengths (Figure 31, 32; Appendices L, M), a
substantial improvement for lakes Pretty and Browns.
The improved bluegill condition cannot be related to
decreased abundance of bluegills measured by electrofishing
catch per unit effort (Table 9; Figures 21-24), but this
improved condition is consistent with other observed
70
Table 12. Comparison of mean relative weights of bluegills from spring electrofishing samples between 1988 and 1980-1982 and 1983-1985 for lakes Beulah, Rockland, and Pretty and between 1988-1989 and 1980-1982 and 1983-1985 for Browns Lake with a t-test (Zar 1974; p.105). The asterisk(*) indicates a significant difference at the 0.05 level of significance; t values computed from values in appendices L, M.
------------------------------------------------------LAKE PERIODS TESTED CALCULATED df SIGNIFICANCE
1988 OR 1988-89 t VERSUS
------------------------------------------------------BEULAH (1980-1982) 21.51 437 *
(1983-1985) 11.36 849 * ROCKLAND (1980-1982) 5.98 445 *
(1983-1985) 17.80 990 * PRETTY (1980-1982) 10.58 735 *
(1983-1985) 28.99 1468 * BROWNS (1980-1982) 23.42 1033 *
(1983-1985) 21.97 1498 *
1- 120 I I CJ' 1100· - I
w r $ 1.00 _
w: 90
> - 80 r-<( :....I 70
UJ 60 a:
80
f--_120
:r: CJ 1.10 -UJ 1.00 ° s t
-+-
LU~
> 80 -r-<( _J
w a:
70
60 80
71
BEULAH LAKE.
0 0
-+ + 0 + 0
0 0 + + 0
+ <> + 0
.,...,,
+ + +
+
. . . . 100 120 140 160 180 200· 220·
LENGTH. (mm)· - 1981- + 1983- <> 1988
1982 1985
ROCKLA·ND. LAKE
0
~ ,0 0 ~
...., <>
0 0 0 +
+ + - - 0 - + + - + -- + - + <> --+- + -
-+-
+
. . 100 120. 140 160 180 200 220
I l='NGTH (mm\ &... L- I I I · I I U I./·
- 1981- + 1983- o 1988 1982 1985
Figure 31. Relative weights of bluegills from 1981-1982, 1983-1985, and 1988 in 10-mm length groups in Beulah and Rockland lakes.
r 120
:c (!l 110 -w 100
5 <:>
901 uJ I > +
- 88 r <! 70 _J w 60 a: 80
~ 120 :I; C, 110 --w $ 100
1If > -r <{ _J
98
80
70
60
0
+
-
w a: 80
0 0
<>
+ + +
100
- 1981-1982
<> ..... 0 .....
--
100
- 1981-1982
0
+
-
72
PRE-TTY LAKE·
0 + <> ~ -
~ '-'
+ - + ,& + <> + +
+
120 140 160 180 200
LENGTH (mm) + 1983- <:> 1988
1985
BROWNS: LAKE·
-<> ....
0
0 <> .£..
T ~ -+-- + +
. . . . 120 140 :160 180 ·200
LENGTH (mm) + 1983-
1985 0 1988-
1989
220.
220
Figure 32. Relative weights of bluegills from 1981-1982, 1983-1985, and 1988 (1988-1989 in Browns Lake) in 10-mm length groups in Pretty and Browns lakes.
73
changes, i.e. increased CUE and mean length of largemouth
bass (Table 8; Figures 15, 17, 19) and increased mean length
of harvested bluegills (Table 7). As explained above, these
improvements could be related to the length limit
regulations even though electrofishing CUE of bluegills did
not change if the increased predation by largemouth bass was
not sufficient to overcome the inherent variability of catch
data and the selectivity of electrofishing for the part of
the bluegill populations containing the persistently
abundant smaller fish.
Relative weight of bluegills in Lake Beulah decreased
significantly with increasing length of bluegills in the
three time periods (Figure 31; Appendix N; Mayers 1988).
This negative relation suggests a shortage of available food
for the larger bluegills in Lake Beulah despite the apparent
improvement in trophic conditions for bluegills in the
course of the study.
GROWTH
Largemouth Bass
There appeared to be little change in growth of
largemouth bass. I found significant increases in
instantaneous growth rate for 2 of 9 age groups in Lake
Beulah, 1 of 10 in Rockland Lake, 1 of 9 in Pretty Lake, and
5 of 10 in Browns Lake (Table 13; Figure 33; Appendix 0). I
Table 13. Comparison of instatltaneous growth rates and length increments of largemouth bass of various age groups in all lakes from 1979 to 1988. F values computed from values in appendix o, (Steel and Tor~ie 1960). +=positively significant, - = negatively significant, and o = not significant at the 0.05 level of significance.
INSTANTANEOUS GROWTH
BEULAH ROCKLAND PRETTY BROWNS AGES df F SLOPE df F SLOPE df F SLOPE df F SLOPE --------------------------------------------------------------------------------------1-2 2-3 3-4 4-5 5-6 6-7 7-8 8-9 9-10 10-11
AGES
1-2 2-3 3-4 4-5 5-6 6-7 7-8 8-9 9-10 10-11
1,8 0.350 O 1,8 1.480 O 1,8 6.005 + 1,8 6.981 + 1,8 0.312 0 1,6 1.810 O 1,4 4.683 O 1,2 3.971 O 1,1 0.022 0
BEULAH df F SLOPE
1,8 1,8 1,8 1,8 1,8 1,6 1,4 1,2 1,1
1.049 0.017 1.115 3.951 0.047 1.182 6.048 4.064 0.030
0 0 0 0 0 0 0 0 0
1,8 0.130 1,8 1.610 1,8 2.587 1,8 2.360 1,8 9.837 1,5 0.001 1,3 3.616 1,2 1.207 1,3 1.649 1,1 3.682
0 0 0 0 + 0 0 0 0 0
1,7 0.671 1,7 0.250 1,7 3.514 1,7 0.059 1,7 3.269 1,6 2.712 1,5 8.178 1,2 4.473 1,115.870
0 0 0 0 0 0 + 0 0
LENGTH INCREMENTS
ROCKLAND df F SLOPE
1,8 1,8 1,8 ,1, 8 1,8 1,5 1,3 1,2 1,3 l,1
0.012 1.518 1.746 1.731 8.417 0.002 4.788 0.001 0.653 5.869
0 0 0 0 + 0 0 0 0 0
PRETTY df F SLOPE
1,7 1,7 1,7 1,7 1,7 1,6 1,5 1,2 1,1
0.295 0.097 0.752 0.564 0.008 0.607 6.962 4.100 1. 779
0 0 0 0 0 0 0 0 0
1,7 1.280 1,8 0.080 1,8 0.008 1,817.089 1,8 34.638 1, 8 8. 99·6 1,7 7.643 1,6 3.118 1,3 7.298 1,1 1.112
BROWNS
0 0 0 + + + + 0 + 0
df F SLOPE
1,7 1,8 1,8 1,8 1,8 1,8 1,7 1,6 1,3 1,1
0.879 0.595 0.466 5.563
30.995 7.099 9.368 3.881 3.284 5.700
0 0 0 + + + + 0 0 0
-..J ~
w I- 2. 5
<t a: I
2
I-$ 1.5 0 a: (9 1
I
1-z <:I:0.5
1-
BEULAH LAKE
1-2
2-3
3-4
4-5
. . 5-6
~=======~======================== 6-7 7-8
(J) 0 z -+--~f-----+----+----+----+----+---+----+----+---1-------1
- 1978 1980 1982 1984 1986 1988
YEAR Figure 33. Regressions of instantaneous growth rate by age group of largemouth bass in Beulah Lake from 1979 to 1988. Figure is a representation of data in table 13,
-.J U1
minus age groups 8-9, and 9-10. Values used to calculate regressions are in appendix o.
76
obtained similar results when I compared instantaneous
growth rates of the age groups with at-test between the
pre-regulation period (1979-1981) and the post-regulation
period (1986-1988)(Appendix P). Comparing length
increments, I found significant increases for 1 of 10 age
groups in Rockland Lake and 4 of 10 for Browns Lake (Table
13). Hence, the most evidence of an increase in growth was
for Browns Lake, but for it, as well as the other lakes, the
changes may have been fortuitous. I doubt that growth
increased because: 1, of the inconsistency of growth among
age groups (Table 13); 2, relative weight of largemouth bass
declined in all lakes (Table 11); and 3, lack of a
theoretical basis for the length limits to increase growth
of largemouth bass.
My calculated length at age one for each lake was much
lower than the southeast Wisconsin average (Figures 34, 35)
of (Druckenmiller 1972). I agree with Mayers (1988) that
length at age one of the southeast Wisconsin average is
erroneous. The va--iue given is nut only higher than any that
occurred in the study lakes (Appendix Q), but also is higher
than lengths at age one for other lakes (Appendix R). I
calculated length at age in the spring, whereas
Druckenmiller (1972) determined growth from length at
capture of fish caught throughout summer. Because fish
caught in late summer are longer than fish caught in spring
at any age, his mean lengths should average longer than
those back-calculated at annulus formation. Therefore, my
lengths at age are not comparable to his.
i"""' E 550
t: 500 ...._,, 450
:C 400
I- 350
(!J 300 · 2 W 250
_J 200
_J 150
4
77
LAKE BEULAH
r- 100
0 50 +---+----11---+----t--t---t---t---t--+---I---+ r 0 1. 2 3 4 5 6 7 8 9 10 11
~
E 550
E 500
~ 450
:C 400 l-e:, 350
2 300
W 250
_J 200
_J 150
<( 100·
AGE
ROCKLAND LAKE
lo I-
50+--+---t--+--+--+--+--t--+--+-+--+--+ 0 1. 2 3 4 5 G 7 B 9 1.0 1.1. 12
AGE
------·· - 1980-
1982
1983-1.985
-- 1988
~ w1s AVG
- 1980-1.982
1983-19Wi
-- t. 988
~ IJIS AVG
Figure 34. Total length (mm) at age for years 1980-1982, 1983-1985, and 1988 of largemouth bass in Beulah and Rockland lakes; and the southeastern Wisconsin average (Druckenmiller 1972).
/.'""-
E 550 E ~500
:r: 450
400 I-e, 350
2 300 w 250 _J
200 _J
150 <{ I- 100
0 50
I-
r"\ E 500
E 450 '-,,I
J: 400
l-350
~ ~ ~(9 300
2 zs0 w ..J 200
J1s0 <( 100 l-
78
PRETTY LAKE
0 1 2 3 4 S 6 7 8 9 10 11 12
AGE
BRO\NNS LAKE
o 50 +----f--+----l'---+---+---+-+--t---t------tl--t---t
I- 0 1 2 3 4 5 . 6 7 8 9 · 10 11 12
AGE
- 1.980-1982
1983-1985
-- 1988
~ WIS AVG
- 1980-1982
1983-1985
-- 1988-1989 ·
~ UIS AVG
Figure 35. Total length (mm) at age for years 1980-1982, 1983-1985, and 1988 (1988-1989 in Browns Lake) of largemouth bass in Pretty and Browns lakes; and the southeastern Wisconsin average (Druckenmiller 1972).
79
Bluegills (and Pumpkinseeds in Browns Lake)
The length limit regulations on largemouth bass did not
appear to change growth of bluegills and pumpkinseeds. Of 64
possible changes in instantaneous growth rate or length
increment that I analyzed for bluegills, only two were
significant; length increased for one age group in each,
Lake Beulah and Pretty Lake (Table 14). Again results were
similar, although slightly different, when I compared length
increments of the age groups with at-test between the
pre-regulation (1979-1981) and post-regulation (1986-1988)
time periods. I found no change in growth rate in any age
group for Beulah, Rockland, and Browns lakes, and increases
for 3 of 6 age groups in Pretty Lake (Appendix P). Results
were similar for pumpkinseeds in Browns Lake (Appendices P,
T) •
As with largemouth bass, this meager evidence of
increased growth relat~d to the length limit reyuiations may
be fortuitous. Mean length of bluegills caught by
electrofishing did not change (Table 9). All of the
bluegills and pumpkinseeds aged for growth analysis were
obtained by electrofishing. The increase in mean length of
harvested bluegills could have been caused, rather than by
change in growth, by changes after the length limit
regulations in the proportion of various lengths of
bluegills present in the part of the population caught by
I
I Table 14. Comparison of instantaneous growth rates and length increments of bluegills of various age groups in all lake from 1979 to 1988. F values computed from values in appendix s, (Steel and Tbrrie 1960). +=positively significant, - = negatively significant, and o = not sighificant at the 0.05 level of significance.
INSTANTANEOUS GROWTH
BEULAH ROCKLAND PRETTY BROWNS AGES df F SLOPE df F SLOPE df F SLOPE df F SLOPE ---------------------------~----------------------------------------------------------1-2 2-3 3-4 4-5 5-6 6-7 7-8 8-9 9-10
AGES
1-2 2-3 3-4 4-5 5-6 6-7 7-8 8-9 9-10
1,6 1.251 0 1,8 0.153 O 1,8 0.010 O 1,8 0.056 0 1,8 4.505 O 1,7 1.830 O 1,6 0.032 O 1,2 0.034 O 1,2 0.455 0
BEULAH df F SLOPE
1,6 1.156 1,8 0.006 1,8 0.020 1,8 0.031 1,8 6.210 1,7 4.627 1,6 0.075 1,2 0.025 1,2 0.075
0 0 0 0 + 0 0 0 0
1,8 1.487 1,8 0.102 1,8 1.457 1,8 0.540 1,8 0.008 1,5 1.242 1,1 9.533 1,1 0.168
0 0 0 0 0 0 0 0
1,7 4.731 1,7 2.615 1,7 1.111 1,7 4.097 1,7 0.487 1,7 4.998 1,3 1.011 1,2 0.384
0 0 0 0 0 0 0 0
LENGTH INCREMENTS
ROCKLAND df F SLOPE
1,8 1.234 1,8 0.256 1,8 0.072 1,8 0.665 1,8 0.062 1,5 0.809 1,1 3.214 1,1 9.674
0 0 0 0 0 0 0 0
PRETTY df F SLOPE
1,7 0.686 1,7 1.787 1,7 0.385 1,7 4.279 1,7 1.912 1,710.165 1,3 1.291 1,2 0.867
0 0 0 0 0 + 9 0
1,7 0.633 1,7 0.019 1,8 2.689 1,8 2.064 1,7 0.090 1,6 0.619 1,3 0.089
BROWNS
0 0 0 0 0 0 0
df F SLOPE
1, 7 0. '572 1,7 0.462 1,8 0.935 1,8 0.035 1,7 0.442 1,6 0.072 1,3 0.060
0 0 0 0 0 0 0
CD 0
81
anglers, i.e. a greater proportion of larger bluegills in
that part of the population after the regulations were
effective.
My calculated lengths at age for bluegills (Figure 36,
37) and pumpkinseeds were also lower (Appendices Q, U) -- as
were length at age for bluegills in other lakes (Appendix V)
-- than length at age of Druckenmiller (1972). Values from
the two studies are not comparable for bluegills and
pumpkinseeds for the same refsons as for largemouth bass.
MORTALITY
Largemouth bass
I expected mortality rate of largemouth bass to
decrease after imposition of the length limit regulations.
Annual mortality rates did appear to decrease in all lakes,
·····---and-a signif'icant decrease (1988-1~ versus 1980-191t2}
occurred in Browns Lake (Tables 15, 16; Figures 38, 39).
Annual mortality rates were remarkably similar in the lakes
before the length limits, 65, 65, 65, and 64% (Table 15) and
averaged 51%, range 40-59%, in the four lakes after 1982.
Novinger (1987) found mortality rates of 38 and 30% for
protected largemouth bass before and after imposition of a
381mm minimum length limit in Table Rock Reservoir,
Missouri.
~
E 240
E '--,/200
:r: r- 160
C, 2 UJ ...I
120
80
40
82
LAKE BE.LILAH
.J <t r 0 I-
0-+-----11-----+--+-________ _
0 1 2. 3 4 S 6 . 7 B 9 10 11 12
AGE
~ ROCKLAND LAKE E 240
E '-" 200
J: r- 160 C,
~-~--z:120
w ....J. 80
....J <{ 40
lo I-
0-------------11---+---+--+--+--0 1 2 3 4 S 6 7 B 9 10 11. 12
AGE
- 1980-1982
--- 1983-1985
-- 1988
.)K.. LJIS AVG
- 1980-1982
--- 1983-1.985
-- 1988
~ IJIS AVG
Figure 36. Total length (mm) at age for years 1980-1982, 1983-1985, and 1988 of bluegills in Beulah and Rockland lakes; and the southeastern Wisconsin average (Druckenmiller 1972).
83.
,-... PR·ETTY LAKE E 240 E
'-._,/200
J: ~ 160
Cl 2 120·
LU ...J 80
...J <( 40
l-o 0-t---t--t---t---,r--i---t--t----f--4----f.
I- 0
,-... E 240
E ~200
!:C I- 160
CJ 21?0
w ...J 80
...J <J: 40
l-
1 2 3 4 5 G. 7 8 9 i.0
AGE
BRO\NNS ·LAKE.
o 0-------------------1- 0 1 2 3 4 5 6 7 8 9 10
AGE
- 1980-1982
1983-1985
-- 1988
~::.. WIS AVG
- 1980-1.982
1983-1985
-- 1.988-1.989
->t<.- IJJS AVG
Figure 37. Total length (mm) at age for years 1980-1982, 1983-1985, and 1988 (1988-1989 in Browns Lake) of bluegills in Pretty and Browns lakes; and the southeastern Wisconsin average (Druckenmiller 1972).
84
Table 15. Total annual and instantaneous mortality (A and Z), and survival (S) rates of largemouth bass, bluegills, and pumpkinseeds (Browns Lake only) for 1980-1982, 1983-1985, and 1988 (1988-1989 in Browns Lake), r is the correlation coefficient. Rates calculated from data from spring electrofishing samples.
LAKE PERIOD
BEULAH ·1,80-1982 1983-1985 1·988
ROCKLAND 1980-1982 1983-1985 1988
PRETTY 1980-1982 1983-1985 1988
BROWNS 1980-1982
BEULAH
1983-1·985 1988-1989
1980-1982 1983-1985 1988
A(%)
65 57 51
65 53 57
65 48 59
64 42 40
44· 61 80
·ROCKLAND . 19Jl0-li82 56
PRETTY
BROWNS
BROWNS
1983-1985 65 1988 62
1980-1982 1983-1985 1988
1980-1982 1983-1985 1988-1989
1980-1982 1983-1985 1988-1989
76 73 53
76 67 56
73 70 57
LARGEMOUTH BASS
z S(%)
1.050 35 0.849 43 0.716 49
1.051 · 35 0.753 47 0.843 43
1.046 35 0.649 52 0.901 41
1.079 34 0.551 58 0.506 60
r
0.961 0.995 0.920
0.970 0.994 0.880
0.982 0.986 0.950
0.970 0.961 0.980
BLUEGILLS
0.598 0.949 1~619
0-813 1.·049 0.962
1.447 1.305 0.745
1.420 1.104 0.831
56 39 20
44-35 38
24 27 47
24 33 44
0.970 0.980 0.910
0-. 9--S-9 0.883 0.930
0.994 0.976 0.990
0.963 0.968 0.710
· · ·puHPKINSEED
1.291 1.211 0.852
27 30 43
0.981 0.863 0.760
AGES
3-8 3-8 2-8
3-8 3-8 2-6
3-8 3-8 4-8
5-9 5-12
3-9
··5-11 4-10 6-8
-J--9 3-9 4-7
5-9 5-9 5-8
5-8 3-8 3-7
5-8 4-7 3-6
n
292 382 206
577 355 260
243 468
84
163 148 434
281 574
74
56--5 752 113
473 674
72
645 655 254
198 174 153
-------------------------------------------------------------
85
Table 16. Comparison of total annual mortality of largemouth bass from spring electrofishing sa.-mples between 1988 and 1980-1982 and 1983-1985 for lakes Beulah, Rockland, and Pretty and between 1988-1989 and 1980-1982 and 1983-1985 for Browns Lake with at-test (Zar 1974; p. 228). The asterisk(*) indicates a significant difference at the 0.05 level of significance; t values computed from values in appendix w.
LAKE
BEULAH
ROCKLAND
PRETTY
BROWNS
PERIODS TESTED 1988 OR 1988-89
VERSUS
(1980-1982) (1983-1985)
(1980-1982) (1983-1985)
(1980-1982) (1983-1985)
(1980-1982) (1983-1985)
RESIDUAL CALCULATED df SIGNIFICANCE MEAN t
SQUARE
0.314 -1.76 9 0.152 -0.66 9
0.373 -0.83 7 0.216 0.41 7
0.169 -0.89 7 0.096 1.62 7
0.110 -2.61 8 * 0.110 -0.29 11
6
> CJ 5
2 W 4
:J 03 w a: 2 LL
C 1 ...J
86
LAKE· BEULAH
0 ~--f----t---+---t---t--~----'---''--lf------'!-----+----t----1
7
>6 (J Zs w
0
:J 4 a W3 £E LL 2
C 1 ...J
1 2
- 1980-1982
3 5 6 7 8 9 10 11 12
AGE )t( 1983- X 1988
1985
ROCKLAND LAKE
X
0+---f---t---+----+---+---+-~-==1i---r---t---t---1
0 1 2
- 1980-1982
3 5 6 7
AGE >t< 1983-
1985
8 9 10 11 12
X 1988
Figure 38. · Catch curve from spring electrofishing samples from 1980-1982, 1983-1985, and 1988 for largemouth bass in Beulah and Rockland lakes. Natural logarithm of numbers caught versus age.
6
> 0 5
2 w 4
:J a 3
UJ a: 2 u.. C: 1
.....J 0
0 1 2 3-
- 1980-1982
6
> u 5
2 w 4
=> a 3
w a: 2 u. C 1
.....J 0
0 1 2 3
- 1980-1982
87
PRETTY LAKE
4 5 6 7 8 9 10 11 12
AGE >+< 1983- X 1988
1985
BROWNS LAKE
4 5 6 7
AGE >+< 1983-
1985
8 9 10 11 12.
X 1988-1989
Figure 39. Catch curve from spring electrofishing samples from 1980-1982, 1983-1985, and 1988 (1988-1989 in Browns Lake) for largemouth bass in Pretty and Browns lakes. Natural logarithm of numbers caught versus age.
88
Bluegills (and Pumpkinseeds in Browns Lake)
I would expect mortality of bluegills and
pumpk:inseeds in Browns Lake -- to increase if the length
limits caused a substantial increase in predation by
largemouth bass. However, change in mortality of these
panfish was inconsistent -- some increased, some decreased,
and most did not change (Tables 15, 17; Figures 40, 41).
The inconsistency may be attributable to many of the
bluegills being too large to be vulnerable to predation by
the largemouth bass. The mortality rates were determined
for bluegills and pumpkinseeds of age 3 and older (Table
15); hence, of fish longer than about 60mm (Figures 36, 37;
Appendix Q). Many of these fish would be too large to be
eaten by largemouth bass.
