Efficts of ANGLING on a PREVIGUSLY FISHED and an UNFISHED WARMWATEH. FI:3H COMMUNITY in TWO Small LAKES in CENTRAL WISCONSIN

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EFFiCTS OF ANGLING ON A PREVIGUSLY FISHED AND AN UNFISHED WARMWATEH. FI:3H COMMUNITY IN TWO SMAll LAKES IN CENTRAL WISCONSIN

Larry E. Goedde

Wisconsin Cooperative Fishery Research Unit

A ~rhesis submitted in partial fulfillment of the requirements for the degree MASTER OF SCIENCE

Co~lege of Natural Hesources

UNIVERSITY OF 'fJI0CUNJIN Stevens Point, Wisconsin

May, 1980 APPROVED BY THE GRADUATE COMMITTEE OF:

Dr. Daniel W. Coble, Committee Chairman Professor of Fisheries

Or. enry E. Booke Profe sor of Fisheries

~ Dr. John Heaton Professor of Fisheries

i i Abstract

Population structure and other vital statistics were determined for warmwater fish populations in two adjacent lakes in central Wisconsin for two successive 3-year per iods. Allen Lake (7.8 ha) containing bluegill (Lepomis

macrochirus), pumpkinseed (Lepomis gibbosus), ye~low perch

(Perea flavescens), and largemouth bass (Micropterus ~ moides) was open to angling during, and for years before this investigation. Mid Lake (4.7 ha), with the same spe

cies plus northern pike (Esox lucius~ was closed to angling for 20 years before angling was permitted at the beginning of the second .3-year period. Before angling in I"iid Lake a large proportion of the populations was large, old fish, and total annual mortality rates, which were natural mor tality rates, were low. The exploited populations in Allen

~ake were mainly composed of small or intermediate size fish throughout the study. After angling in IV!id lake the fish populations and their vital statistics became like those in Allen Lake: length and age frequency distributions shifted to smaller sizes, population density and standing stocks decreased for larger fish ana increased for smaller fish, mean age and life spans decreased, mortality rates increased, and proportional stuck density generally declined from val ues above to values below recommended ranges. The changes

iii in population structure were most pronounced for yellow perch followed in order by pumpkinseed, bluegill, large mouth bass, and northern pike. Estimated fishing effort was 83 hrs/ha in May 1976, tht= first month that Nid La.ke was opened to anglj,.ng, and it was 36 hrs/ha ir.. IVlay l9'f9. Estimated exploitation rates in May 1976 for fish of sizes acceptable to anglers were 86, 74, 35, 53, anci 46%, respec tively for the species just mentioned, and most of those caught were taken in the first two days. Growth rates in r•:id lake did not change within the period of this study, but bluegill in Allen Lake were growing slowly or "stunted.tt 1Uectrofishing provided more representative samples of lengths and ages of 1·ish present than fyke nets, hoop nets, or fish traps.

iv ACKNOWJ.ELGEMF.NTS

I wish to thank the Wisconsin Cooperative l''ishery He search Unit for the funds and equipment that made this study possible. I thank the Wisconsin Department of Natural Resources for their permission to conduct the study. I express my sincere thanks to my advisor and com mittee chairman, Dr. Daniel Coble, for· his patient guidance throughout the study and for his critical editing of this manuscript. I also wish to thank committee members Dr. Henry Booke, :Vr. Fred Copes, and Dr. Jack Heaton for their advice and review of the manuscript. I am indebted to the many students who helped in the collection of data during the six years of this investiga tion. I also appreciate the efforts uf Chris Hoe and Carol McGee in typing this manuscript. I want to give special thar.ks to my parents for their love and support, and to a close friend, Spring Brooks, for her encouragement and friendship.

v TABLE OF CONTENTS

ABSTRACT . . .. i i i ACKNOWLEDGEMENTS v

LIST OF TABLES . v i i LIST OF FIGURES xi

LIST OF APPENDICES X i i i INTRODUCTION .. 1 Study Area

MATERIALS AND METHODS 4 Sampling Methods 4 Age Frequency . . . . . 6 Proportional Stock Density 7 Creel Survey ...... 8 Population Estimates .. . 1 2 Mortality and Exploitation Rates 1 3 Length-Weight Relationships . 1 3 Growth ..... 14

RESULTS AND DISCUSSION ..... 1 5

Gear Selectivity ..... 1 5 Age-Frequency Distributions 23 Length-Frequency Distributions 32 Proportional Stock Density 39 Creel Survey ...... 46 Fishing Pressure and Harvest 46 Angler Characteristics .. . 55 Population Estimates ...... 57 Mortality and Exploitation Rates 62 Length-Weight Relationships 71 Growth 74 Conclusions . 78 LITERATURE CITED 80 APPENDICES 87

vi LIST OF TABLES

Table 1. Fish sampling methods and effort in 1974 through 1979 at Mid and Allen Lakes . . . 5 Table 2. Minimum length (mm) of stock and quality size fish used to calculate PSD indices for each species ...... 7 Table 3. Common and scientific names of species caught by electrofishing, fyke nets, hoop nets, fish traps and angling ...... 16 Table 4. Age-frequency distributions (%) and mean length (mm) at each age of largemouth bass from Mid Lake before (1974-75-76) and after (1977-78) angling, and for Allen Lake for the same years. N is the sample size for each period ...... 24 Table 5. Age-frequency distributions (%) and mean lengths (mm) at each age of yellow perch from Mid Lake before (1974-75-76) and after (1977-78 and 1977-78-79) angling, and for Allen Lake for the 1974-75-76 and 1977-78 periods. N is the sample size for each period ...... 26 Table 6. Age-frequency distributions (%) and mean lengths (mm) at each age of pumpkinseed from Mid Lake before (1974-75-76) and after (1977-78) angling, and for Allen Lake for the same years. N is the sample size for each period ...... 27 Table 7. Age-frequency distributions (%) and mean lengths (mm) at each age of bluegill from Mid Lake before (1974-75-76) and after (1977-78) angling, and for Allen Lake for the same years. N is the sample size for each period ...... 29 Table 8. Mean ages (from APPENDIX G) of largemouth bass, yellow perch, pumpkinseed, and blue gill in Mid Lake before (1974-75-76) and after (1977-78) angling, and in Allen Lake for the same years (Ricker 1975: 32) ...... 30 vii ------~------

LIST OF TABLES (continued)

Table '9. Mean 1 ength (mm) and percentages of large, intermediate, and small bluegill, pumpkinseed, yellow perch, largemouth bass, and northern pike in electrofishing samples from Mid and Allen Lakes . . 39 Table 10. Proportional Steck Density (PSD) indices (%) for Mid Lake species before and after angler exploitation ...... 41 Table 11. Proportional Stock Density (PSD) indices (%) for Allen Lake species subjected to angler exploitation in every year . . . 43 Table 12. Estimated fishing pressure (angler hours) and harvest (number of fish) at Mid Lake for the first month of the fishing sea son in 1976 and 1979. Data from APPEN DICES J and K. Catch per hour of angling is given in parentheses ...... 51 Table 13. Opening weekend and first month angling effort for lakes of various areas. All lakes are in Wisconsin except for Mill and Third Sister Lakes, Michigan . . . . 53 Table 14. Mean length (mm) plus or minus one stan dard deviation for each species measured by the creel clerk in 1976 and 1979. The number measured is in parentheses 55 Tilble 15. Number of anglers traveling various dis tances (km) to Mid Lake in 1976 and 1979. Distance in miles and percent of anglers in each range is given in parentheses ...... 57 Table 16. Percent of anglers using various baits. Totals for each year do not equal 100% because some anglers used more than one kind of bait ...... 57

vii i LIST OF TABLES (continued)

Table 17. Estimated number and standing stock in May 1976 and 1979 of Mid Lake blue gill, pumpkinseed, yellow perch, and largemouth bass larger than 99 mm and northern pike larger than 299 mm and for all five species larger than the mlnl mum lengths observed in the 1976 creel survey ...... 58 Table 18. Total annual mortality (A), survival (S), and instantaneous mortality (Z) rates for each species in Mid Lake be fore (1974-75-76) and after (1977-78) angling and in Allen Lake for correspond ing periods and for the entire period from 1974 through 1978. r is the cor relation coefficient from catch curve regressions (Ricker 1975) ...... 63 Table 19. Total annual mortality rate(%) for var ious species in the absence of fishing or predicted (Snow 1978) if fishing were absent ...... 64 Table 20. Exploitation rates (%) for Mid Lake species for the opening weekend in 1976 and for the month of May in 1979. The minimum length for which exploitation rates were calculated is given in parentheses for each species . . . . . 67 Table 21. Exploitation rates at the opening of new or previously unfished lakes for Mid Lake species. Angling effort is given in hours per hectare and period surveyed is in parentheses ...... 68 Table 22. Length-weight relationships and correla tion coefficients (4) for bluegill, pump kinseed, yellow perch, and largemouth bass from Mid and Allen Lakes, and nor thern pike from Mid Lake. Mid Lake 1974 and 76 samples represent unexploited populations, all remaining samples represent exploited populations ...... 72 ix LIST OF TABLES (continued)

Table 23. Instantaneous growth rates for pumpkin seed, bluegill, yellow perch, and large mouth bass from Mid Lake before (1974- 75-76) and after (1977-78) angling and from Allen Lake (Ricker 1975: 217) . . 75 Table 24. Length increments (mm) between ages for pumpkinseed, bluegill, yellow perch, and largemouth bass from Mid and Allen Lakes. Mid Lake 1974-75-76 represents unexploited populations; the remaining samples represent exploited populations (APPENDIX N) • • • • • • • • • • • • • 76

X LIST OF FIGURES

Figure 1. Length-frequency distributions of blue gill and pumpkinseed in fyke net, fish trap, and electrofishing samples in 1978 and 1979 from Mid Lake. . . . . 18 Figure 2. Length-frequency distributions of blue gill and pumpkinseed in fyke net and electrofishing samples in 1976, 78, and 79 from Mid Lake ...... 19 Figure 3. Length-frequency distributions of yel low perch in fyke net and electrofishing samples in 1976, 78, and 79 from Mid Lake ...... 20 Figure 4. Length-frequency distributions of nor thern pike in fyke net and electrofish ing samples in 1976, 78, and 79 from Mid Lake ...... 21 Figure 5. Length-frequency distributions of pump kinseed from Mid Lake before (1974-75- 76) and after (1977-78-79) angling, and from Allen Lake for the same periods 33 Figure 6. Length-frequency distributions of blue gill from Mid Lake before (1974-75-76) and after (1977-78-79) angling, and from Allen Lake for the same periods 34 Figure 7. Length-frequency distributions of yel low perch from Mid Lake before (1974-75- 76) and after (1977-78-79} angling, and from Allen Lake for the same periods 35 Figure 8. Length-frequency distributions" of largemouth bass from Mid Lake before (1974- 75-76) and after (1977-78-79} angling, and from Allen Lake for the same periods ...... 3 6 Figure 9. Length-frequency distributions of northern pike from Mid Lake before (1974-75-76) and after (1977-78-79} angling . . . . 37

xi LIST OF FIGURES (continued)

Figure 10. Tic-tac-toe graphs showing yearly trends in weighted prey and preda tor PSD's for Mid and Allen Lakes. Predator PSD's were weighted for Mid Lake largemouth bass and nor thern pike, but for Allen Lake, the predator PSD is for largemouth bass only. Data from APPENDICES Il and I2 ...... 45 Figure 11. Observed angling effort (hrs) for days surveyed in May 1976 and 1979 at Mid Lake. Circled points repre sent 16-hour surveys, all other points represent 8-hour surveys . . . . . 47 Figure 12. Number of each species in the observed harvest for days surveyed in May 1976 at Mid Lake. Circled points represent 16-hour surveys, all other points represent 8-hour surveys ...... 48 Figure 13. Number of each species in the observed harvest for days surveyed in May 1979 at Mid Lake. Circled points represent 16-hour surveys, all other points represent 8-hour surveys ...... 49

xii LIST OF APPENDICES

APPENDIX A. Wisconsin Department of Natural Re sources lake survey map showing Allen, Mid, and Hartman Lakes all within the boundries of Hartman Creek State Park ...... 87 APPENDIX B. Composition of water samples repre senting Mid and Allen Lakes. Sam ples were taken on October 16 and December 6, 1979 from the ground water table which fills Allen Lake, the outflow of Allen Lake, and at the inflow and outflow of Mid Lake. Methods of analysis are given in APHA (1975) ...... 88 APPENDIX C. Aquatic macrophytes found in Mid and Allen Lakes in June 1978 . . 89 APPENDIX D. Weighted predator and prey PSD's computed from estimates of population size and from the number of stock size fish caught in electrofishing samples as weighting factors in 1976 and 1979 ...... 90 APPENDIX E. Estimated catch per unit effort (CUE) by anglers during unsurveyed per iods on opening weekend in 1976...... 91 APPENDIX F. Mean length (mm) + standard devia tion (S.D.), sample size in paren theses, and range of lengths of fishes caught in Mid Lake in 1976, 78, and 79 in fyke net, hoop net, fish trap, and electrofishing samples, and by angling . . . . 92 APPENDIX G. Calculation of mean age in unex ploited populations of Mid Lake and in exploited populations of Mid and Allen Lakes (Ricker 1975: 32). 95

X i i i LIST OF APPENDICES (continued)

APPENDIX H. Length-frequency distributions of pumpkinseed, bluegill, yellow perch, largemouth bass, and nor thern pike in Mid Lake electrofish ing samples in 1974, 75, and 76 be fore angling and in 1977, 78, and 79 after angling, and for the same years for exploited populations in Allen Lake. n is the number caught ad justed to a standardized effort of 4 circuits of the lake ...... 101 APPENDIX I. Mid and Allen Lpke prey and Mid Lake predator PSD's (%) weighted by the number of stock-sized fish caught for each species in electrofishing samples (From APPENDIX D) . . . . 110 APPENDIX J. Estimated effort and harvest of blue gill, pumpkinseed, yellow perch, largemouth bass, and northern pike in the opening weekend and for the remainder of May 1976 at Mid Lake ...... · . 112 APPENDIX K. Estimated effort and harvest of blue gill, pumpkinseed, yellow perch, and largemouth bass in the opening week end and for the remainder of May 1979 at Mid Lake ...... 118 APPENDIX L. Estimates {%) of total annual mortal ity (A), annual expectation of death by natural causes (v), and annual exploitation rates (u) for large mouth bass, northern pike, bluegill, pumpkinseed, and yellow perch from several lakes in several locations ...... 123 APPENDIX M. Back-calculated lengths for pumpkin seed, bluegill, yellow perch, and largemouth bass in Mid and Allen Lakes in the 1974-75-76 and 1977-78 periods ...... 124 xiv LIST OF APPENDICES (continued)

APPENDIX N. Length increments compared among samples with a paired t-test (Zar 1974: 121). Table values oft are at 0.05 level of significance ...... 140 APPENDIX 0. Instantaneous rates of growth (G) compared among samples with a paired t-test (Zar 1974: 121). Table values of t are at 0.05 level of significance . . . . 141 APPENDIX P. Mean total length (mm) at each age for pumpkinseed, bluegill, yellow perch, and largemouth bass from Midland Allen Lakes and the His- consin state average (Snow 1960) 142

XV l.

INTRODUCTION

Knowl.edge of the effects of angling on warmwater fish populations is essential. for successful management of ex ploited warmwater fish communities. Objectives of this study in two smal.l lakes in central Wisconsin were to de scribe vital statistics of unexpl.oiteci fish populations in Mid lake (4.7 ha) in 1974, 75, and 76; to document changes in the populations after they were subjected to angl.ing in 1977, 78, and 79; and to compare the fish populations with those in adjacent Allen Lake (7.8 ha), which had been ex ploited for many years. The vital. statistics were age and length-frequency distributions, yearly trends in population and community structure measured by proportional stock density indicies (Anderson 1976), population density and standing stock estimates, total. annual mortality anci exploitation rates, length-weight relationships, anci growth rates.

Study Area Allen lake and. Mid _;__ake are the upper two of thi·ee adjacent man-made impoundments at the source of Hartman Creek, in Waupaca County, Wisconsin (APPENDIX A). The impoundments were constructed in the early 1900's by George All.en,Sr., as private hatchery ponds. Mr. Al.l.en 1.ost the hatchery in 19)5 as a result of the depression (G. Al.l.en, 2

Jr. , Stevens Point, Wisconsin, personal communication). The lakes were used by the state hatchery system for fish culture from 1938 through l955 (D. Czeskleba, roreman of Wild Hdse Yish Hatchery, Wisconsin Lepartment of Natural Hesources, personal communication). After 1955 the .lakes became part of the Hartman Creek Hecreation Area, anci in

1966, Hartman Creek ~tate Park (r"l. lang, Superintendent,

Hartman Creek State Park, Wisconsin Department of ~atural Hesources, personal communication). With the opening of the park in 1966, Allen iake, the

uppermost lake, was opened to ang~ing for panfish only, and in 1972 it was opened to angling i'or all species. Mid Le.ke remained closed to all public fishing until May l,

1976, when anglers were permitted to harvest ?.ny species (M. Primising, Assistant Area Fish fl'1anager, Wautoma, Wisconsin, Wisconsin Department of Natural hesources, per sonal communication). Harvest regulations, from the time angling was permitted, were daily bag limits of 5 each for

northern pike (~ lucius) and largemouth bass (Microp terus salmoides) and 50 panfish in aggregate, which in cluded yellow perch (Perea flavescens), bluegill (Lepomis macrochirus), pu..'llpkinseed (::,epomis gibbosus), and green sunfish (lepomis cyanellus), and a closed season for large mouth bass and northern pike from March l until the first Saturday in 1'-'iay. 3

Water quality and physical characteristics of Mid and Allen }akes were similar (APPENDIX B). Water flows from Allen lake to l'Hd Lake over a distance of 487 m. Both lakes had hardwater (Hem 1975) with potential for high pro ductivity based on total alkalinity Uloy.le 1946). Naximum depths were l. 8 m in Mid Lake and 2. '{ 11m for Allen l,ake. ' The ~ater was clear allowing light penetration to the bot- tom and submergent plants were abunuant throughout both lakes. By late spring aquatic macrophytes (APPENDIX C) made fishing from the shoreline difficult. 4

i"IA'rERIAlS Al-iD ME'fHGD3

Sa.mpling Nethods A variety of methods was used to capture fish

(T~ble 1). A 230 vo~t DC and AC electroshocker was fished at night in spring, 1974 through 1979; AC was used on three occasions when the DC unit malfunctioned. Al.L samples were collected in April or May, with the exception of 1978's June sample which was delayed because of equipment prob lems. Fyke nets of 5 em stretched mesh and leads varying from 12.2 to 18.3 m long were fished in 1976, 78, and 79. In 1978 hoop nets of 5 em stretched mesh with a 30.5 m

~ead, and two ~5.2 m wings were set with wings at approxi mately 45° angles to the lead. Hectangular fish traps 119 X 61 X 51 em covered with 6 or 13 mm mesh hardware cloth with an opening 7.6 em ~n diameter were a..Lso used in 1978 and 1979. Captured fish were measured (mm), weighed (g), fin clipped, scale samples were collected, and fish released. Fish were measured every year and weighed in 1974, 76, 77, and 78 in both lakes. Scale samples were taken from rHd and Allen lake bluegi~l, pumpkinseed, yellow perch, large mouth bass, and northen1 pike in 1974 through 1978 and from yellow perch in l'iid lake in 1979. Fish larger than 100 mm (northern pike longer than 300 mm) were marked in both 5

TABLE 1. Fish sampling methods and effort in 1974 through 1979 at Mid and Allen Lakes. Dates Mid lake Dates Allen Lake sampled crear Effort sampled Gear Effort DC DC May 21, electi·o- 4 May 21, electro- 3.5 22, 1974 shocker circuits 22, 1974 shocker circuits DC DC; f"~ay 21, electro- 4 May 21, electro- 4 22, 1975 shocker circuits 22, 1975 shocker circuits AC AC May 16, 17, electro- 6 April 13, electro- 2.5 18, 1976 shocker circuits 1976 shocker circuits April 7-15, 6 fyke 997 1976 nets net hrs May 1-30, creel 40 hrs 1976 survey per week DC DC May 19, electro 2 Lay 23, electro- 1.5 1977 shocker circuits 1977 shocker circuits June 12, AC electro- 2 June 5, DC electro- 2 1978 shocker circuits 1978 shocker circuits June 19- 3 fyke 270 23, 1978 nets net hrs 2 hoop 180 nets net hrs 2 fish 182 traps trap hrs May l, 3, DC electro- 3 May 4, DC electro- l 1979 shocker circuits 1979 shocker circuits .bpri1 23- 6 fyke 858 29, 1979 nets net hrs 5 fish '/12 traps trap hrs Nay 5-30, creel 40 hrs 19'19 survey per week 6 lakes in 1974 and '"/5, and in Mid lake in 1976, 78, and 79 with an upper caudal fin clip, before release.