POPULATION ESTIMATES AND EXPLOITATION OF LARGEMOUTH BASS IN
ROCKLAND LAKE
The estimated population density (number/hectare) of
largemouth bass longer than 130mm in Rockland Lake did not
change significantly from 1980 to 1988 (Figure 42; Table 18;
Appendix X). Because electrofishing was used to capture
largemouth bass for both marking and recaptures, estimated
population densities are probably underestimates of the
correct population number (Ricker 1975), but the bass should
be consistent from year to year. Population size of a
89
Table 17. Comparison of total annual mortality of bluegills andpumpkinseeds (Browns Lake only) from spring electrofishing samples between 1988 and 1980-1982 and 1983-1985 for ·1akes Beulah, Rockland, and Pretty and between 1988-1989 and 1980-1982 and 1983-1985 for Browns Lake with at-test (Zar 1974; p. 228). The asterisk(*) indicates a significant difference at the 0.05 level of significance; t values computed from values in appendix w.
BLUEGILLS ----------------------------------------------------------------LAKE PERIODS TESTED RESIDUAL CALCULATED df SIGNIFICANCE
1988 OR 1988-89 MEAN t VERSUS SQUARE
----------------------------------------------------------------BEULAH (1980-1982) 0.190 4.52 6 *
(1983-1985) 0.250 2.91 6 * ROCKLAND (1980-1982) 0.100 1.00 7
(1983-1985) 1.290 -0.15 7
PRETTY (1980-1982) 0.060 -4.49 5 * (1983-1985) 0.180 -2.05 5 *
· BROWNS (1980-1982) 0.720 -1.55 5 (1983-1985) 0.610 -0.70 7
PUMPKIN SEED ~--------------- --------------------------------------------
BROWNS (1980-1982) (1983-1985)
0.380 0.920
-1.25 -0.67
4 4
7
>-() 6
2 5 w :J 4 a W 3 a: LL z
5 1
90
LAKE B.EULAH
0 J----4----4----+---+---+----+----+---+--+-->!<---+----; 0
7
> CJ 6
2 5 w ::J 4 cr w 3 a: LL 2
C: 1 _J
0 0
1. 2
- 1980-1982
1. z
- 1980-1982
3
3
4 5 6 7 8 9 1.0 1.1 12
AGE )4( 1983-
1985 X 1988
ROCKLAND LAKE
>t<
-
)+( )t<;
>I<
4 5 6 7 8 9 1.0 1.1. 1.2
AGE >t< 1983-
X 1988 1985
Figure 40. Catch curve from spring electrofishing samples from 1980-1982, 1983-1985, and 1988-for bluegills in Beulah and Rockland lakes. Natural logarithm of numbers caught versus age.
7
>- 6 _O 2 UJ
5
:J 4 a UJ 3
0: lL 2
C 1 _J
0 0
7
>- 6 CJ 2 5 w :J 4 a liJ 3
-~-4 lL 2
C: 1 _J
0 0
1 2 3
- 1980-1982
1 2 3
- 1980-1982
91
PRE·TTY LAKE·
5 6 7 8
AGE )f( 1983-
1985
BROWNS LAKE
s
X
6 7
AGE
>t< 1983-1985
8
9 10 11 12
X 1988
9 10 11 12
X 1988-:-1989
Figure 41. Catch curve from spring electrofishing samples from 1980-1982, 1983-1985, and 1988 (1988-1989 in Browns Lake) for bluegills in Pretty and Browns lakes. Natural logarithm of numbers caught versus age.
w 0: 80 4 r CJ w :c ........
0: w ca 2 :J 2
60
40
20
0 1979
V R
----
ROCKLAND LAKE 0
0
0 0 0 ~) 0
0
1981 1983 1985 198? 1989
YEAR, -3.058 + 6094.20 F - 4.38 NOT SIGH -0.38 H - 2221 -
Figure 42. Regression of population estimates from spring electrofishing samples in Rockland L~ke from 1980 to 1988, with the regression equation, F value, correlation coefficient (R), and sample size (N). F value computed from values in appendi~ X, (Steel and Torrie 1960). "Not sign." indicates no significant relation at the 0.05 level of significance.
I.O :N
93
Table 18. Schnabel population estimate (number/hectare), 95% confidence interval (CI), estimated standing stock, and mean individual weight of largemouth bass in Rockland Lake in Springs, 1980-1988. Estimated exploitation rate (u) for 1980, 1982, 1984, 1986, and 1988.
-------- --------------PO?UlATIOff NINlNUN STANDING HEAN INDlVIDUAl
PERIOD ESTINATE LEHGTH CH) 95% Cl · STOCK Ckg/ha> WEIGHT Cg) u (%)
----------------------------------------------------------------------------------SPRING 1980 23 >170 a 14-37 87
77 >130 b S◄-113 26
SPRING 1981 ◄6 >160 b 38-57 13 291
SPRING 1982 39 >135 ab 28-58 10 266 31
SPRING 1983 38 >130 b 24-5◄ 12 310
SPRlHG 1984 19 >200 a 12-29 6 326 64 38 >140 b 27-57 8 219 32
SPRING 1985 38 >140 b 27-S6 7 190
SPRING 1986 32 >180 a 14-34 9 281 19 36 >130 b 14-3◄ 10 267 17
SPRING 1987 31 >130 b 17-38 8 245
~····~··seRUCGl.9as. 32 >200 ~ 14-33 t 260 76 44 >140 b 41-69 10 221 ss
----------------------------------------------------------------------------------a ftini1u1 size harvested by anglers in the corresponding year. b Nini1u1 size for the population esti1ate in the corresponding year.
94
largemouth bass population with a in the slot length limit
should not necessarily change. Increased numbers of
protected bass in the slot could be offset by harvest of the
smaller bass -- which is what occurred in Rockland Lake
( Figure 6) .
The high estimated density of 77 per hectare in 1980
(Table 18) was probably caused by the strong year class of
1978 (Figure 16). The size of the 1978 year class decreased
every year from 1979 to 1982, and the year class did not
reach the slot in great numbers after 1982 (Figure 16;
Appendix G). In 1988, the estimated density of 44 per
hectare (Table 8) was probably caused by the increased
number of largemouth bass longer than 305mm (Figure 16).
When I compared my estimated population densities of
largemouth bass longer than 199mm to those predicted by
electrofishing catch per unit effort from the regression
equation of Hall (1986), I found differences between the two
methods occurred within years, but overall estimated and
predic'ted popuratiort densities aia not differ fTable 19).
These results suggest that although densities of largemouth
bass calculated by either method may not be exactly
accurate, the two methods do provide reliable indications of
population size of largemouth bass.
The estimated exploitation rate of largemouth bass
longer than 130mm by anglers remained relatively consistent
from 1980 to 1988 except in 1986 when the exploitation rate
decreased to 17 percent (Table 18). Exploitation too might
Table 19. Estimated and predicted densities (number/hectare) of largemouth bass (~200mm) in Rockl~nd Lake compared with a paired t-test (Sokal and Rohlf 1981). Estimated dens~ties based on Chapman-modified Schnable population estimates (Ricker 1975). Predicted densities based on the regression equation, log Y = 1.2274 log X - 0.5489 (Hall 1986), where Y is the predicted density and Xis the spring electrpfishing catch per unit effort (CUE).
--------------------------------------------------------------------------EFFORT NUMBER
YEAR (hr) CIAPTURED CUE PREDICTED ESTIMATED DIFFERENCE
DENSITY DENSITY PRED. ~ EST. --------------------------------------------------------------------------1980 4.2 97 23.1 13.3 14.6 -1.30 1981 3.7 335 90.5 71. 3 35.1 36.20 1982 3.7 130 35.1 22.3 27.4 -5.10 ~ ••:
1983 5.9 116 19.7 10.9 22.6 -11.70 1984 3.7 130 35.1 22.3 19.2 3.10 1985 3.6 122 33.9 21.3 20.8 0.50 1986 2.5 179 71.6 53.4 36.4 17.00 1987 3.1 154 49.7 34.1 31.4 2.70 1988 3.4 136 40.0 26.2 32.4 -6.20
CALCULATED t = 0.55 df = 8
\0 U1
96
not change depending on the extent of harvest of fish
shorter than the slot. The low exploitation rate in 1986 is
consistent with the low number of fish harvested in that
year (Figure 6). The increase in exploitation rate to 55%
in 1988 may have been caused by the large number of bass
harvested between 200-299mm and the large illegal harvest
(Figure 6).
Exploitation rates of largemouth bass longer than
200mm were also calculated (Table 18). Exploitation rates
for the larger bass were 87, 64, 19, and 76% in 1980, 1984,
1986, and 1988, respectively. These values too indicate no
change in exploitation of bass longer than 200mm, which
would include fish shorter than the slot size. The low
value in 1986 may be caused by the low number of largemouth
bass harvested from length groups both above and below the
slot, and the small illegal harvest (creel section).
High exploitation rates indicate the importance to
anglers of harvesting largemouth bass, and suggest that
anglers can affect fish populations profoundly (Goedde and
Coble 1981).
97
CONCLUSION
The purpose of the regulations was to improve
largemouth bass and bluegill fishing. The regulations were
expected to result in more larger largemouth bass in the
populations and the anglers' catch. They were also expected
to result in more large bluegills in the populations and
creel because of increased predation by the higher densities
of largemouth bass on bluegills.
Some of the expected or desirable changes for
largemouth bass were realized. The regulations were
effective in reducing the harvest rates of protected bass
while the harvest rate of legal largemouth bass increased in
three of four lakes (Table 20; Figures 3-6). Relative
abundance -- measured as spring electrofishing CUE -- or
mean length of protected bass increased (Table 20; Figures
15, 17, 19). Unexpected, and not satisfactorily explained,
results were lack of increase in angler catch rate (Figures
----ft8----i-l l} and a 9eneral deeline in r~lative wei9M ('I'able 20;
Figures 29-30). Hence, there was some improvement in the
largemouth bass populations, but it might not be apparent to
anglers.
Expected and desirable changes occurred for bluegills
too. Both mean length of harvested bluegills and relative
weight of bluegills increased (Table 21; Figures 12, 13,
31-32). Some expected, or at least plausible, changes,
however, were not evident. Electrofishing CUE did not
Table 20. Summary of results of largemouth bass: results of regression analysis, t-tests and Chi-square tests of data from creel surveys and spring electrofishing for largemouth bass for the period 1980 through 1~88. "Pro." and "Unpro." ihdicates largemouth bass of protected and unprotected sizes respectively. ~Pre." is pre-regulation years (1980-1982), "Post." represents the time period 1983-1985. #=an interpretation of the data. +=positively signif~cant, - = negatively significant, and o = not significant.
tlEASURES
HARVEST RATE (no/ha) PRO
UNPRO ALL
FISHING EFFORT <hr/ha) NEAN LENGTH (11) CATCH RATE <no/ha)
BEllAH LAKE
1980-1988
+ +
)30011
RELATIVE ABUNDANCE <no/hr) + IIEAN LENGTH <11> 0 INSTANTANEOUS GROWTH RATE LENGTH INCRENENT
ALL
0 0 0
0 10 10
ROCKLAND LAKE PRETTY LAKE
TH£ SPORT FISHERY, CREEL SURVEY
1980-1988 1980-1986
0
)30011 All
0 0 0
1980-1988
•
(40011 >40011
THE POPULATION, ElECTROfISHIN6
+ 0
10 10
0
• 0
PRE-1988 ~OST-1988 PRE-1988 POST-1988 PRE-1988 POST-1988
RELATIVE IIEl&ffT TOTAL ANNUAL NORTALITY
0 0 0 0
+ 0 0 0
ALL
0 0 0
10 10
BROWNS LAKE
(40011
+ 0
1980-1988
+
}40011
+
PRE-1988 POST-1988
0
All
0 + 0
ID 10
I.O 00
Table 21. Summary of results of bluegill: results of regression analysis, and t-tests of data fro~ creel surveys and spring electrofishing for bluegills for the perioO 1980 through 1988. "Pre." is pre-regulation years (1980-1982), "Post." represents the time period 1983-1985. #=an interpretation of the data. +=positively significant, - = negatively significant, and o = not significant.
ltEASURES
FISHING EFFORT (hr/ha) HARVEST RATE Cno/ha) NEAN LENGTH Cu) CATCH RATE Cno/ha)
RELATIVE ABUNDANCE (no/hr) NEAN LENGTH (11)
INSTANTANEOUS GROWTH RATE LENGTH INCRENENT
RELATIVE WEIGHT TOTAL ANNUAL NORTALITY
BEUlAH LAKE
All
ROOO.AND LAKE PRETTY LAKE
THE SPORT FISHERY, CREEL SURVEY
All
BROIINS LAKE
All All ----------------------------------------------------------------------------------------------
0 0 + 0
+ 0
110 ID
0 0 + 0
THE POPULATION, ELECTROFISHIN6
0 0
10 10
PRE-1988 POST1-l988 PRE-1988 POST-1988 PRE-1988 POST-1988
+ t
+ +
+ 0
+ 0
+ +
0 0 0 0
0 0
10 10
PRE-1988 POST-1988
+ 0
♦
0
0 0 ♦
0
+
10 10
100
decrease, and mean length of electrofishing samples did not
increase. Also growth rate of bluegills did not change.
Hence, there were important improvements in both the
bluegill populations and c~eel, but ther~ is scope for
further improvements.
I suspect that the improvements attained in this study
could be maintained if the regulations and associated public
education are maintained. Further improvement can probably
be obtained -- although it may not be spectacular -- if the
illegal harvest is reduced (Figures 3-6). The illegal
harvest might be reduced through some combination of public
education effort and increased law enforcement. Still
further improvements would likely require more intensive
management, e.g. substantial panfish removal or increased
macrophyte control or both in combination with the length
limit regulations.
101
LITERATURE CITED
Ager, L. M. 1988. Effects of an increased size limit for largemouth bass on fish populations in West Point Reserv~ir. D-J Job Prog. Rep., Prog F-033-study 5, Georgia Department of Natural Resources., Atlanta.
Anderson, R. o. 1976. Management of small warmwater impoundments. Fisheries (Bethesda) 1(6):5-7, 26-27.
Anderson, R. o., ands. J. Gutreuter. 1983. Chapter 15 in L. A. Nielson and D. L. Johnsons, editors. Fisheries techniques. American Fisheries Society, Bethesda, Maryland.
Anderson, R. o., and A. S. Weithman. 1978. The concept for balance for coolwater fish populations. Pages 371-381 in R. L. Kendall, editor. Selected coolwater fishes of North America. American Fisheries Society Special Publication Number 16, Bethesda, Maryland.
Carlander, K. D. 1977. biology. Volume 2.
Handbook of freshwater fishery Iowa State University Press, Ames.
Druckenmiller, H. s. 1972. Updated age-length averages for southeastern Wisconsin game fishes. Wisconsin Department of Natural Resources, Fish Management Report Number 55, Madison, Wisconsin.
Eder, S. 1984. Effectiveness of an imposed slot length limit of 12.0-14.9 inches on largemouth bass. North American Journal of Fish Management 4:469-478.
Frie, R. v. 1982. Measurement of fish scales and back-calcu_l._9-tion of body leri_gtJ:iE using a digitizing pad and microcomputer. Fisheries (Bethesda) 7(6):5-8.
Goedde, L. E. 1980. Effects of angling on a previously fished and an unfished warmwater fish community in two Wisconsin lakes. Master's thesis. University of Wisconsin, Stevens Point, Wisconsin.
Goedde, L. E. and D. W. Coble. a previously fished and an community in two Wisconsin American Fisheries Society
1981. Effects of angling on unfished warmwater fish lakes. Transactions of the 110:594-603.
Hall, T. J. 1986. Electrofishing catch per hour as an indicator of largemouth bass density in Ohio impoundments. North American Journal of Fisheries Management 6:397-400.
102
Hillman, w. P. 1982. Structure and dynamics of unique bluegill populations. Master's thesis. University of Missouri, Columbia, Missouri.
Hoey, J. w. and L. C. Redmond. 1974. Evaluation of opening Binder Lake with a length limit for bass. Pages 100-105 in J. L. Furik, editor. Symposium on overharvest and management of largemouth bass in small impoundments. North Central Division, American Fisheries Society Special Publication Number 3, Bethesda, Maryland.
Kempinger, J. J., W. S. Churchill, G. R. Priegel, and L. M. Christenson. 1975. Estimate of abundance, harvest, and exploitation of the fish population of Escanaba Lake, Wisconsin, 1946-69. Wisconsin Department of Natural Resources, Technical Bulletin No. 84, Madison, Wisconsin.
Legler, R. E. 1977. New indices of well-being for bluegills. Master's thesis. University of Missouri, Columbia, Missouri.
Li, J. C. 1969. Statistical inference I. Edwards Brothers Inc., Ann Arbor, Michigan.
Mayers, D. A. 1988. Effects of three years of minimum and slot length limit regulations for largemouth bass. Master's thesis. University of Wisconsin, Stevens Point, Wisconsin.
Michaelis, K. R. 1982. A study of the warmwater fisheries in four lakes in southeast Wisconsin. Master's thesis. University of Wisconsin, Stevens Point, Wisconsin.
___ Novotny, D. w., and G. R. Priegel. 1974. Electofishing boats: inproved designs and operational guid~lines to increase the effectiveness of boom shockers. Wisconsin Department of Natural Resources, Technical Bulletin Number 73, Madison, Wisconsin.
Novinger, G. D. 1987. Evaluation of a 15.0-inch minimum length limit on largemouth bass and spotted bass catches at Table Rock Lake, Missouri. North American Journal of Fisheries Management 7: 260-272.
Novinger, G. D., and R. E. Legler. 1978. Bluegill population structure and dynamics. Pages 37-49 in G. D. Novinger and J. G. Dillard, editors. New approaches to the management of small impoundments. North Central Division, American Fisheries Society Special Publication Number 5, Bethesda, Maryland.
103
Prendergast, L. 1984. Evaluation of largemouth bass minimum and slot length limit regulations. Master's thesis. University of Wisconsin, Stevens Point, Wisconsin.
Reynolds, J. B., and L. R. Babb. 1978. Structure and d-ynami-cs ef lar~uth bass popula-t-ions. Pa-ges 5-0-62 in G. D. Novinger and J. G. Dillard, editors. New approaches to the management of small impoundments. North Central Division, American Fisheries Society Special Publication Number 5, Bethesda, Maryland.
Ricker, w. E. 1975. Computation and interpretation of biological statistics of fish populations. Fisheries Research Board of Canada Bulletin 191, Department of the Environment Fisheries and Marine Services, Ottawa, Canada.
Schumacher, E. R., and R. Rebicek. 1977. Browns Lake chemical rehabilitation project evaluation survey, 1975. Wisconsin Department of Natural Resources Survey Report, Madison, Wisconsin.
Scheirer, J. W. 1988. Angling characteristics and vital statistics of fish populations in Long Lake, Fond Du Lac County, Wisconsin. Master's thesis. University of Wisconsin, Stevens Point, Wisconsin.
Sokal, R. R., and F. J. Rohlf. 1981. Biometry, 2nd edition. Freeman, New York, New York.
Steel, R. G. D., and J. H. Torrie. 1960. Principles and procedures of statistics. McGraw-Hill Book Company., New York, New York.
Wege, G. J., and R. O. Anderson. 1978. Relative weight ----- (Wrt--:- a new i-n-dex -o-f -condition for largemouth bass.
Pages 79-92 in G. D. Novinger and J. G. Dillard, editors. New approaches to the management of small impoundments. North Central Division, American Fisheries Society Special Publication Number 5, Bethesda, Maryland.
Zar, J. H. 1974. Biostatistical analysis. Prentice-Hall Inc., Englewood Cliffs, New Jersey.
104
Appendix A. Common and scientific names of species caught by electrofishing (E), and angling (A) during spring 1988 to spring 1989 in the four study lakes.
GEAR
EA
EA
E A
EA
EA
EA
E A
E
E A
E
EA
E
E A
EA
E
E
E
E
E
COMMON NAME
Bluegill
Pumpkinseed
Yellow Perch
Green Sunfish
Warmouth
Largemouth Bass
Northern Pike
Walleye
Bowfin
Yellow Bullhead
Brown Bullhead
Black Bullhead
Rock Bass
Black Crappie
Carp
White sucker
Grass Pickeral
Lake Chubsucker
Golden Shiner
SCIENTIFIC NAME
Lepomls macrochirus
Lepomls gibbosus
Perea flavescens
Lepomis cyanellus
Lepomis gulosus
Micropterus salmoides
Esox lucius
Stlzostedion vitreum vitreum
Anlia calva
Ictalurus natalis
Ictalurus nebulosus
Ictalurus melas
Ambloplltes rupestris
Pomoxis nigromaculatus
Cyprinus carpio
Catostomus commersoni
Esox americanus
Erimyzon sucetta
Notemigonus crysoleucas
105
WISCONSIN
WAUKESHA
oPretty Lake 26 ha
Beulah Lake c{f' 338 ha
WALWORTH
RACINE
OBrowns. Lake 0 160 ha
Rockland Lake 16 ha
Appendix B. Location of the four study lakes in three counties in southeast Wisconsin.
wc11-.,.--,. n•••J1• ~t~"":.":"..:..-.:::.~.-:::'~M:::-::.-::.:,.~k:------~l{l!~~~C~
.... ' ht I
.. '-!~ ~~~ ',,, ....
"~~-···:
Beulah Lake area= 338 ha
LEGEND ToPOGIIA,.,.IC sYl,IIClt.S
I IIIUSN
mean depth = 5. 2 m ,. _,,.._u ~ maximum depth= 17.7 m •c - 0
CI.CfJICO
• oasr.-.;o A -ICIA.TUll"'-
1" 11:MCN
• DlltLL"'O ■ lltsOIIT
LAIi[ ICITTCIM SYMIOLS
P PUT
.... lilUCtl
C CLAY
" ...... K $AHO
St SILT
r, G••-tL
...... STCEP SI.Cl'(
•./'"'- 1!"0(.r .. 1T[ S~Lo,[ _.."'--• .JI. -- S,,,,t,G ___ .., ll<T[""llt[NT S,tl[Aal
-:: PC"""'JCltT NLET
~ PC-IC~T CUTLtT
.....L: -ti 11\JHL[
1111 ICCflOCK T S~"f:"Gll<T YlGCTATl()lt
J. [M[IIG(,n Ylllt'rATIOO<
rLOATING Y[G[TATOt .. ~&SlfAGS
0 ACC[SS 0NI..T <> ACC[SS WITM P••A"'G ♦ IOA1 LIY[IIT
d ,O:,' fOOd ,,O:,' 2000 FT.
GIIArHIC SCALE
179.C WITH ISl. *lf[tl AIIU t34.0 ACtlCS
v-..!>Cfl sn. ocnw 11•1. ovc• 20 , .. OCPT" 34 °4
VO..JMC 14,Z7t.o •c•c rt 10UL Al."'- 168 ,.~lil SNCR(Lltf( ,,_, MIL[S
MAIIMl,JM 0[,-Tl-4 ~- ,t.
SP[C1U r,, flSM
!i g 12, .. t . MU$1ll(
frl Put( WALL[Y[
L.M. IASS I,
SM.IASS .. .. ,,$tt TtlC)uT
MAPP[O: DCC. 19~4 R[Y1$£0: S[P0 T ,sn [0U1PMc,,r, SON~A
X X
X
SURF&CC uttlll 1 [L[VATl()N; 107.'4 MSl,
Appendix c. Hydrographic ma~s of Beulah, Rockland, Pretty, and Browns Lakes.
...... 0 0)
HO!£• 5££ .. o, '°' 1£_._ 0£SC!li'T101t
LEGEND TOPOGRAPHIC SYM901.S
I """" ..... STUI> SloPf: PW """"Al.LT 1'000£0 . ...,-,_ 11,D('""''' s,,o,,t,<Nt w W000CO ....... _ ..... IWISM C Cl.[&11£0 ,. .. STU'!tD - -• -IC~T\.#l&L
,.,,,....,. M[IIMITThT STR(&,. ... 1£1«:MM&llo( =-::: ,tlhl&,C"1 IIO\.tT
• llWtLL..C ~ l{IIIUN("T ~L[T
II ll(SOIIT ..J..: l)&M
LAKE BOTTOM SYMBOLS ,. PUT • RUIIL[ ... IIUCC ... l[OIIOCC C CLAY T S~M[IIGC"T ~G[!&T,O,, .. ... , J. [M[IIG[WT ~G(TA'hO',
s,. .. .., ... rLOAT, ... vtGl:T&TIO'f
SI SILT ST\.Oll'S I Sl<~GS Ge G'IAll(L
0 ACCCSSCMJ ._ ACCtsS "''" ,u.,,,, ♦ 10.tT LIY['"
'-· t ~~-~~\'l ~~~· .. \ ., 1.,,,, ; :,.,.,. . . .
,~~~, • • I
.. ~ n:\:"·X< ':---:~- v,>~ :-.·,:._._,'. -~,-' "-·'. ' '
. -~ . /'i' 2000 rT.
179.S WITH ISL WAT[ll U[& l!-4.0 &(R[S
""OCII Sn: OCPTM IS% OY(lt ZO rt. O(PTM 34 %
VOi.WC 14,271.0 ACO[ rt. TOTAL AI.C. 161 '-'- M. SM()ll[LoN[ 1'-S MILU MUt"U" D(PTM 51 rt.
Arrows in 1Beulah Lake indicate area electrofished.
Ait>pendix c. (continued)
Sl>(C ,u c, r,sM
~
lh MUS,1111.1[ frC. ,.,.[
*.I.LL[~(
L .... IASS X SM el.lS ~NltSH l TIIOUT
tt~PPCX 0£C. :9~4 Rtv, stO: SEl''T. 1tl1 tou,..,t~T. SONU
X
X
X
SIJlrACC .._,Cit • [L[YAT,O'<: 101.9'1 !!ISi.
I-'
0 -.J
Rockland Lake
area• 16 ha
108
mean depth c 3.1 m
maximum depth= 7.6 m
"'• I A fl fll Wt!",r.n .. :.1 .. """"llfl o, IIAIUIIAl HCSou11,cc LAKE SURVEY MAP __IIOCIILAllll-- --IIACINL_
· 4.••l Cou• ,v 1
I
I 0
I
..
I ® . ·---.
Appendix c.
__ sec. __;,1-- 1,_--1_., 1t_J~c.·
............................ . .. ... .... ... ··-· ... .. . .................. ..........
twtW.1&111Ul,tB
(continued)
109
Pretty Lake
area • 26 ha
w1•e0HIIN CONSl:IIVATION ocrAIITMCHT
IHI JtJIS, •••--••·•--• • Ct1v'!U .. ....,••••• .... W.C.I. •-• • Cff:lft'l"l fl I'...,_
Appendix c. (continued)
mean depth a J.7 m
maximum depth • 9.5 m
LAl(E SURVEY MAP ~•• rM:TTT ___ _ ......... .:a _______ _
e -•-----· -· ·-•.11•1: • ----·· -•- 0'1A"A"A •- • • •• • c-•• WAI/IIUHA ___ •• •••
• J
1M ••••••• ••••• ····~ ........ u, ..... _ ----....... ..__ ,, , .. , ..... _ --· ••~•U..•no:____ __
Browns Lake area= 160 ha
d pth = 2.4 m mean e = 13.4 m maximum dep th
LEGEND &• Pl11C SYM801.S TOPOG""
II IIA\ISH PW -TIAI.LT WOODCD
w WOODtD C CLlAM:D p P&STU'ltD A AGRICIA.'IU'IAL
IIM 111:NCH MA'h( . Dwt:LLl"G
l!l ll[SO'IT
E BOTTOM SYMBOLS LAK p PEAT
"' .MUCtl
C CLAY .. MAIi\.
S4 $ANO
•· • to ,x-x-169 '- "'.c D.•BM ..... ~E.,. rJ Loki oo .. -
"R R COMl 19'J'tl I ' ..... 769 26 °"'"' ..... , .. 768 l Elt,. d IP'10.0, "'
' ~=;400~--:eo~of· =~,200~·■-;,600;; ,r
0 G~L~H,C SCLL[
Appendix c. (continued)
I'
R
1111 T ,L·
. ..
RUIIIIL[
IIEDIIOCt< . vtGETATIO>I SUIIMEIIGl:t(f lM[IIG[ltf ~ATIOO.
'LOATIHO Y[G[TAtl()H
ST\.OIIPS a Sff.lGS
SPEC l[S C, f ISH
ltil iii
4 e., MU$••£ N. PIK[ X
1 WALL(~[ ' L.M. IIASS X I s .... IIASS
I
H.NFISH X
TROUT I J
MAPP[O: flit. 19~) R[YoSEO: OCT. 1967 EOUIPM["'T. THRU IC[
--.J.
SUl"C[ ... TCR )' [L[YAToO"'. 7611.
J
I-' I-'
0
Appendix D. Length - frequency distributions of largemouth bass in electrofishing samples in spring and fall of 1988 in a]l lakes and spring of 1989 in Browns Lake.
-----------------------------~-----------------------------------------------------BEULAH ROCKLAND PRETTY BROWNS
LENGTH SPRING FALL SPRING FALL SPRING SPRING FALL SPRING GROUP (mm) 1988 1988 1988 1988 1988 1988 1988 1989 -----------------------------------------------------------------------------------80-89 1 90-99 1 1 100-109 2 2 2 2 110-119 2 3 6 2 5 3 ...... 120-129 3 1 0 3 1 3 7 2 ......
...... 130-139 14 4 1 2 0 5 9 10 140-149 26 5 6 1 1 6 22 15 150-159 23 10 10 0 2 10 13 17 160-169 16 14 33 5 7 1 4 14 170-179 15 3 30 21 3 7 6 10 180-189 7 8 22 11 12 7 3 7 190-199 9 9 22 12 8 8 4 11 200-209 5 20 8 5 4 9 6 12 210-219 14 25 3 0 7 13 12 22 220-229 8 15 1 3 8 10 7 14 230-239 7 9 4 10 3 11 5 13 240-249 9 7 13 15 4 32 7 20 250-259 14 9 18 7 4 26 4 18 260-269 6 4 14 7 4 23 4 16 270-279 8 4 8 6 10 25 1 9 280-289 9 3 2 1 3 15 5 15 290-299 6 7 4 2 7 17 4 20
Appendix D. (continued)
----------------------------------------------------------------------------------BEULAH ROCKLAND -PRETTY BROWNS.
LENGTH SPRING FALL SPRING FALL SPRING SPRING FALL SPRING GROUP (mm) 1988 1988 1988 1988 1988 1988 1988 1989 -----------------------------------------------------------------------------------300-309 7 4 6 3 8 10 6 ,21 310-319 3 6 7 1 2 5 4 28 320-329 3 3 15 1 4 6 7 20 330-339 4 7 10 3 4 5 13 12 340-349 2 1 8 2 0 4 3 17 350-359 0 4 4 2 2 1 3 13 360-369 1 2 3 2 2 2 5 14 370-379 0 1 1 0 1 1 2 15 380-389 2 2 3 1 1 4 1 12 390-399 1 0 1 1 1 4 4 8 400-409 3 2 1 1 2 3 1 1 I-'
I-'
410-419 0 1 1 0 0 1 2 3 N
420-429 0 0 0 0 0 2 1 5 430-439 0 3 1 0 0 3 0 2 440-449 0 0 1 0 0 0 0 2 450-459 4 1 1 1 0 2 0 4 460-469 0 0 0 0 1 1 0 4 470-479 0 0 0 0 2 2 5 480-489 0 0 2 0 1 3 2 490-499 0 1 1 3 3 500-509 0 1 0 0 510-519 0 0 0 1 520-529 0 1 0 530-539 0 0 540-549 1 0 550-559 0 560-569 1 570-579 580-589
TOTALS 230 197 266 137 126 291 187 441
Appendix E. Length - frequency distributions of bluegills, purnpkinseeds, yellow perch, green sunfish, and warrnouth in electrofishing samples in spring and fall of 1988 in all lakes and spring of 1989 in Browns Lake.
---------------------------------~---------------------------------------------------------BEULAH LAKE
-------------------------------------------------------------------------------------------LENGTH BLUEGILL PUMPKINSEED YELLOW PERCH G. SUNFISH WARMOUTH GROUP (mm) SPRING FALL SPRING FALL SPRING FALL SPRING FALL SPRING FALL ---------------------------------~---------------------------------------------------------40-49 50-59 60-69 2 1 70-79 5 1 1 80-89 10 3 1 90-99 19 4 1 100-109 11 5 1 4 2 1 110-119 12 7 0 2 5 3 3 1 120-129 17 6 2 1 10 1 0 8 130-139 26 10 3 2 5 3 1 4 2 140-149 30 11 6 3 3 0 4 2 150-159 17 25 1 2 1 3 1 7 4 160-169 12 20 1 2 0 3 4 1 170-179 8 27 1 1 2 4 1 180-189 12 27 2 1 5 1 1 190-199 3 14 0 1 1 200-209 2 1 0 1 1 210-219 1 1 220-229 230-239 240-249 250-259
TOTALS 186 162 1 17 13 32 22 10 0 34 12
.....
..... w
Appendix E. (continued)
--------------------------------~----------------------------------------------------------ROCKLAND LAKE
----------------.---------------------------------------------------------------------------LENGTH BLUEGILL PUMtKINSEED YELLOW PERCH G. SUNFISH WARHOUTH GROUP (mm) SPRING FA.LL SPR NG FALL SPRING FALL SPRING FALL SPRING FALL --------------------------------~----------------------------------------------------------40-49 2 50-59 2 60-69 3 7 70-79 15 34 1 1 80-89 8 8 3 1 1 3 90-99 30 8 1 2 1 1 4 2 100-109 33 16 2 2 2 1 1 3 2 110-119 28 14 4 16 1 2 2 .... 120-129 14 16 7 2 19 12 1 4 4
.... ~
130-139 14 18 14 11 1 2 5 140-149 19 27 4 3 5 2 6 4 150-159 14 15 3 1 3 3 5 5 160-169 3 8 1 3 1 5 170-179 5 17 2 6 180-189 10 20 1 4 3 190-199 5 8 1 2 200-209 1 5 1 210-219 2 1 220-229 230-239 1 240-249 250-259
TOTALS 202 227 21 14 44 55 5 2 42 34
LENGTH GROUP (mm)
30-39 40-49 50-59 60-69 70-79 80-89 90-99 100-109 110-119 120-129 130-139 140-149 150-159 160-169 170-179 180-189 190-199 200-209 210-219 220-229
TOTALS
Appendix E. (continued)
PRETTY LAKE . - ~ -- - -- --- - --BLUEGILL PUMPKINSEED Y. PERCH G. SUNFISH WARMOUTH
1
8 12
5 22 17 24 21 45 53 56 47 27 18
5
361
1 1
1
2 1
1
7
1
1 0
1
1
2
1 1
6
1--' 1--' Ul
Appendix E. (continued)
-------------------------------------------------------------------------------------------------------------------------BROWNS LAKE
-----------------------------------------1--------------------------------------------------------------------------------LENGTH BLUEGILL PUMPKIN SEED YELLOW PERCH GREEN SUNFISH WARHOUTH GROUP (mm) SPRING FALL srRING FALL SPRING FALL SPRING FALL SPRING FALL
1988 1989 1988 1988 1989 1988 1988 1989 1988 1988 1989 1988 1988 1989 1988 I -----------------------------------------1--------------------------------------------------------------------------------
40-49 4 I-' I-'
50-59 4 °' 60-69 1 40 8 1 3 1 70-79 26 91 34 4 12 3 1 80-89 43 79 61 17 14 10 1 1 1 90-99 74 105 105 26 23 16 1 11 3 100-109 97 56 81 24 16 15 7 11 2 110-119 80 28 86 26 8 17 10 25 1 120-129 34 16 65 19 23 17 10 14 2 130-139 16 13 29 27 23 8 5 7 2 1 1 140-149 9 5 22 16 11 2 2 3 2 150-159 6 6 9 4 6 1 1 1 160-169 2 4 4 4 1 1 1 170-179 3 2 1 1 180-189 190-199 200-209 210-219 220-229
TOTALS 388 454 506 164 144 91 35 75 14 2 1 2 0 0 0
117
Appendix F. Bluegill and prey weighted Proportional Stock Densities (PSD%) from 1980 to 1985 and 1988 (1988 and 1989 f--o-r Browns Lake) in the study lakes. Prey weighted PSD was not calculated when number of stock size fish or prey species was less than 30 because Novinger and Legler (1978) suggested 30 as a minimum number of fish to determine PSD.
---------------------------------------------------------------LAKE YEAR BLUEGILL PREY WEIGHTED
PSD ( \) PSD (\) ---------------------------------------------------------------
BEULAH 1980 32 28 1981 52 1982 35 1983 23 1984 35 34 1985 28
1988 31 32
ROCKLAND 1980 16 1981 17 1982 10 11 1983 13 11 1984 10 1985 35
1988 21 25
PRETTY 1980 5 8 1981 5 10 1982 4 4
-- 1-9-8-3 1-6 1984 10 13 1985 8 10
1988 29
BROWNS 1980 2 2 1981 1 1 1982 2 2 1983 4 3 1984 3 5 1985 2 4
1988 2 2 1989 4 5
Appendix G. Length ffequency distributions of largemouth bass in sprin9 electrofishing sample in 1980 to 1988 (1980 to 1989 in Browns Lake) from the study lakes .. These data are plotted in figures 14, 16, 18, an¢l 20 as number per hour. i
---------------------1------------------~----------------------------· 'BEULAH
---------------------~-----------------------------------------------YEAR
(ELECTROFISHING EFFORTi HOURSl' · 1980a 1981a 1982b 1983b · 1984c 1985c 1986 1987 1988
LENGTH (mnl-) · · ·(4.0) ( 3 • 6· ) ( 3 • 9 ) (4.9) (3.7) ·( 3 • 2 ) . ( 3 • 9 ) (4.0)- (3.6)
---------------------------------------------------------------------30-39 40-49 50-59 60-69 70-79 1
· · 80-89 3 90-99 1 2 2 14 100-109 2 1 1 26 110-119 1 23 I-'
I-'
120-129 2 1 1 16 CX)
130-139 l l 1 15 '140-149 16 1 9 1 2 1 1 7 150-159 24 4 7 9 8 4 5 8 9 160-169 8 10 18 6 16 7 9 12 5 170-179 5 18 25 7 16 10 5 10 14 180-189 5 11 31 7 13 4 10 11 8 190-199 5 9 14 8 8 4 23 8 7 200-209 12 21 2 16 10 8 24 13 9 210-219 20 21 2 26 17 1·4 19 12 14 220-229 16 16 7 16 14 20 21 11 6 230-239 13 3 .. 8 13 12 21 18 8 240-249 6 10 4 4 8 8 16 28 9 250-259 7 9 5 3 12 13 10 17 6 260-269 1 7 6 1 11 10 6 12 7 270-279 3 3 s 4 11 9 2 9 3 280-289 3 6 2 1 6 4 3 9 3 290-299 4 8 4 4 4 1 5 6 4 300-309 3 2 6 2 2 6 5 1 2 310-319 1 2 2 2 4 3 4
Appendix G. (continued)
·---------------------1-----------------------------------------------BEULAH
YEAR ·(ELECTROFISHING EFFORT, HOURS)
1980a 1981a 1982b 1~83b 1984~·1985c 19~6 1987 · 1988 · LENGTH (mm) (4.0) (3~6) ( 3 ~-9) (4.9) (3.7) (3.2) (3.9) (4.0) (3.6) ---------------------------------------------------------------------320-329 2 2 1 2 5 5 6 1 330-339 2 1 2 1 2 1 4 340-349 1 4 2 1 2 s 3 2 350-359 1 1 2 1 1 1 1
· 360-369 1 3 1 1 2 3 370-379 2 1 2 1 1 1 380-389 1 1 1 1 3 390-399 1 1 4 2
· 400-409 1 2 1 410-419 3 4 420-429 1 1 1 2 430-439 1
t-'
1 t-'
· 440-449 2 1 1 1. \D
450-459 1 460-469 1 470-479 480-489 1 1 490-499 500-509 1 1 510-519 520-529 530-539 1 540-549 550-559 2 560-569 1 1 570-579 ---------------------------------------------------------------------·. TOTAL 160 173 158 143 192 166 213 212 230
a Hlcha·elis 1982 bPrendergast 1984 c Mayers 1988
I Appendix G. (continued)
--------------------~---------------------------------------------~--ROCKLAND
---------------------------------------------------------------------YEAR
(ELECTROFISHING EFFORT, HOURS) 1980a 1981a 1982b 1983b 1984c 1985c 1986 1987 1988
LENGTH (mm) (4.2) (3.7) (3.7) (5.9) (3.7) ( 3. 6) (2.5) (3.1) ( 3. 4)
--------------------~------------------------------------------------30-39 40-49 50-59 60-69 70-79 1 1 80-89 2 1 2 90-99 3 1 1 1 1 1 100-109 1 1 1 1 110-119 3 1 1 1 7 1 2 I-'
120-129 1 5 5 N
130-139 43 2 13 5 1 0
140-149 72 ·25 2 1 3 6 150-159 so 2 3 8 5 5 10 160-169 27 12 11 4 16 7 1 1 33 170-179 17 20 17 3 23 30 5 11 30 180-189 11 21 30 2 22 44 8 17 22 190-199 6 67 14 2 19 21 9 24 22 200-209 3 125 5 2 14 12 16 20 8 210-219 4 96 2 3 17 2 12 21 3 220-229 2 47 2 8 12 14 7 11 1 230-239 8 12 8 22 15 12 8 9 4 240-249 13 9 14 13 10 22 30 9 13 250-259 12 5 19 3 2 16 32 7 18 260-269 6 3 26 4 5 7 26 6 14 270-279 15 2 25 5 3 14 14 13 8 280-289 4 1 6 2 5 5 8 8 2 290-299 4 7 7 7 12 4 17 11 4 300-309 5 1 10 5 10 18 6 310-319 2 4 10 3 l 6 6 7
Appendix G. (continued)
ROCKLAND ---- ----------------------------------- ·---------------------------
YEAR (ELECTROFISHING EFFORT, HOURS·)
1980a 1981a 1982b 1983b 1984c 1985c 1986 1987 1988 LENGTH (mm) (4.2) (3.7) (3.7) (5.9) ( 3. 7) (3.6) (2.5) (3.1) (3.f}·'···
---------------------------------------------------------------------320-329 1 1 6 2 2 6 5 15 330-339 3 1 1 9 6 2 2 10 340-349 5 2 3 5 1 2 2 8 350-359 3 1 3 1 6 2 4 360-369 2 4 1 1 2 2 3 370-379 4 1 2 2 2 2 1 380-389 1 1 2 1 1 3 390-399 2 3 1 1 1 1 400-409 1 1 1 1 1 I-'
N
410-419 2 1 1 I-'
420-429 1 1 430-439 1 2 1 440-449 2 1 1 450-459 1 2 1 1 1 1 460-469 2 1 1 2 470-479 1 1 1 1 1 480-489 1 1 1 1 2 490-499 1 1 1 500-509 2 1 1 1 510-519 1 520-529 1 2 1 530-539 540-549 ---------------------1------------------------------------------------TOTAL 330 465 206 179 218 228 265 215 266
a Michaelis 1982 b Prendergast 1984 c Mayers 1988
Appendix G. (continued)
--------------------~------------------------------------------------PRETTY
----------- ---------_,_ -----------------------------------------------YEAR
(ELECTROFISHING EFFORT, HOURS) 1980a
11981a 1982b 1983b 1984c 1985c 1986 1987 1988
LENGTH (mm) ( 1. 6) (1.6) (3.2) (2.9) ( 3. 0) ( 3. 6) (2.6) (2.6) (2.6) ---------------------------------------------------------------------30-39 40-49 50-59 60-69 1 1 2 70-79 1 5 3 80-89 2 4 1 90-99 2 1 1 1 1 1 100-109 1 1 1 3 2 2 110-119 9 1 5 1 8 1 6 I-'
N
120-129 4 3 2 4 1 3 1 2 1 N
130-139 4 5 2 2 1 14 1 6 140-149 5 4 2 5 1 7 3 10 1 150-159 3 9 3 3 4 4 2 3 2 160-169 3 4 2 2 8 3 7 4 7 170-179 7 12 7 3 7 2 11 8 3 180-189 3 9 8 4 8 6 7 12 12 190-199 4 6 6 3 7 5 8 7 8 200-209 1 18 8 7 7 11 4 6 4 210-219 5 14 14 5 7 12 5 5 7 220-229 9 10 5 2 8 13 8 1 8 230-239 6 5 7 8 3 9 6 6 3 240-249 6 8 5 2 7 11 6 8 4 250-259 6 1 2 4 8 5 6 4 260-269 3 3 1 1 4 7 4 4 4 270-279 7 1 1 2 7 9 6 8 10 280-289 4 2 4 1 7 2 7 3 290-299 4 2 2 7 7 7 300-309 3 3 5 3 7 8 310-319 4 2 1 4 2 2 3 2
Appendix G. (continued)
PRETTY ---------------------------------------------------------------------
YEAR (ELECTROFISHING EFFORT, HOURS)
LENGTH (mm) 1980a 1981a 1982b 1983b 1984c 1985c 1986 1987 1988 (1.6) tl.6) (3.2) (2.9) (3.0) (3.6) (2.6) (2.6) (2.6)
---------------------------------------------------------------------320-329 330-339 340-349 350-359 360-369 370-379 380-389 390-399 400-409 410-419 420-429 430-439 440-449 450-459 460-469 470-479 480-489 490-499 500-509 510-519 520-529 530-539 540-549 550-559
1 1 2
1 1 1
1 2 1 1
1 3 4 1
2
2
1
TOTAL 111 119 92
a Michaelis 1982 b Prendergast 1984 c Mayers 1988
1 1
1
1
73
2 3 4 4 2 2 4 4 1 2 2 4 2 2 1 2 2 1 1 1 4 2
1 1 2 1 1
1 1 1 2
4 1 2 1 1 1 1
1 1
1 1
110 159 122 154 126
I-' N w
I Appendix G. (continued)
-------------------------,--------------------------------------------------- .