Age Frequency Age-frequency distributions were determinea frow length-frequency distributions accoruing to the ratio of each age found in each centimeter length interval. A stra tified random sample of fish scales from each centimeter length interval was aged for all species except northern pike. Scales from 10 fish were ranaomly chosen for one centimeter length classes with the stipulation that one fish for each millimeter would be selected when available. Cleaned scales were mounted between glass slides for small fish, and impressions were made for scales of large fish on heated (40°C) cellulose acetate slides. ScaJ.es or impressions were p:t·ojected at a magnification of 40X. Annuli were recognized by, l) spacing of circuli, 2) a clear zone devoid of circuli, and 3) cutting over or marked disruptions of circuli (Burress 1949; Regier J.962; Bagenal and Tesch 1978). Scales were read at least twice or until I felt confident with two consecutive identical readings. Subsamples of scales that I aged were checked by two experienced scale readers to confirm my aging. 7

Proportional Stock Density I used the proportionaL stock density index (PSD) of Anderson (1976) to evaluate population and community structure. PSD was defined as the percent of "quality-size" fish found in a "stock." Stock and quality-size were defined by Anderson (1976) for bluegill anti J_argemouth bass and Anderson and Weithman (1978) for yellow perch and northern pike (Table 2). For pumpkinseed I used the values for stock and quality size that Anderson gave for bluegill. Anderson ana Weithman (1978) suggested that in diverse com munities a prey and predator PSD could be calculated by weighting PSD's of each species by their relative abun dance, and that community structure could be evaluated by

plotting prey PSD against the predator P~D on a tic-tac- toe graph.

TABLE 2. Minimum length (mm) of stock and quality size fish used to calculate PSD indicies for each species.

Species Stock :Length Quality length

Bluegi..1.l 76 150 Pumpkinseed 76 150 Yellow perch 130 200

~ orthern pike 350 530

Largemouth bass 200 300 8

I calculated a weighted prey and predator PSD by two methods using the formula from Snedecor and Cochran (1974) for a weighted mean,

where Pw was the weighted mean prey or predator PSD, P was the PSD for each prey or predator species, anu \'! was the weighting factor. }'or the first method I used population estimates when they were available from fVlid i.ake popula tions in 1976 and 1979 as weighting factors. Because population estimates were not calculated for Nid lake in 1974, 75, 77, or 78 nor ever in Allen l.ake, 1 also used the num ber of stock-sized fish in electrofishing samples (an estimate of relative abundance of each species) a.s a weighting factor. PSD's weighted by population estimates and by reJ.ative abundance in electrofishing catches were similar (APPENDIX D ) •

Creel Survey A creel survey was conauctea on Mid Lake for the first month of the fi~hing season in 1916, May l through May 30, and in 1979, f-!ey 5 through i"lay 30. Categories of angling, shore and boat, were stratified into weekend, including holidays, AM (0600-1400 hrs) and PM (1400-2200 hrs) periods and weekday AM and PM periods (Green 1972; Kmiecik 1980). All weekends and holidays and 3 weekdays were censused so 9

that 40 hrs/week were surveyed. Periods were randomly sel ected with the restric·tions that morning and afternoon periods of the same day were not surveyed, and no weekday was missed for more than two consecutive weeks. A 16-hour survey was conducted on the last day, ivJay 30, 1976, and on opening day r·lay 5, 1979.

The creel clerk, stationed at a point where he cou~d

view the entire lake, interviewed ang~ers at the completion of their trip or at the end of a morning pe.r·iodo Informa tion collected included: moue of fishing (boat or shore), number in party, distance traveled, length of trip, bait used, species sought (in order of preference), and number of each species of fish caught and released. 1'/hen allowed by anglers, fish were examined for fin clips, and lengths were recorded; all anglers were cooperative. Shore anglers, number of boats, and anglers per boat could be seen at once from the vantage point on the lake and were counted hourly. Total shore and boat angling ef fort were estimated from the sum of hourly instantaneous counts for each morning e.nd afternoon period. The first instantaneous morning count was weighted with information from interviews to include effort expended by anglers be fore 0600 hrs, which occurred only on a few occasions. Angling after 2200 was never observed; most anglers left before 2100 hrs. Estimated harvest for each surveyed AN 10 or PM period was the product of catch per effort from inter views and total effort from instantaneous counts 0Jeuhold and Lu 1957). Estimated effort and harvest for opening weekend in

1979, and the remainder of ~1ay in 1976 and 1979, were de termined from estimated effort and. harvest for surveyed periods described above. The number of angler hours or fish harvested by shore or boat anglers were averaged for the month, or for opening weekend, and multiplied by the number of possible periods that could have been surveyed (Jesien

1977; P~iecik 1980). This method assumes reasonably uni form daily effort and harvest, which occurred in 1979, and after opening weekend in 1976. The pattern of effort and harvest were irregular, but fairly uniform, and due to the random nature of the creel survey, estimates should not have been biased. :Fishing effort and harvest were not uniform on the opening weekend in 1976, and estimates based on assumed uniformity would have been biased and inaccurate. In 1976 the AM period was surveyed on the opening day (Saturday) and the PM period on the second day (Sunday). Throughout the survey it was apparent that more effort was spent on Saturday in the AM period and more effort on Sunaay in the PM period. Effort and harvest were high on opening morn ing, then they markedly decreased. Kmiecik (1980) found ll a similar opening weekend pattern on Sunset lake, Wisconsin, and he showed from a complete survey that estimates assuming uniform effort and harvest were biased. Therefore, I adjusted my estimates for effort ano harvest for the 1976 openinf weekend to eliminate the bias. Sffort and harvest for the unsurveyed period on each day was estimated from the period surveyed on that day. To estimate effort I used the ratio of the mean observed PlVi effort to the mean observed AM effort for all Saturdays surveyed, anu the ratio of the mean observed AM effort to the mean observed PM effort for all Sundi:l.ys surveyed in r•lay 1976. :2;stimated effort for an unsurveyed period on openin,'~ weekend was the product of the appropriate ratio and the observed effort from instantaneous counts, for the period surveyed that day (APPENDIX Jl). To estimate harvest in unsurveyed per iods, I multiplied the catch per unit effort (CU~) for un surveyed perious by the estimated effort in unsurveyed perious, which were calculated as explained above. CU~ for unsurveyed periods was estimated by multiplying the ratio of CUE observed in surveyed periods to population estimates at the beginning of the surveyed periou, by the estimated population size at the begimJing of an unsurveyed period (APi'El•IJ:.IX E). Confidence intervals were calculated for estimates of 12

effort and harvest in 1976 and 1979, for the month, exclud ing opening weekend, accordlng to Cochran (1963) as de scribed by Green (1972). The confidence intervals were calculated for shore and boat categories in AM and PM per iods, and for the sum of those categories.

Population Estimates Population estimates were calculated for 1976 and 1979 for fishes: 1) larger than the smallest size marked, and 2) larger than the minimum length kept by anglers. Although fishes were marked and examined for marks in several years, population estimates could be calculated on~y in 1976 and 1979 when extra effort, mainly fyke nets, was expended to catch fish. In other years estimates would have been biased because the number of marked fish (M) times the number examined for marks (C) was less than four times the population estimate (N), and there were less than four recaptures for each species (Hobson and Regier 1964; Ricker 1975). For fishes larger than the minimum length kept by ang~ers, in 1976, popu~ation size was esti mated from Chapman's modification of the Petersen Formula

(Ricker ~975: eouation 3.7); the fish were caught for marking by electrofishing and fyke netting, and recaptured by angling and examined for marks by the creel clerk. Chapman's modification of the Schnable Formula (Ricker - 13

1975: equation 3.17) was used to estimate all other population sizes because angling was not an efficient means of

I recapture, either because fish smaller than the size acceptable to anglers were marked (1976 and 1979) or too few marked fish were caught (larger fish in 1979).

Mortality and Exploitation Rates Annual mortality (A, Z) and survival {S) rates were calculated from catch curves {LUcker 1975: 33; Robson and Chapman 1961). In Mid Lake, before angling, annual mortal ity equaled natural mortality. Exploitation rates for spe cies in Mid Lake were estimated by dividing estimated har vests by population estimates {Ricker l975).

Length-Weight Relationships Both functional and predictive least squares regres sions of length-weight relationships were calculated for each species. Ricker (1973) stated that GM functional regressions are more accurate than traditional predictive regressions for describing length-weight relations. I calculated both because predictive regressions have been used extensively in the past, and some statisticians have not accepted Licker's recommendation of functional regressions (Jolicoeur 1975; Ellison and Rosenberger 1979). Analysis of covariance with adjusted mean intercepts (Li 1969: 393) 14 and Student's t-test (Zar 1974: 228) were used to test dif ferences among least squares regressions and the t-test was used to compare slopes of functional regressions.

Growth Instantaneous true growth rates, G, were computed from functional length-weight relations and back-calculated lengths (Ricker 1975: 207). Lengths were back-calculated :from a functional regression of total length on anterior scale radius (Humphreys 1978: 6).

/ 15

RESULTS AND DISCUSSI0ll

Gear Selectivity Electrofishing produced more species (Table 3), yielded greater numbers of each species (APPENDIX F), and broader size ranges than any other gear (Figures 1 and 2). Four teen species ~ere collected by electrofishing. The yellow bullhead (2 individuals) was the only species found that did not appear in electrofishing samples; electrofishing was the only gear effective in.catching largemouth bass, other than angling (APPLNDIX G). ;:)anderson (1960), Boc cardy and Cooper (1965), and Reynolds and Simpson (1978) found electrofishing to be nearly as efficient in determin ing species composition as rotenone samples. Fish traps were effective for small bluegill and pump kinseed, but did not capture larger panfish (Figure 1). Fyke nets anc hoop nets caught fish of similar sizes

(APPEl~ IIX F2), were more selective for larger panfish than electrofishing (Figures 1, 2, anci 3), and seemed to provide represer;.tative samples of northern pike (F'igure 4). J.ngling selected larger panfish and gamefish (APPELLICES Fl e..nd F3). The relatively greater catches of large panfish in the fyke nets compareti with the electroshocker couid be caused by: 1, lower vu~nerability of small than large panfish to fyke nets, or 2, lower vulnerability of the large panfish 16

TABLE 3. Comiilon and scientific names of species caught by electrofishing, fyke nets, hoop nets, fish traps, and angling.

Gear Common Name Scientific Name

Electrofishing Bluegill lepomis macrochirus Pumpkinseed Lepomis gibbosus Green sunfisha Lepomis cyanellus largemouth bass ~·opterus salmoides Yellow perch Perea flavescens Northern pik~ Esox lucius Tiger muskie E80i lucius Esox -maBguinongy--- White sucker0 Catostomus commersoni Central mudminnow Umbra limi :t'a the ad minnow PimephaleS promelas Golden shiner Notemigonus cr{soleucas Common shiner d Notropis cornu us Blackchin shiner Notropis heterodon Brook stickleback Culaea inconstans Fyke nets Bluegill Lepomis macrochirus Pumpkinseed c ~epomis gibbosu~ :i..argemouth bass Micropterus salmoides Yellow perch Perea flavescens Northern pik~ Esox lucius Tiger muskie Esoi lucius Esox -miSguinongy--- Yellow bullheaaf Ictaluris na.talis Hoop nets Blueg1ll Lepomis macrochirus Pumpkinseed f Lepomis g1. bbosus largemouth bass Micropterus sa~moides Yellow perch Perea flavescens Northern pike Esox lucius 17

TABLE 3 (continued)

Gear Common I arne !::>c ientific 1·: arne

Fish traps Bluegill ~epomis macrochirus Pumpkinseed lepomis gibbosus largemouth bassf Micropterus salmoides Yellow perch e Perea flavescens Northern pike Esox lucius Golden shinerf d NOtemigonus crysoleucas Brook stick~eback Culaea inconstans Angling Bluegill iepomis macrochirus Pumpkinseed f Lepomis gibbosus Green sunfish Lepomis cyanellus largemouth bass Micropterus salmoides Northern pike ~ lucius aRepresented by 20 individuals. bRepresented by 3 individuals. c~epresented by 4 inaividuals. dRepresented by 10 individuals. eRepresented by 5 individuals. fRepresented by 2 individuals. 18

Fyke nets ~ Pumpkinseed N = 138 ~ Bluegill N = 397

Fish traps I '- (J) ..n mJ Pumpkinseed N =368 E f1J Bluegill N = 527 z:::>

Electrofishing ~ Pumpkinseed N = 525 ~ Bluegill N = 869

50 100 150 200 250 Total length (mm)

FIG URE l. l ength-frequency distributions of b1uegill and pumpkinseed in fyke net, fish trap, and electrofishing samples in l9'f8 and 1979 from Mid :.ake. 19

Fyke nets

&:i Bluegill N =747 60 W1 Pumpkinseed N =276

'- 20 Q) ..0 § 100 z Electrofishing

60 ~ Bluegill N = 1137

40 ~ Pumpkinseed N =663

25 50 75 100 125 150 175 200 225 250 275 Total length (mm)

F·IGURE 2. Length-frequency distributions of bluegill ana pumpkinseed in fyke net ana electrofishing samples in 197 6, 78, and 79 from I'1i d lake. 20

Yellow perch Electrofishing N = 175 20

70 L... Cl) ...0 60 Yellow perch E :::> Fyke nets N =390 z 50

100 150 200 250 300 350 Total length (mm) fiGURE 3. Length-frequency distributions of yellow perch in fyke net and electrofishing samples in 1976, 78, and 79 from Mid Lake. 21

25 Northern pike 20 Fyke nets N = 173 15

~ (1) 5 _Q E z:::> Northern pike Electrofishing N = 128

100 200 300 400 500 600 700 800 900 Total length (mm)

FIGURE 4. Length-frequency distributions of northern pike in fyke net and electrofishing samples in 1976, 78, ru1d 79 from Mid lake. 22

to electroshocking. Reynolds and Simpson (1978) thought that larger bluegill may inhabit deeper water making them less vulnerable to electrofishing. Although that may have occurred in this study, both fyke nettine and electrofish ing were conducted in shal.low water. Moreover, the larger members of the two other panfishes, pumpkinseed and yell.ow perch, also were more vulnerable to tyke nets. I consider the electrofishing samples to be most representative of the size structure of the fish populations in this study be cause: 1, electrofishing catches contained sizes of pan fish covering the entire length ranges of fishes caught in traps and fyke nets (Figures 1, 2, and 3), and 2, elec trofishing is generally considered to be more, not less, efficient for l.arge than smaller fishes, especially l.arge mouth bass (Sullivan 1956; heynolds and Simpson 1978). Because of the reasons given above and because electro fishing was the only gear used in ~llen Lake, comparison of fish populations-in the remainder of this thesis (ex cept for creel surveys and population estimates) are based on electrofishing data. In subsequent sections I conclude on the basis of electrofishing data that angling reduced the number of larger a.nd older panfish. fw'lore large panfish were also caught in fyke nets before than after angling. If electrofishing underestimated the proportion of larger pan- 23 fish, that conclusion would be conservative because the greater bias would have occurred when larger panfish were most abundant, i.e., before angling.

Comparison of Age Frequency Distributions: 1974 through 1978 Angling influenced the age structure of largemouth bass, yellow perch, pumpkinseed, and bluegill populath.~ns. Age frequency distributions, mean age, and length of life indicated that unfished populations were older than angler- exploited populations. Populations subjected to angling had lower percentages of older fish, lower mean ages, and shorter life spans. Age frequency distributions of unexploited and exploit ed largemouth bass populations were dissimilar whereas age frequencies were similar among exploited populations (Table 4). Before angling, 51% of the largemouth bass electrofishing catch from Mid Lake was older than age 4 compared with 16, 11, and 13·~ older than age 4 in exploited populations of l':id :Lake in 1977-78 and Allen :0ake in 1974- 75-76 and 1977-78, respectively. The decrease of largemouth bass older than age 4 probably resulted from angling; large mouth reached the minimum length taken by anglers, 270 mm from my observations in the creel survey, between ages 3 and 4. TABLE 4. Age-frequency distributions (%) and mean .J.ength (mm) at each age of largemouth bass from Mid Lake before (1974-75-76) and after (1977-78) angling, and for Allen lake for the same years. h is the sample size for each period.