·BROWNS ---------------------------------------------------------------------------· YEAR
( ELECTROFI SHI NG EFFORT;·.- ·HOURS l --- :. 1980a'l981~ 1982b 1983b 1984c1985c 1986 1987 '19'88 '1989
LENGTH (mm) (2.8) (5.3) '(4.4) (8.4) (5.7) (4~7) (5.8) (5~5) (5.2) (4.9}
---------------------------------------------------------------------------30-39 40-49 50-59 1 60-69 9 70-79 4 10 2 1 80-89 2 90-99 3 1 100-109 1 4 1 2 110.;..119 2 1 1 2 3 ,_.
120-129 1 3 3 2 N ~
130-139 1 4 1 11 1 5 10 140-149 2 2 21 1 6 15 150-159 1 27 9 10 17 160-169 6 1 2 2 21 15 1 14 170-179 - 4 3 2 28 28 7 10· 180-189 2 4 1 1 3 1 12 -__ ·29 7 7 190-199' 1 4 2 2 1 13 27 8 11 200-209 5 1 4 2 1 10 22 9 12 210-219 2 9 1 1 3 1 10 23 13 22 220-229 3 7 1 1 2 12 10 14 230-239 1 8 2 2 6 9 11 13 240-249 3 11 5 21 32 20 250-259 2 7 2 2 1 6 13 - 26 18 260-269 3 8 3 3 16 23 16 270-279 3 6 4 1 2 1 4 12 25 9 280-289 3 3 4 2 3 4 8 15 15 290-299 2 3 7 1 3 4 7 17 20 300-309 2 4 2 5 5 11 10 21 310-319 3 l 2 2 1 3 2 6 5 28
Appendix G. (continued)
---------------------------------------------------------------------------BROWNS·
---------------------------------------------·------------------------------YEAR
: . · (ELECTROFISHING EFFORT, HOURS) 1980a 1981a 1982b 198Jb· 19a4c 1985c 1986 1987 1988 1989
· LENGTH (mm) (2.8) (5.3) (4.4) (8.4) (5.7) (4.7) (5.8) (5~5) (5.2) (4.9) --------------------------~------------------------------------------------320-329 2 3 1 7 1 1 6 20 330-339 6 4 7 3 1 3 7 5 12 340-349 6 2 3 2 3 4 17 350-359 8 2 2 5 2 3 4 1 1 13 360-369 7 9 2 5 1 1 4 2 2 14 370-379 5 8 3 7 1 2 5 1 1S 380-389 3 3 7 2 1 3 5 4 12 390-399 3 9 5 6 1 4 3 4 8
f--'
N
·400-409 2 3 4 5 5 1 5 5 3 1 U1
410-419 1 6 9 8 s 3 3 3 1 3 420-429 3 6 8 4 2 1 5 2 5 430-439 4 7 3 3 3 4 3 2 440-449 1 1 3 1 3 3 3 3 2 450-459· 2 2 4 3 4 5 2 2 4 460-469 4 5 3 4 1 4 470-479 1 3 2 5 480-489 4 1 1 1 3 1 2 490-499 1 1 2 3 3 3 500-509 1 1 510-519 1 1 520-529 530-539 -------------------------------------------------------------------------------
. TOTAL 89 137 89 124 61 68 242 331 291 441
a Michaelis 1982 b Prendergast 1984 c Mayers 1988
en 1x Length frequency distributions of bluegills in spring electrofishing samples in 1980 to 1988 (1980 to 1989 in Browns Lake} from the study lakes. Subsample size is the number of fish measured to determine length distribution of the entire sample (total}. These data are plotted in figures 21-24 as number per hour. ----~----------------------------------------------------------------·. BEULAH
YEAR (ELECTROFIS·HING EFFORT,-<HOUR'S·)· ··· .
· 1980a · 1981a 1982b. '1983b ·1984c · 1985c 1986 · 1987 1988 LENGTH·-(mm) · (4.0) (0.4) (0.3) (4.9) (3.7) (3.2) (3.9t (4:.o-> (3~6·) · ·-------------------------------------------·----------·----------------0-9 5 10-19 20-29 30-39 40-49 50-59 5 6 13 60-69 1 4 4 21 51 14 70-79 9 2 4 13•· . · 36 19 35. · 9·0-e9 33 1 2 ·77 19 25 115 76 71 90-99 66 4 s 183 57 19 165 145 ·135· 100-109 42 5 4 136 42 50 286 114 78 110-119 75 9 10 10-2 · 125 144 315 284 85 120-129 70 9 15 72 98 169 315 278 120 130-139 103 14 15 111 87 251 172 297 '184.
·140-149 112 12 9 136 106 276 150 · 278 212 150-159 98 15 9 106 91 157 122 215 120
· 160-169 70 14 8 72 91 88 143 101 85 170-179 52 23 7 38 64 75 64· 51 57· 180-189 14 5 6 26 27 25 21 19 85 190-199 5 1 2 4 11 13 14 21
·200-209 6 14 210-219 ------------------------------------------------------------~--------TOTAL SUBSAMPLE I
a Michaelis 1982
759 112 95 1071 822 1311 1940 1946 1317 162 118 178. 251 217 209 · 271 308 186
b Prendergast 1984· · · c·Hayers 1988
I-'
. N O'I
Appendix H. (continued) ..
---------------------------------------------------------------------ROCKLAND
---------------------------------------------------------------------YEAR
(ELBCTROFISHING EFFORT, ·HoURs•)·· 1980a 1981a 1982b 1983b 1984c 1985c 1986 1987 1988
LENGTH (mm) ( 4. 2) (2.7) (0.7) (2.9) ( 3. 7) (3.6) (2.5) (3.1) (3.4)
---------------------------------------------------------------------0--9 10-19 4 20-29 4 30-39 4 40-49 12 10 2 50-59 2 3 3 3 3 60-69 4 4 20 33 31 27 30 6 11 70-79 41 15 28 26 53 125 41 33 56 80-89 45 7 15 46 50 88 23 42 30 90-99 127 59 15 139 235 88 15 19 113 100-109 368 96 26 111 159 91 63 33 124 · 110-119 192 59 50 41 70 61 58 125 105 120-129 61 66 20 18 156 115 53 75 53 130-139 61 73 7 39 145 47 32 17 53 140-149 123 92 10 69 47 68 13 25 71 150-159 78 51 5 33 31 105 18 42 53 160-169 61 11 2 21 22 119 15 53 11 170-179 33 15 5 3 25 61 7 19 19 180-189 16 18 3 8 11 17 10 28 38 190-199 4 2 3 3 19 19 200-209 1 5 8 4 210-219 220-229
TOTAL SUBSAMPLE I
1238 566 211 598 1041 1025 383 544 760 303 154 229 232 373 303 231 196 202
a Michaelis 1982 b Prendergast 1984 c·Mayers 1988
I-'
N ....J
Appendix H. (continued) ___________________ j _______________________________ -__ -__ -------------PRETTY
---------------------------------------------------------------------YEAR
(ELECTROFISHING EFFORT, HOURS) 1980~ 1981a 1982b 1983b 1984c 1985c 1986 1987 1988
LENGTH (mm) (1.6) (1.6) (0.3) (1.7) (1.3) (1.2) (1.5) (1.6) (1.6) -------------------~-------------------------------------------------0-9 2 10-19 20-29 30-39 2 3 40-49 50-59 3 1 J 9 7 3 24 60-69 30 1 16 40 23 20 35 70-79 93 6 1 10 23 21 124 111 15 80-89 273 32 7 65 67 38 124 67 65 I-'
90-99 18? 155 16 105 51 67 78 119 50 N co
100-109 100 252 41 128 114 74 89 157 71 110-119 64 194 50 180 126 65 89 113 62 120-129 67 100 41 162 110 79 73 69 133 130-139 36 55 25 97 97 59 70 77 156 140-149 22 36 12 60 40 26 82 53 165 150-159 16 29 6 76 30 15 35 14 138 160-169 12 13 2 39 25 7 21 9 80 170-179 6 3 26 11 8 10 9 53 180-189 3 3 2 4 2 8 15 190-199 2 3 200-209 210-219 ---------------------------------------------------------------------TOTAL 916 875 203 973 698 512 825 831 1063 SUBSAMPLE I 588 271 326 372 367 488 474 530 361
a Michaelis 1982 b Prendergast 1984 c Mayers 1988
Appendix H. (continued)
·---------------------------------------------------------------------------BROWNS
---------------------------·-----------------------------------------------YEAR·.
·. {ELECTROFISHING. EFFORT, ·HOURS) 1980a 1981a 1982b 1983b 1984c 1985c 1986 1987 198& 1989
LENGTH (mm) < 2. 8 > < 2., > < o. 3 > < 3 .1 > < s·~ 1 > < 1. 8 > < 2. a> < 2. a> < 2. 6 > < 2. 6 >
0-9 10-19 20-29 30-39 40-49 13 50-59 6 5 13 60-69 16 0 34 4 3 129 .· · 70-79 2 63 111 16 177 11 77 293 80-89 34 15 4 115 325 ·72 · 124 124 127 254 ......
N
90-99 201 121 12 52 167 314 250 215 218 338 I.O
100-109 325 307 28 104 152 298 257 403 286 180· 110-119 198 383 40 183 111 120 238 4·22 235 90 120-129 76 165 25 193 136 56 136 347 100 51 130-139 28 59 8 89 92 29 39 181 47 42 140-149 · 6 15 5 37 41 11 27 41 26 16 150-159 8 3 2 21 22 19 7 57 18 19 160-169 6 3 6 3 7 11 6 13 170-179 5 4 10 180-189 6 2 190-199 2 200-209. 5 210 .. 219 ---------------------------•----------------------------------·--------------
. 'TOTAL 894 1071 126 883 1163 943 1300 1820 1142 1460 SUBSAMPLE I 316 363 309 169 368 354 536 483 388 45-t
a Michaelis 1982 b Prendergast 1984 · c Mayers 1988
Appendix I. Mean Relative Wei~ht {Wr%) of largemouth bass in 10-mm length groups from 1981-1982 and 1988 (1988-1989 in Browns Lake) from spring electrofishing samples in the study lakes. Sample means compared with at-test (Sokal and Rohlf 1981; section 9.4). All statistical tests were at the 0.05 level of significance. 1980-1982 data from Mayers (1988).
-----------------------------------------------------------------------------------------' · ·BEULAH LAKE
--·----·----------·------------------------------.-----·---------------------------------------PRE· ( 198·1'•19·82 )a 1988 · CALCULATED··
··'LENGTH GROUP N MEAN SD ·+9·5\ N MEAN SD +95\ t df . (mm). Wr CI Wr CI -----------------------------------------------------------------------------------------50-59 60-69 70-79 80-89 90-99· · 100-109· · 2 114.70 · 2 .55· ·22. 9·1 110-119 120-129 2 116.63 6. 29 · 56.51 130-139 12 95.32 24.60 15.63 140--149 1 78.56 24 88.16 17.74 7.49 150-159 11 108.88 33,74 22.67 28 92.45 17.44 6.76 -1.54 37 160-169 28 93_-59 12~24 ·4.75 17 95.50· 14.22 7.31 0.45 43 170-179 35 95.53 13, 17 · 4.52 ·15 95.85 13.29 7.36 0.08 48· 180-189 . 40 92.85 12~44 3.98 7 97.88 8~51 1 .·a1 1.33 45 190.;..199 · 22 94.68 10.61 4.71 9 9·3. 57 · ·to. 1s 8.26 -0.26 29 200-209 12 93.37 8.02 5.10 5 89.74 4.65 5.77 -1.17 15 210-219 11 89.66 11.08 7.44 14 '91.98 10.59 6.11 0.53 23 220-229 17 92. 91 · 8.58 4.41 8 95.40 5·. 4·3 ··· 4.54 0.88 23 230-239 7 99.41 28.32 26.20 7 85.09 8.61 7.96 -1.28 12 240-249 14 93.84 13~93 8.05 8 93.29 8. 48· · · 7.09 -0.12 20 250--259 13 91.35 10J99 6.65 14 89.77 7.46 4.31 -0.43 25 260-269 12 9'1.47 8~31 s~28 6 86. 20 · 7. 84· · 8.23 -1.32 16 270-279 8 93.28 11~40 9.53 8 95.12 7.04 5.89 0.39 14 280-289 8 90.31 6 .166 5.57 9 95.99 9.27 7.13 1.46 15 290-299 11 93.86 7.69 5.17 5 90.45 6.55 8.13 -0.91 14
I-' w 0
Appendix I. (continued)
-------------------------------~-------------------------------·--------------------------· : BEULAH LAKE
-------------------------------~----------------~----------------------------------------PRE (198l!-1982)a 1988 CALCULATED .
· LENGTa GROUP N HEAN SD +95\ N HEAN SD +95\ t df (mm) wr CI Wr Cl
------------------------------------------------------------------------------------------300-309 8 86.66 11.43 9.56 3 100.05 9 .·67 ··24 .02 1.94 9
'310-319 3 95.17 10.80 26.83 8 96.86 5.10 4.26 0.26 9 320-329 4 9·1. 79 8.~7 13.80 3 82.06 9. 99· 24.81 -1.35 5 330-339 3 94.50 3.57 8.87 4 88.64 3.73 5.93 -2.11 5 340-349· 6 97.73 3.50 3.67 2 82.73 4.33 38.90 -4.44 b 6
· 350-359 1 94.12 360-369 1 87.16
"370-379 ·3 88.11 2.10 5.37 380-389 2 72.35 . 31. 50 283.01 2 80.12 2.38 21.38 0.35 2 390-399 1 92.59 I-'
400-409 · 3 85.60 5.42 13.47 w
410-419 I-'
420-429 430-439 440-449 2 91.36 3.06 27.48 450-459 1 87.12 460-469 470-479 480-489 490-499 500-509 510-519 520-529 530-539 540-549 1 94.71 550-559
WEIGHTED MEAN 93.84 92.43
a WEIGHT DATA FOR SPRING 1980 NQT AVAILABLE. b PRE REGULATION · RELATIVE WEIGH'l'S 'SI GNI FI CANTLY · GREA'TER •· ·
Appendix I. (continued)
-----------------.-----------------------------------------------------------------------ROCKLAND LAKE
----------------------------------------------~------------------------------------------PRE (198l--1982)a 1988 · CALCULATED LENGTH GROUP N HEAN SD +95\ N HEAN SD +95\ t df
Wr CI Wr CI -----------------------------------------------------------------------------------------50-59 60-69 70-79 1 185.60 80-89 90-99 1 146.51 100-109 1 96.91 f-'
w 110-119 4 112.79 23.46 37.33 2 148.20 14.33 128.75 2.28 4 N
120-129 130-139 2 114.31 1.37 12.33 1 152.31 140-149 2 110.45 3.41 30.64 150-159 5 100.29 14.}6 17.59 14 91.85 23.94 · 13.82 -0.94 17 160-169 20 100.12 7. 5 3.67 33 96.62 17.16 6.10 -1.01 51 170-179 27 99.64 11. ◄ 3 4.52 29 97.50 11.79 4.48 -0.69 54 180-189 40 100.13 9.87 3.16 22 95.12 10.86 4.82 -1.79 60 190-199 24 101.01 11.Q9 5.02 22 97.71 9.97 4.42 -1.02 44 200-209 15 94.68 7.21 3.99 8 94.29 7.15 5.98 -0.12 21 210-219 12 101.52 10.Q7 6.91 3 89.59 5.76 14.28 -2.61 b 13 220-229 12 93.35 10.72 6.81 1 90.43 230-239 17 100.65 16. ◄ 8 8.47 4 98.48 1. 74 · 2.77 -0.53 19 240-249 22 101.91 18.77 8.32 13 94.90 2.64 1.60 -1.72 31 250-259 24 96.15 7.$0 3.16 17 93.16 7.70 3.96 -1.24 39 260-269 28 91.47 7.47 2.90 14 93.08 4.41 2.55 0.88 40' 270-279 25 92.04 7.38 3.05 8 89.33 4.37 3.65 -1.27 31 280-289 7 93.67 12.87 11.90 290-299 11 90.79 10.14 7.22 6 94.05 6.20 6.51 0.79 15
I Appendix I. (continued) ·~ -----------------------------------------------------------------------------------------
ROCKLAND LAKE
--------------------------------~--------------------------------------------------------PRE (1981-1982)a 1988 CALCULATED
LENGTH GROUP N MEAN s~ +95\ ·N MEAN SD +95\ t df Wr CI Wr CI
--------------------------------~--------------------------------------------------------300-309 6 98.31 23.81 24.99 4 91.44 8.01 12.74 -0.65 8 310-319 4 93.36 7.31 11.64 9 89.96 7.21 5.55 -0.78 11 320-329 2 87.31 4.80 43.16 15 90.61 7.29 4.04 0.85 15 330-339 2 98.38 16.95 152.33 10 88.36 7.54 5.39 -0.82 10 340-349 2 89.48 5.21 46.84 8 84.82 4.87 4.07 -1.15 8 350-359 1 90.83 4 91.48 7.32 11.65 360-369 2 97.57 7.51 67.51 5 95.76 22.47 27.90 -0.16 5 370-379 1 86.96 1 81.81 380-389 1 102'. 26 1 94.12 390-399 2 92.16 2.02 18.17 1 94.17 400-409 1 84.91 I-'
410-419 2 44.82 45.03 ·407. 01 1 90.73 w w
420-429 1 100.42 430-439 1 93.20 1 90.25 440-44·9 2 84.93 15.04 135.13 1 99.76
·450.;.459 3 96.16 7.83 19.46 1 90.95 460-469 1 93.01 470-479 2 96.25 0.29 2.60 480-489 1 89.67 2 99.73 0.75 6.74 490-499 1 97.25 500-509 2 91.14 5.26 47.25 510-519 520-529 1 117.44 530-539 540-549 550'-559
WEIGHTED MEAN· 97.50 95.38
a 'WEIGHT DATA FOR SPRING 1980 NOT AVAILABLE. b PRE REGULATION REL'ATIVE WEIGHTS SIGNIFICANTLY GREATER. ·
Appendix I. (continued)
·• --------------------------------1---------------------------------------------------------PRETTY LAKE
-------------------------------~--------------------------·-------------------------------PRE (198l-1982)a 1988 CALCULATED
·LENGTH GROUP N HEAN SD +95\ N · HEAN SD +95\ t df Wr CI Wr CI
-------------------------------~---------------------------------------------------------50-59 1 499.59 60-69 70-79 80-89 1 209.77 90-99 1 146.51
I-' w
100-109 1 124.60 1 112.90 ,.i::,.
110-119 1 90.48 7 110.58 45.88 45.83 120-129 5 93.92 19.02 23.61 1 121.07 130-139 6 101.76 19.99 20.99 140-149 6 103.71 s.22 5. 48 · 1 112.86 150-159 12 96.50 10.63 6.76 2 140.63 27.86 250.31 2.21 C 12 160-169 6 84.83 15.21 31.92 7 115.30 · 13 .11 12.13 3.84 C 11 170-179 19 93.29 8.30 4.00 3 104.92 16.35 40.62 1.21 20 180-189 17 88.18 7.62 3.91 12 103.98 16.47 10.46 3.11 C 27 190-199 12 90.93 5.34 3.39 8 100.61 15.27 12.77 1.72 18 200-209 18 90~75 5.:5 2.71 4 99.03 6.99 11.12 2.22 C 20 210-219 24 89.58 9. 2 4.07 7 95.43 8.25 7.63 1.59 29 220-229 16 88.02 9.38 5.00 8 97.91 6.55 5.48 3.00 C 22 230-239 12 89.33 7.95 5.06 2 95.59 1.84 16.53 2.37 C 12 240-249 11 91.35 15.36 10.33 4 91.98 3.28 5.22 0.13 13 250-259 2 88.32 5.38 48.37 4 90.58 7.24 11.52 0.43 4 260-269 5 94.96 8.30 10. 30 · 4 91.63 10. 90· 17.37 -0.51 7 270-279 2 92.67 0.47 4.22 10 96.53 9.13 6.53 1.33 10 280-289 2 86.77 0.94 8.49 2 90.69 8.71 78.25 0.63 2 290-299 2 99.60 2.30 20.64 7 88.70 5.15 4.76 -4.30 7
Appendix I. (continued)
-----------------------------------------------------------------------------------------PRETTY LAKE
-----------------------------------------------------------------------------------------PRE (1981-1982)a 1988 'CALCULATED
'LENGTH GROUP N HEAN SD +95\ N HEAN SD +95\ t df Wr CI Wr CI
--------------------------------~-------------------------------------------------~------300-309 1 10"6. 06 s 86.60 5.00 6.21 310-319 3 83.88 4.25 10.57 5 89.64 4.92 6.11 1.74 6 320-329 2 89.78 0.18 1.59 4 9.4.45 7.49 11.92 -1.42 4 330-339 1 99.79 4 86.05 8.64 13.75 340-349 l 86.50 350-359 2 91.70 2.93 26.29 2 83.72 4.67 41.96 -2.05 2 360-369 2 92.92 1.96 17.61 2 78.83 4.46 40.04 -4.09 2 370-379 1 83.89 1 83.89 380-389 6 90.26 9.04 9.49 1 83.19 390-399 5 84.54 2.69 3.34 1 95.01 400-409 1 83.02 2 80.86 1.64 14.73 .....
w 410-419' Ul
420-429 3 83~34 10.01 24. 88 · 430-439 440-449 2 95.54 2.44 21.88 450-459 460-469 2 95.97 0.32 2.91 1 77.65 470-479 480-489 490-499 500-509 510-519 520-529 530-539 1 89.88 540-549 550-559
WEIGHTED HEAN 93.29 98.59
· a. WEIGHT DATA FOR SPRING 1988 NOT AVAILABLE. c 1988 RELATI'VE WEIGHTS SIGNIFICU'l'LY GREATER.