Lake A~e Years 1 2 3 4 b 7 8 9 IO N

Mid 1974-75-76 17.7 8.6 10.8 11.8 14.5 21.0 14.5 1.1 186 length 80 157 216 370 345 352 380 453 Mid 1977-78 9.1 40.0 27.3 8.0 9.1 3.7 2.3 1.1 88 Length 78 168 255 321 337 367 401 Allen 1974-75-76 l.) 50.8 23.7 13.7 4.2 5.0 1.1 0.3 380 length 86 154 216 273 316 352 393 443 Allen 1977-78 4.1 52.1 19.8 11.6 5.8 3.3 1.7 0.8 0.8 121 Length 84 198 268 269 )25 577 432 467 458 ------,

The un~xploited yellow perch population had a high

percentage of perch o~der than age 5, that was not found in exploited populations. In Mid Lake electrofishing samples before angling, 46% of the yellow perch were older than age 5 (Table 5). Kelso and ward (1977) found 28% in the unexploited yellow perch population of west Blue Lake, Manitoba to be older than age 5. Angling seemed to remove nearly all of these older yellow perch. No yellow perch older than age 5 were found in Hid Lake samples after angling and only two perch beyond age 5 were caught in Allen Lake from 1974 through 1978. Eshenroder (1977) aiso found a disappearance of yellow perch older than age 5 in

~aginaw Bay, Lake Michigan, which he attributed to an in tense commercial and sport fishery. Older ana larger pumpkinseed seeilled to be highly sus ceptible to angling. Age frequency distributions declined sharply in exploited populations at ages with mean lengths corresponding to 150 mm; the minimum length kept by most anglers (Table 6). Pumpkinseed reached a length of 150 mm by age 4 in Mid lake. Before angling, 37% of the pumpkin seed in Mid Lake samples were between ages 4 through 10. After exploitation, no pumpkinseed older than age 5 and

only 8)6 of ages 4 and 5, were found in Mid Lake sa:aples. In Allen Lake 22 and 23% of the pumpkinseed in 1974-75-76 TABLE 5. Age-frequency distrj_butions ('f-.) and mean lengths (mm) at each a}e of yel~ow perch from Mid lake before (1974-75-76) and after (1977-78 ana. 197'1-78-79 angling, and for Allen Lake for the same years. l';'• is the sample size for each perioa.

A~e Lake Years ~ 2 3 4 b 7 8 9 10 N

Mid 1974-75-76 0.5 23.4 3.9 10.7 15.6 23.4 17.6 4.9 0.5 0.5 205 Length 79 128 170 208 250 278 292 303 327 320 Mid 1977-78 9.1 63.6 4.6 9.1 13.6 22 length 120 143 220 226 265 Mid 1977-78-79 1.9 b).l 26.2 6.8 1.9 103 iength 101 130 190 2J.O 262 Allen 1974-75-'(6 2.9 53.2 15.2 27.7 o.y o.o 0.2 553 Length 93 123 157 165 200 260 Allen 1977-78 6.7 1).3 33.5 22.2 24.4 45 length 87 160 189 209 219 TABLE 6. Age-frequency distributions (%) and mean length (mm) at each age of pumpkinseed from Mid lake before (1974~75-76) and after (1977-78) angling, and for Allen lake for the same years. N is the sample size for each period.

Age Lake Years l 2 3 4 5 b 7 s 9 I~ N

Mid 1974-75-76 17.4 24.1 21.2 11.5 9.7 10.7 1.9 2.7 0.3 0.5 373 Length 49 81 119 165 193 201 212 207 230 248 Mid 1977-78 5.4 59.5 26.8 8.1 0.2 410 length 53 74 120 150 170 Allen 1974-75-76 1.6 22.8 53.6 20.8 1.1 0.1 858 Length 47 71 115 132 142 180 Allen 1977-78 0.7 33.0 43.3 16.6 6.1 0.2 427 Length 49 76 91 130 145 180 28

and 1977-78 samples, respectively, were of ages 4 and 5; however, pumpkinseed did not reach a .Length of .L50 rnm until after age 5 in Allen Lake at which point the age frequency declined sharply. Patriarche (1960) and Schneider (1973) alRo founu pumpkinseed to be highly vulnerable to angling in loon and Mill Lakes. Although older bluegill in lVlid Lake did not disappear after angling there was a large reduction of those vulner able to anglers (Table 7). Bluegill in Mid Lake reached the minimum length taken by anglers, J..50 mm, between ages 3 and 4, and 40% of the bluegill collected from the unex ploited population were older than age 3. After angling,

only 5% of the bluegill in Mid Lake samples were o~der than age 3. Allen Lake ha.d a higher percentage of bluegill between ages 3 and 6 than the unexploited Nid Lake population, but bluegill younger than age 6 in Allen :_ake were too small to appeal to anglers. Six-year-old bluegill in Allen Lake had a mean length of 158 and 148 mm in 1974-75-76 and 1977-78 compared with 214 and 235 mm in Mid Lake in 1974-75-76 and 1977-78, respectively. The creel survey on Mid Lake indi cated that bluegill smaller than 150 mm were not desirable to most anglers; therefore, bluegill younger than age 6 suf fered little exploitation in Allen Lake. TABLE 7. Age-frequency distributions (%) and mean lengths (mm) at each age of blue- giJ..l from Mid lake before (1974-75-76) ana after (1977-78) angling, and for Allen Lake for the same years. N is the sample size for each period.

A~e Lake Years 1 2 3 4 b 7 8 9 IO N

Mid 1974-75-76 29.7 15.8 15.4 6.4 7.3 10.4 10.0 2.9 1.2 1.0 519 Length 43 83 140 171 191 214 228 234 248 258 Mid 1977-78 7.2 51.5 36.1 3.1 1.0 0.3 0.5 0.3 623 Length 49 82 137 186 213 235 244 261 Allen 1974-75-76 2.3 30.0 30.4 16.8 14.2 3.8 2.0 0.5 0.1 3284 Length 50 67 86 99 133 158 188 195 205 Allen 1977-78 6.6 16.3 3.4 41.3 19.9 12.1 0.3 0.1 1665 Length 46 75 97 98 118 148 171 190

1\) 1..0 30

Change in mean population age was another indication that anglers were removing old.er fish. Mid Lake populations protected from angling in 1974-75-76 had hir,her mean ages than populations subjected to angling (Table 8; APPZNDIX G). In 1977-78, after exploitation, Mid lake populations had mean ages similar to those of Allen :lake populations, and with the exclusion of yellow perch, the mean age of populations in Allen Lake did not change appreciab~y from the 19'(4-75-76 period to the 1977-78 period. Lower mean age in exploited populations was probably due to anglers removing older fish anc not to variation in year class strength. It seems unlikely that the mean ae;e TABlE 8. t'lean ages (from APP:FJ-iDIX G) of largemouth bass, yellow perch, pumpkinseed, ano bluegill in l•Jid l.ake before (1974-75-76) and after (1977-78) angling, and in Allen IJake for the same years (Ricker 1975: 32).

Nean Age Species Lake 1974-7;-76 1977-7S largemouth bass Mid 4.9 3.1 Allen 2.9 2.9 Yellow perch Mid 4.9 2.7 Allen 2.8 3.6 Pumpkinseed Mid 4.5 3.2 Allen 3.3 3.4 Bluegill Jliiid 5.2 3.2 Allen 4.0 4.1 31

-of all four species in f.Jid Lake would decrease because of synchronized variation in year class strength, particularly

when mean ages of populations, except yellow perch, in ad~

j acent Allen l-ake did not change. In addition, effects of variable year class strength were reduced by my pooling data for the three-year period before and the two-year period after fishing. Such pooling of data, however, apparently did not remove the effect of variation in year class strength for yellow perch in Allen lake. The increase in mean age of yellow perch in Allen lake from 2.8 in 1974-75- 76 to 3.6 in 1977-78 was probably caused by one or more strong year. classes passing through the population. Maximum life spans of yellow perch, pumpkinseed, ann bluegill appeared to be reduced appreciably by angling, and the length of life of largemouth bass was reduced to a lesser extent. In the unexploited community, yellow perch, pumpkinseed, .and bluegill were found up to age 10. After fishing, no yellow perch or pumpkinseed older than age 5, and no bluegill older than age 8 were found in Mid Lake s~:ples. Largemouth bass up to age 8 were present in unex ploi ted and exploited l'Ud Lake samples, ana one 9-year old largemouth bass was found in Allen i8ke. The absence of largemouth bass older than age 8 in f'dd Lake in 1974-75-76 may have been due to the removal of unknown numbers of 32

largemouth bass from 1968 through 1973 by management biolo gist for stocking other waters (M. lang; personal communica tion)& Schneider (1971) found 11-year old largemouth bass, and 9-year old panfish in the unexp1oited community of Mill lake, Michigan.

Comparison of length Frequency Listributions: 1974 through 1979 Changes in populations that were evident in the age frequency distributions were also apparent in the length frequency distributions, in which data from an additional year (1979) were obtained. Populations protected from fishing had higher percentages of large fish than those ex ploited by anglers. Length frequency distributions of fvlid Lake pumpkinseed, bluegill, yel.Low perch, and largemouth bass changed after angling into distributions that were similar to exploited Allen Lake populations ( 1-'igures 5, 6, 7, and 8; APPENDIX H). For northern pike intermediate lengths dominated both the unexploited and exploited populations although the mode shifted slightly towards smaller fish~ and northern pike longer than 675 mm dis appeared after exploitation in Mid Lake (Figure 9). Year classes varying in strength and growth could account for these changes in uorthern pike. Previous studies of an unexploited warm water community by Schneider (1971) 33

Pumpkinseed Mid lake - 1974-75-76 N: 373 ---- 1977-78-79 N: 786

•' .•' '' • ' •• ' ' .I \ . ' .• '

50 75 100 125 150 175 200 225 250 Total length (mm)

FIGURE 5. Length-frequency distributions of pumpkinseed from Mid lake before (1974-75-76) and after (1977-78-79) angling, and from Allen Lake for the same periods. 34

12 Bluegill 10 I'\ \ Mid Lake I \ 8 I \ -1974-75-76 N=520 I \ I I ---1977-78-79 N: 1097 6 \ '• 4 ''' -· ,,, .., +-c 2 (J) u 0 '- (J) Bluegill c.. I·~ I 12 I I Aller1Lake I I I I I -1974-75-76 N=3284 10 I I I I ---1977-78-79 N:2382 8 ' 'I 6 '' '' 4 '' 2 '' 0 25 50 75 100 125 150 175 200 225 250 Total Length (mm)

FIGURE 6. length-frequency distributions of bluegill from IV1 id lake before ( 1974-75-76) and after ( 197'1-78-79) angling, and from Allen l-ake for the same periods. 35

I . II Yell ow perch II I I I I Mid Lake I I I I ----1974-75-76 N: 199 I I I I ----1977-78-79 N: 100 I I I I . I H 1 I II 1 I I I 1 I I I I II I I d I I II I I I I I I I I I II I I I I t I \ "E2 (J) ~ (1)14 Yellow perch 0.. Allen Lake. 12 ..' II -1974-75-76 N: 554 I I 10 I I ----1977-78-79 N: 138 I I I II I I I I I I I I I I II I I II I I I I I I I I 1 • II ' 6 I I I I • I 'I I • I I I • I ~ 1 • 4 I II I II ' '•~~ 2 I I ••I 0 100 150 200 250 300 350 TC?~(]I Length (mm)

FIGURE 7. Length-freguency distributions of yellow perch from Mid lake before ll974-75-76) and after (1977-78) angling, and from Allen.Lake for the same periods. 36

Largemouth bass Mid Lake nI -1974-75-76 II I I N:184 I I 8 1 I ----1977-78-79 I I N=137 I I I I I I I 4 I I +-2 c: Q)O u ~ Largemouth bass ~10 Allen Lake -1974-75-76 N:337 8 I II ----1977-78-79 N:128 II

50 100 150 200 250 300 350 400 450 500 550 Total Length (mm)

FIGUKE 8: length-frequency_ distributions_of largemouth bass from I•1id lake before \1974-75-76) ana after (1977- 78-79) angling, and from Allen lake for the same periods. A 1\ Northern Pike· I \ I Mid lake· I I 1974- 75- 76 N 162 .... I ' ,, ---1977- 78- 79 N 198 r:: I \ I \ (I) I \1 \ u I ~ \ I.. I \ (I) I \ 8 I c.. ) \ ~ '\ 6 I /\ I I \ I ' 4 \ I ' .. '\ \. 2 ' ...... ,

375 475 575 675 775 875 Total length (mm) FIGURE 9. Length-frequency distributions of northern pike from Mid Lake before (1974-75-76) and after (1977-78-79) anGling. 38 and of lightly exploited communities by Patriarche (1960) and Clady (1970) also revealed high numbers of large and old fishes. Mean lengths and percentages of large fish, for species found in electrofishing samples from Mid Lake before angling, decreased after angling and were then similar to those found in Allen lake (Table 9). In !'lid I.ake mean length of bluegill, pumpkinseed, yellow perch, largemouth bass, and northern pike decrea,eed by et, 31, 87, 42, ana 22 mm, respectively. Percentages of large fish found in Nid Lake populations decreased by 37, 35, 55, 35, and 20% after angling for the same species, respectively. After exploitation in Mid lake, populations were dominated

by small and intermediate-size fish as in Allen ~ake popula tions.

Proportional Stock Density Anderson (1976) described an inaex for evaluating fish population structure derived from length-frequency distri bution which he called proportional stock density (PSD). PSD was defined as the percentage of "quality-size" fish in

a stock (See Methods ~ection for values of stock and

quality-size for each species). The Central ~tates Pond Management Work Group (Novinger ru1d Dillard 1978) used the PSD index as a systematic method of comparing population TABLE 9. r•1ean length (mm) and percentages of large, intermediate, and small bluegill, pumpkinseed, yellow perch, largemouth bass, and northern pike in electrofishing samples from Iv1id and .Allen Lakes.

Species lake Year Nean Large Inter Small length mediate ( 150 mm) (60-149 mm) ( 59 mm) Bluegill Mid 1974-75-76 132a,b 44 25 31 Mid .1.977-78-79 97a,c 7 84 9 Allen 1974-75-76 l09b,d 8 86 b Allen 1977-78-79 101 c,d 5 91 6 ( 150 mm) (60-149 mm) ( 59 ·mm) Pumpkin seed Hid 1974-75-76 57 57 6 i1:id 1977-78-79 2 96 2 Allen 1974-75-76 95 2 Allen 1977-'(8-79 2 9b 2 ( 250 ' mm) (160-249 mm) ( 159 mm) Yellow Mid l974-'(5-r{6 59 16 25 perch Mid 1977-78-'79 4 25 71 Allen 1974-75-76 1 14 8? A.Llen 1977-'78-79 3 59 38 ( 3VO rnm) (200-299 mm) ( 199 mm) l.arge I'-1id 19'74-75-76 j5 17 28 mouth Mid .197'7-78-79 20 }8 42 bass Allen 1.9'14-75-76 ll 29 60 Allen J.977-78-'t9 14 51 35 ( 500 rnm) (400-299 mm) ( 399 mm) Northern fviid 1974-75-76 447 31 43 26 pike Miu 1.977-78-79 425 11 60 29 a,b,c,dFor each species lengths with same superscript were significantly differ-· ent when compared with a t-test (lar 1974: 105) at the 0.05 level of significance. 40 structureti of largemouth batis and bluegill. To achieve a sustained quality fishery, PGD ranges of 40 through 6016 for largemouth bass (Reynolds and Babb 1978J and 20 through 40% for bluegill (Novinger and Legler 1978) were considered the best management objectives for a mixed fishery (when man aged primarily for a bluegill fishery the upper bluegill range may extend to 6Qra). At P~D's above t~e upper ranges recruitment was too low to sustain a population, and below the lower range, density of recruits was too high, imped ing growth of quality-size fish. Unexploited Mid Lake largemouth bass and bluegill PSD's were higher than the re commended upper ranges in 1974 anQ 1975, but in 1976 the largemouth PSD fell within the 40 and 60% range, and blue gill were near the upper 60fo limit (Tab~e ~0) • .Anderson and Weithman (19t8) felt that this concept could be applied to any predator an(l prey l::lpecieo. 'l'hey developed PSD indiceti for coolwater bpec~es ana gave pos sible management objectives of ~0 through 50% for panfish

(yellow perch) and 30 through 60;'o for gamefish (northern pike, musxellunge, walleye, and smallmouth bass). The management objective ranges of PSD for yellow perch and northern pike of Anderson and weitham (1978) have not yet been field tested. In this study I used PSD indices to evaluate chru1ge in population and community structure, but l am not con- 41

fident that PSD ranges given as management objectives in the

previous studies are the best for l'viid and allen Lakes. ~,;om munity structure in these lakes is more complex than simple largemouth bass/bluegill communities because species com position is more diverse, and yellow perch play the role of both prey and predator. Nevertheless, I feel that the con cept is valid, and that PSD's can be used to identify shifts in community structure.

P~D's of Mid Lake pumpkinseed, bluegill, yellow perch, largemouth bass, and northern pike decreased after exploita•

tion (Table 10). Pumpkinseed and bluegill PS~'s were high TABLE 10. PSD (%) for Mid Lake species before and after angler exp~oitation.

Before anglin~ After anglin~ Species 1974 ~975 ~97 1977 ~978 1 79

Largemouth bass 94 86 55 50 22 ~5 Northern pi.Ke 18 4 24 9 40a 4 B~uegiJ..L 71 71 63 12 11 11 P~mpkinseed 54 47 47 4 3 3 · Y, llow perch 72 84 97 50b 20a 13 •

~~.. ~ay be unreliable due to small sample of 10 fish. bf'1ay be unreliable due to small sample of 6 fish.

and relatively stable before exploitation, 63 to 717o for

bluegill and about 5~ for pumpkinseed. In the first year after exploitation pumpkinseed and bluegill PSD's declined

sharply, and they remained low thereafter, about ~ for 42

pumpkinseed and J.15'o for bluegill. 'l1 he P3D of yel.J.OW perch ranged from 72 to 9'/% before angling, and it was 1)';·6 after angling in 19'(9 ( 19'/'f and. 19'/8 P~D 1 s were pro batl.J.y not re liable because they were based on samples of only 6 and lU fish). High unexploited J.argemouth bass PSD's (55 to 94'?1o) declined to 51.1;0 in l9r1'7 after angling and then fell more sharply to 22';o in 1.9'/8. The 19'1'1 sample size was re.Latively small (14 stoc.K-size bass); however, .Keynolds and Simpson ( 1978) found that .t:::>D could be esth.1ated within lWo of the true PSD from eiectrofishing samples of ~ to lL stock-size largemouth bass at the 9070 confidence level. Gne weakness of PSD is that it is an index only of the relat1ve density of quality-size to stocK-size fish. It provides no informa tion on abundance of fish. If both quality (> 500 mm) and stocK t~ ~ou mm) size of largemouth bass decreased after angling, the decr~ased abundance may not be apparent in . the PSD index.

Northern pike :PSD ranged froni 4 to ~4.''o in unexplo1 ted and exp.Loi ted populations. 'tilth the exclu:::;ion of the 19'/8 samp.Le, wh 1ch was based on only lO pike, r.urthern pi.Ke l.JlJ also declined after angling. 'J:he low l.Slj of northern pike in 1975 is unexplained,but may have been caused by weak year classes.· Allen lake fishes had ..I:'SJ)'s similar to those of exploited populations in Mid Lake (Table 11). Both bluegill and pumpkinseed PSD's were less than 9% in 5 of 6 years, and in both species the PSD was higher in one of the 6 years, 14 and 18%, values still much lower than found for unexploited bluegill and pumpkinseed. Yellow perch PSD was probably influenced by year class strength. In 1974, '/5, and 76 yel~ow perch PSD was less than 5%, but in 1978 and 1979 the PSD increased probably as a strong year class reached a length of 2UO mm (qua~ity-size for yellow perch). Large mouth bass PSD in Allen Lake was variable and always less than that of unexploited largemouth bass in Mid Lake. TABLE 11. PSD (%) for Allen Lake species subjected to angler exploitation every year.