Appendix I. (continued)
-----------------------------------------------------------------------------------------BROWNS LAKE
--------------------------------~--------------------------------------------------------PRE (1981-1982)a 1988-1989 · · · CALCULATED·'
'•'LENGTH GROUP N HEAN SD +95\ N HEAN SD +95\ t df Wr CI Wr CI
. -----------------------------------------------------------------------------------------50-59 60-69 70-79 80-89 90-99 I-'
100-109 1 112.90 1 91.35 w 0)
110-119 5 92.30 30.48 37.84 120-129 4 116.63 5.13 · 8.16 130-139 14 92.71 13.95 8.05 140-149 20 86.55 17.82 8.34 150-159 28 96.04 25.13 9.75 160-169 1 85.15 14 92.22 13.92 8. 04' 170-179 3 88.94 8. 58 21.33 16 91.23 10.59 5.64 0.41 11· 180-189 5 93.55 6.38 7.93 13 99.49 12.11 7.32 1.35 16
· 190-199 4 91.05 6. 913 11.03 18 102.00 ·16. 63 8.27 2.09 C 20 200-209 6 94.81 9.9~ 10.40 21 99.08 9.87 4.49 0.93 25 210-219 9 95.53 4.88 3.75 35 98.16 9.68 3.32 1.14 42 220-229 8 91.26 10.08 8.43 24 98.87 9.17 3.87 1.89 30 230-239 10 106.84 22.99 16.45 24 1-00. 25 7.50 3.17 -0.89 32 240-249 10 98.23 9.9~ 7.13 52 100.70 7.93 2.21 0.74 60 250-259 6 97.71 8.59 9.02 44 102.36 9.03 2.74 1.24 48 26'0-269 7 101.17 8.12 7.51 39 99~34 7.45 2.41 -0.56 44 270-279 10 102.19 13.26 9.49 34 98.86 6.92 2.42 -0.76 42 280-289 7 102.84 11.28 10.43 30 102.29 8.80 3.28 -0.12 35 290-299 10 101.48 6.64 4.75 33 100.21 6.71 2.39 -0.53 41
Appendix I. (continued)
-----------------------------------------------------------------------------------------·BROWNS LAKE
-----------------------------------------------------------------------------------------PRE ( 1981-~1982 )a 1988-1989 CALCULA1'ED
·LENGTH· GROUP N HEAN SD +95\ N HEAN SD +95\ t df wr CI Wr CI
------------------------------------------------------------------------------------------300-309 3 92.34 8.56 21.28 32 97.17 310-319 3 96.44 4.07 10.12 35 96.45 320-329 5 102.51 8.75 10.86 25 95.77 330-339 8 109.39 16.56 13.85 17 101.99 340-349 2 104.44 11.31 101.63 21 96.12 350-359 4 98.54 12.09 19.24 14 97.42 360-369 10 105.25 5.91 4.23 16 98;15 370-379 11 104.04 12.68 8.52 15 96.68 380-389 10 110.13 11.85 8.48 16 100.29 390-399 14 106.06 8.96 5.17 11 97.74 400-409 5 106.25 9.35 11.61 4 101.30 410-419 . 15 110.94 7.10 3.93 4 99.63 420-429 8 109.55 8.00 6.70 7 100.83 430-439 4 110.68 7.10 11.28 s 100.35 440-449 4 106.33 8.36 13.31 2 96.56 450-459 4 . 109. 56 9.24 14.70 6 100.20 460-469 4 95.24 470-479 8 99.64 480-489 3 98.32 490-499 1 108.51 6 102.23 500-509 510-519 1 83.81 1 85.81 520-529 530-539 540-549 550-559
WEIGHTED' HEAN 102.72 98.39
a· WEIGHT DATA FOR SPRING 1980 NOT AVAILABLE. b PRE REGULATION RELATIVE WElGHTS: SIGNlFlCANTLY GREATER.· c 1988-1989' REL·ATIVE WEIGHTS SIGN·fFICANTLY GREATER.
7.41 2.67 0.94 33 8.47 2.91 0.00 36 9.54 3.94 -1.55 28
14.78 7.60 -1.08 23 9.95 4.53 -1.00 21 8.39 4.84 -0 .17. · 16 5.99 3.19 -2.96 b 24 6.41 3.55 -1.77 24 6.79 3.62 -2.39 b 24 7.78 5.23 -2.48 b 23 · 6.54 10.41 -0.93 7 6.82 10.85 -2.92 b 17
11.37 10.52 -1.69 13 12.54 15.57 -1.56 7 7. 59 68.19 -1.44 4
14.01 14.70 -1.27 8 16.66 26.51
7.08 5.92 3.25 8.07 8.41 8.83
...... w -...J
Appendix J. Mean Relative Weight (Wr%) of largemouth bass in 10-mm length groups from 1983-1985 and 1988 (1988-1989 in Browns Lake) from spring electrofishing samples in the study lakes. Sample means compated with at-test (Sokal and Rohlf 1981; section 9.4). All statistical tests were at th~ 0.05 level of significance. 1983-1985 data from Mayers (1988).
--------------------------------------------------------------------------------------- -·-·BEULAH LAKE
. ··-----------------------------------------------------------------------------------------( 1983-1985 )· 1988· CALCULATED' .. · . '· •·, E-ENGTH' GROUP ff HEAN SI> +95\ -N .HEAN SD , ·+95\ t df
<mm> Wr CI Wr CI
---------------------------------------·--------------------------------------------------· 50-59 60-69 10·-19 1 80-89 90-99 100-109· 2 164.63 73.16 ·657.32 110-119 1 79.17 120-129· 3 109.51 8.34 20.72 2 116.63· 6.29 56.51 1.09 3 130-139 4 121.12 60.51 96.50 12 95.32 24.60 15.63 -0.83 14 140-149 14 100~18 21~59 12.46 24 68.16 17~·,,,t- 7.49 -1.76 36 150-159 · 24 99.38 16.4~ 6.93 28 92.45 17.44 6.76 -1.47 50 160-169 32 99.01 18.0l 6.50· 17 95.50 14.22 7.31 -0.75 47 170-179 27 98.89 12.0 4.77 15 95.85 13.29 7.36 -0.73 40 180-189 24 95.15 16.0 6.79 7 97.88 8.51 7.87 0.59 29
· '190-199 24 95.77 11.a• 5.01 9 93·_57 10.75 8.26 -0~51 31 200-209 40 94. 3.3 9.6J 3.08 ·5 89.74 4.65 5.77 -1.78 43 210-219 -62 · 97. 91 31.08 ·1.89 14 91.98 10.59 6.11 .;.1.22 74 220-229 42 91. 9·9 8.23 2.56 ·8 95.40' 5.43· 4.54 1.48 48
·230.;.239 29 92.00 8~25 3.14 7 ·85.09 8.61 7.96 -1.92 34 240-249 25 94.16 14.31 S'.91 8 93.29 8. 48· · 7.09 -0.21 31
- 2·s·o-2s9 25 91.19 8.7f 3.59 14 89.77 7.46 4.31 -0.54 37 260-269' 21 aa.02· 11.-ai 5~39 6 86.20 7.84 8.23 -0.44 25 270-279 19 90.04 6.9 6.73 8 95.12 7.04 5.89 1.72 25 280-289 8 84·. 27 14.2$ 11.95 9 95.99 9.27 7.13 1.98 15 · 290-299 14 89.94 10.34 5.97 5 90.45 6.55 8.13 0.13 17
~
w (X)
Appendix J. (continued)
BEULAH LAKE -------------------------------~---------------------------------------------------------
(1983-~985) 1988 CALCUL·ATED · LENGTH GROUP N HEAN D +95\ N HEAN SD +95\ t df (mm·) Wr CI Wr CI -----------------------------------------------------------------------------------------. 300-309 8 87.21 13.12 11.48 3 100.05 9.67 24.02 1.74 9 310-319 9 87.43 13.39 10.30 8 96.86 5.10 4.26 1.96 15 320-329 4 89.45 5.24 8.33 3 82.0{; 9. 99· · 24.81 -1.17 s
, 330-339 s 88.07 5.32 6.61 4 88.64 3.73 5.93 0.19 7 340-349 2 92.30 1.34 12.09 2 82.73 4.33 38.90 -2.99 2 350-359 3 85.73 12.30 61.13 360-369 4 94.25 5.39 e.·se • 1 87.16· 370-379 380-389 4 93.86 2.l7 3.76 2 80.12 2.38 21.38 -6.68 b 4 390-399 3 94.22 3.1!6 7.85 1 92.59 f--'
400-409 3 101.19 10.86 26.99 3 85.60 5. 42" 13.47 -2.22 4 w I.O
-410-419 1 95.66 420-429 3 93.38 1.35 3. 35 ·
· 430-439 440-449 450-4S9 2 90.81 13.42 120~54 1 87.12 460-469 470-479 1 111. 36 · 480-489 490-499 1 102.07 ·
· 500-509 510-519
'520-529 530-539 1 104.32 540-S49 1 94.71 550-559 ·
WEIGHTED.HEAN ... 95.00 92.43
· 'b ·1983-1985'RELATIVE WE'IGHTS· St~NIFICANTLY GREATER.
Appendix J. (continued) ·1 -----------------------------------------------------------------------------------------
·ROCKLAND · LAKE -------------------------------.-----·-·-----------------------------------------------------
1983-1~85 1988 CALCUJ[.,ATED LENGTH GROUP N HEAN SD +95\ N HEAN SD +95\ t df
Wr CI Wr CI ------------------------------~----------------------------------------------------------50-59 60-69 70-79 80-89 90-99 2 154.50 11.30 101.50
· 100-109 1 ,,,, . ....,1. 35 ..... 110-119 2 75.47 3.i68 33.07 2 148.20 14.33 128.75 6.95 C 2 ~
120-129 5 105.94 19.1 91 24.71 0
130-139 13 96.86 12.,90 7.80 1 152.31 140-149 27 87.27 12 .i44 4.92 2 110.45 3.41 30.64 6.82 C 27 150-159 13 86.91 12-149 7.55 14 91.85 23.94 13.82 0.68 25 160-169 25 91.95 13 .i09 5.40 33 96.62 17.16 6 .10 · 1.18 56 170-179 50 89.90 12.31 3.50 29 97.50 11.79 '4.48 2.71 C 77
· ·180..;189 59 92.32 10.89 2.84 22 95.12 10.86 4.82 1.03 79 190-199 36 90.20 13.01 4 .·40 22 97.71 9.97· 4.42 2.47 C 56 200-209 21 92.34 10 .:76 4.90 8 94.29 7.15 5.98 0.57 27 210-219 19 88·. 24 ll .146 5.52 3 89.59 5.76 14.28 0.32 20 220-229 30 87.29 7 -195 2.97 1 90.43 230-239 45 90.02 7.81 2.34 4 98.48 1.74 2.77 5.82 C 47 240-249 41 91.73 7.35 2.32 13 94.90 2.64 1.60 2.33 C 52 250-259 20 91.92 8 .146 3.96 17 93.16 7.70 3.96 0.47 35 260-269 16 90.66 5 .166 3.03 14 93.08 4.41 2.~5 1.3l. 28 270-279 18 88.69 6 .'17 3.07 8 89.33 4. 37 · 3.65 0.30 24 280-289 11 88.04 4.41 2.96 290-299 21 87.48 5.26 2.40 6 94.05 6.20 6.51 2.36 C 25
Appendix J. (continued)
--------------------------------~--------------------------------------------------------' ROCKLAND LAKE
-----------------------------------------------------------------------------------------1983-198$ 1988 CALCULATED- ·
-- LENGTH GROUP N MEAN SI> +95\ N MEAN SD +95\ t df Wr CI Wr CI
--------------------------------~--------------------------------------------------------300-309 13 87.12 5.48 3.31 4 91.44· 8.01 12.74 1.01 15 310-319 14 90.52 7.02 4.05 9 89.96 7.21 5.55 -o·.18 21 320-329 9 92.34 6. 2() · 4.77 15 90.61 7.29 4.04 -0.62 22 330-339 14 88. 5·0 .. ..,.8 ◄ 4.52 10 88.36 7.54 5.39 -0.04 22 340-349 9 87.50 7.67 5.90 8 84.82 4.87 4.07 -0.87 15 350-359- 4 90.56 3.74 5.95 4 91.48 7.32 11.65 360-369 4 84.66 8.50 12.02 5 95.76 22.47 27.90 1.02 7 370-379 4 90.73 7.62 12.12 1 81.81 380-389 2 91.02 1.4~ 12.82 1 94.12 ·390-399 4 88.67 6.5 10.35 1 94.17 I-'
~ 400-409 3 95.53 1.67 4.15 1· 84.9-1 I-'
410-419 1 90.73 420-429 430-439 2 83.64 9.34 83.88 1 90.25 440-449 1 85.17 1 99.76 450-459 1 89.06 1 90.95 460-469 1 95.35 470-479 1 94.52 480-489 1 83.39 2 99.73 0.75 6.74 490-499 2 101.85 6.58 59.10 500-509 2 88.89 6.00 53.95 510-519 520-529 1 77.91 530-539 540-549 550-559
WEIGHTED MEAN 90.42 95.38
C 1988 RELATIVE WEIGHTS· SIGNIFICANTLY GREATER.
Appendix J. (continued)
-----------------------------------------------------------------------------------------PRETTY LAKE
-------------------------------~---------------------------------------------------------1983-198$ 1988 CALCULATED' LENGTH GROUP N MEAN SD +95\ N · MEAN ·so +95\ t df
Wr CI Wr CI -------------------------------♦---------------------------------------------------------50-59 60-69 1 392.97 70-79 1 358.73 80-89 2 192.10 1 209.77 90-99 1 146.51 1 146.51 I-'
100-109 1 137.02 1 112.90 ~
29.,o N
110-119 5 107.39 36.99 7 110.58 45.88 45.83 0.15 10.00 120-129 8 109.42 51.90 43.40 1 121.07 130-139 17 95.42 13.66 7.02 140-149 13 104.99 21.24 12.83 1 112.86 150-159 11 99.06 12.~8 8.25 2 140.63 27.86 250.31 2.07 11 160-169 12 87.70 16.$9 10.54 7 115.30 13.11 12.13 4.00 C 17 170-179 12 93.95 21.74 13.81 3 104.92 16.35 40.62 0.97 13 180-189 18 94.27 11.93 5.93 12 103.98 16.47 10.46 1.76 28 190-199 15 93.96 14.35 7.45 8 100.61 15.27 12.77 1.02 21 200-209 25 95.43 13.ll 5.50 4 99.03 6.99 11.12 0.82 27 210-219 24 94.55 10.~2 4.61 7 95.43 8.25 7.63 0.23 29 220-229 23 89.50 9.43 4.07 8 97.91 6.55 5.48 2.77 C 29 230-239 19 90.40 7.61 3.66 2 95.59 1.84 16.53 2.38 C 19 240-249 21 se-~63 1.;1 3.70 4 91.98 3.28 5.22 1.41 23 250-259 14 92.15 11. 5 6.79 4 90.58 7.24 11.52 -0.33 16 260-269 12 91.72 7.Q9 4.50 4 91.63 10.90 17.37 -0.02 14 270-279 18 92.48 6.00 2.98 10 96.53 9.13 6.53 1.26 26 280-289 12 88.68 6.90 4.41 2 90.69 8.71 78.25 0.31 12 290-299 4 90.25 4.$9 7.30 7 88.70 5.15 4.76 -0.52 9
Appendix J. (continued)
---------------------------------------------------------------· -------------------------·PRETTY LAKE
-----------------------------------------------------------------------------------------· · LENGTH GROUP N
1983-1985 ·HEAN SO
Wr +95\
CI
1988 CALCULATED N HEAN SD +95\ t df
Wr CI ----·-------------------------------------------------------------------------------------300-309 8 91.46 4.25 3.56 5 86.60 5.00 6.21 ;..l. 80 11.00 310-319 7 87.69 3.9~ 3.64 5 89.64 4.92 6.11 0.73 10 320-329 2 88.65· 2.9 26.08 4 84.45 7.49 11.92 -0.98 4 330-339 ·2 89.57 3.oi 27.30 4 86.05 8.64 13.75 -0.73 4.00 340-349 4 92.88 6.31 10.04 350-359 3 96.74 7.99 18.35 2 83.72 4.67 41.96 -2.29 3 360-369 2 86.26 6.93 62.23 2 78.83 4.46 40.04 -1.28 2 370-379 1 83.89 380-389 1 83.19 390-399 2 94.92 4.29 38.51 1 95.01 400-409 1 122.15 2 80.86 1.64· 14.73 410-419 3 92.62 8.0V 20.06 420-429 3 93.87 6.93 15.88 430-439 2 95.20 2.23 40.10 440-449 1 94.22 450-459 460--469 1 99.11 1 77.65 '470-479 480-489 490-499 500-509·
·. 510-519 520-529 530-539 540-549 550-559
WEIGHTED HEAN· 96.24 98.59
c 1988 RELATIVE 'WEIGHTS 'SlGNIFIC.ANTLY 'GREATER.
I-' ~ w
Appendix J. (continued)
-----------------------------------------------------------------------------------------BROWNS LAKE· .
-------------------------------·---------------------------------------------------------1983-1985 1988-1989 CALCULATED LENGTH GROUP N MEAN SD +95\ N HEAN SD +95\ t df
Wr CI Wr CI -----------------------------------------------------------------------------------------50-59 1 51.64 60-69 9 49.48 11-:6 8.96 70-79 12 125.09 112. 8· 71.72 80-89 90-99 3 75.71 22.46 55.81
· 100-109 4 92.63 19.93 31.72 1 91.35 I-'
~
110-119 2 77.34 9.09 81.64 5 92.30 30.48· 37.84 0.99 5 ~
120-129 1 112.18 4 116.63 5.13 8.16 130-139 5 114.75 16.23 20.65 14 · 92.71 13.95 8.05 -2.65 b 17 140-149 2 113.56 2. 4 25.51 2·0 86.55 17.82 8.34 -6.05 b 20 150..;.15·9 28 96.04 25.13 9.75 160-169 4 111.02 9. ()7 14.43 14 92.22 13.92 8.04 -3.21 b 16 170-179 1 84.73 16 91.23 10.59 5.64
· 180-189 5 117.27 44.32 55.03 13 99.49 12.11 7.32 -0.88 16 190-199 5 101~85 9.,·o 12.29 18 102.00· 16.63 8.27 0.03 21 200-209 7 99.59 11. 7 10.61 21 99.08 9.87 4.49 -0.11 26 210-219 5 107.39 15.71 19.51 35 98.16 9.68 3.32 -1.28 38 220-229 1 96.80 24 98.87 9.17 3.87 230-239 2 109.17 5.21 46.77 24 100.25 7.50 3.17 -2.24 b 24
· 240-249 52 100.70 7.93 2.21 250-259 5 104.12 13.10 16.27 44 102.36 9.03 2.74 -0.29 47 260-269 3 102.75 13.~2 33.09 39 99.34 7.45 2.41 -0.44 40 270-279 4 105.79 7.ll9 11.44 34 98.86 6.92 2.42 -1.83 36 280-289 5 101.15 3.89 4.83 30 102.29 8.80 3.28 0.48 33 290-299 4 92.75 6.82 10.85 33 100.21 6.71 2.39 2.07 C 35
Appendix J. ( continued)
--------------------------------~-------------------------------------------------·-------BROWNS LAKE
-----------------------------------------------------------------------------------------1983-1985 1988-1989 CALCULiATED
LENGTH GROUP N HEAN SD +95\ ·N HEAN SD +95\ t df· Wr CI Wr CI ________________________________ , _________________________________________________________
300-309 10 103.80 7.04 5.04 32 97.17 7.41 2.67 -2.57 b 40 310-319 6 106.76 4.9! 5.23 35 96.45 8.47 2.91 -4.15 b 39 320-329 8 103.42 7.4 6.23 25 95. 77 · 9.54 3.94 -2.35 b 31 330-339 7 102.08 4.46 4.12 17 101.99 14.78 7.60 -0.02 22 340-349 s 117.98 23.4~ 29.13 21 96.12 9.95 4.53 -2.04 24 350-359 10 104.88 8.80 12.59 14 97.42 8.39 4.84 -2.09 b 22 360-369 7 111-. 89 25.75 23. 82 · 16 98.15 5.99 3.19 -1.40 21
· 370-379 8 102.29 4 .1;4 3.47 15 96.68 6.41 3.55 -2.54 b 21 380-389 3 105.62 12.44 · 30. 91 16 100. 2·9 6.79 3.62 -0.72 17 390-399 7 105.52 7. 6:2 7.05 11 97.74 7.78 5.23 -2.09 16 400-409 11 10'2. 56 6.3[ 4.24 4 101.30 6. 54, · 10.41 -0.33 13 .....
.i:::,.
410-419 16 103.86 8.57 4.57 4 99.63 6.82 10.85 -4.23 b 18 lil
420-429 14 104.02 6.22 3.59 7 100.83 11.3!7 10.52 -0.69 19 430-439 13 98.74 9. 613 5.83 5 100.35 12.54 15.57 0.26 16 440-449 7 102.99 7.9~ 7.33 2 96.56 7.59 68.19 -1.05 7 450-459 11 104.25 5.7() 3.83 6 100.20 14.01 14.70 -0.68 15 460-469 8 106~05 6.28 5.25 4 9S.24 16.66 26.51 -1.25 10 470-479 2 116.88 7.80 71.56 8 99.64 7.08 5. 92 -2.85 b 8 480-489 6 101.-47 4.61 4.84 3 . 98.32 3.25 8.07 -1.19 7 490-499 1 108.82 6 102.23 8.41 8.83 500-509 510-519 1 85.81 S20-529 530-539 540-549 550-559
WEIGHTEDMEAtf 102~12 98.39
b 1983-1985 ·REt;ATIVE 'WEIGHTS SIGNIFICANTLY GREATER. C 1988-1989 RELATIVE WEIGHTS SIGNIFICANTLY ·-GREATER'. ·
146
Appendix K. The Wr regression equation of largemouth bass (> 100mm) from Pretty Lake in 1988 and at-test of the significance of the slopes (Sokal and Rohlf 1981; p. 473). The period exhibited a significant negative slope at the 0.05 level of significance. Wr values are from appendix I, J and are plotted in figure 30.
PERIOD
1988
a REGRESSION EQUATION
Y = -0.12X + 128.26
CALCULATED t
-8.24
d.£.
29
-----------------------------~----------------------------a Y is the Wr value and X ls the length group.
Appendix L. Mean Relative Weight (Wr%) of bluegills in 10-mm length groups from 1981-1982 and 1988 (1988-1989 in arowns Lake) from spring electrofishing samples in the study la~es: Sample means compared with at-test (Sokal and Rohlf 1981; section 9.4). All stat1st1cal tests were at the 0.05 level of significance. 1983-1985 data from Mayers (1988).
-----------------------------------------------------------------------------------------BEULAH LAKE
PRE (1981-l982)a 1988 CALCULATED LENGTH GROUP N HEAN SD +95\ N HEAN SD +95\ t df
Wr CI Wr CI -----------------------------------------------------------------------------------·------30-39 40-49 50-59 60-69 1 70-79 3 80-89 4 90-99 14 100-109 12 110-119 28 120-129 37 130-139 39 140-149 27 150-159 25 160-169 25 170-179 24 180-189 19 190-199 4 200-209 210-219 220-229
WEIGHTED HEAN·
92.14 89.32 97.58 90.19 96.58 92.37 90.43 89.48 91.55 89.09 90~41 86.19 83.85 83.59
89.59
22.01 54.68 7.46 11.88 6.93 4.01
17.10 10.86 12.46 4.83 8.71 2.91 8.85 2.87
14.21 5.62 10.21 4.22 10.24 4.23
9.61 4.06 9.87 4.76 4.41 7.02
a WEIGHT DATA FOR SPRING 1980 NOT' AVAILABLE. c 1988 RELATIVE WEIGHT·SIGNIFICANl'tY· GREATER·~·
2 70.45 5 108.25
10 109.30 19 115.09 11 104.77 13 114.10 17 104.50 26 102.36 31 99.46 16 97.17 12 95.87
8 101.47 12 90.30
3 93.59 2 100.10
96.97
14.67 131.80 13.37 16.60 1.35 6 10.17 7.27 2.38 C 12 13.82 6.66 6.78 C 31 9.36 6.29 1.44 21 9.75 5.89 6.06 C 39 6.42 3.30 6.65 C 52 7.12 2.88 6.47 C 63 8.85 3.25 2.50 C 56 6.64 3.54 3.07 C 39 7.03 4.47 1.89 35 8.30 6.94 4.33 C 30 9.56 6.07 1.81 29 5.85 14.55 2.48 5 7.24 65.05
...... ~ ...J
Appendix L. (continued)
-------------------------------~---------------------------------------------------------ROCKLAND LAKE
-----------------------------------------------------------------------------------------PRE (1981-1982)a 1988 CALCULATED
LENGTH GROUP N HEAN SD +95\ N HEAN SD +95\ t df Wr CI Wr CI
-----------------------------------------------------------------------------------------30-39 40-49 50-59 2 33.68 2.12 24.45 60-69 23 71.73 26.13 11.30 3 89.89 30.57 75.95 0.98 24 70-79 35 89.77 18.'76 6.45 15 102.17 15.68 8. 68 · 2.41 C 48 I-'
~ 80-89 18 93.73 12.91 6.42 8 103.54 15.27 12.77 1.58 24 co 90-99 27 93.95 7.'11 3.46 31 104.40 17.07 6.26 3.07 56 100-109 38 95.70 8.07 2.65 34 105.57 11.28 3.93 4.23 C 69 110-119 65 94.19 9.19 2.28 28 109.52 10.63 4.12 6.64 C 91 120-129 31 95.07 6.95 2.55 14 105.77 7.18 4.14 4.67 C 43 130-139 18 90.47 8.91 4.43 14 104.32 12.21 7.05 3.57 C 30 140-149 22 93.58 5.89 2.61 19 106.15 12.28 5.92 4.08 C 39 150-159 15 92.70 7.12 3.95 14 101.34 7.27 4.20 3.23 C 27 160-169 6 97.75 8.93 9.37 3 103.06 10.66 26.48 0.74 7 170-179 10 94.47 8.53 6.11 5 101.45 3.77 4.68 2.19 C 13 180-189 7 97.88 8.61 7.97 10 102.36 9.60 6.87 1.01 15 190-199 2 87.20 14.99 131.11 5 97.52 18.99 23.58 0. 77 · 5 200-209 1 137.26 1 92.34 210-219 220-229
WEIGHTED HEAN 91.86 104.50
a WEIGHT DATA FOR SPRING 1980 NQT AVAILABLE. c 1988 RELATIVE WEIGHTS SIGNIFICANTLY GREATER.
Appendix L. (continued)
PRETTY LAKE -----------------------------------------------------------------------------------------
PRE (1981-1982)a 1988 CALCULATED LENGTH GROUP N HEAN SD +95\ N HEAN SD +95% t df
Wr CI Wr CI -----------------------------------------------------------------------------------------30-39 1 125.32 40-49 50-59 1 35.61 8 77.16 29.91 25.01 60-69 1 72.75 12 93.84 15.81 10.05 70-79 4 115.72 10.60 16.87 5 90.75 13.87 17.22 -3.06 b 7 80-89 20 89.45 10.00 4.68 22 97.93 12.38 5.49 2.45.c 40 t-'
90-99 35 90.10 12.51 4.30 17 95.78 10.35 5.32 1.73 50 ~ \.0
100-109 76 91.13 9.68 2.21 24 93.83 8.68 3.67 1.29 98 110-119 91 88.10 9.44 1.97 21 97.27 16.12 7.34 2.51 C 110 120-129 75 88.24 7.78 1.79 45 95.62 13.87 4.16 3.27 C 118 130-139 50 84.06 7.91 2.25 53 92.16 9.24 2.55 4.79 C 101 140-149 29 87.90 14.15 5.38 56 87.96 10.91 2.92 0.02 83 150-159 19 90.33 11.10 5.35 46 89.30 9.61 2.85 -0.35 63 160--169 7 88.43 5.22 4.84 28 84.61 12.26 4.75 -1.26 33 170-179 1 91.48 18 90.12 28.83 14.34 180-189 4 84.56 3.81 6.06 190-199 200-209 210-219 220-229
WEIGHTED HEAN 88.64 91.52
a WEIGHT DATA FOR SPRING 1980 NOT AVAILABLE. b PRE REGULATION RELATIVE WEIGHTS.SIGNIFICANTLY GREATER.· c 1988 RELATIVE WEIGHTS SIGNIFICANTLY GREATER.
Appendix L. (continued)
BROWNS LAKE -----------------------------------------------------------------------------.-- .--------
PRE (1981-1982)a 1988-1989 CALCULATED LENGTH GROUP N MEAN SD +95\ N MEAN SD +95\ t df
Wr CI Wr CI -----------------------------------------------------------------------------------------30-39 40-49 4 76.20 11.95 19.01 50-59 4 108.81 62.18 98.92 60-69 1 23.03 41 129.59 17.77 5.61 70-79 5 75.13 10.01 12.43 117 111.06 17.79 3.26 7.53 C 120 I-'
80-89 16 76.81 11.94 6.37 122 108.16 11.61 2.08 9.91 C 136 U1 0
90-99 40 82.43 12.75 4.08 178 102.51 10.24 1.50 9. 3l. C 216 100-109 78 85.00 8.87 2.00 153 97.35 10.06 1.59 9.56 C 229 110-119 105 87.20 8.78 1.70 108 98.12 10.15 1.94 8.40 C 211 120-129 72 85.53 9.04 2.13 49 94.27 11.09 3.19 4.58 C 119 130-139 29 86.58 7.32 2.79 23 88.06 12.67 7.02 o.os 50 140-149 17 84.37 7.64 3.93 14 96.12 9.21 5.32 3.81 C 29 150-159 7 93.84 16.00 14.81 11 93.26 12.27 8.24 0.0$ 16 160-169 1 107.03 6 102.61 17.24 18.10 170-179 3 98.12 16.28 40.45 180-189 2 89.49 11.06 99.37 190-199 200-209 210-219 220-229
WEIGHTED MEAN 85.14 103.13
a WEIGHT DATA FOR SPRING 1980 NOT AVAILABLE. c 1988-1989 RELATIVE WEIGHTS Sll'GNIFICANTLY GREATER.
Appendix M. Mean Relative Weight (Wr%) of bluegills in 10-rnrn length groups from 1983-1985 and 1988 (1988-1989 in Browns Lake) from spring electrofishing samples in the study lakes. Sample means compared with at-test (Sokal and Rohlf 1981; section 9.4). All statistical tests were at the 0.05 level of significance. 1983-1985 data from Mayers (1988).
BEULAH LAKE -----------------------------------------------------------------------------------------
1983-198'5 1988 CALCULATEll LENGTH GROUP N HEAN SID +95\ N HEAN SD +95\ t df
Wr CI Wr CI ------------------------------------------------------------------------------------------30-39 40-49 50-59 1 95.27 60-69 2 72.85 66. 819 600.97 2 70.45 14.67 131.80 -0.05 2 70-79 3 108.76 31.~0 77.77 5 108.25 13.37 16.60 -0.03 6 80-89 27 105.11 18. 015 7.14 10 109.30 10.17 7.27 0.89 35 90-99 61 102.71 14.00 3.58 19 115.09 13.82 6.66 3.40 C 78 100-109 51 102.74 11. 3i2 3.18 11 104.77 9.36 6.29 0.63 60 110-119 80 100.60 10.18 2.40 13 114.10 9.75 5.89 4.56 C 91 120-129 70 97.80 10.71 2.56 17 104.50 6.42 3.30 3.32 C 85 130-139 89 96.69 8.61 1.82 26 102.36 7.12 2.88 3.40 C 113 140-149 104 94.65 9. 511 1.85 31 99.46 8.85 3.25 2.61 C 133 150-159 74 93.06 10. 910 2.52 16 97.17 6.64 3.54 1.97 88 160-169 55 97·-~ 43 8. 812 2.38 12 95.87 7.03 4.47 3.59 C 65 · 110-179 38 83.92 12.]J9 4.01 8 101.47 8.30 6.94 4.96 C 44 180-189 17 83.52 7.Sl 3.86 12 90.30 9.56 6.07 2.05 C 27 190-199 5 74.92 8.50 10.55 3 93.59 5.85 14.55 3.67 C 6 200-209 2 100.10 7.24 65.05 210-219 220-229
WEIGHTED MEAN 95.91 96.97
c 1988 RELATIVE WEIGHT SIGNIFIC~TLY GREATER.
~
U1 ~
Appendix M. (continued)
-------------------------------~---------------------------------------------------------ROCKLAND LAKE
-------------------------------~---------------------------------------------------------1983-1985 1988 CALCULATED ·
LENGTH GROUP N MEAN SD +95\ N MEAN SD +95\ t df Wr CI Wr CI
-------------------------------~---------------------------------------------------------30-39 1 125.32 40-49 2 72.49 o.oo 50-59 3 79.19 57.49 142.83 60-69 32 85.62 32.69 11.79 3 89.89 30.57 75.95 0.23 33 ..... 70-79 67 92.22 19.49 4.76 15 102.17 15.68 8.68 2.12 C 80 Ul
80-89 62 93.84 14.$0 3.71 8 103.54 15.27 12.77 1.70 68 N
90-99 164 98.99 13.37 2.11 31 104.40 17.07 6.26 1.67 193 100-109 127 99.52 10.19 1.79 34 105.57 11.28 3.93 2.83 C 159 110-119 59 96.57 9.lo 2.48 28 109.52 10.63 4.12 5.49 C 85 120-129 97 94.31 8. 9 1.69 14 105.77 7.18 4.14 5.46 C 109 130-139 81 93.10 10.93 2.42 14 104.32 12.21 7.05 3.22 C 93 140-149 64 95.32 11.$4 2.89 19 106.15 12.28 5.92 3.42 C 81 150-159 55 92.17 11.00 2.98 14 101.34 7.27 4.20 3.75 C 67 160-169 51 89.78 7.l6 2.07 3 103.06 10.66 26.48 2.13 C 52 170-179 28 87.97 6.G4 2.58 5 101.45 3.77 4.68 6.41 C 31 180-189 12 87.50 12.$0 7.94 10 102.36 9.60 6.87 3.15 C 20 190-199 2 100.79 16.37 147.11 5 97.52 18.99 23.58 -0.23 5 200-209 2 80.10 9. (1)3 81.09 1 92.34 210-219 1 68.14 220-229
WEIGHTED MEAN 94.72 104.50
c 1988 RELATIVE WEIGHTS SIGNIFI¢ANTLY GREATER.
Appendix M. (continued)
-------------------------------~---------------------------------------------------------. PRETTY LAKE
-----------------------------------------------------------------------------------------1983-1985 1988 CALCULATED
· LENGTH GROUP N HEAN $D +95\ N HEAN SD +95\ t df Wr CI Wr CI
-----------------------------------------------------------------------------------------30-39 1 197.52 1 40-49 50-59 10 11·3. 31 33.84 24.21 8 60-69 44 108.94 33.~0 10.29 12 70-79 36 94.46 18.90 6.40 5 80-89 96 84.61 15.$9 3.16 22 90-99 131 83.87 13.76 2.38 17 100-109 179 84.98 9.;9 1.43 24 110-119 196 84.82 9. 7 1.38 21 120-129 195 84.35 9.10 1.29 45 130-139 144 82.40 8.49 1.40 53 140-149 69 80.94 9.15 2.20 56 150-159 59 83.96 9.36 2.44 46 160-169 35 84.70 10.13 3.48 28 170-179 24 84.82 9.98 4.22 18 180-189 6 77.80 5.12 5.38 4 190-199 1 94.63 200-209 210-219 220-229
WEIGHTED HEAN 85.55
b 1983-19.85 RELATIVE WEIGHTS SI¢;NIFICANTLY GREATER. c 1988 RELATIVE WEIGHTS ·SIGNIFICANTLY GREATER.
125.32
77.16 29.91 25.01 -2.40 b 16 93.84 15.81 10.05 -2.21 b 54 90.75 13.87 17.22 -0.53 39 97.93 12.38 5.49 4.32 C 116 95.78 10.35 5.32 4.28 C 146 93.83 8.68 3.67 4.62 C 201 97.27 16.12 7.34 3.47 C 215 95.62 13.87 4.16 5.20 C 238 92.16 9.24 2.55 6.72 C 195 87.96 10.91 2.92 3.84 C 123 89.30 9.61 2.85 2.86 C 103 84.61 12.26 4.75 -0.03 61 90.12 28.83 14.34 0.75 40 84.56 3.81 6.06 2.39 C 8
91.52
f-' U1 t,J
Appendix M. (continued)
-------------------------------~---------------------------------------------------------BROWNS LAKE
-------------------------------~------------------------------------------------- -------1983-19815 1988-1989 CALCULATED
LENGTH GROUP N MEAN SD +95\ N MEAN SD +95\ t df Wr CI Wr CI
-----------------------------------------------------------------------------------------30-39 40-49 4 76.20 11.95 19.01 50-59 2 191.99 19.74 4 108.81 62.18 98.92 60-69 3 59.92 17.~1 177.37 41 129.59 17.77 5.61 6.79 C 42 ..... 70-79 53 100.20 21.r 42.50 117 111.06 17.79 3.26 3.22 C 168 U1
80-89 151 94.89 13. 5 5.91 122 108.16 11.61 2.08 8 .• 74. C 271 ~
90-99 181 101.30 15. 3 2.16 178 102.51 10.24 1.50 0.89 357 100-109 180 95.72 11. 1 2.21 153 97.35 10.06 1.59 1.36 331 110-119 115 90.76 9. 9 1.73 108 98.12 10.15 1.94 5.51 C 211 120-129 101 86.71 9.16 1.81 49 94.27 11.09 3.19 4.14 C 148 130-139 57 82.81 8.94 1.81 23 88.06 12.67 7.02 1.81 78 140-149 24 86.39 9.27 2.37 14 96.12 9.21 5.32 3.13 C 36 150-159 18 83.92 9.47 3.91 11 93.26 12.27 8.24 2.16 C 27 160-169 3 89.95 12.25 4.71 6 102.61 17.24 18.10 1.27 7 170-179 1 99.53 30.43 3 98.12 16.28 40.45 180-189 190-199 200-209 1 90.33 210-219 220-229
WEIGHTED MEAN 94.07 103.13
c 1988-1989 RELATIVE WEIGHTS SI~NIFICANTLY GREATER.
155
Appendix N. The Wr regression equation of bluegill (> 80mm) from Beulah Lake and at-test of the significance of the slopes (Sokal and Rohlf 1981; p. 473). All three periods exhibited a significantly negative slope at the 0.05 level of significance. Wr values are from ·appendix L, Mand are plotted in figure 31. 1981-1982 and 1983-1985 data from Mayers (1988).
PERIOD a
REGRESSION EQUATION
1980-1982b Y = 96.8 - 1.033X
1983-1985b Y = 109.9 - 2.513X
1988 Y = 103.4 - 1.773X
CALCULATED t
-5.47
-12.70
-4.55
a Y ls the Wr value and X ls the length group. b Mayers (1988)
d.f.
12
12
13
Appendix o. Instantaneous growth (G) and length increments (mm) of largemouth pass in the study lakes. Values determined from last two annuli on scales for all years except 1986, in which the first and second annuli from the scale edge were used1. Number in parenthesis represents sample size for instantaneous growth and length increments.
--------------------------------------------------------~------------------------------------------------------ ------------------------------~------------------BEUlAH
--------------------------------------------------------~-------------------------------------------------------------------------------------------------------
AGES
SPRING 1980 - SPRING 1982
YEAR or GROWTH
1979 1980 1981
HEAN SD
INSTANTANEOUS GROWTH RATES ==========================
rALL 1982 - FALL 1985
-----~--------------------------------------------------YEAR or GROWTH IIEAN SD
AGES 1982 1983 1984 1985
FALL 1986 - rALL 1988
-------------------------------------------------YEAR Of' GROWTH IIEAN SD
AGES 1986 1987 1988 ------------------------------------------------ --------------------------------------------------------- -------------------------------------------------1-2 1,849 2-3 o. 798 3-4 0.514 4-5 0.250 5-6 0.309 6-7 0.274 7-8 o. 142 8-9 o. 163 9-10 0.094 10-11
2,299 1,797 1.982 0,276 1.209 0.913 0.973 0.212 0.725 0.641 0.627 0,106 0.860 0.501 0.412 0.141 0.353 0.971 0.544 0.370
0.337 0,306 0.045 0.233 0.188 0.064
0.163 0.094
1-2 71.3(36) 88.6(45) 88.6(54) 2-3 52.3(78) 72.2(96) 59,4(44) 3-4 44.3(39) 55.1(34) 55.7(62) 4-5 24.1(18) 41,4(12) 48,3(22) 5-6 36,8(7) 37,6(5) 108.0<2>
82.8 9.988 61.3 10.089 51.7 6.416 37.9 12.467 60.8 40.878 39.4 11,667 22.1 7.778 18.5
6-7 31,1(6) 47.6(2) 7-8 16.6(3) 27.6(2) 8-9 18.5(2) 9-10 12. 9(1) 12.9 10-11
1-2 1,259 2,015 1.535 2-3 0.626 1.141 0.805 3-4 0,458 0.654 0.509 4-5 0.404 0.469 0.365 5-6 0,218 0.334 0.306 6-7 0.263 0.252 0.236 7-8 0.202 0.203 8-9 0.201 0.184 9-10 0.132 0,080 10-11 0.080
LENGTH INCREIIEHTS
1.911 1.680 0.348 1.218 0.948 0.279 0,594 0.554 0.087 0.357 0.399 0.051 0,385 0.311 0.070 0.182 0.233 0.036 0.244 0.216 0.024
0,193 0.012 0.106 o. 037 0.080
1-2 2-3 3-4 4-5 5-6 6-7 7-8
5~.8<60> 10.2c60> 55.4C65> 66.9<3> 3JICl03) 63,4(102)46.1(93) 63,5(26) 31,3(22) 48.3(98) 37.3(79) 39.7(28) 38.0(18) 41.1(28) 32.4(35) 28.1(26) 2$.6(2) 34.3(24) 32.5(7) 34,2(6) 27.8(2) 28.3(8) 28,3(7) 22,3(1)
64.3 10.574 54.0 10.952 39.9 6.020 34.9 5.789 31.7 4.117 26.7 2.926 27.6 2.335 25.2 4.445 13.4 1.697 12.3
8-9 9-10 14.6(1) 10-11
25.1(5) 28.1(2) 29.7(1) 28.3(2) 22,0(1)
12.2(1) 12.3(1)
1-2 2-3 3-4 4-5 5-6 6-7 7-8 8-9 9-10 10-11
2.17 1.22 0.86 0.62 0.51
0.34
1. 99 1.03 0.86 0.66 0.51 0.44
0.43
2.10 1.11 0.88 0,63 0.65 0,42
1-2 76.6(42) 71.2(92) 67.2(77) 2-3 61,4(27) 59,0(42) 59.0(24) 3-4 56,5(34) 59.7(27) 60.2(26) 4-5 56,1<8> 5.5(34) 53.0(7) 5-6 51,9(3) 54,3(8) 63.5(9) 6-7 52.4(3) 49,1(4) 7-8 47.82(1) 8-9 67.1(1) 9-10 10-11
2,08 0.09 1.12 0.09 0.87 0.01 0,64 0.02 0,56 0.08 0,43 0.02 0,34 0.43
71.7 59.8 58.8 54.5 56.6 50,7 47.8 68,1
4.75 1.36 2.00 1.57 6.11 2.33
..... U1
°'
Appendix o. (continued)
---------------------------------------------------------------------------------------------------------------------------------------------------------------PRETTY
----------------------------------------------------------------------------------------------------------------------------------------------~----------------INSTANTANEOUS GROWTH RATES ==========================
Sf>RIN6 1980 - Sf>RIN6 1982 FALL 1982 - FALL 1985 FALL 1986 - FALL 1988 ------------------------------------------------ --------------------------------------------------------- ------------------------------------------------
YEAR or GROWTH tlEAN SD YEAR or GROWTH tlEAN SD YEAR or GROWTH NEAN SD --------------------------- ------------------------------------ --------- --------·
AGES 1979 1980 1981 A6ES 1982 1983 1984 1985 A6ES 1986 1987 1988 ----------------------------- --------------------------------------------------------- ------------------------------------------------
1-2 0.942 1.907 2,092 1,647 0,618 1-2 1.018 1,988 1,580 1.198 1.446 0.431 1-2 2,63 1,60 2,11 o. 72 2-3 0.683 l, 720 1.150 1,102 0,397 2-3 0,913 1,553 1.242 0,830 1,135 0,331 2-3 1.62 0.99 1.31 0,44 3-4 0.330 0.694 0,726 0.583 0,220 3-4 0.622 0,803 0.687 0.558 0,668 0,105 3-4 0,82 0,79 0.80 0.03 I-'
4-5 0.265 0.698 0.534 0.499 0.219 4-5 0.501 0.470 0.472 0.362 0.451 0.061 4-5 0.55 0.53 0.54 0.01 U1 ...J
5-6 0.280 0.320 0.437 0.345 0.082 5-6 0.193 0.347 0.370 0.338 0,312 0.080 5-6 0.48 0,44 0.46 0.03 6-7 0.186 0,249 0.218 0.045 6-7 0.381 0,273 0.246 0.222 0.281 0.070 6-7 0,58 0.37 0.47 0,15 7-8 0,168 0.168 7-8 0.190 0.160 0,139 0,188 0, 169 0.020 7-8 0,39 0.46 0,43 0,05 8-9 8-9 0.130 0,073 0.150 0,118 0.040 8-9 0.24 0.24 9-10 9-10 0.130 0,125 0,092 0.118 0.020 9-10 10-11 10-tl 0.102 0.091 0.097 0,008 10-11
LENGTH INCRENENT ================
1-2 44.4(36) 68,8(39) 61,3(8) 58,2 12,498 1-2 30.2(29) 70.7(30) 51.7(31) 34.4(16) 48.8 16.409 1-2 84.5(33) 60,9(35) 72.7 16.69 2-3 60.4(52) 80.0(78) 62.0(46) 67.5 10.884 2-3 50.9(25) 82.4(5) 68.2(46) 48.0(8) 62.4 16,055 2-3 76.8(42) 57.5(33) 67,1 13.60 3-4 38,3(12) 59,7(19) 9,8(20) 49.3 10,710 3-4 40,7(32) 60.1(25) 48.9(60) 41,5(14) 48,6 8,302 3-4 59.6(23) 55.5(42) 57.6 2.88 4-5 35.7(8) 71.3(1) 57.5(12) 54,8 17,949 4-5 411, l{l2) 43. 0(25) 39. 1(31) 29. 7(23) 38.2 5,902 4-5 48.3(13) 48,8(23) 48.5 0,34 5-6 44.8(1) 39,1(3) 56,1(3) 46.7 8,652 5-6 li7,S(4) 35,0(8) 34,7(21) 31.7(10) 29.7 8,285 5-6 50.3(5) 46.0(13) 48.4 3.38 6-7 26.1(3) 33.3(1) 29,7 5.091 6-7 6~.3(2) 37.0(3) 28.3(38) 22,9(10) 38,l 18,391 6-7 70,8(1) 44,8(5) 57.8 18.37 7-8 22,8(1) 22.8 7-8 20.l(l) 19,8(5) 16,2(5) 21. 9(11) 19,5 2,837 7-8 46.2(1) 68.1(1) 57,l 15,46 8-9 8-9 16.9(1) 9.5(2) 17,6(2) 14.7 4.488 8-9 31.5(1) 31.S 9-10 9-10 19.3(2) 20.3(2) 12,6(1) 17.4 4,187 9-10 10-ll 10-11 16. 7(1) 12.6(1) 14,7 2,899 10-11
(Appendix o. (continued)
--------------------------------------------------------~------------------------------------------------------------------------------------------------------ROCKLAND
--------------------------------------------------------i------------------------------------------------------------------------------------------------------INSTANTANEOUS 6ROIITH RATES --ss:---z--•-•--•=••--=-==
SPRIN6 1980 - SPRIN6 1982 FALL 1982 • FALL 1985 FALL 1986 - FALL 1988 ----------------------------------------------- -------------------------------------------------------- ------------------------------------------------