An!ler exyloited Species 1974 197597& 977 1978 1979

Largemouth bass 39 12 13 28 31 9 Bluegill 18 6 5 3 3 Pumpkinseed ~ 6 8 14a 2 '0.4 Yellow perch ~ 5 1 44 5~ 37

~ay be unreliable due to a small sample size of 8 fish.

Yearly trends in community structure can be followed by plotting prey PSD against predator PSD on what Anderson (197b) termed a tic-tac-toe graph. He used a tic-tac-toe graph to observe change in community structure in evaluat ing the effectiveness of largemouth bass length limits, 44 over a 10-year period, in the largemouth bass/bluegill com munity of Phillips Lake, Missouri (Anderson 1976). Ander~on and Weithman (1978) suggested that the structure of diverse communities could be assessed in this manner by weight1ng the PSD of each species according to their relative abun dance, which I did for Mid and Allen Lakes (Figares 10; APPENDICES 11 and 12). Parallel vertical linea represent objective ranges for predators; the lower range 35% is mid way between the 30% suggested for northern pike and 40% for largemouth bass; the suggested upper range was 60% for both predators (Anderson and Weithman 1978), Parallel horizontal lines are objective ranges for prey, ana are mid way between those suggested for bluegill (Novinger ru1d Legler 1978) and yellow perch (Anderson and Weithman 1978). PSD•s for Mid and Allen Lakes never fell in the center panel of the tic-tac-toe graph, the most desirable area formed by intersecting objective ranges for predators and prey. There was an abrupt change in the community struc ture of Mid Lake after angling from a high proportion of quality-size fish to a low proportion of quality-size pre dators and prey. All points from exploited communities were well below recommended management objectives for prey and predators, except 1974 Allen ~ake predators. I also pre pared a tic-tac-toe graph for Mid Lake bluegill and large- 45

MID LAKE

1975 r----~-1974 1976

------~-----~------1 I I I I I ____ ....._ ___ L _____ I_ I I ------20 1 I 1974 l 10 _.,(,. -----r ~~ I 1979• Ts761i/i I ! 10 20 30 40 50 60 70 80 90 100 Predator PSD FIGURE 10. Tic-tac toe graphs showing yearly trends ir. weighted prey and predator J:i~:;' s for f>'~id ana Al:..en 1 akes. Predator PS:D's were weighted for Mid Lake largemouth tass and northern pike, but for Al~en Lake, the predator PSD is fur largeraouth bass only. Data from AP:F1J::DICE:3 Il and 12. ------

mouth bass only, and that graph was s~milar to that of com b~ned prey and predators. I believe that the objective range of 25 through 45% for prey PSD may be too low for diverse communit~es in Wisconsin. Two points, 1975 and 1976, representing the unfished community fell within the objective range for pre dators; however, all points were above the objective range for prey. Only one of the 58 ponds studied by the Central States Pond Management Work Group fell within the window formed by the ~ntersecting largemouth bass and bluegill objective ranges; that pond had not been fished for 18 years (Anderson .1978). lf unfished populations have age ana length structure and dynamic rates that are character iStic of a. balanced community, then perhaps the management objectives should be set higher for prey species.

Creel Survey: Mid Laxe 1976 and 1979

:Fishing Pressure and Harvest Harvest anu fishing pressure in 1976 fol.Lowed a pat tern of exponential decline, but in 1979 both were low and irregular ( F'igures ll, 12, ana 13). l:'eaks ir... harvest cur responded with peaks in effort in buth years. The highest fishir~g pressure and. harvest were observed at the opt:;..-.:.ing of l'<:id l.ake in 1976. Effort a:1d harvest were low and ir- 47

1979

~ ::J 0 ...c '- Q) 1976 -0> c 120 <(

80 60 40

1 5 10 15 20 25 30 May

FIGURE 11. Observed anglir~g effort (hrs) for days surveyed in May 1976 ru1~ 1979 at Mia iake. Circled points represent 16-hour surveys, all other points represent 8-huur surveys. 48

largemouth bass Northern pike N = 187 N = 48

10 ""'0 Q) 1n 60 ;;• Q) 50 Pumpkinseed L.> N = 94 0 40 ...c L. 30 Yellow perch N = 255 ~ 20 E 10 z:> 70 Bluegill 60 N =45 50 40 30 20 10 ~'

5 10 15 20 25 30 5 10 15 20 25 30 May May

FIGU!lli :.;.2. Number o:f each species in the observed harvest :for days surveyed in May 1976 at Mid Lake. Circled points represent 16-hour surveys, all other points represent 8-hour surveys. 49 Largemouth bass N 11 10 =

10 Northern pike N = 1

Yell ow perch -o 10 Q) N = 14 +- C/) Q) > Pumpkinseed "- N = 31 ...c0 "- Q) ...0 E ::::> z Bluegill N =54 30

5 10 15 20 25 30 May

FIGURE 13. Number of each species in the observed harvest for days surveyed in May 1979 at Mid Lake. Circled points represent 16-hour surveys, all other points represent 8-hour surveys. 50

regular fur the remainuer of J.V:ay 1976 alld all of J.. ay 1979 •

.t>. bout o1"e tL ird of the effort ar1L1 tw" thirds of the harvest

for ~ay 1976 took place iL the first two aays of the fishing season (Table 12). Or.. the opeL.ing weeker.. d, iL l976, ang lers fished an 'estimated. 389 hours and caught 768 fish at a rate of 2.02 fish per hour. In friay 1979 only 10% cf the tutal effort and 2% of the total harvest occurred on ope11-

ing weekena when 3 fish were caught in 36 hours of ang~ing, a.catch rate of 0.08 fish per hour. Estimated a:c.gling effort, harvest, ana fishing success, for the en tire month of r1ay, were higher in 1976 than in 1979 (Table 12; APPENDICES J and K). In l"iay 1976, 1,078 angling hours yielded a combined harvest of 1,297 fish at a rate of 1. 20 fish per hour. In Jv.ay 1979 angler·s fished an estimated 290 hours to catch 205 fish a catch rate of 0.71 fish per hour. Fishing pressure on JVlid Lake in May 1976 (83 hrs/ha) was within the range reported for waters which might be ex pected to have high fishirlg pressure (Table 1:5), but below this range in l\'lay 1979 (8 hrs/ha). I<.:stimates Gf fisi1ing pressure for ar• opening weekend or for the first month of a fishir~g season are not common in the li te1.atu..1.:e. 1:he o:.:Lly lakes that I could finu to compare to Mia lake fishi11g pressure cor1tained twc.-story fisheries--Thomas, 1,.rothy, 51

TABl~ 12. hstimated fishing pressure (angler hours) and harvest (number of fish) at ~lid Lake for the first month of the fishing season in 1976 and 1979. Data from AP~BNDICES J and K. Catch per hour of angling is given in parenthesis.

Opening Percent Remainder Percent Total weekend harvest of May harvest 1976 Angling ;S9 b89 1078 effort hours/ha 8~ 147 229 Combined 786 100 529 100 1297 harvest ( 2. 02) (0.76) ( 1. 20) Yellow 373 48 97 l8 470 perch (0.96) (0.14) (0.44) Bluegill 154 20 286 54 440 (0.40) ( 0. 41) (0.41) Pumpkinseed 116 15 61 12 lT/ ( 0. 30) (0.09) ( 0 .16) Largemouth 59 8 35 ., 95 bass ( 0.15) (0.05) (0.09) Northern 66 9 50 9 116 pike (0.17) (0.01) (0.11) 1979 Angling ~6 254 ~90 effort hours/ha 8 54 62

Combined 3 100 202 100 ~05 harvest ( 0.08) (0.79) (0.71) Yellow 0 0 22 10 22 perch (0.00) (0.09) (0.08) Bluegill 1 33 87 4} 88 (0.03) (0.34) ( o. }0) Pumpkinseed 0 0 63 31 63 (0.00) (0.25) ( 0. 22) 52

TABLE 12 (continued) Largemouth 2 67 29 15 31 bass ( 0. 06) (0.11) (0.11) Northern 0 0 1 1 1 pike (0.00) (0.004) (0.00)) and Sunset Lakes, where catchable trout were stocked an nually; Gass Lake near the city of fvli1waukee; and Mill and Third Sister Lakes, Michigan, which were both previously closed to angling. Opening weekend fishing effort at Mid Lake in 1976 was slightly higher than the two-story fisher ies in Wisconsin or Mill Lake, Michigan, but in 1979 opening weekend effort at Mid Lake was much lower. In 1979, fishing effort at Mid Lake for the month of May was only one fourth of the 1976 effort at Mid Lake. May 1979 fishing pressure at Mid Lake was higher than at Third Sister lake in April 14 through May 5, 1942, similar to May 1976 effort at Dorothy lake, but far below the May effort at the other lakes. The lower fishing pressure at Mid lake in 1979 may be characteristic of a warmwater fishery in Wisconsin (assuming that the 1976 pressure was unusually high for a warmwater fishery that was not near a large city), or it may have been lower because of a reputation for poor fishing. Most of the 1976 fishing effort on Mid Lake came from locai ang lers, but in 1979 only a few local anglers fished ft'•id Lake ------,

Table 13. Operoln'J weekend and first moroth an

Lal:e Area Period Angling Source ha surveyed effort hrs/ha

Mid 4.7 opening 82.8 Present study weel:end (May 1,2, 1976) May 3-30, 1976 146.7 Present study May 1976 229.5 Present study

Mid 4.7 opening weekend (May 5,6, 1979) 7.6 Present study May 7-30, 1979 54.1 Present study May 1979 61.7 Present study

Thomas 13.0 opening 32.2 Jesien 1977 weekend (May 1,2, 1976) May 3-30, 1976 358.3 Jesien 1977 May 1976 390.1 Jes i en 1977

Dorthy 39.0 opening weekend (May 1,2, 1976) 26.6 Jesien 1977 May 3-30, 1976 44.3 Jesien 1977 May 1976 70.9 Jesien 1977

Sunset 26.0 opening 70.0 Kmiecik 1980 weekend (May 3,4, 1975) May 5-30, 1975 125.0 Kmiecik 1980 May 1975 195.0 rJniecik 1980 Sunset 26.0 opening 58.0 Kmiecik 1980 weekend (May 1,2, 1976)

May 3-30, 1976 124.0 Kmiec H. 1980 May 1976 182.0 Kmiecik 1980

Sunset 26.0 opening 62.0 Kmiecik 1930 weekend (May 5,6. l979) May 7-30, 1979 115.3 Kmiecik 1980

May 1979 177.0 Kmiecik 19~n

Gass 2.6 May 1976 723.G nelonger 1977

•un 55.0 opening 70.0 Schneider 1973 weekend (Aug.1,2, 1969)

Third Sister 4.0 Apr. 14-H,ly 5, 21.0 Brown & Bell 1942 1942 54

(See section on Angler Characteristics). Local people who visited the park in 1979 frequently commented that fishing had been poor on Mid Lake after the first year. Species contribution to the creel changed from yellow perch dominating in the 1976 survey to domination by bluegill and pumpkinseed in 1979. On opening weekend in 1976 yellow perch was the most important species in the creel comprising 48% of the harvest. Bluegill ranked second forming 20% of the harvest (Table 12). For the remainder of May in 1976 bluegill became the most important species accounting for 54% of the harvest, and yellow perch ranked second compris ing 18% of the harvest. In May 1979 bluegill and pumpkin seed accounted for 4) and 31% of the harvest, and yellow perch, ranked fourth, forming only 10% of the harvest. Only one northern pike was observed in the 1979 creel survey. However, the northern pike harvest apparently was higher in the ice fishing season. Anglers and park person nel reported good catches of northern pike in the 1978-79 ice fishing season. Snow (1978) found that the highest catch rate of northern pike from Murphy Flowage, Wisconsin, occurred through the ice in November. Anglers harvested the large fish from the populations in 1976, and in 1979 all species caught by anglers were smaller (Table 14). Mean lengths of the observed harvest of large mouth bass, pumpkinseed, yellow perch, and bluegill in 1976 decreased in 1979 by 63, 58, 52, and 43 mm, respectively. 55

TAB.LE 14. Mean length (mm) plus or minus one standard deviation for each species measured by the creel clerk in 1976 and 1979. The number measured is in parenthesis.

1276 1979 Species Opening Remainder Opening ..ttemainder weekend of May weekend of May

Yellow perch ~82 + 28 259 .:!:. 43 2~0 .:!:. 59 (216) (53) (0) ( 6) Pumpkinseed 202 .:!:. 14 193 .:!:. 25 144 .:!:. 16 (46) (31) (0) ( 32) Bluegi11 251 .:!:. 22 228 .:!:. 18 250 188 .:!:. 34 (51) (ll6) (1) (53)

Largemouth 365 .:!:. ~5 362 .:!:. 35 301 302 .:!:. 45 bass (25) ( l3) ( 2) (9) Northern pike 544 .:!:. 67 504 .:!:. 43 412 (26) ( 17) ( 0) ( l)

Angler Characteristics The creel of a few anglers accounted for a high percent age of the total harvest in 1976 and ~979, but the large mouth bass harvest was evenly distributed among anglers. On opening weekend in 1976, 15% of the anglers caught 51% of the fish harvested, and 24% of the anglers caught no fish. For the remainder of May 1976, 10% of the anglers accounted for 57% of the fish removed, and 46% of the anglers went home with no fish. In May l979 1~ of the anglers caught 56

55% of the fish, and 68% of the ang~ers caught no fish. Snow (1978) found a similar trend on Murphy :F'lowage, Wis consin, where 10% of the anglers took 5~/o of the harvest, and 37% of the ang~ers caught no fish, over a 15-year per iod. Largemouth bass were distributed more evenly among Mid Lake anglers than other species. The highest catch of largemouth bass by any angling party was 3 in 1976 and 1 in

~979. Panfish were sought by Mid Lake anglers more frequently than the gamefish (largemouth bass and northern pike).

In 1976 and 1979, 51 and 4~ of the anglers interviewed listed a panfish species as their primary prey. On~y 13 and 26% of the anglers in 1976 and 1979, proclaimed game fish their primary target. About one third of the anglers, 36% in 1976 and 32% in 1979, did not state a species pre ference. In 1976 almost half of the fishing effort came from local anglers (within 32 ki~ometers), but in 1979 only a few lccal anglers fished ~1id ..L.ake (Table .15). In 1979 there was a slight increase in the number of anglers who traveled more than 80 kilometers to reach IV1id Lake, but a large decrease in the number of anglers traveling less than 80 kilometers to Mid Lake. 57

TAB.LE 15. Number of anglers traveling various distances (km) to Mid take in 1976 and 1979. Distance in miles and percent of anglers in each range are given in parenthesis.

Year Distance traveled to Mid Lake 0 - 32 33 - 80 81 - 161 162 - 322 Total (0 - 20) (21 - 50) (51 - 100) (100 - 200)

1976 94 75 17 5 191 (49) (39) ( 9) ( 3) (100) 1979 5 40 21 9 75 ( 7) (5'3) (28) ( 12) (100)

Baits used by anglers in 1976 remained nearly the same in 1979 (Table 16). Worms were used by the majority of anglers, artificial lures were second, and minnows third.

TABLE 16. Percent of anglers using various baits. Totals for each year do not equal 100% because some anglers used more than one kind of bait.

Year Percent using each bait Worms Minnows Artificial Other lures

1976 59 16 39 1 1979 57 13 36 0

Population estimates and standing stocks: I-lid Lake 1976 and 1979

Population density and standing stock of fishe~, larger than the minimum length kept by anglers, decreased in Mid lake after fishing (Table 17). Before angling in Mid ~ake, TABlE ..l. 7. Estimated number and standing stock in May 1976 and 1979 of Mid lake bluegill, pumpkinseed, yellow perch, and largemouth bass larger than 99 mm and northern pike larger than 299 mm and for all five species larger than the minimum lengths observed in the 1976 creel survey.

Species Year of Number 95% Average Standing estimate confidence weight per stock interval fish ( g) (kg) Bluegill 1976a 1246 896 to 1795 258 309 (> 15U mm) 1979 459 260 to 793 165 72 BJ.uegill 1976 1440 .1083 to 2064 164 2~6 (1_ 100 mm) 19'19 2945 2201 to 4U40 059 174 Pumpkinseed l976a 238 169 to 354 203 48 (,t. 150 mm) 1979 10 32 to 198 084 6 Pumpkinseed 1976 435 325 to 660 118 51 (l. 100 mm) 1979 1834 130.1 to 2692 042 11 Yellow perch 1976a 571 485 to 683 341 195 <..~. 165 mm) 1979

Yellow perch 1976 539 457 to 645 327 176 <..~. 100 mm) .1.979 927 396 to 2897 039 36 Largemouth bass 1976a 176 8~ to 407 596 105 (l 210 mm) 1979 101 43 to 338 532 54 Largemouth base 1976 172 8~ to 347 343 59 (l. 100 mm) ..L979 186 6~ to 930 260 48

\.11 (X) TABLE 17. (continued) Northern Jike 1976a 271 160 to 490 772 209 (_ 4-'0 mm .1979 164 9) to 434 628 103 Northern Jike 1976 224 162 to 341 583 131 (_ 300 mm 1979 326 197 to 582 514 168

~stimates from Chapmans modification of Petersenis formula (Ricker 1975; p. 78) all other estimates were from Chapman's modification of Schnabel's formula (Ricker 1975; p. 97).