YEAR or 6ROIITH tlEAN SD YEAR or 6ROIITH NEAN SD YEAR or 6ROIITH NEAN SD --------------------------- ------------------------------------ ---------------------------
A6ES 1979 1980 1981 AGES 1982 1983 1984 1985 AGES 1986 1987 1988 ------------------------------------------------ -----~--------------------------------------------------- ------------------------------------------------1-2 2.110 3.160 2,530 2,606 0,530 1-2 2,036 3.447 2.530 2.033 2.467 0.670 1-2 2.18 2.57 2.53 2.43 0.22 2-3 1.129 1.546 1.163 1.279 0.232 2-3 1.004 I. 726 0.980 0.986 I. 174 0.368 2-3 1. 13 0.97 1.04 1.05 0.08 3-4 0,976 0,587 0.873 0.812 0.202 3-4 0,886 0.597 0.590 0.565 0.660 0.152 3-4 0.65 0.64 0.72 0.67 0.04 4-5 0.390 0.449 0.368 0.402 0.042 4-5 0.432 0.437 0.228 0.432 0.382 0.103 4-S 0,69 o.so 0.54 0,57 0,10
I-'
5--6 0.298 0.308 0.322 0.309 0.012 5-6 0.356 0.370 0.219 0.403 0.337 0.081 5-6 o.so 0.43 0.55 0.49 0.06 Ul
6-7 0.223 0.332 0.227 0.261 0.062 6-7 0.270 0.183 0.083 0.179 0,094 6-7 0.34 0.34 co
7-8 0.108 0,244 0,176 0.096 7-8 0.147 o. 186 0.167 0.028 7-8 0.27 0.27 8-9 0.159 0.130 0.170 0.018 8-9 0.124 0.124 8-9 0.13 o. 13 9-10 0.115 0.151 0.133 0.025 9-10 0.111 0.117 0.080 0.103 0.020 9-10 10-11 0.133 0.133 10-11 0.120 0.093 o. 107 0.019 10-11 11-12 0.636 0.636 11-12 11-12
LENGTH INCRENENT ----------=-----
1-2 74.7(71) 106.4(38)94.0(51) 91.7 15,975 l-2 72.6(92) 114.0(74)96.6(62) 75.9(19) 89.8 19.330 l-2 93.2(70) 97.1(124)91,4(36) 93,9 2.92 2-3 75.9(63) 85.6(118)72.0(24) 77.8 7.003 2-3 64.4(63) 95.3(112)64.8(77) 65.9(16) 72.6 15,147 2-3 73.6(37) 67,1(70) 67.9(13) 69.S 3.55 3-4 75.4(12) 47.3(32) 67.8(64) 63.5 14,535 3-4 69.7(23) 51.2(33) 52.9(39) 45.4(7) 54.8 10.439 3-4 54.3(26) 55.2(37) 59.0(12) 56.2 2.54 4-5 43.8(10) 49.7(3) 34. 7(4) 42.7 7.557 4-5 38.1(43) 40.9(9) 23.9(10) 49.9(1) 38.2 10.781 4-5 61. 4 (3) 49.8(26) 54.3(3) 55.2 5.83 5-6 33.8(4) 39.7(44) 32.7(2) 35.4 3.764 5-6 $.6(5) 39,7(15) 25.5(4) 47.6(1) 37.4 9.157 5-6 59.6(6) 45.4(3) 70,3( l > 58.4 12.49 6-7 30.8(2) 46.3(5) 28.6(1) 35.2 9.647 6-7 27.7(2) 21.8(9) 11.9(1) 20.5 7.984 6-7 46.4(6) 46.4 7-8 12,0(2) 31.0(3) 21.5 13.435 7-8 14.8(1) 24.5(4) 19.7 6.859 7-8 38.72(1) 38.7 8-9 24.0(1) 18.2(2) 21.1 4.101 8-9 17,2(2) 17.2 8-9 21.8(1) 21.8 9-10 16.0(3) 22.2(2) 19.1 4.384 9-10 20. 3(1) 18. 5(1) 11. 9(1) 16.9 4.423 9-10 10-11 20.1(3) 20, 1 10-11 13,2(1) 14.3(1) 13.8 0.778 10-ll 11-12 9.5(1) 9.5 11-12 11-12
Appendix o. (continued)
---------------------------------------------------------------------------------------------------------------------------------------------------------------BROWNS
---------------------------------------------------------------------------------------------------------------------------------------------------------------INSTANTANEOUS 6ROVTH RATES ==========================
SPRING 1980 - SPRING 1982 FALL 1982 - FALL 1985 FALL 1986 - FALL 1988 ------------------------------------------------ --------------------------------------------------------- -----------------------------------------------
YEAR or GROWTH "EAN SD YEAR or GROWTH NEAN SD YEAR OF GROWTH NEAN SD
--------------------------- -~---------------------------------- ---------------------------A&ES 1979 1980 1981 A&ES 1982 1983 1984 1985 AGES 1986 1987 1988 ------------------------------------------------ --------------------------------------------------------- ------------------------------------------------1-2 2.208 1.161 1.685 0.740 1-2 1,167 1.408 0.827 1. 195 1.149 0,240 1-2 1. 98 2.30 2.49 2.30 0.28 2-3 1.318 1.504 2,282 1. 701 0.511 2-3 1,433 2.052 l, 716 0,686 1.472 0.582 2-3 1,16 1. 74 l, 77 1.56 0.34 3-4 0.806 1.352 l,170 I, 109 0.278 3-4 1.093 1. 903 1.0% 0.837 1,232 0.463 3-4 1 ,04 1.29 1.16 l, 17 o. 13 4-5 0.338 0,507 0.519 0.455 0.101 4-5 0.563 0.868 0.462 0,691 0,646 0.175 4-5 0,84 0,80 0.98 0,87 0,10 5-6 0,276 0.238 0,315 0.276 0.039 5-6 0.298 0.257 0.447 0.392 0,349 0.087 5-6 0,50 0.53 0,68 0.57 0.10 6-7 0,181 0.180 0,246 0,202 0,038 6-7 0, 192 0.152 o. 178 0.174 0.174 0.017 6-7 0.39 0.33 0.48 0,40 0.07 ..... 7-8 0.105 0.140 0.123 0.025 7-8 0.176 0, 108 0.138 o. 122 o. 136 0.029 7-8 o. 16 0.29 0,33 0.26 0.09 Ul
8-9 0.104 0.104 8-9 0,160 0,094 0.097 0.121 o. 118 0.030 8-9 0.25 0.12 0.26 0.21 0.08 I.O
9-10 9-10 0.103 0.087 0.089 0.093 0.009 9-10 0.21 0,18 0,20 0,02 10-11 · 10-11 0,081 0.012 0.109 0,087 0.019 10-11 ll-12 11-12 0.040 0,083 0,062 0.030 ll-12 12-13 0.068 0.068 12-13 12-13
LENGTH INCREffENTS =================
1-2 74.9(19) 29.0(6) 52.0 32.456 1-2 38.6(45) 43,3(11) 24.4(28) 39.4(33) 35.6 8.372 1-2 54.6(48) 77.3(52) 79.4(97) 70.4 13.75 2-3 80.5(85) 80.3(43) 113.2(6) 91.3 18.937 2-3 751,2(24) 121.0(37)90.6(20) 30,5(74) 80.7 37,704 2-3 54.3(70) 84,0(48) 87.2(105) 75.2 18.18 3-4 73.2(44) 86.3(45) 102.0(33) 87.2 14,420 3-4 7q.7(15) 139,3(16)89.0(32) 47.1(38) 91.8 39.141 3-4 67.3(28) 87.7(70) 69.6(44) 74.8 11. 19 4-5 39.0(54) 52.5(14) 61.2(25) 51), 9 11. 186 4-5 561, 2(56) 85. 2(5) 45.4(27) 62.5(16) 64.4 16.805 4-5 74.6(8) 68.0(28) 78.8(51) 73,8 5.44 5-6 32.4(22) 27.0(35) 38,9(26) 32,8 5.'58 5-6 3~.9(36) 33,2(11) 54.0(8) 41,5(10) 42.9 9,439 5-6 53.1(5) 58.0(8) 65.8(32) 59,0 6,40 6-7 20,0(5) 21.5(8) 34.7(6) 25.4 8.089 6-7 20.9(25) 10.6(18) 23.8(12) 24.0(1) 19.5 6,311 6-7 47.2(8) 40.0(5) 50.3(18) 45.8 5.26 7-8 14.5(1) 16.9(8) 15.7 1.697 7-8 18.3(7) 15.9(19) 20,4(10) 15.6(2) 17,3 2,252 7-8 20.4(1) 39.5(8) 39. 1(10) 33.0 10.92 8-9 12.7(1) 12.7 8-9 191.0(2) 13, 9(7) 14. 9(4) 16.0(3) 14.9 2,207 8-9 35,6(1) 16,1(1) 33.5(6) 28.4 10.73 9-10 9-10 14.9(3) 13.7(6) 12.0(1) 13.5 I. 457 9-10 31,5(1) 25.5(8) 28,5 4.23 10-11 10-11 10, 5(1) 11, 2(2) 15.6(2) 12.4 2.765 10-11 11-12 ll-12 5,3(1) 12,4(1) 8.9 5,020 11-12 12-13 8. 4(1) 12-13 12-13
Appendix P. Comparison of inlstantaneous growth rates of largemouth bass, bluegills and pumpkinseeds (Brown Lake} of various age groups in all lakes between 1988 and pre-regulation (1979-1981} y~ars, with at-test (Zar 1974; p.105}. The asterisk(*) indicates a significant diffelrence at the O. 05 level of significance; t values computed from values in appendices o, s.
Largemouth Bass
----------------------~-----------------------------------------------
AGES BEULAH
df t
INSTANTANEOUS GROWTH RATES
ROCKLAND df t
PRETTY df t
BROWNS df t
----------------------·-----------------------------------------------1-2 4 0.585 2-3 4 1.106 3-4 4 3.953* 4-5 4 2.773 5-6 4 0.073 6-7 2 3.561 7-8
BEULAH AGES df t
4 -0.531 3 0.750 4 -1.616 3 0.538 4 -1.194 3 1.685 4 2.683 3 0.324 4 5.124* 3 2.970
2 2.276
LENGTH INCREMENT
ROCKLAND df t
PRETTY df t
3 1.123 4 -0.398 4 0.344 4 5.057* 4 4.744* 4 4.306* 3 2.496
BROWNS df t
----------------------------------------------------------------------1-2 4 -1.743 4 0.235 3 1.045 3 0.758 2-3 4 -0.255 4 -1.827 3 -0.031 4 -1.064 3-4 4 1.825 4 -0.863 3 1.270 4 -1.173 4-5 4 2.292 4 2.263 3 -0.606 4 3.190* 5-6 4 -0.177 4 3.057* 3 0.312 4 5.180* 6-7 2 1.344 2 2.085 4 3.669* 7-8 3 2.699
..... Q)
0
BEULAH AGES df t
Appendix P. (continued)
Bluegills
INSTANTANEOUS GROWTH RATES
ROCKLAND df t
PRETTY df t
BROWNS df t
----------------------------------------------------------------------1-2 3 1.499 4 1.550 3 9.279* 3 0.658 2-3 4 0,344 4 0.266 3 2.334 3 1.325 3-4 4 -1.025 4 2.044 3 1.610 4 -2.404 4-5 4 0.239 4 0.382 3 4.614* 4 -1.208 5-6 4 2.110 4 -0.076 3 2.166 3 0.212 6-7 3 1.929 3 6.491* 7-8
-----------------------~----------------------------------------------
BEULAH AGES df t
LENGTH INCREMENT
ROCKLAND df t
PRETTY df t
BROWNS df t
-----------------------~----------------------------------------------1-2 3 2.008 4 2.074 3 0.721 3 0.686 2-3 4 -0.886 4 0.339 3 0.909 3 1.325 3-4 4 -1.567 4 0.284 3 0.408 4 0.703 4-5 4 -0.067 4 -0.065 3 3.089 4 0.030 5-6 4 2.009 4 0.333 3 1.390 3 1.461 6-7 3 2.708 3 4.427* 7-8
-----------------------·----------------------------------------------
I-'
O'l I-'
162
Appendix P. (continued)
Pumpkinseeds
INSTANTANEOUS LENGTH GROWTH RATE INCREMENT
------------- ----------AGES df t df t ----- ------------- -------------1-2 3 3.488* 3 2.219 2-3 ----- -----3-4 3 0.405 3 3.243* 4-5 4 -0.178 4 1.934 5-6 3 -1.395 3 0.436
163
Appendix Q. Total length (mm) at age of largemouth bass and bluegills in the four study lakes, and pumpkinseeds (Browns Lake) for 1979-1981, 1982-1985, and 1988 (1988-1989 for Browns Lake) time periods; and tlie southeastern Wisconsin average (Druckenmiller 1972). 1980-1982 and 1983-1985 data from Prendergast (1984) and Mayers (1988) respectively.
------------------------ -----------------------------------------------------------------AGE
SPECIES LAKE PERIOD 1 2 3 4 5 6 7 8 9 10 11 12 13 -----------------------------------------------------------------------------------------------------LARGENOUTH BEULAH 1979-1981 104 172 227 285 319 371 418 415 395 386 567 BASS 1982-1985 94 156 211 253 292 35S 39S 443 4S7 470 438
1988 80 143 206 256 30S 355 414
ROCKLAND 1979-1981 102 171 227 282 3S5 396 448 457 457 491 509 470 1982-1985 91 163 225 280 324 375 411 463 466 519 494
1988 88 162 23S 282 338 427 443 459 534
PRETTY 1979-1981 86 145 215 271 359 398 437 531 1982-1985 69 134 205 244 280 315 378 390 369 462 490
1987 84 145 200 236 293 327 379 464 403
BROWNS 1979-1981 76 166 230 289 370 398 417 437 498 513 1982-1985 70 113 202 251 337 390 425 438 453 457 466
1988 71 151 212 236 309 354 375 418 450 474
S.E. WIS. AVERAGE 198 217 267 351 363 409 439 419
BLUEGILL BEULAH 1979-1981 75 96 121 141 159 167 171 175 178 181 174 1982-1985 67 94 120 145 165 174 184 185 194
1988 29 64 90 116 140 159 176 187
ROCKLAND 1979-1981 45 77 108 137 153 171 174 178 171 175 172 1982-1985 54 72 IOI 134 165 173 187 204 200
1988 41 67 97 139 170 184
PRETTY 1979-1981 6S 86 104 128 143 159 163 165 1982-1985 44 61 79 99 125 142 159 167 173 185
1987 36 54 73 93 121 146 159 171
BROWNS 1979-1981 55 80 99 102 113 130 150 166 188 1982-1985 53 79 100 121 132 146 155 156 173 161
1988 45 71 94 117 133 148 163
S.E. IIIS. AVERAGE 119 137 157 183 193 203 224
PUNPKINSEED BROWNS 1979-1981 66 79 93 100 119 128 134 119 1982-1985 80 102 122 133 143 154
1988 41 67 95 125 149 163
S.E. WIS. AVERAGE 117 127 142 155 163
Appendix R. Back calculated total lengths (mm) of largemouth bass in some lakes.
---------------------------------~---------------------------------------------------------------
1 2 3 4 5 6
ANNULUS
7 8 9 10 11 12 13 -----------------·---------------~---------------------------------------------------------------Wisconsin, Browns Lake
Mraz and Threinin (1957)
Wisconsin, Long Lake(l988) Scheirer (1988)
Wisconsin, Lake Mendota Bennet (1937)
Wisconsin, Average of means from
91 170 229 272 305 345 411 452 467 478 498 521 511
53 155 243 310 357 392 416 48 476
114 246 320 366 396 437 460 478 480 503 518
drainage and seepage lakes. 77 159 232 305 318 376 423 Snow (1969)
HI, WI, MN, SD, mean carlander (1972)
94 184 255 294 336 364 390 414 443
I Appendix s. Instantaneous grtwth {G) and length increments {mm) of bluegills in the study lakes, and pumpk'nseeds (Browns Lake). Values determined from · last two annuli on scales for all years except 1986, in which the first and sec~nd annuli from the scale edge wee used. Number in parenthesis represents sample size for inst~ntaneous growth and length increments.
-------------------------------------------------------~-------· ----------------------------------------------------------------------------------------------BEULAH Bluegills
------------------------------------------------------------,·--------------------------------------------------------------------------------------------------INSTANTANEOUS GROWTH RATES =-========================
SPRING 1980 - SPRING 1982 fALL 1982 - fALL 1985 fALL 1986 - fALL 1988 ----------------------------------------------- --------------------------------------------------------- ------------------------------------------------
YEAR or GROWTH NEAN SD YEAR or GROWTH tfEAN SD YEAR or GROWTH !NEAN SD -------------------------- ----~----------------------------- ---------------------------
AGES 1979 1980 1981 AGES 1982 1983 1984 1985 AGES 1986 1987 1988 ------------------------------------------------ ---------~---------------------------------------------- ----------------------------------~-------------1-2 2.134 1,486 1,810 0.458 1-2 1.335 0.565 1.870 1.257 0,656 1-2 2,51 2.30 2.15 2.32 o. 18 2-3 1.255 1.362 1.344 1.320 0.057 2-3 1~141 0.474 1,326 1,347 1.072 0,409 2-3 1,32 1.50 o. 12 l.35 0.14 3-4 0,826 0.930 0.946 0,901 0,065 3-4 0;190 0.347 0,843 0,960 0.733 0.268 3-4 0.93 0.79 0.79 0,84 0.08 4-5 0.509 0.669 0,719 0,632 o. 110 4-5 0J644 0,313 0,604 0.547 0.527 o. 148 4-5 0.73 0.61 0.61 0,65 0.07 5-6 0,205 0,410 0,440 0.352 0, 128 5-6 0,427 0.220 0.366 0,392 0,351 0.091 5-6 0.58 0.56 0.45 0.53 0,07 6-7 0,231 0.214 0.361 0.269 0.080 6-7 0.311 0.172 0,250 0.200 0.233 0.061 6-7 0.44 0.35 0,39 0.06 7-8 0.132 o. 168 0,312 0.204 0.095 7-8 0;250 0.090 0,231 0, 170 0,185 0,072 7-8 0.17 0,17 8-9 0.123 0.125 0,124 0.001 8-9 0,089 0.137 o. 113 0.034 8-9 9-10 0.149 o. 103 0, 126 0,033 9-10 0.038 0, 116 0.077 0.055 9-10 10-11 0.058 0.120 0,089 0.044 10-11 10-11 11-12 0,134 0,134 11-12 11-12
LENGTH INCRENENTS
--=--------=-----l-2 29.3(1) 26. 7(7) 28.0 1.838 1-2 26.1~5) 15,9(2) 29.9(8) 24,0 7.240 1-2 29.3(23) 33.1(7) 31, 9(16) 31,5 I, 96 2-3 28.2(24) 33,2(13) 33.6(9) 31, 7 3.009 2-3 29.1(62) 16,8(22) 29.3(21) 35.6(3) 27.7 7.869 2-3 27,9(20) 32,1(23) 29.4(36) i9.8 2, ll 3-4 25,4(23) 31,0(28) 29,5(27) 28,6 2.899 3-4 23.0(142) 14,3(75) 27,2(48) 33. 7(9) 24.6 8.128 3-4 26,8(44) 23.2(20) 26.4(14) 25,5 1, 93 4-5 19.2(24) 26,9(30) 29.1(23) 25,1 5.198 4-5 25.4(~1) 14,4(38) 25,1(64) 22.7(22) 21,9 5,140 4-5 27,1(50) 22.4(44) 25.2(74) 24,9 2,37 5-6 8.8(6) 19.2(31) 20,3(22) 16,1 6.346 5-6 17,8(~7) 10.9(43) 17,9(88) 19,2(27) 16,5 3,755 5-6 24.8(23) 25.1(50) 21,5(31) 23,8 l, 98 6-7 11.5(11) 10.5(18) 17.9(4) 13.3 4.015 6-7 12.3( 3) 9,2(14) 13,7(19) 11,4(2) 11,7 I.BBB 6-7 27.3(1) 21,9(23) 18.6(5) 22,6 4.39 7-8 6.1(9) 8,6(15) 16.8(10) 10.5 5,597 7-8 12.0(4) 5.1(3) 13,2(5) 10,3(7) 10.2 3.571 7-8 10.0(1) 10,0 8-9 6.0(3) 6. 7(10) 6.4 0.495 8-9 4,8(3) 7,5(2) 6,2 1,909 8-9 9-10 7.9(3) 5.6(9) 6,8 l,626 9-10 2.1( l) 7.6(1) 4.9 3,889 9-10 10-11 3,4(1) 6. 7(10) 5,1 2,333 10-11 10-11 11-12 6. 7(1) 6,7 11-12 11-12
I-' er, Ul
Appendix s. (continued)
Bluegills
ROCKLAND -----------------------------------------------------------------------------------------------------------------------------------------------~---------------
INSTANTANEOUS &ROUTH RATES ========~=================
SPRIN6 1980 - SPRING 1982 FALL 1'82 - FALL 1985 FALL 1986 - FALL 1988 ------------------------------------------------ --------------------------------------------------------- ------------------------------------------------
YEAR or &ROUTH ltEAN SD YEAR OF &ROUTH KEAN SD YEAR OF GROWTH KEAN so --------------------------- -~---------------------------------- --------------------------
AGES 1979 1980 1981 AGES 1982 1983 1984 1985 AGES 1986 1987 1988 -------- -------------------------------- --------------------------------------------------------- ------------------------------------------------1-2 1.760 1,532 2,107 l,800 0.290 1-2 1. 998 1. 966 1,653 1.652 1,342 o. 191 1-2 2.52 1. 91 2.10 2, 18 0.31 2-3 l.305 1.096 2.133 l.5ll 0.548 2-3 1,682 1,107 1.365 1.312 1,367 0,238 2-3 1,82 1,46 1,51 1,60 0,19 3-4 0.990 0.929 0.697 0.872 0.155 3-4 1,325 0,882 0.971 1,038 1,054 0.192 3-4 1.41 1.02 1.10 1.18 0.21 4-5 0,090 0.531 0.961 0,527 0,435 4-5 0,818 0.502 0,652 0.674 0.662 0.129 4-5 0,81 0.48 0,61 0.63 o. 17 5-6 0.589 0,510 0.538 0.546 0.040 5-6 0.460 0,266 0,336 0,262 0,331 0,092 5-6 0,47 0.47 0.69 0.54 0.13 6-7 0.332 0.259 0.301 0.297 0.037 6-7 0.345 0,250 0.137 0,244 0.104 6-7 0.29 0.29 7-8 0, 160 0,196 o. 178 0.025 7-8 0,324 0,324 7-8 8-, 0.300 0.196 0.248 0.074 8-9 0.243 0.243 8-9 CHO 0.169 0,169 9-10 CHO 10-tl 0.150 0.150 10-tl 10-11
LENGTH INCRENENTS =================
1-2 29.8(15) 26.1(23) 2',2(42) 28.4 1. 986 1-2 2,.5(44) 31.8(35) 28.4(55) 26.0(10) 28.9 2.410 1-2 33.6(20) 30.3(22) 30.8(30) 31.6 1. 75 2-3 29.9(39) 31.5(43) 43.8(38) 35.1 7.605 2-3 37.3(101)27.8(60) 32.3(37) 34.4(32) 33.0 3.999 2-3 40.8(46) 34.7(20) 34.8(42) 36.7 3.51 3-4 32,2(11) 36.2(75) 50.1(14) 39.5 9.395 3-4 41.2(67) 32,6(102)31.9(58) 35,8(21) 35.4 4.238 3-4 51.9(9) 34.4(46) 38.6(27) 41.7 9.15 4-5 31.7(26) 24.6(15) 38.2(9) 31.5 6,802 4-5 30.9(36) 25.0(55) 29.1(95) 28.6(19) 28.4 2.473 4-5 33.6(7) 23,1(9) 28.1 (6) 28.3 5.25 5-6 24.2(8) 27.6(30) 23.0(2) 2.9 2.386 5-6 2~.3(5) 16. 2(7) 16.9(8) 12.9(25) 16.6 3.035 5-6 21. 5(2) 23,3(7) 34.0(4) 26.3 6,71 6-7 15.3(12) 14.8(10) 15.5(2) 15.2 0.361 6-7 1Q.9C2) 14. 7(1) 7.4(3) tl.O 3.651 6-7 15.0(2) 15.0 7-8 7.8(2) 11,1(11) 9,5 2.333 7-8 12,0(4) 12,0 7-8 8-9 13.4(1) 11 .1(6) 12.3 1,626 B-9 9.6(1) 9.6 8-9 9-10 9,3(2) 9.3 9-10 9-10 10-ll 8,6(1) 8.6 10-11 10-11
..... °' °'
Appendix s. (continued)
Bluegills
----------------------------------------------------------~---------------------------------------------------------------------------------------------------PRETTY
INSTANTANEOUS &RIIIITH RATES ==========================
SPRING 1980 - SPRING 1982 FALL 1982 - FALL 1985 FALL 1986 - FALL 1988 --------- ------------------------------- --------------------------------------------------------- ------------------------------------------------
YEAR OF GROWTH NEAN SD YEAR OF GROWTH NEAN SD YEAR or GROWTH NEAN SD
--------------------------- ------------------------------------ ---------------------------AGES 1979 1980 1981 AGES 1982 1983 1984 1985 AGES 1986 1987 1988 ------------------------------------------------ --------~------------------------------------------------ ---------------------------------·--------------l-2 l.155 l.284 1.159 l.199 0.073 1-2 l.553 1.420 t.154 1,267 1.349 0.175 1-2 1.70 1.64 l.67 0.04 ..... 2-3 1.034 0.829 0.948 0.937 o. 103 2-3 0.835 2-3 1.13 l .37 1.25 0.17
O'l t.295 0.897 1.141 1.042 0.214 -..]
3-4 0.890 0.826 0.694 0.803 o. 100 3-4 l.008 0.672 0.745 t.088 0.878 0.201 3-4 0.88 1.02 0.95 0.10 4-S 0.720 0.734 0.540 0.665 0.108 4-5 0.772 0.590 0.577 0.890 0.707 0.151 4-S 0.95 0.97 0.96 0.02 S-6 0.450 0.602 0.531 0.529 0.074 5-6 ~.727 0.516 0.370 0.569 0.546 0.147 5-6 0.61 0.67 0.64 0.04 6-7 0.399 0.329 0.316 0.348 0.045 6-7 0.586 0.431 0.366 0.554 0.484 0.103 6-7 0.53 0.56 0.54 0.02 7-8 0.270 o. 199 0.235 0.050 7-8 0.319 0.254 0.295 0.289 0.033 7-8 8-9 0.164 0.164 8-9 o. 150 0.159 0.187 0.165 0.019 8-9 9-10 9-10 o. 136 0.136 9-10
LENGTH INCRENENTS =================
1-2 18.6(11) 20.7(2) 18.9(2) 19.4 , • 136 1-2 19.5(15) 24.4(6) 18.5(4) 24.4(2) 21.7 3.144 1-2 19.4(99) 20.9(24) 20. 1 1.09 2-3 21.1(34) 18.0(12) 19.8(10) 19.6 t.557 2-3 21.*(39) 18.1(42) 18.5(34) 24.4(22) 20.6 2.920 2-3 19.5(25} 24.5(9) 22.0 3.56 3-4 24.3(12) 23.0(61) 16.9(20) 21 .4 3.951 3-4 20.,(30) 19.8(49) 20.4(57) 29.1(9) 22.6 4.390 3-4 20.8(39) 24.4(25) 22,6 2,51 4-5 23.9(25) 25.5(38) 17.6(37) 22.3 4. 177 4-5 18.7(43) ,21.5(35) 21.7(55) 29.3(27) 22.8 4.545 4-5 29.4(19) 30.4(39) 29.9 0.71 5-6 16.8(12) 24.0(38) 20.0(15} 20.3 3.607 S-6 20,5(88) 21,4(44) 16.0(26) 22.4(25) 20,l 2.825 S-6 22.3(10) 26.2(19) 24.3 2.75 6-7 17.7(23) 14.2(17) 13.4(3) IS.I 2.287 6-7 20.3(6) 20.9(46) 17.6(31) 26.0(13) 21.2 3.507 6-7 21.9(4) 24. 3( 10) 23. 1 1.74 7-8 13.2(3) 8.9(10) 11, I 3.041 7-8 17.1(5) 13.3(22) 14.7(11) 15.0 1. 922 7-8 8-9 8.3(5) 8.3 8-9 7.6(2) 8.5(2) 10.0(8) 8.7 1. 212 8-9 9-10 9-10 7.8(2) 7.8 9-10
Appendix s. (continued) Bluegills
--------------------------------------------------------------/------------------------------------------------------------------------------------------------BROWNS
--------------------------------------------------------~------------------------------------------------------------------------------------------------------INSTANTANEOUS GROWTH RATES ==========================
SPRING 1980 - SPRING 1982 FALL 1982 - fALL 1985 FALL 1986 - FALL 1988 ------------------------------------------------ --------------------------------------------------------- ------------------------------------------------
YEAR Of GROWTH "EAN SD YEAR Of GROWTH ~AN SD YEAR or GROWTH KEAN SD --------------------------- ------------------------------------ ---------------------------
AGES 1979 1980 1981 AGES 1982 1983 1984 1985 AGES 1986 1987 1988 ------------------------------------------------ --------------------------------------------------------- ------------------------------------------------1-2 1,437 2.135 1.786 0.494 1-2 1. 924 1,657 1.819 1,833 1.808 o.111 1-2 2.33 2.31 1.56 2.07 0.44 2-3 0.818 0.782 0.800 0.025 2-3 0.944 0,772 0.698 0.580 0.749 0,152 2-3 0.89 0.98 o. 781 0.88 0.10 ......
°' 3-4 0.573 0.638 0.659 0.623 0.045 3-4 0.710 0.552 0.483 0.513 0.565 0.101 3-4 0.56 0.55 0.56 0.56 0.01 CX)
4-5 0.597 0.461 0.455 0.504 0.080 4-5 0.656 0.407 0.339 0,360 0.441 0.146 4-5 0.32 0.42 0,51 0.42 0.09 5-6 0.306 0.362 0.448 0.372 0.072 5-6 0.610 0.444 0,263 0.248 0.391 0.171 5-6 0,34 0.43 0.39 0.06 6-7 0.213 0.251 0.422 0.295 0.111 6-7 0.493 0.359 0,214 0.240 0.327 0.128 6-7 0.19 0.19 7-8 0.187 0.500 0.344 0.221 7-8 0.369 0.295 0.230 0,298 0.070 7-8 8-9 0.142 0.142 8-9 0.120 0.120 8-9 9-10 9-10 0.171 0.171 9-10
LENGTH INCRE"ENTS =================
1-2 28. 1(4) 33.6( 12) 30.9 3,889 1-2 30.8(52) 35.5(56) 33.7(31) 34.8(2) 33,7 2,070 1-2 35.2(47) 37,1(38) 28.3(53) 33.5 4,62 2-3 21,6(2) 16,7(24) 19.2 3.465 2-3 20.1(33) 23.5(31) 20.2(66) 14.9(11) 19.7 3,554 2-3 22.8(34) 23,8(47) 21.1(45) 22.6 I .28 3-4 15.5(22) 18.5(1) 18. 2(13) 17.4 1,652 3-4 17,6(40) 20.2(34) 17.8(29) 17.2(37) 18,2 1.356 3-4 17.6(35) 17.5(34) 19.5(26) 18.2 1.12 4-5 20.5(30) 13,2(43) 13.6(7) 15.8 4.104 4-5 18.4(29) 16,5(31) 14.5(17) 13.7(10) 15.8 2.109 4-5 12,1(10) 15,4(35) 20,2(34) 15.9 4.12 5-6 11.3(10) 12.8(62) 14.5(21) 12,9 1.601 5-6 20.7(28) 19.5(21) 11.7(25) 10.7(8) 15.7 5.178 5-6 14.3(10) 19.2(21) 16.8 3.50 6-7 9.4(5) 10.3(26) 14.5(7) 11.4 2.722 6-7 16.0(13) 17.9(11) 10,1(6) 11.1(10) 13.8 3.770 6-7 9.8(2) 9.8 7-8 8.5(12) 23. 7(1) 16.1 10,748 7-8 19.9(4) 14.2(11) 10.3(5) 14,8 4,828 7-8 8-9 7.6(6) 7.6 8-9 9. 2(1) 6,2(2) 7.7 2.121 8-9 9-10 . 9-10 8. 9( 1 > 8,9 9-10
Appendix S. (continued)
Pumpkinseeds
--------------------------------------------------------------------------------------------------------------·------------------------------------------------BROWNS
--------------------------------------------------------------------------------------------------------------------------------------------------------------INSTANTANEOUS GROWTH RATES --------=-------------=---
SPRING 1980 - SPRING 1982 FALL 1982 - FALL 1985 FALL 1986 - FALL 1988 ------------------------------------------------ --------------------------------------------------------- ------------------------------------------------
YEAR or 6ROIITH MEAN SD YEAR Of GROIITH MEAN SD YEAR or GROWTH MEAN SD
-------------------------- ------------------------------------ --------------------------- I-'
AGES 1979 1980 1981 AGES 1982 1983 1984 1985 AGES 1986 1987 1988 O'l I.O
------------------------------------------------ -------·------------------------------------------------- ------------------------------------------------1-2 1.556 l.480 1,518 0.054 1-2 1,217 1,290 1,454 3,219 1,795 0.954 1-2 I, 99 2.24 1. 78 2,00 0.23 2-3 0,841 0.841 2-3 0,906 0,801 0,751 1.118 0.894 0.163 2-3 0.99 1.08 1.00 1.02 0.05 3-4 0,772 0,653 o. 713 0.084 3-4 0,721 0.582 0,509 0,702 0.629 0.101 3-4 0,65 0,71 0.89 0.75 0.12 4-5 0,782 0.530 0.625 0.646 0.127 4-5 0.519 0.450 0.405 0.630 0.501 0,098 4-5 0.65 0.53 0.71 0,63 0,09 5-6 0,363 0,440 o.~ 0,397 0.039 5-6 0,381 0.522 0,622 0.508 0.121 5-6 0.29 0.37 0.33 0.06 6-7 0.384 0,252 0.318 0.093 6-7 0,280 0,280 6-7 7-8 o.~3 0,293 7-8 7-8 8-9 8-9 8-9
LENGTH INCRENENTS =================
1-2 26. 7(1) 24. 9( 18) 25.8 1,273 1-2 21;9(23) 24.7(8) 27.9(23) 46.4(1) 30,2 11.058 1-2 32,8(27) 38,1(32) 27.6(27) 32,8 5.26 2-3 17,4(24) 17.4 2-3 22.2(55) 21,3(41) 19,7(37) 29,4(4) 23,2 4,293 2-3 25.0(13) 27.5(27) 23.7(37) 25.4 1.95 3-4 17,2(16) 15,9(8) 16.6 0.'19 3-4 1915(43) 20.1(47) 17,1(68) 21.1(8) 19,5 1,700 3-4 20.9(18) 22.8(13) 28,1(34) 23.9 3.75 4-5 20.2(36) 16.3(22) 19.1(17) 18,5 2.011 4-5 15.15(9) 16.3(19) 15.6(27) 19.1(11) 16,6 1.688 4-5 22.3(2) 20.1(18) 27,5(20) 23.3 3.80 5-6 10,9(17) 14.5(25) 13.3(6) 12.9 l.833 5-6 12.3(7) 19.9(5) 21,7(8) 18.0 4,989 5-6 11,6(2) 16,6(2) 14.1 3.59 6-7 9. 7(1) 9,2(11) 9.5 0.354 6-7 9.10(3) 9.0 6-7 7-8 9.9(2) 9,CJ 7-8 7-8 8-9 8-9 8-9
170
Appendix T. Comparison of instantaneous growth rates and length increments of pumpkinseeds of various age groups in Browns Lake from 1979 to 1988. F values computed from values in appendix s, (Steel and Torrie 1960). +=positively significant, - = negatively significant, and o = not significant at the 0.05 level of significance.
AGES
1-2 2-3 3-4 4-5 5-6 6-7 7-8 8-9 9-10
AGES
1-2 2-3 l-4 4-5 5-6 6-7 7-8 8-9 9-10
-INSTANTANEOUS GROWTH
BROWNS df F SLOPE
1,7 2.19 0 1,6 4.08 0 1,7 0.32 0 1,8 0.01 0 1,6 0.01 0 1,1 0.59 0
LENGTH INCREMENT
BROWNS df F SLOPE
1,7 2.45 0 1,6 4.88 0 1,7 14.98 ... 1,8 4.18 0 1,6 0.83 0 1,1 4.69 0
0.06 0
171
Appendix u. Comparison between length at age in 1988 of largemouth be bluegills, and pumpkinseeds (Browns Lake), with the southeast Wiscons: average (Druckenmiller 1972) with a paired t-test (Zar 1974; p.lll). Afl statistical.: -ce-sts were at tne 0.05 level of significance. Where significant changes occurred, the southeast Wisconsin average had the larger value.
SPECIES LAKE
LARGEMOUTH BEULAH BASS ROCKLAND
PRETTY BROWNS
BLUEGILLS BEULAH ROCKLAND PRETTY BROWNS
PUHPKINSEED BROWNS
CALCULATED t
6.08 1.65 3.80 4.86
10.40 4.90
16.92 28.14
4.17
d.f. AGES SIGNIFICANT
6 1-7 yes 7 1-8 no 7 1-8 yes 7 1-8 yes
6 1-7 yes 5 1-6 yes 6 1-7 yes 6 1-7 yes
4 1-5 yes
Appendix V. Back calculated total lengths (mm) of bluegills in some lakes.
-------------------------~---------------------------------------------------
Wisconsin, Lake Wazeecha Wolff (1974)
Wisconsin, Long Lake(1988) Schelrer (1988)
Wisconsin, Lake Mendota El-Shany (1976)
1
44
26
43
Wisconsin, Average of means from drainage and seepage lakes. 38
Snow (1969)
HI, WI, MN, SD, mean 45 carlander (1972)
2 3 4
ANNULUS
5 6 7
76 109 138 175 195 219
8
57 92 135 169 192 218 218
95 135 163 181
79 109 142 165 183 201 203
86 115 145 164 180 191 201
9
173
Appendix w. Number of largemouth bass, bluegills and pumpkinseeds (Browns Lake) in each age class from 1980-1982, 1983-1985, and 1988 (1988-1989 in Browns Lake) from spring electrofishing samples, and the regression equations used for the catch curves shown in figures 38-41.
LARGEMOUTH BASS
LAKE PERIOD
BEULAH a 1980-1982b 1983-1985b 1988
1 2 3 4
2 192 198 69 4 109 206 112 0 102 47 30
ROCKLAND 1980-1982b 20 389 420 127 1983-1985b 4 206 208 66 1988 2 124 70 37
PRETTY
BROWNS
1980-1982b 1983-1985b 1988
3. 76 180 6 52 120 3 28 26
1980-1982b 4 1983-198Sb 24 1988-1989 184
10 105 15 27
189 141
37 74 34
107 37 98
5
18 38 38
17 48 26
20 44 18
84 45 49
AGE CLASS 6 7 8
6 14
9
7 19
3
3· 23 10
55 29 28
0 9 3
6 10
6
2 7 4
15 34 22
1 3 0
2 4
1 6 1
8 23
9
9
1 0 1
3
0 1
1 8
11
10
1 2
6
1
6
1
4
2
BEULAH 1980-1982b
1983-1985b 1988
Y = 8.30 - 1.05X, for ages 3-8, Yhere X ls age class and Y 1s Ln abundance of the age class.
ROCKLAND 1980-1982b 1983-1985b 1988
PRETTY 1980-1982b 1983-1985b 1988
BROWNS 1980-1982b 1983-1985b 1988-1989
Y = 7.74 - 0.80X, for ages 3-8. Y = 6.19 - 0.72X, for ages 2-8.
Y • 8.80 - l.OSX, for ages 3-8. Y = 7.48 - 0.75X, for age~ 3-8. Y = 6.78 - o.e~x, for ages 2-6.
Y = 8.02 - 1.0SX, for ages 3-8. Y = 6.86 - 0.65X, for ages 3-8. Y = 7.62 - 0.90X, for ages 4-8.
Y = 10.20 - l.08X, for ages 5-9. Y = 6.98 - 0.55X, for ages 5-12. Y = 6.72 - 0.51X, for ages 3-9.
a One was added to these values used in the catch curve. b Mayers 1988
12
1
1
174
Appendix w. (continued)
--------------------------------------------------------------------------------BLUEGILLS
--------------------------------------------------------------------------------AGE CLASS
1 2 3 4 5 6 7 8 9 10 ];1 12 LAKE PERIOD --------------------------------------------------------------------------------BEULAH 1980-1982b 0 9 51 121 120 71 31 41 9 5 4
1983-1985b 0 6 98 243 188 104 27 6 5 1 1988 0 8 25 22 49 55 25 1
ROCKLANDa 1980-1982b 4 116 340 110 66 24 20 4 1 1983-1985b 7 150 358 255 134 2 0 2 1 1988 0 41 38 87 17 13 4
PRETTY 1980-1982b 0 25 368 320 359 75 33 5 1 1983-1985b 1 55 140 356 359 232 65 16 2 1988 3 66 25 69 107 52 28 11
BROWNS 1980-1982b 2 16 125 201 402 176 62 5 1983-1985b 3 233 329 203 79 32 11 1 1988-1989 33 213 216 141 162 73 5
BEULAH 1980-1982b y = 7.84 - 0.60X, for ages 5-11. 1983-1985b y = 9.80 - 0.95X, for ages 4-10. 1988 y = 13.93 - 1.62X, for ages 6-8.
ROCKLAND 1980-1982b y = 8.21 - 0.81X, for ages 3-9. 1983-19--SSb y = 9-. 0-4 - 1.-8-S-:X, f-or ages 3-9. 1988 y = 7.45 - 0.96X, for ages 4-7.
PRETTY 1980-1982b y = 13.19 - 1. 45X, for ages 5-9. 1983-1985b y = 12.93 - l.30X, for ages 5-9. 1988 y = 7.42 - 0.75X, for ages 5-8.
BROWNS 1980-1982b y = 13.46 - l.42X, for ages 5-8. 1983-1985b y = 9.63 - 1.l0X, for ages 3-8. 1988-1989 y = 7.55 - 0.83X, for ages 3-7.
a One was added to these values used in the catch curve. b Mayers 1988
Appendix w. (continued)
------------------------------------------------------------------------------~-PUMPKINSEED'
AGE CLASS 1 2 3 4 5 6 7 8 9 10 11 12
LAKE PERIOD ----------------------------~---------------------------------------------------BROWNS
BROWNS
1980-1982b 0 1983-1985b 0 1988-1989 0
1980-1982b 1983-1985b 1988-1989
b Mayers 1988
19 34 44 117 9~ 158 160 6 86 93 68 55
68 5 6
10 3
Y = 11.49 - 1.29X, for ages 5-8. Y = 9.06 - 1.21X, for ages 4-7. Y = 7.09 - 0.8SX, for ages 3-6.
3
f--'
...J lJ1
Appendix x. Estimated population density (number/hectare) of largemouth bass from electrofishing in spring in Rockland Lake, 1980 - 1989, and results of regression analysis of est~mated population density versus time. ''No" indicates not significant at the 0.05 level of significance.
-------------------------------------------------------------------------------------YEAR
1980 1981 1982 1983 1984 1985 1986 1987 1988 F VALUE SIGNIFICANT
POPULATION ESTIMATE 77 46 39 38 38 38 36 31 44 4.38 NO (NO/ HA) ------------------------------------------------------------------------------~------
Appendix Y. Results of regression analysis from spring electrofishing samples of largemouth bass and bluegills in the four study lakes. "Pro." and "Unpro." indicates protected and unprotected size largemouth bass respectively. +=positively significant, - = negatively significant, and o = not significant at the 0.05 level of significance. Duplicate of relative abundance and mean length by electrofishing tests in table 20.
nEASURES
LARSEnOUTH BASS
SPRIN6 ELECTROFISHIN6
BEULAH LAKE )30511 All
KEAN LENSTH 0 0 NUKBER/HOUR •
BlUESILLS
SPRIN6 ELECTROFISHINS KEAN LENSTH NUNBER/HOUR
0 ♦
ROCKLAND LAKE )30511 All
0
• 0
0 0
PRETTY LAKE PRO UNPRO All
0 0 0
0 0
BROWNS LAKE PRO UNPRO ALL
0 0 0
0