\Jl \.0 60

there were an estimated ~65 bluegill (2 !50 mm), 51 pumpkin seed(> 150 mm), 121 yellow perch (~ 165 mm), 37 largemouth bass (> ~70 mm), and 58 northern pike (1 430 mm) per hectare and 66, 10, 41, 22, and 45 kg/ha, respective~y. After three years of angling on Mid 1ake density and standing stock estimates for bluegill, pumpkinseed, ~argemouth bass, and northern pike,of lengths acceptable to anglers, de creased to 93, 15, 21, and 35 per ha, and 15, l., 11, and 22 kg/ha respectively. Estimates of yellow perch larger than 165 mm were not possible in 1979 because too few were caught. Density of intermediate-sized fishes increased in Mid Lake after angling. Schnabel population estimates for blue gill,pumpkinseed, yellow perch, and largemouth bass larger than or equal to 100 mm long and for northern pike larger than or equal to 300 mm ~ong increased from 1976 to 1979 for all five species (Table 17). Length-frequency distri butions also showed decreases in ~arge fishes and increases in intermediate sizes from 1976 to ~979 (~'igures 5, 6, 7, 8, and 9; APPBNDICES Hl through H5). Changes in standing stocks (kg) of intermediate-sized fishes in Mid lake after angling were variable. Standing stocks of bluegill, yellow perch, and largemouth bass de creased from 72 to 51% after angling, but standing stocks increased from 28 to 49% for pumpkinseed and northern pike (Table 17). The increases or decreases probably were deter- 61 mined by the balance between weight lost from removal of the larger flsh and that gained from the greater densities of intermediate-s1zed fish. I tried to reduce bias in my population estimates by marking as many fish as practical and. by us1ng as many kinds of gear as practical. Robson and Regier (1964) stated that bias in Petersen estimates would be ~ess than 2% if the number marked and releasea (M) times the number examined for marks (C) exceeded iour times the population est1mate (N). I achieved that criterion. Also I used three kinds of gear to catch fish for Petersen population estimates, electro fishing, fyke nets, and angling. I used the former two kinds of gear to capture all species of fish except large mouth bass for Schnabel population estimates. My Schnabel population estimates for largemouth bass and yellow perch may be more biased than the other estimates. Schnabel estimates for largemouth bass were calculated from catches with one gear, electrofishing, for both marking and recapturing. Schneider (1971) found that population estimates from electrofishing data alone were consistently lower than those obtained from trap nets or from the com bined effort of both gears. However, Jesien (1977) found little difference in population estimates for the white sucker (Catostomus commersoni) calculated from electrofishing data 62

alone and estimates obtained when electrofishing was used for marking and angling for recapture. Chadwick (1976) found population estimates of yellow perch to be underes timated by 8.5 times because males on spawning ground con tinually reentered trap nets. My 1976 Schnabel estimate of yellow perch larger than 100 mm long may be underestimated because of an inflated recapture rate of spawning yellow perch in fyke nets. About 40% of the yellow perch caught in fyke nets in 1976 were spawners.

Mortality and Exploitation Rates Total annual mortality, calculated from catch curves, was low for unexploi ted fish populations. Total annual mortality equaled natural mortality in Nid Lake in 1974, 75, and 76 since angling was prohibited and deaths due to sampling were negligible. Estimates of natural mortality for pumpkinseed and bluegill were 42 and 30~ (Table 18). Catch curves for unfished yellow perch and largemouth bass populations were too irregular for estimation of mortality. The irregularity was probably due to fluctuating year class strength. Chang (1971) also found an irregular catch curve for a lightly exploited population of largemouth bass which he attributed to fluctuating year classes. High percentages of large and older yellow perch (Figure 7; Table 5) ana largemouth bass (Figure 8; Table 4J in the unfished Nid Lake Table 18. Total annual mortality (A), survival (S), and instantaneous mortality (Z) rates for each species in Mid Lake before (1974-75-76) and after (1977-78) angling and in Allen Lake for corresponding periods and for the entire period from 1974 through 1978. r is the correlation coefficient from catch curve regressions (Ricker 1975).

Species Lake Combined A s z r Ages samples

Pumpkinseed Mid 1974-75-76 .42 .58 -0.548 -.93 2-10 Mid 1977-78 .83 .17 -1.770 -.94 2-5 Allen 1974-75-76 .88 .12 -2.138 -.98 3-6 Allen 1977-78 .81 .19 -1.667 -.95 3-6 Allen 1974-1978 .85 .15 -1.929 -.98 3-6 Bluegill Mid 1974-75-76 .30 .70 -0.366 -.86 3-10 t~i d 1977-78 .61 .39 -0.933 -.93 2-8 Allen 1974-75-76 .76 .24 -1.427 -.97 5-9 Allen 1977-78 .88 .12 -2.110 -.96 5-8 Allen 1974-1978 .80 .20 -1.625 -.98 5-9 Yellow perch Mid 1974-75-76~ t•1i d 1977-78-79 .69 .31 -1.179 -.99 2-5 Allen 1974-75a76 .69 .31 -1.185 -.94 2-5 Allen 1977-78 Allen 1974-1978 .68 .32 -1.139 -.95 2-7 Largemouth Mid 1974-75-76a bass Mid 1977-78 .45 .55 -0.589 -.98 2-8 Allen 1974-75-76 . 56 .44 -0.822 -.97 2-8 Allen 1977-78 .46 .54 -0.611 -.99 2-9 Allen 1974-1978 .54 .46 -0.788 -.99 2-9

~atch curves were too irregular for estimates. ell.ow perch from f'lid lake was the only species aged in 1979. 0' VI 64 community indicated low mortality rates for those species too. l"ly estimates of mortality in the absence' of fishing were lower than those in the literature for pumpkinseed and blue gill (Table 19). Estimates of annual mortality for populations not subjected to angling are rare in the literature. For the estimates in Table 19 I calculatea annual mortality rates, from catch curves, for unexploited yellow perch in West Blue Lake, Manitoba (Kelso and Ward 1977) and for "typical" unexploited year classes in Mill Lake, Michigan {Schneider 1971); Snow (1978) predicted what mortality rates would have been, in the absence of fishing,

TABLE 19. Total annual mortality rate (%) for various spe cies in the absence of fishing or predicted (Snow 1978) if fishing were absent. S:Qecies A Ages Source Pumpkinseed 46 2 to 8 Schneider 1971 Pumpkinseed 68 Snow 1978 Bluegill 48 2 to 8 Schneider 1971 Bluegill 53 Snow 1978 Yellow perch 75 1 to 8 Schneider 1971 Yellow perch ~7 1 to 10 Kelso & Ward 1977 Largemouth bass 48 4 to 11 ::>chneider 1971 largemouth bass 35 Snow 1978 Smallmouth bass 33 4 to 11 Clady 1975 Northern pike 60 Snow 1978 Black crappie 43 .::in ow 1978 Rock bass 2j Snow 1978 65

for exploited fish populations in Murphy Flowage, Wisconsin using regression analysis. With the exclusion of two esti mates (60 and 75% for northern pike and yellow perch) most estimates of annual mortality in unexploited populations were near or below 50C!G. Estimates of natural mortality vary greatly for species with fluctuating year classes (per haps because of fluctuating year classes). Natura:i.. mortal ity rates for unperturbed populations of ye:i..low perch range from 27 (Kelso and Ward 1977) to 75% (Schneider 1971) and for lake whitefish (Coregonus clupeaformis) from 20 to 80% (Healey 1975). Colvin (1975), in a review of the literature on exploited walleye (Stizostedion vitreum) populations, which commonly have fluctuating year classes, found a wide

range in annual (~8 to 65%) and natural (4 to 37%) mortal

ity rates (exploitation rates ranged from 16 to 6~fo). After l'Hd I.ake was opened to angling, annual murta:i..i ty rates increased to rates like those estimated for Allen J.ake fish populations (Table 18). Pumpkinseed in Mid and Allen l.akes, when subjected to angling, had es tima.ted an nual mortality rates exceeding 8~h. Bluegill estimated annual mortality increased from 30 to 61% after angling was allowed on Mid Lake, which was lower than 76 and 88% estimated for Allen Lake bluegill in 1974-75-76 and 1977- 78. I cannot explain why annual mo.r·tali ty increasea in Allen l..ake from the 1974-75-76 period to the 1977-78 period. 66

Estimated annual mortality rates for exploited yellow perch were 69>;6, and for exploited largemouth bass, they ranged from 45 to 56% in Mid and Alien Lakes. Annual mortality rates that I ca~culated for the exp~oited populations were within ranges published for exp1oited populations of each species (APPENDIX L). Exploitation rates were high in the first month that

Mid Lake was opened to angling, in 1976,and the gr~atest proportion of the harvest occurred on the opening weekend (Table 20). More than half of the monthly exploitation, in May 1976, occurred in the first two days of angling for all species except bluegill. large yellow perch, pumpkin seed, and largemouth bass were highly vulnerable to angling with 86, 74, and 5~, respectively,harvested in the first month of angling. Bluegill (35%) and northern pike (46%) were not quite so vulnerable; however, their exploitation rates in the first month were as high as annual exploita tion rates in other waters (APPENDIX L). High exploitation rates seem to be common in waters opened to angling for the first time. Exploitation rates, similar to those found in this study, were also .found i11 the first few days of angling on new or previous~y un fished lake: (Table 21). Schneider ( ~973) at Mill Lake,

Michigan, observed exp~oitation rates, in the first three days of angling after a five-ye~r closure, that approxi- 67

TABLE 20. Exploitation rates (%) for Mid Lake species for the opening weekend in 1976 and .for the month of May in 1976 and 1979. The minimum length for which exploitation rates were calculated is given in parenthesis for each species.

Species May 1, 2, May 1 - 30, May 5 - 30, 1976 1.976 1979

Pumpkinseed 49 74 20 (.140 mm) Yellow perch 69 86 ( 165 mm)

Bluegill .i3 l.b ( .i50 mm) ~" Largemouth bass 34 53 30 (270 mm) Northern pike 24 46 (4~0 mm) TABLE 21. Exploitation rates at the opening of new or previously unfished lakes for Mid Lake species. Angling effort is given in hours per hectare and period surveyed is in parentheses. lake Area Largemouth Yellow Bluegill Pumpkin- Northern Angling Source ha bass perch seed pike effort hrs/ha Mid, Wis. 4.7 54 69 13 49 24 83 This (May 1,2, study 1976) Mill, Mich. 55.0 35 61 13 29 8 95 Schnei- (Aug. 1,~, der, 1969) 1975 Third Sister, 4.U 31 24 )4 21 Brown & Mich. (April Ball, 14-May 5~ 1942) 1942 Jo Shelby, 12.5 66 26la Hedmond Mo. (1st 2 1974 days of angling) Little Dixie, Mo. (1st 2 83.0 48 134a Redmond days of 1974 angling) Sterling 14.2 48 78a Redmond Price, Mo. 1942 (lst 2 days of angling) TABlE 21. (continued) Austin, Mo. 8.9 39 276a Redmond 1974 (lst two days of angling) Sever, Mo. 6}.9 34 50 a Redmond 1974 (let two days of angling) aAngling effort estimated by multiplying number of trips per ha by 4 hrs; the average length of a fishing trip lChurchill and Snow 1964; This study) 70

mated those found at Mid Lake for the first two days of angling. At Third Sister Lake, Michigan, Brown and Ball (1942) observed high exploitation rates when controlled experimental fishing was allowed after a nine-year closure to anglers. High initial exploitation rates on largemouth bass were reported by Redmond (1974) for several new lakes in I\1issouri.

These high exploitation rates must have a substantial effect on fish populations. Exploitation rates exceeding 30% in the first few days of angling and exceeding 50% in the first month of a fishing season would reduce markedly the numbers of fish of sizes sought by anglers. Decreased density of the larger fish should tend to reduce exploita tion rates, which, therefore, would be sma.J..ler in estab lished fisheries. Schneider (1973) demonstrated a rela tionship between declining exploitation rates and density of fish large enough to be kept by anglers. Exploitation rates in Mid :Lake in May 1979, three years after angling began, were smaller than in May 1976 {'l'able 20). also first month exploitation rates in Nid I,ake (lable 20) and in the other lakes newly opened to fishing ( 'Iab.J..e 21) were generally greater than those in estabiished fisheries (APPENDIX l). There is evidence that largemouth bass learn to avoid angler's lures (Anderson and Heman 1969; Schneider 1973; Heidinger ~975). Such learning also may 71 reduce exploitation rates with time for that species. However, Redmond (1974) found that in a preseason 16-day fish-for-fun period largemouth bass did not learn enough about avoiding angler lures to appreciably lower exploitation rates.

Length-Weight Relationships Significant differences that occurred among Mid lake regressions did not reveal an influence of angling (Table 22). Slopes of the regressions of weight on length de clined for pumpkinseed and largemouth bass in Mid ~ake after angling, but they declined for the same species at the same times in Allen lake too. The same slopes in creased for yellow perch and bluegill in ivlid lake, but sample size was small for yellow perch (2U fish in 1977 and 78), and'for bluegill, the difference was significant for functional regressions but not for the predictive regres sions. Northern pike showed no change after angling. 'I'hese resul. ts may have been affected by variation among years, in stage of development of gametes, in sex ratio of samples, and in sizes of fish in s~p~es. I calculated length-weight regressions for Mid Lake populations on pooled data for years be~ore and years after angling; however, for Allen Lake separate length weight regressions were calculated for each year. l,o Table 22. Length-weight relation;hips and correlation coefficients (r) for bluegill, ~umpkinseed, yellow perch, and lar9emouth bass from Mid and Allen Lakes and northern pike from Mid Lake. Mid Lake 1974&76 samples represent unexploited populations all remaining samples represent exploited populations. Species Lake Combined Number Least Squares Regression r G~1 Function a 1 Regression sam~les of fish

Bluegill Mid 1974&76 236 ln W= -10.32 + 2.93 1n TL .94 *ln W= -11.27 + 3.11 ln TL Mid 1977&78 298 ln W= -10.93 + 3.04 l n TL .91 ln W= -12.35 + 3.35 ln TL

Allen 1974 340 ln W= -13.14 + 3.44 ln TL .97 ln W = -13.58 + 3.54 ln TL Allen 1976 457 **ln W = -12.09 + 3.22 ln TL .98 **1 n W= -12.43 + 3.29 ln TL

Allen 1977 433 ln W= -10.60 + 2.93 ln TL .95 ln W= -11.32 + 3.08 ln TL Allen 1978 249 **ln W= -7.85 + 2.33 ln Tl .88 **1 n W = -9.28 + 2.64 ln Tl Pumpkinseed Mid 1974&76 175 ln W = -13.80 + 3.64 ln TL .99 1n W= -13.95 + 3.67 ln Tl l•lid 1977&78 219 **ln W= -11.78 + 3.24 ln Tl .97 **1 n W= -12.24 + 3.34 ln TL Allen 1974 87 ln W= -13.48 + 3.57 ln Tl .99 1n W= -13.66 + 3.61 ln TL Allen 1976 76 *ln W= -12.28 + 3.31 ln TL .97 1n W= -12.82 + 3.42 ln TL Allen 1977 104 ln W = -12.27 + 3.31 ln TL .96 1n W= -1?..89 + 3.49 ln TL Allen 1978 136 **1 n .W = -10.81 + 3.02 ln TL .98 **1 n W= -11.04 + 3.07 ln TL

Yellow perch Mid 1974&76 138 ln W= -11.50 + 3.07 ln TL .96 ln W= -12.29 + 3.21 ln TL Mid 1977&78 20 **1 n 1-J = -15.92 + 3.91 ln Tl .93 **ln W= -17.44 + 4.21 ln Tl

Allen 1974 103 ln W= -13.54 + 3.44 ln TL .91 ln W= -15.26 + 3.80 ln Tl Allen 1976 55 ln W = -14.40 + 3.61 ln TL .99 1n W= -14.57 + 3.46 ln TL Allen 1977 7 ln W = -13.36 + 3.36 ln TL .99 ln W= -13.58 + 3.43 ln TL Allen 1978 37 ln W= -11.75 + 3.09 ln TL .99 ln W= -11.88 + 3.12 ln TL Largemouth Mid 1974&76 119 ln W = -13.70 + 3.45 ln TL .99 ln W= -13.98 + 3.50 ln TL bass l~i d 1977&78 73 **ln W = -10.96 + 2.96 ln TL .99 **ln W= -11.08 + 2.99 ln TL

Allen 1974 167 ln W = -1?.32 + 3.19 ln TL .99 1n W= -12.37 + 3.20 ln TL Allen 1976 22 ln W= -11.82 + 3.11 ln TL .94 1n W= -12.91 + 3.32 ln TL

Allen 1977 23 1n W= -12.14 + 3.16 ln TL .99 1n W= -12.19 + 3.16 ln TL Allen 1978 35 **ln l-J = - 9.04 + 2.62 ln Tl .94 *ln W= - 9. 92 + 2. 77 ln Tl

Northern Mid 1974&76 85 1n 1 ~ = -10.48 + 2.74 ln TL .96 ln W= - 9. 77 + 2. 63 ln TL -10.83 + 2.81 ln TL -.3 pike Mid 1977&78 11 ln H = -10.99 + 2.83 ln TL .99 1n W= 1\.) ------·------·-- . ------·------*Significant difference between regression equations at 95~ confidence level. **Significant difference between regression equations at 9~% confidence level. 73 significant difference was found between length-weight regressions for Miu lake populations in .i.974 and 1976 or in 1977 and 1978; therefore, data were pooled for 1974-76 and 1977-78 before regressions were calculated. Significant differences were found among length-weight regressions for all species except yellow perch in Allen iake; therefore, re gressions were calculated for each year. Differences between the least squares and functional regressions were similar. Slopes of functional regressions were consistentJ.y higher than slopes of predictive regres_ sions. In 11 out of 1' cases, results comparing function,al regressions agreed with those comparing predictive regres sions on the same data. However, when length-weight equa tions for Mid ~ake bluegill were compared for perio~s be fore and after fishing, a significant difference was found between the slopes of functional regressions, but no sig nificant difference was found between s~opes of predictive regressions. ~·he opposite occurred when length-we igh't equations for Allen lake pumpkinseed were compared in 1974 and 1976; no significant difference was founu between func tional regression slopes whereas slopes of predictive re gressions were significantly different. 74

Growth Stunting of bluegill may be a long term effect of ang ling when it leads to dense unbalanced populations (Bennett 1943; Anderson 197); Price 1977), but no change in growth was seen in Mid lake populations after two years of angling. Instantaneous growth rates (Table 23) and length increments (Table 24; derived from APPENlJIX M) were not significantly different (APPENDICES N and O) among fished and unfished Mid lake populations. Clady (1975) also found no change in growth of largemouth bass and smallmouth bass in the first two years after exploitation in two previously unex ploited Michigan lakes. The term, stunted, although not well defined, has been used to refer to slow growing fish populations which are so dense that food limits growth. Bluegill, and to a lesser extent pumpkinseed, in Allen Lake were growing slower than in Mid lake (Tables 23 and 24), and bluegil.l growth was well below the state average (APPENDIX P). length incre ments in 1974-75-76 were significantly lower in Allen lake than Mid Lake for bluegill and pumpkinseed younger than age 5. These differences could be caused by an inverse relation between growth and density; there were fewer young bluegill and pumpkinseed in Mid J._ake than in Allen Lake in 1974-75- 76 (Tables 6 and 7; APPENDICBS Hl, H2, H6, and H7). TABLE 25. Instantaneous growth rates for pumpkinseed, bluegill, yellow perch, and largemouth bass from Mid lake before (1974-75-76) and after (1977-78) angling and from Allen Lake for the same years (Ricker 1975: 217). Data derived from AFPENDIX M and significant differences given in APPENDIX D.

Species Lake Combined A samples 1-2 2-3 3-4 4-5 5-6 6-7 7-8 8-9 9-10

Pumpkinseed Mid 1974-75-76 2.1097 1. 7748 1. 2577 0.6192 0.3179 0.1598 0.2459 ~tid 1977-78 2.2798 1. 6194 1.0233 0.6386 Allen 1974-75-76 2.3386 1.8309 1.2045 0.6551 Allen 1977-78 1.5797 0.9366 1.1034 0.5224 Bl uegi 11 Mid 1974-75-76 2.3867 1. 7271 1.1935 0.6379 0.3631 Mid 1977-78 0.1967 0.1533 0.1158 0.1871 3.3395 1.8644 1.1778 0.7091 0.4471 0.3117 0.2148 Allen 1974-75-76 1.1338 0.9661 0.7390 0.6123 Allen 0.3451 0.3636 0. 2377 1977-78 1.5899 0.8928 0.6032 0.4904 0.4365 0.4456 Yellow perch Mid 1974-75-76 1. 2111 1. 1066 0.7888 0.5504 0.2869 0.1740 0.1192 0.1191 Mid 1977-78 1. 5914 1.0984 0.8972 0.8227 Allen 1974-75-76 1. 3575 1.0818 0.6935 Allen 1977-78 1.5407 1.1112 0.6809 0.4574 0.2848

Largemouth r~i d 1974-75-76 2.4464 1.1860 1.3057 0.4955 0.4115 0.2927 bass r~; d 0.1674 1977-78 4. 1949 2.0027 0.5210 0.5865 0.5414 0.2862 Allen 1974-75-76 2.0989 1.1727 0.6027 0.6264 0.4280 Allen 1977-78 0.3722 2.3376 1.1758 0. 9100 0.7551 0.4590 0.4662 0.4483 0.1878 TABlE 24. Length increments (mm) between ages for pumpkinseed, bluegill, yel low perch, and largemouth bass from Mid Lake before (1974-75-76) and after (1977-78) angling, and from Allen l,ake for the same years. Data derived from APPENDIX M and significant differences given in APPENDIX N.

Species Lake Combined Age samples l-2 2-3 3-4 4-5 5-6 6-7 7-8 8-9 9-10

Pumpkinseed r~i d 1974-75-76 33.8 48.0 48.9 29.8 16.7 9.3 13.7 9.3 Mid 1977-78 33.0 40.1 39.1 28.1 Allen 1974-75-76 28.4 35.5 30.2 20.1 Allen 1977-78 27.0 21.1 34.9 20.7 Bluegill Mid 1974-75-76 44.7 62.1 58.2 34.8 24.6 13.4 11.9 9.4 14.9 ~1i d 1977-78 48.5 52.5 57.5 43.4 29.2 20.4 16.4 Allen 1974-75-76 20.9 22.5 22.1 25.1 16.8 21.2 14.8 Allen 1977-78 27.7 21.8 15.3 15.4 17.1 22.4 Yellm1 perch Mid 1974-75-76 43.1 43.1 45.2 37.9 21.7 14.2 10.4 10.7 Mid 1977-78 42.4 43.5 51.9 44.8 Allen 1974-75-76 38.5 33.6 30.4 Allen 1977-78 54.3 52.4 39.4 30.6 14.4 Largemouth Mid 1974-75-76 88.7 63.9 92.1 49.3 47.2 32.9 22.5 bass r·1i d 1977-78 113.2 109.0 49.7 59.7 51.3 32.4 Allen 1974-75-76 75.6 64.0 47.9 56.0 44.2 38.1 Allen 1977-78 109.8 80.9 67.8 67.7 47.9 59.4 53.8 29.7 77

Backiel and LeCren (1967) stated that a large change in den sity results in an inverse change in growth of fish popula tions. Both instaEtaneous growth rates and length incre ments were significant~y greater for largemouth bass in

Al~en LaKe in 1977-78 than in 1974-75-76. I cannot explain this difference, but only speculate that it may be density related.

Growth or mean length at age in Mid and Al~en la.Kes compared to the state average (Snow l960) varied with spe cies (APPENDIX P). Pumpkinseed ages 1 through 3 in Mid Lake and ages 1 through 5 in Allen Lake were simi~ar to the state average, but older pumpkinseed in Mid Lake grew faster than the state average. B~uegill in Mid iake grew much faster, and in Allen Lake much slower, than the state average. Yellow perch grew faster in both Mid and Allen Lakes than the state average. Mean lengths at each age for largemouth bass in l-1id Lake were similar to Allen lake in 1974-75-76, with ages 1 and 2 being similar to the state average. In 1977-78 mean lengths at ages 1 through 3 in Mid and Allen lakes were higher, and ages 4 through 7 lower, than those given for the state average. 78

Conclusions Angling had a dramatic effect on fish populations in Mid Lake changing their dynamics ana structure to resemble exploited populations in Allen Lake. Unexploited Mid lake populations were dying at low rates and had .high proportions of large and old fish. Exploitation rates for the first month of fishing on Mid Lake, in 1976, were higher than the annual natural mortality rate for unfished populations of bluegill and pumpkinseed, and probably, of yellow perch and largemouth bass too. Total annual mortality rates in creased for Mid Lake populations after angling, and were similar to those rates estimated for exploited populations in adjacent Allen lake. Age and length structure of Nid lake populations changed after fishing from predominantly old and large fish to young populations dominated by small and intermediate size fish--again similar to exploited populations in Allen iake.

These changes in the fish popu:ations of fv: id Lake were not reflected in changes in growth rates with~n the first two years after angling began. A longer-term effect of population structure on growth was suggested by comparison of growth of the panfish in the two lakes in the period be fore Mid J,ake was open to fishing. In that period when Allen Lake had much denser populations of small and inter- 79

mediate size bluegill and pumpkinseed, growth of those species was slower in Allen Lake than in Mid Lake. When Mid Lake was first opened to ang:ing, it provided a spectacular fishery (many large fish creeled) for a few days only. Now r-1id Lake, like Allen I:ake, provides a recrea tional fishery of marginal quality. Unless the lakes are managed in a manner to reduce the harvest of the larger fish (e.g., slot length limits, trophy fishing only, catch

and release only) the quality of the fishery wil~ not im prove. The presence of three adjacent lakes in the park, Allen, Mid, and Hartman, allows for simultaneous variation in management strategy and resulting fisheries. 80

LITERATUHE CITED Anderson, R. 0. 1973. Application of theory and research to management of warmwater fish populations. Transactions of the American Fisheries ~ociety 102 (1): 164-171. Anderson, R. 0. 1976. Management of small warmwater impound ments. Fisheries 1 (6}: 5-7, 26-28. Anaerson, R. 0. 1978. New approaches to recreational fishery management. Pages 73-78 in G. D. Novinger ana J. G. Dillard, eds. New approaches to the management of small impoundments. North Central Livision of the American lt'isheries Society Special Publication Number 5. Anderson, R. 0. and M. L. Heman. 1969. Angling as a factor influencing catchability of largemouth bass. Transac tions of the American Fisheries 5ociety 98 (2): 317-320. Anderson, R. o. and A. s. Weithman. 1978. The concept of balance for coolwater fish populations. Pages 371- 381 in R. L. Ke,ndall, ed. Selected coolwater fishes of North America. American Fisheries Society Special Publication Number 11. APHA. 1975. Standard methods for the examination of water and waste water. Fourteenth edition. American Public Health Association, New York. 1193 pp. Backiel, T. and D. E. LeCren. 1967. Some density relation ships for fish population parameters. Pages 261-293 in s. ~. Gerking, ea. The biological basis of freshwater fish proauction. John Wiley and Sons, Inc., New York. :Oagenal, T. E. ana :F. W. Tesch. 1978. Age and growth. Pages 101-1~6 in T. B. Bagenal, ed. Hethods for assess ment of fish production in fresh waters. IBP Handbook Number 3, Third Edition. Blackwell Scientific I)ublica tions, Oxford london. Belonger, B. 1977. Intra-department memorandum to Lee Kerner, Gass lake Case File. Wisconsin Department of Natural Resources, Fisheries Jl'lanagement, Plymouth Station.

Bennett, G. W. 1943. Management of sma~l artificial lakes. Bulletin of the Illinois Natural History Survey 22 (3): ,57-376. 81

Bennett, G. W. 1945. Largemouth bass in Ridge iake, Coles County, Illinois. Bulletin of the Illinois Natural History Survey 26 (~): 217-276. Boccardy, J. A. and E. L. Cooper. 1963. The use of rotenone and electrofishing in survey1ng small streams. Transactions of the American Fisheries Society 92 (3): 307-310. Burress, R. M. 1949. The growth rates of bluegills and largemouth bass in fertilized and unfertilized ponus in Central Missouri. Master of Arts Thesis. Univer sity of hissouri, Columbia. 79 pp.

Brown, c. J. D. and R. c. Ball. ~942. A fish population study of Third Sister lake. Transactions of the American Fisheries Society 72: 177-186. Chadwick, B. M. P. 1976. Zcological fish production in a small precambrian shield lake. Environmental Biology of fisheries l (1): 13-60. Chang, K. B. 1971. Population characteristics of largemouth bass and bluegill in a Missouri pond with an evaluation of some sampling methods. Master of Arts Thesis. University of Nissouri, Columbia. 93 pp. Churchill, W. and H. Snow. 1964. Characteristics of the sport fishery in some northeastern Wisconsin lakes. Wisconsin Department of Natural kesources, Technical Bulletin Number 32. 47 pp. Glady, M. D. 1970. Hegulation of fish populations in three lightly exploited populations in three lightly exploited lakes in northern Michigan. Doctoral Thesis. Univer sity of ZVlichigan, Ann Arbor, Michigan. 86 pp. Glady, M. D. 1975. The effects of a simulated angler har vest on biomass and production in lightly exploited populations of smallmouth and largemouth bass. Transactions of the American Fisheries Society 104 ( 2): 270-~76.

Clady, M. L. 1977. ~istribution and relative exploitation of yellow perch tagged on spawning grounds in Onei~a Lake. New York F'ish and Game Journal 24 (2): 168-177. 82

Cochran, w. G. ~96). Sampling techniques. Seconu edition. John Wiley and Sons, Inc. New York. 413 pp. Co~e, c. F. ~966. Virtual population estimates of ~arge mouth baes in Iake Fort Smith, Arkansas, 1957-60. Transactions of the American Fisheries Society 95 (l): 52-55. Colvin, M. A. 1975. The wa:.aeye population and fishery in the Red Cedar niver, Wisconsin. Master of Science Thesis. University of Wisconsin, Stevens Point. 97 pp.

Cooper, G. W, and w. c. Latta. ~954. Further studies on the fish population and exploitation by angling in Sugarloaf lake, 'vlashtenaw County, Michigan. Papers of the Michigan Academy of Science, 39: ~09-22).

Cooper, G. P. and R. N. Schafer. ~954. Studies on the population of legal-size fish in Whitmore Lake, Washtenaw and Livingston Counties, Michigan. Transac tions of the 19th North American Wildlife Conference: 2)9-259. Ellison, D. G. and J. L. Rosenberger. 1979. Evaluation of linear regressions in fisheries research. A paper presented at the 41st Midwest Fieh and Wild~ife Confer ence, Champaign-Urbana, Illinois. Eshenroder, h. l. 1977. Effects of intensified fishing, species changes, and spring water temperatures on yellow perch, Perea flavescens, in Saginaw Bay. Journal o1· the l''isheries Research board ot Canada 34 (10): 18}0-1838. Gerking, s. D. 1952. VitQl statistics of the fish popula tion of Gordy Lake, Indiana. Transactions of the American Fisheries Society 8~: 48-67.

~reen, D. M. 197~. Characteristics of a small-lake fishery as determined by a creel census. New York Fish and Game Journal 19 (2): 155-167. HeQley, M. C. 1975. Dynamics of exploited whitefish popula tions and their management with special reference to the Northwest Territories. Journal of the Fisher~es Re search Board of Canada 3~: 417-448. Heidinger, h. C. 1975. life histury and biology of the largemouth bass. ~ages 11-20 in H. Cleppt:r, ed. b~ack bass bio~ogy and management. Sport },ishing Institute, Washington, L. C.

Hem, J. L. ~975. Study and. interpretation of chemica_;_ char acteristics of natural waters. U. S. ~apartment of Interior. Geological Survey Water-supply Paper 1473. 365 pp. Humphreys, J. D. 1978. Population dynamics of lake white fish, Coregonus clupeaformis, in lake Michigan east of Door County, Wisconsin. Master of Science Thesis. University of Wisconsin, Stevens Point. 69 pp. Jesien, R. V. 1977. The contribution of stocked trout to the sport fishery of three small vJisconsin lakes. Master of Science Thesis. University of Wisconsin, Stevens Point. 124 pp. Jolicoeur, P. 1975. Linear regressions in fishery research: some comments. Journal of the Fisheries Research Board of Canada '2 (8): 1491-1494. Kelso, J. R. M. and F. J. Ward. 1977. Unexploited percid populations of West Blue lake, Manitoba, and their interactions. Journal of the Fisheries Hesearch Board of Canada 34 (10): 1655-1669. Kmiecik, N. E. 1980. An evaluation of rainbow trout strains in the sport fishery of three vJisconsin lakes and for trout ranching in Minnesota winterkill lakes. Master of Science Thesis. University of Wisconsin, Stevens Point. 107 pp.

:Kempinger, J. J. , W. S. Churchill, G. FL. Priegel, and i.. M. Christenson. 1975. Estimate of abundance, ha1~est, and exploitation of the fish population of Escanaba lake, Wisconsin, 1946-69. wisconsin Department of Natural Resources Technical Bulletin Number 84. 30 pp. Kempinger, J. J., and R. F. Carline. 1978. Changes in population density, growth, ana harvest of northern pike in Bscanaba lake after a 22-inch size limit. Wisconsin Department of Natural Resources Technical Bulletin Number 104. 1~ pp.

LaFaunce, D• .A., J. B. Kimsey, and .rl. 1. L;hadwick. 1964. The fishery at Southerland Reservoir, San Diego County, California. California ]'ish ana Game 50 ( 4): 271-291. 84

li, J. c. H.. 1969. ~tatistical Inference I. .Edwards Brothers, Inc., Ann Arbor, Michigan. 658 pp.

Maloney, J. E., D. h. Schupp, and W. J. ~cidmore. 1962. Largemouth bass population and harvest, Gladstone ~-ake, Crow Wing County, Minnesota. Transactions of the American Fisheries Society 91 (1): 42-52. McCormack, J. c. 1965. Observations on the perch popula tion of Uls water. Journal of Animal Ecology 34: 463-478. Moyle, J. B. 1946. Some indices of lake productivity. Transactions of the American Fisheries 7o: 322-354.

Novinger, G. D., and J G G. Dillard, eds. 1978. New approaches to the management of small impoundments. North Central Di~ision of the American Fisheries Society Special Publication Number 5. 133 pp. Novinger, G. D., and R. E. Legler. 1978. Bluegill popula tion structure and dynamics. Pages 37-49 in G. D. Novinger and J. G. Dillard, eds. New approaches to the management of small impoundments. North Central Division of the American Fisheries Society Special Publication Number 5.

Neuhold, J. ~~., and K. H. Lu. 1958. Cree~ census methods. Utah Department of Fish and Game publication Number 8. 36 pp. Patriarche, M. H. 1959. Annual report on lakes at the Rifle River Area 1958-63. Unpublished. Patriarche, M. H. 1960. A twelve-year history of fishing in the lakes of the Rifle River Area, ugemaw County, Michigan, 1945-1956. Michigan Lepartment of Conser vation. Miscellaneous Pub~ication !Jumber 13. 45ppp.

Price, R. 1977. Age and growth of an unbalanced bluegil~ population in Michigan. Transactions of the American Fisheries Society. ~06 (4): 35~-553. Rawstron, H.. A. 1967. Harvest, mortality, and movement of selected warmwater fishes in Folsom LaKe, California. California Fish and Game 53 (1): 40-48. 85

Rawstron, R. A., and K. A. Hashagen, Jr. ~972. Mortality and survival rates of tagged largemouth ba~s at Merle Collins Reservoir. California Fish and Game 58 ()): 221-230. Redmond, L. c. 1974. Prevention of overharvest of large mouth bass in Missouri impoundments. Pages 54-68 in J. L. Funk, ed. Symposium on overharvest and manage ment of largemouth bass in small impounaments. North Central Division of the American Fisheries Society ~pecial Publication Number 3. Regier, H. A. 1962. Validation of the scale method for estimating age and growth of bluegills. Transactions of the American Fisheries Society 91 (4): 362-374.

Reynolds, J. B., andi. h. Babb. 1978. ~tructure and dynam ics of largemouth bass populations. Pages 50-61 in G. D. Novinger and J. G. Dillard, eds. New approaches to the management of small impoundments. North Central Division of the American Fisheries Society Special Publication Number 5. Reynolds, J. B. and D. E. Simpson. 1978. Evaluation of fish sampling methods and rotenone census. Pages ll-24 il: G. D. Novinger and J. G. Dillard, eds. New approaches to the management of small impounaments. horth Central .L-ivision of the American Fisheries Society ~pecia~ Publication Number 5. Hicker, W. E. 1945. Natural mortality among Indiana blue gill sunfish. Ecology 26 (2): 111-121. hicker, W. E. 1945b. Abunaance, exploitation, and mortality of fishes in two ~akes. Investigation of lnciana Lakes and Stxeams ~ (17): 345-448. Ricker, W. E. 1955. Jt·ish and fishing in ;:>pear .._ake, Indiana. Investigation of Indiana lakes and Streams, 4: 117-162. Ricker, w. E • .L973. linear regressions in fishery research. Journal of the Fisheries ~esearch Board of Canada 30: 409-434. Ricker, w. E • .L975. Computation and interpretation of biological statistics of fish popu.Lations. Lepartment of the Environment Fisheries ana Narine Serv1.ce Bulletin 191. 382 pp. 86

Robson, D. s. and H. A. Regier. 1964. Santple size in Petersen mark-recapture experiments. Transactions of the American Fisheries Society 93 (3): ~~5-226. Sanderson, A. E., Jr. 1960. Results of sampling the fish population of an 88-acre ponu by electrical, chemical, and mechanical methods. Proceeaings of the 14th Annual Conference of the Southeastern Association of Game and Fish Commissioners: 185-198.

/ Schneider, J. c. 1971. Characteristics of a population of warmwater fish in a Southern .tviichigar... ~ake. Michigan .Lepartment of l~atural Resources Research and !:evelop ment Report ~umber 236. Schneider, J. c • .1913. Angling on Mill :Lake, l\lichigan, af ter a 5-year closed season. Michigan Academician 5 (3): ~49-)55.

Snedecor, G. VI., and W. G. liochran. 1974. ::>tatistical methods. Sixth edition. Iowa State University Press,, Ames, Iowa. 593 pp.

Snow, H. E. ~960. Comparative growth rates of eight spe cies of fish in thirteen Wisconsin lakes. Wisconsin Department of Natural Resources Research Report ~umber 46. 23 pp. Snow, H. E. 1974. Effects of stocking northern pike in Murphy :E'lowage. Wisconsin l•epartment of Natural Resources Technical Bulletin Number 79. 20 pp. Snow, H. E. 1978. A 15-year study of the harvest exploita tion, and mortality of fishes in Murphy Flowage, Wisconsin. Wisconsin Department of Natural Resources Technical Bulletin Number ~0~. ~2 pp. Snow, H. E., and T. D. Beard. 1972. A ten-year stuay of native northern pike in Bucks Lake, Wisconsin. Wiscon sin Department of Natural Resources Technical Bulletin Number 56. 20 pp. Sullivan, C. 1956. The importance of size gro u.ping ir. popu ~ation estimates employing electric shockers. The Progressive Fish Culturist 18 (4): 188-190. Zar, J. H. 1974. Biostatistical analysis. Prentice-Hall, Inc., Englewood Cliffs, New Jersey. 620 pp. APPENDIX A. Wisconsin Department of Natural Resources lake survey map showing Allen, t4id, and Hartman Lakes all within the boundries of Hartman Creek State Park.

Sll.fE OF WISCONSIN LAKE SURVEY HARTMAN ~UPACA DEPARTMENT OF NATURAL RESOURCES LAKE COUNTY --SEC.___§_ T. ..=..Z.k_N. R.~E*

}It~

ll II II II 3611" ------~ ·~··

•r-----... [ ----- !l,r .• , 0 ~ ~~~ Tot111 Ac•r rut \\

.. l-~·~·-·---·20 •o 5'J 80 IQO 120 ACfi! F(ET

NOTE :.Entire orto Is wlth:l11 Hortman's Creek EO~~=~~:HJca-,-.ll.t50<.1l.Cil Ne..AR1L---5 t.l.tPPEO ~ ~ ~dote Pork AREA ~a___ AC~£.$ ® l1101fl tllll/lo SitU tlepe WAft~ [L£V. ~N UNDER 3FT . f:! ll'e•f••'' _,., ~ .. M._ lo4~f>ll>!r tllortl•u --l...L._. -t. ~ WotodU A*':AIItoll/1 LAIC[ IIH TO .. SYIIII!IOLS OYER 20FT.__!l_% ,.,,.tot © (IIIUU - Sptlr-t Gr. Grout :. Stu"'l>' a $n091 VOLU""E~ACRE FT :l• P'ltfortttll -~ '"'IU/IIolltlll .__ .... ,. 1111. PvO'i!lt' . T-:)TAL, AU<. __LU-_P Phi ,'!)~

APPENDIX B Composition• of water samples representing Mid and Allen Lakes. Samoles were taken on October 16 and December 6, 1979 from the ground water table which fills Allen Lake, the outflow of Allen Lake, and at the inflow and outflow on·r·1id Lake. l~ethods of analysis are from APIIA (1975).

Ground water a Allen outflow Mid infl0\"1 Mid outflow Dec. 6 Analysis Oct. 16 Dec. 6 Oct. 16 Dec. 6 Oct. 16 Dec. 6 Oct. Hi Time of day (A. i•1.) 8:45 9:10 9:15 9:30 9:35 9:50 10:00 10:15 Air Temp. oc 2 -13 2 -13 2 -13 2 -13 Water Temp. oc 10 10 9 3 9 3 9 3 7.96 pH 7.60 7.45 8.00 7.92 7.90 7.90 8.00 Conductivity umho/cm 330 340 310 345 328 350 330 345 Alkalinity 178 170 176 mg/1 as caco3 151 159 158 178 172 Total Hardness 132 134 132 mg/1 as Caco3 134 131 122 120 129 Dissolved ozyegen (mg/1) 6.5 5.8 9.5 10.7 9.5 11.2 9.2 10.7 0.75 BODs-20C (mg/1) 0.4 0.10 1.50 0.90 1.25 0.55 1.50 .476 1.148 .308 l

aGround water samples were taken from a well on ;the west end of Allen Lake.

' 89

APPENDIX C

Aquatic macrophytes found in Mid and Allen Lakes in June 1978.

Scientific name Common name

Ceratophyllum demersum coon tail Chara spp. s ton ewa rt Myriophyllum exalbescens norhern watermilfoil Nuphar luteum spatterdock Potamogeton pectinatus sago pondweed Potamogeton zosteriformis flatstem pondweed Spirodela polyrhiza big duckweed 90

APPENDIX D Weighted predator and prey PSD's computed from estimates of population size and from the number of stock size fish caught in electrofishing samples as weighting factors in 1976 and 1979. Weighted Predator PSD 1976 Predator PSD weighted by population estimates for largemouth bass ( ~ 270 nm) and northern pike ( :::= 430 nm). 55 (176) + 24 (271) 176 + 271 = 40

Predator PSD weighted by the number of stock-sized largemouth bass and northern pike caught jn Mid lake electrofishing samples. 55 (55) + 24 (50) 55 + 50 = 36

1979 Predator PSD weighted by population estimates for largemouth bass ( ~ 270 mm) and northern pike (~ 430 mm). 35 (101) + 4 (164} 101 + 164 = 16

Predator PSD weighted by the number of stock-size largemouth bass and northern pike caught in Mid lake electrofishing samples. 35 ( 37) + 4 (50) 37 + 50 = 17

Weighted Prey PSD

1976 Prey PSD weighted by population estimates for bluegill (~ 150 mm), pumpkinseed (~ 140 mm), and yellow perch (~ 165 nvn). 63 (1246) + 41 (238) + 97(571) 1246 + 238 + 571 = 70

Prey PSD weighted by the number of stock-sized bluegill, pumpkinseed, and yellow perch -~aug~t jn rtid la~e electrofishing-samples •.. 63 (142 } + 47 (116) + 97 (81) 142 + 116 + 81 = 66 ------,

APPENDIX E Estimated catch per unit effort (CUE) by anglers during unsurveyed periods on opening weekend in 1976. CUE T2 CUE Tl CUE T2 = P2 CUE Pl P2 Pl OR Pl

CUE T3 CUE .T2 CUE T3 = P3 CUE T2 P3 = P2 OR P2

where CUE Tl is the observed catch per unit effort for the saturday AM period, CUE T2 is the estimated catch per unit effort for the unsurveyed PM period on saturday, Pl is the population estimate for fish larger than the minimum lengths harvested at the beginning of saturday•s AM period, P2 Pl minus the harvest in saturday•s AM period, CUE T3 is the estimated catch per unit effort for the unsurveyed AM period on sunday, and P3 P2 minus the estimated harvest in saturdays PM period. 92

APPENDIX Fl

Mean length (mm) ±standard deviation (S.D.), sample size in parenthesis, and range of lengths of fishes caught in Mid Lake in 1976 by electrofishing, fyke nets, and angling.

Species Electrofishing Fyke nets Angling X± S.D. (n) X± S.D. (n) X± S.D. (n) Range Range Range

Bluegill 121 ± 79.6 (267) 210 ± 38.4 (246) 226 ± 17.4 {187} 25 - 275 115 - 265 150 - 265 Pumpkinseed 135 ± 54.9 (137) 182 ± 33.7 (90) 198 ± 18.5 (94) 45 - 250 85 - 225 140 - 240 Yellow perch 278 ± 37.9 (82) 270 ± 39.4 (367) 273 ± 31.2 (255) 120 - 320 150 - 340 165 - 330 Northern pike 486 ± 93.0 (54) 496 ± 87.1 (48) 523 ± 59.6 (48) 265 - 815 265 - 835 430 - BOO Largemouth bass 239 ± 115.9 (85) --- ± --- (2) 361 ± 34.0 (45) 55 - 535 255·& 365 270 - 400 APPENDIX F2 Mean length (mm) ±standard deviation (S.D.), sample size in parenthesis, and range of lengths of fishes caught from Mid Lake in 1978 by electrofishing, fyke nets, hoop nets, and fish traps.

Species Electorfishing Fyke nets Hoop nets Fish traps X± S.D. (n) X ± S.D. (n) x ± S.D. (n) X ± S.D. (n) Range Range Range Range

Bluegill 91 ± 35.0 (359) 171 ± 48.4 (96) 177 ± 52.0 (52) 87 ± 21.4 (79) 35 - 260 110 - 265 75 - 255 50 - 140 \0 w P.umpkinseed 97 ± 26.0 (149) 134 ± 17.3 (21) 159 ± --- (4) 94 ± 20.2 (43) 50 - 160 105 - 160 135 - 190 50 - 145

Y'ellow perch 146 ± 46.1 (15) --- ± --- (2) --- ± --- (2) --- ± --- (3) 80 - 265 240 & 240 200 & 265 110 - 170

Northern pike 458 ± 143.2 (12) 508 ± 111.6 (12) 493 ± 73.5 (9) 429 ± 99.4 (5) 95 - 610 380 - 820 380 - 575 305 - 555

Largemouth bass 257 ± 63~5 (31) 217 ± 54.8 (3) 263 ± 88.6 (5) --- ± --- (1) 75 - 400 185 -280 120 - 335 55 APPENDIX F3 Mean length (mm) ±standard deviation (S;D.), sample size in parenthesis, and range of lengths of fishes caught from Mid Lake in 1979 by electrofishing, fyke nets, fish traps, and angling.

Species Electrofishing Fyke nets Fish traps Angling X± S.D. (n) X± S.D. (n) X± S.D. (n) X± S.D. (n) Range Range Range Range

Bl uegi 11 106 ± 34.3 (473) 150 ± 43.1 (302) 83 ± 17.3 (448) 187 ± 35.0 (54) 40 - 255 75 - :_265 35 - 150 125 - 260

Pumpkinseed 98 ± 25.8 (376) 127 ± 16.5 (117) 84 ± 25.0 (324) i42 ± 15.6 (31) 55 - 165 75 - 185 55 - 160 115 - 175

\0 Y·ell ow perch 144 ± 34.8 (78) 229 ± 48.2 (16) 158 ± 31.4 {23) 234 ± 57. 5 (14) ~ 80 - 280 175 - 320 120 - 235 140 - 330

Northern pike 418 ± 65.3 (60) 447 ± 84.5 (59) --- ± --- (2) --- ± --- (1) 265 - 580 290 - 640 110 & 505 410

Largemouth bass 260 ± 83.3 (48) (0) --- ± --- (1) 303 ± 43.4 (11) 95 - 435 55 240 - 360 95 APPENDIX Gl Calculation of mean age in the unexploited populations of Mid Lake (Ricker 1975; 32). MCA=L 1 N Bl uegi 11 1974-75-76 ~·1ean Age = MCA + 1st vulnerable age Age Coded age N T 3 0 80 0 625 4 1 33 33 MCA = 283 = 2.209 5 2 38 76 6 3 54 162 Mean Age = 5.209 7 4 52 208 8 5 15 75 9 6 6 36 10 7 5 35 283 625 Pumpkinseed 1974-75-76

Age Coded age N T 3 0 79 0 333 4 1 43 43 MCA = 218 = 1. 528 5 2 36 72 6 3 40 120 r~ean Age = 4.528 7 4 7 28 8 5 10 50 9 6 1 6 10 7 2 14 218 333 Ye 11 ow perch 1974-75-76

Age Coded age N T 2 0 48 0 583 3 1 8 8 MCA = 204 = 2.860 4 2 22 44 5 3 32 96 6 4 48 192 Mean Age = 4.860 7 5 36 180 8 6 8 48 9 7 1 1 10 8 1 1 204 583 Largemouth bass 1974-75-76 Age Coded age N T 2 0 16 0 448 3 1 20 20 MCA = 153 = 2.928 4 2 22 44 5 3 27 81 ~1ean Age = 4.928 6 4 39 156 7 5 27 135 8 6 2 12 153 448 96 APPENDIX G2 Calculation of mean age in the exploited populations of Mid Lake {Ricker 1975; 32). MCA=r 'fr Bluegill 1977-78 Mean Age = MCA + Age Coded age N T 1st vulnerable age 3 0 225 0 59 4 1 19 19 MCA = 257 = 0.229 5 2 6 12 6 3 2 6 Mean Age = 3.229 7 4 3 12 8 5 2 10 257 59 Pumpkinseed 1977-78 Age ·Coded age N T 3 0 110 0 35 4 1 33 33 MC~ = 144 = 0.243 5 2 1 2 144 35 Mean Age = 3.243

Yellow perch ~977-78

Age Coded age N T 2 0 14 0 14 3 1 1 1 MCA = 20 = 0.700 4 2 2 4 5 3 3 9 Mean age = 2.700 20 M

Largemouth bass 1977-78

Age Coded age N T 2 0 35 0 3 I 90 24 24 MCA = 80 = 1. 125 4 2 7 14 5 3 8 24 Mean age = 3.125 6 4 3 12 7 5 2 10 8 6 1 6 80 9()" 97 APPENDIX G3 Calculation of mean age of the exploited bluegill population in Allen Lake (Ricker 1975; 32). MCA=r I N Bl uegi 11 1974-75-76 Mean Age = MCA + 1st vulnerable age ~-- Coded age N T 3 0 998 0 2206 4 1 553 553 ~1CA = 2223 = 0.992 5 2 465 930 6 3 124 372 Mean age = 3.992 7 4 65 260 8 5 17 85 9 6 1 6 2223 2206

Bluegill 1977-78 Age Coded age N T 2 0 272 0 3261 3 1 57 57 MCA = 1555 = 2.097 4 2 688 1376 5 3 331 993 Mean age = 4.097 6 4 201 804 7 5 5 25 8 6 1 6 1555 3261

Bluegill combined mean age

Age Coded age N T 2 0 1257 0 7690 3 1 1055 1055 MCA = 4763 = 1.615 4 2 1241 2482 5 3 796 2388 Mean age = 3.615 6 4 325 1300 7 5 70 350 8 6 18 108 9 7 1 7 4763 7690 98 APPENDIX G4 Calculation of mean age of the exploited pumpkinseed population in Allen Lake (Ricker 1975; 32). MCA:r T N Pumpkinseed 1974-75-76 Mean Age = MCA + Age Coded age N T 1st vulnerable age 3 0 460 0 199 4 1 178 178 MCA = 648 = 0.307 5 2 9 18 6 3 1 3 Mean age = 3.307 648 199

Pumpkinseed 1977-78

Age Coded age N T 3 0 185 0 126 4 1 71 71 MCA = 283 = 0.445 5 2 26 52 6 3 1 3 Mean age = 3.445 283 126

Pumpkinseed combined mean age

Age Coded age N T 3 .0 645 0 325 4 1 249 249 MCA = 931 = 0.349 5 2 35 70 6 3 2 6 Mean age = 3.349 931 325 99

APPENDIX G5 Calculation of mean age of the exploited yellow perch population in Allen Lake (Ricker 1975; 32). MCA=E I N Yellow perch 1974-75-76 Mean Age = MCA + Age Coded age N T 1st vulnerable age 2 0 294 0 410 3 1 84 84 MCA = 537 = 0.764 4 2 153 306 5 3 5 15 ~1ean age = 2.764 6 4 0 0 7 5 1 5 537 410

Yellow perch 1977-78

Age Coded age N T 2 0 6 0 68 3 1 15 15 MCA = 42 = 1.619 4 2 10 20 5 3 11 33 Mean age = 3.619 ---:42 68"

Yellow perch combined mean age

Age Coded age N T 2 0 300 0 478 3 1 99 99 MCA = 579 = 0.826 4 2 163 326 5 3 16 48 Mean age = 2.826 6 4 0 0 7 5 1 5 579 478 100 APPENDIX G6 Calculation of mean age in the exploited largemouth bass population in Allen Lake (Ricker 1975; 32). MCA=r I N Largemouth bass 1974-75-76 Mean Age = MCA + Age Coded age N T 1st vulnerable age 2 0 193 0 344 3 1 90 90 MCA = 375 = 0.917 3 2 52 104 5 3 16 48 Mean age = 2.917 6 4 19 76 7 5 4 20 8 6 1 6 375 344

Largemouth bass 1977-78

Age Coded age N T 2 0 63 0 112 3 1 24 24 MCA = 116 = 0.965 4 2 14 28 5 3 7 21 Mean age = 2.965 6 4 4 16 7 5 2 10 8 6 1 6 9 7 1 7 116 112

Largemouth bass combined mean age

Age Coded age N T 2 0 256 0 456 3 1 114 114 MCA = 491 = 0.929 4 2 66 132 5 3 23 69 Mean age = 2.929 6 4 23 92 7 5 6 30 8 6 2 12 9 7 1 7 491 456 101

MID LAKE PUMPKINSEED

1974 n•116

0 1975 20 n•122 10

0 1976 n=86

i------LLLLLLLLLLLLLLLLL~~------1977 n•522

;-----~UU~~~UUUUUUUDDU~------1978 n=298

175 200 225 250 n=601 Total Length (mm) APPENDIX H1, Length-frequency distributions of Mid Lake pumpkinseed caught in electrofishing samples before (1974, 75, and 76) and after (1977, 78, and 79) fishing. n is the number caught adjusted to a standardized effort of 4 circuits of the lake. 102

MID LAKE BLUEGILL

-t--~~~~~~~~~~~CL~~=UOL~~~~~LC~~---=~1974 n:161 -r--~~~~~~~~--~~-=L-~-----C~~~~=LCL~~=---1975 n:88

~~~~~~~co~-=dCCLLC~~==~~~~~~~~J=~~1976 n=178

~~~~~~~LULLUODCCLCC~~~~~~~~~~~------1977 n=473

0'-t--~~~ww~~~~~~~~~~~~LL~~~LL--~~~~--1978 n=780 90

10 0 ~--LL,LLL~LU~~~~~~LL~~~CkdU~~~~~~1979 n•767 25 50 75 100 125 150 175 200 225 250 275 Total Length (mm) APPENDIX H2. Length-frequency distributions of Mid Lake bluegill caught in electrofishing samples before (1974, 75, and 76) and after (1977, 78, and 79) fishing. n is the number caught adjusted to a standardized effort of 4 circuits of the lake. APPENDIX H3 . Length-frequency distributions of Mid Lake yellow perch caught in electrofishing samples before (1976, 77, and 78) and after (1977, 78, and 79) fishing. n is the number caught adjusted to a standardized effort of 4 circuits of the lake.

Number ., 0 N .. 0) CD • 0

...... 0w

... 0 0

:I ...a :I .... :I .... :I ..a ico I CD II CD • CD ~ ..... Cll ..... N• CD..... CD ..... !§ ...... CIICJ) f;lCD om ~ ..... CIICJ'I --~ 104

MID LAKE LARGE MOUTH BASS

... t4 .8 t2 E z::I tO 8

0 til

to • II

0 • II

0 ~--~~~--~LL-r-L~~~~~--~~uy~~Lr1979 n=77 50 tOO 150 200 250 300 350 400 450 Total ~gth (mm) APPENDIX H4. Length-frequency distributions of Mid Lake largemouth bass caught in electrofishing samples before (1974, 75, and 76) and after (1977, 78, and 79) fishing. n is the number caught adjusted to a standardized effort of 4 circuits of the lake. 105 MID LAKE NORTHERN PIKE

0 -r~--~~~~~LL~~~------1975 6 n•31 •

o-.--~~~~~~~~~WL-L~~LL~1976 8 n•36 i 6 .c ·E 4 :I 2 2

0-r~~~~~~~~~~--~WL--___ 1977 4 n=62 2

o_.-r-T~~~~,rLT~~~.-,-~-r-1979 200 300 400 500 600 700 800 n::96 Total Length (mm) APPENDIX H5. Length-frequency distributions of Mid Lake northern pike caught in electrofishing samples before (1974, 75, and 76} and after fishing. n is the number caught adjusted to standardized effort of 4 circuits of the lake. 106

ALLEN LAKE

150 BLUEGILL

150

... •••

500

.. 450 1lE ... :I z ...350 250

200

!50

tOO

300

250

200 ,..

tOO ••

n=1138 tO .. .. 100 1H 1SO ... 200 TOUtl Length Cmml APPENDIX H6. Length-frequency distributions of Allen Lake bluegill caught in electrofishing samples in 1974 through 1979 opened to angling in every year. n is the number caught adjusted to standardized effort of 4 circuits of the lake. 107 ALLEN LAKE PUMPKINSEED

10 o-r--~---=~~~~-cLL~~LLLL~~--~---1974 n•328

110

10 3 ~ +-"-----...... c::::L..I=::c:::jLLJ....J....L..ILL.L.I::::CJI::::r:::s:::L...LJt::l:...._.,~- 1975 n=489 10 o-r------=---~~--~~LL~~~~~--~-J~1976 n=132 60

10 o~------~--LL~~~LLLL~~CC~~------1978 n=582 220

200

180

160

140

120

100

20 1979 n:1232 25 50 75 100 125 150 175 Total Length (mm) APPENDIX H7. Length-frequency distributions of Allen Lake pumpkinseed caught in electrofishing samples in 1974 through 1979, and opened to angling in every year. n is the number caught adjusted to a standardized effort of 4 circuits of the lake. -·~'" ,.,._. 'U• .....-. '"'' •'-'' o 0 •'

108 ALLEN LAKE YELLOW PERCH

~--~~~~~~------~------1974 n•321

~e=~~LLLL~~~~--~~------1975 n=175

0 10 0 ;------~~~LL~------1977 20 n=24 10

0 50

0 50 100 150 200 250 300 Total Length (mm) APPENDIX HB. Length-frequency distributions of Allen Lake yellow perch caught in electrofishing samples in 1974 through 1979, and opened to angling in every year. n is the number caught adjusted to a standardized effort of 4 circuits of. the lake. 109

ALLEN LAKE LARGE MOUTH BASS

.. .! 4 E 0 :l (-~~~~~LLLLLLLLL-LC~~_c~~--~------1975 z n=137

2 j---~~~~--~~LLLLLLL---LL------~------1976 12 n-35

0 ,---~------~~~u_~~UUUL~UL~~UL~~UL--_1977 n•84 12

0 ,-----~~--~~~WWWWUUWU--~UL~~L_~~u_ ___ 1978 n=70 34

50 100 150 200 250 300 350 400 450 Total Length (mm) APPENDIX 119. Len9th-frequency distributions of Allen Lake large mouth bass caught in electrofishing samples in 1974 throu9h 1979, and opened to angling in every year. n is the number caught adjuste1 to a standardized effort of 4 circuits of the lake. ------,

110 APPENDIX 11 Prey (bluegill, pumpkinseed, and yellow perch) and predator (largemouth bass and northern pike) PSD's (%) weighted by the number of stock-sized fish caught for each species in electrofishing samples from Mid Lake (from APPENDIX D ). Year Weighted prey PSD

1974 71 (132) + 54 (102) + 72 (67) 132 + 102 + 67 = 65.46

1975 71 (55) + 47 (57) + 84 (25) 55 + 57 + 25 = 63.39

1976 63 (142) + 47 (116) + 97 (81) 142 + 116 + 81 = 65.65

1977 12 (125) + 4 (150) 50 (6) 125 + 150 + 6 = 8.54

1978 11 (187) + 3 (102) + 20 (10) 187 + 102 + 10 = 8.57

1979 11 (393) + 3 (278) + 13 (45) 393 + 278 + 45 = 8.02

Year Weighted predator PSD 1974 94 {55) + 18 (22) 55 + 22 = 72.29

1975 86 (21) + 4 (27) 21 + 27 = 39.87

1976 55 (55) + 24 (50) 55 + 50 = 40.24

1977 50 (14) + 9 {22) 14 + 22 = 24.27

1978 22 (27) + 40 (10) 27 + 40 = 26.86

1979 35 (37) + 4 (50) 37 + 50 = 17.18 111

APPENDIX 12 Prey (bluegill, pumpkinseed, and yellow perch) PSD's (%) weighted by the relative number of stock-sized fish caught for each species in electrofishing samples from Allen Lake (from APPENDIX D ). -

Year

1974 18 (988) + 3 (196) + 3 (58) 988 + 196 + 58 = 14.93

1975 6 (630) + 6 (477) + 5 (131) 630 + 477 + 131 = 5.89

1976 3 (675) + 8 (76) + 1 (84) 675 + 76 + 84 = 3.25

1977 3 (964) + 14 (79) + 44 (9) 964 + 79 + 9 = 4.18

1978 3 (391) + 2 (197) + 53 (34) 391 + 197 + 34 = 5.42

1979 3 (550) + 0.4 (239) + 37 (64) 550 + 239 + 64 = 4.82 ------.

112 .l\PPENDIX J1 Estimated angling effort (hrs) at Mid Lake on opening weekend, and for remainder of May 1976.

Day Period Number of Ratio of Ratio of Estimated £stima surveyed angler hours observed observed effort for effor from instantaneous P~1/AM AM/PM unsurveyed per d counts per effort for effort for period in (angle survey period saturdays sundays each day hours

~1ay 1, 2, 1976; opening weekend Saturday Shore AM 7.0 .606 4.2 11.2 Boat AM 181.2 .903 163.6 344.8 Sunday Shore PM 1.8 .866 1.5 3.3 Boat PM 18.5 .613 11.3 29.8

Total 389.1

Strata Number Mean riumber S.D. Number Estimated 95% of survey of angler hours of total effort confide periods from instantaneous possible (angler interv counts per periods hours) (:t} survey period

May 3 - 30, 1976 Shore Weekend AM 4 5.7 3.9 8 45.6 35.4 PM 5 4.2 1.0 8 33.6 6.3 Weekday AM 7 0.6 1.1 20 12.0 16.5 ~M 4 2.8 4.9 20 56.0 138.2 Boat Weekend AM 4 11.8 13.4 8 94.4 121.0 PM. 5 13.6 9.1 8 108.8 55.3 Weekday AM 7 10.3 13.1 20 206.0 195.6 PM 4 7.1 9.6 20 142.0 272.2

Total 698.4 290.3 Total for month 1087.5 113

APPENDIX J2 Estimated harvest of pumpkinseed at Mid Lake on opening weekend, and for the remainder of May 1976.

lla.Y - Period Number Estimated Estimated Estimated Estimated surveyed of fish CUE for effort for harvest harvest harvested unsurveyed unsurveyed for per day per survey periods periods unsurveyed period periods

May 1, 2, 1976; opening weekend Saturday Shore AM 0.0 .000 4.2 0.0 0.0 Boat AM 69.0 .272 163.6 44.5 113.5 Sunday Shore PM 0.0 .000 1.5 0.0 0.0 Boat PM 0.0 .202 11.3 2.3 2.3

Total 115.8

Strata Number Mean number S.D. Number Estimated 95% of survey of fish of total harvest confidence periods harvested possible interval per survey periods (!) period

May 3 - 30, 1976 Shore Weekend Af-1 4 0.3 0.5 8 2.4 4.5 PM 5 0.7 1.3 8 5.6 7.9 Weekday AM 7 0.0 0.0 20 0.0 0.0 PM 4 0.0 0.0 20 0.0 o.o. - Boat Weekend AM 4 4.3 7.8 8 34.4 70.6 PM 5 1.4 1.7 8 11.2 10.2 Weekday AM 7 0.4 0.8 20 8.0 11.3 PM 4 ·0.0 0.0 20 0.0. 0.0

Total 61.4 73.9 Total for month 177.2 114 APPENDIX J3 Estimated harvest of bluegill at Mid Lake on opening weekend, and for the remainder of May 1976.

flay Period Number Estimated Estimated Estimated Estimated surveyed of fish CUE for effort for harvest harvest harvested unsurveyed unsurveyed for per day per survey periods periods unsurveyed period periods

May 1, 2, 1976; opening weekend Saturday Shore AM 0.0 .000 4.2 0.0 0.0 Boat AM 81.0 .418 163.6 68.4 149.4 Sunday Shore PM 0.0 .000 1.5 0.0 0.0 Boat PM 0.0 .394 11.3 4.5 4.5

Total 153.9

Strata Number Mean number S.D. Number Estimated 95% of survey of fish of total harvest confidence periods harvested possible interval per survey periods (!) period

May 3 - 30, 1976 Shore Weekend At;1 4 0.3 0.5 8 2.4 4.5 PM 5 0.8 1.8 8 6.4 10.9 Weekday Ar;1 7 0.0 20 0.0 Pt·1 4 1.0 2.0 20 20.0 59.9 3oat Weekend AM. 4 18.3 21.5 8 146.4 193.6 PM 5 5.8 6.0 8 46.4 36.6 Weekday Af-t 7 0.9 1.2 20 18.0 17.5 PM 4 .. 2.3 4.5 20 46.0 1~8.0

rotal 285.6 246.4 rotal for month 439.5 115 APPENDIX J4 Estimated harvest of yellow perch at Mid Lake on opening weekend, and for the remainder of May 1976.

Day Period Number Estimated Estimated Estimated Estimated surveyed of fish CUE for effort harvest harvest harvested unsurveyed for for per day per survey periods unsurveyed ~nsurveyed period periods periods

May 1, 2, 1976; opening weekend Saturday Shore AM 0.0 .000 4.2 0.0 0.0 Boat AM 243.6 .727 163.6 118.9 362.5 Sunday Shore PM 0.0 .000 1.5 0.0 0.0 Boat PM 5.5 .433 11.3 4.9 10.4

Total 372.9

Strata Number Mean number S.D. Number Estimated 95% of survey of fish of total harvest confidence periods harvested possible interval per survey periods (!) period

May 3 - 30, 1976 Shore Weekend Af•1 4 0.0 0.0 8 0.0 0.0 PM 5 0.4 0.9 8 3.2 5.4 Weekday AM 7 0.0 0.0 20 0.0 0.0 Pr1 4 0.0 0.0 20 0.0 0.0 Boat Weekend Af·1 4 0.3 0.5 8 2.4 4.5 Pr1 5 3.2 4.3 8 25.6 26.3 Weekday AM 7 2.3 6.0 20 46.0 87.2 PM 4 1.0 2.0 20 20.0 56.9

Total 97.2 95.1 Total for month 470 •. 1 116 APPENDIX J5 Estimated harvest of largemouth bass at Mid Lake on opening weekend, and for the remainder of May 1976. o-ay . Period Nt.tmber Estimated Esttmated Estimated Esttmated surveyed of fish CUE for effort for harvest harvest harvested unsurveyed unsurveyed for per day per survey periods periods unsurveyed period periods

May 1, 2, 1976; opening weekend Saturday Shore AM 0.0 .000 4.2 0.0 . 0.0 Boat AM 29.0 .134 163.6 21.9 50.9 Sunday Shore PM 0.0 .000 1.5 0.0 0.0 Boat PM 7.0 .114 11.3 1.3 8.3

Total 59.2

Strata Number Mean numbe.r S.D. Number Estimated 95% of survey of fish of total harvest confidence periods harvested possible interval per surv.ey periods (:!") period

May 3 - 30, 1976 Shore Weekend AM 4 0.0 0.0 8 0.0 0.0 P~1 5 0.2 0.4 8 1.6 2.7 Weekday· At-1 7 0.0 0.0 20 0.0 0.0 PM 4 0.0 0.0 20 0.0 a~o Boat Weekend. AM 4 1.2 0.9 8 9~6 8.6 Pr·1 5 0.4 0. 9· 8 3.2 5.4 Weekday Atl 7 1.0 1.9 ' 20 20 .. 0 27.6 Pf1 4 o.o 0.0 20 0.0 0.0

Total· 34.4 28.7 Tota 1 for month 93.6. 117 APPENDIX J6 Estimated harvest of northern pike at Mid Lake on opening weekend, and for the remainder of May 1976.

Day Period Number Estimated Estimated Estimate-d Estimated surveyed of fish CUE for effort for harvest harvest harvested unsurveyed unsurveyed for per day per survey periods periods unsurveyed period periods

May 1, 2, 1976; opening weekend Saturday Shore AM 4.0 .506 4.2 2.1 6.1 Boat AM 27.0 .134 163.6 21.9 48.9 Sunday Shore PM 0.0 .455 1.5 0.7 0.7 Boat Pf~ 8.0 .121 11.3 1.4 8.4

Total 65.6

Strata Number Mean number S.D. Number Estimated 95% of survey of fish of total harvest confidence periods harvested possible interval per survey periods (!) period May 3 - 30, 1976 Shore Weekend AM 4 0.0 0.0 8 0.0 0.0 PM 5 0.2 0.4 8 1.6 2.7 Weekday Ar,1 7 0.0 0.0 20 0.0 0.0 PM- 4 0.0 0.0 20 . 0.0 0.0 Boat \.Jeekend AM 4 0.0 0.0 8 0.0 0.0 Pr~ 5 0.8 1.1 8 6.4 6.7 Weekday AM 7 2.1 3.9 20 42.0 56.7 Pf~ 4 0.0 0.0 20 0.0 0.0

Total 50.0 58.7 Total for month 115.6 118

APPENDIX Kl Estimated angling effort (hrs) at Mid Lake on opening weekend, and for the remainder of May 1979. S.D. is the standard deviation.

Strata Number t1e an n ur.1be r S.D. Number Estir.1ated 95% of survey of angler hours of total effort confidence periods observed possible (angler interval per survey periods hours) period

May 5, 6, 1979; opening \·1eekend Shore Ai4 2 9.7 2 19.3 Pf4 1 0.2 2 0.4 Boat M1 2 8.0 2 16.0 PM 1 0.0 2 0.0

Total 35.7

May 7 - 30, 1979 Shore !·.loekend Af·1 5 4.2 3.8 7 29.4 17.7 PH 3 2.0 3.5 7 14.0 45.5 l·leekday ' Af4 3 0.0 17 0.0 Pf•1 7 1.9 1.8 17 32.3 21.5 Boat Weekend AM 5 7.8 13.7 7 54.6 63.7 Pr-1 3 4.6 6.2 7 32.2 81.9 Ueekday AM 3 1.0 1.7 17 17.0 66.3 PM 7 4.4 7.1 17 74.8 7.1

Total 254.3 108.0 119

APPENDIX K2 Estimated harvest of yellow perch.at Mid lake on opening weekend, and the remainder of May 1979.

Strata Number i r-lean number S.D. Number Estimated 95% of survey of fish. D'f total harvest Confidence periods observed possible interval harvested periods <±) per survey period

Hay 5, 6, 1979; opening weekend Shore M1 2 0.00 2 0.0 Pt1 . 1 0.00 2 0.0 Boat Af·1 2 0.00 2 0.0 Pf1 1 0.00 2 0.0

Total 0.0 May 7 - 30, 1979 Shore Heekend AM 5 0.6 1.3 7 4.2 6.2 Pf·1 3 0.0 7 0.0 ~Jeekday At1 3 0.0 17 0.0 PN 7 0.1 0.4 17 1.7 4.6 Boat \-Jeekend Al~1 5 1.6 3.6 7 11.2 16.6 Pf4 3 0.4 5.8 7 2.8 7.6 Heekday AH 3 0.0 17 0.0 PM 7 0.1· 0.4 17 _,.1. 7 4.6

Total ~L6 16.6 ---~--- -~--- ~--~ ------

120

APPENDIX K3 Estimated harvest of pumpkinseed at Mid Lake on opening weekend, and the remainder of May 1979.

Strata Number Nean number S.D. Number Estimated 95% of survey of fish of total harvest confidence periods observed possible interval harvested periods (:t) per survey period

May 5, 6, 1979; opening weekend Shore At1 2 0.0 2 0.0 .PM·.·. 1 0.0 2 0.0 Boat AM 2 0.0 . 2 0.0 PM 1 0.0 - 2 0.0 ~ . .

Total 0.0 t4ay 7 -30, 1979 Shore Heekend M1 5 0.0 7 0.0 . PI~., 3 0.0 7 0.0 \·l~ekday . Al~ 3 0.0 17 0.0 p~., : 7 0.0 17 0.0 Boat ~Jeekend A~·1 5 2.8 6.3 7 19.6 29.1 Pt4. _ 3 3.3 5.8 7 23.1 75.9 Ue~kday AM 3 0.3 :.:; 0.6 17 5.1 22.0 PM. 7 0.9 2.3 17 15.3 27.3 rotal 63.1 58.5 121

APPENDIX K4 Estimated harvest of largemouth bass at Mid Lake on opening weekend, and the remainder of May 1979. ·

------·----

Strata Number r~ean number S.D. Number Estimated 95% of survey of fish of total harvest confidence periods observe·d possible interval harvested periods (±) per survey period

t1ay 5, 6, 1979; opening weekend Shore Ar·1 2 0.0 2 0.0 PM 1 1.0 2 2.0 Boat AM 2 0.0 2 0.0 PM 1 0.0 2 0.0

Total 2.0 May 7 - 30, 1979 Shore I..Jeekend fl.J\1 5 0.0 7 0.0 P~1 · 3 0.0 7 0.0 Heekday AH 3 0.0 17 0.0 PM 7 0.0 17 0.0 Boat Heekend AM 5 0.8 1.8 7 5.6 8.3 Pt-1 3 0.7 0.6 7 4.9 7.6 Heekday AM 3 0.0 17 0.0 P~1 7 0.6 0.9 17 10.2 9.4

Total 28.7 11.4 ------~------

122

APPENDIX K5 -Estimated harvest of bluegill at Mid Lake on opening weekend, and the remainder of May 1979.

Stata Number Nean number S.D. Number Estimated 95% of survey of fish of total harvest confidence periods observed possible interval harvested periods (±) per survey period

f-1ay 5, 6, 1979; opening \t~eekend Shore Ar-t 2 0.5 2 1 P~1 1 0.0 2 0 Boat Ai•i 2 0.0 2 0 ~ PM 1 0.0 2 0

Total 1 Hay 7 - 30, 1979 Shore \·Jeekend .n..-, 5 0.4 0.9 7 2.8 4.2 Pl1 3 0.0 7 0.0 ~~eekday Af~ 3 0.0 17 0.0 P~1 7 0.5 1.1 17 8.5 13.7 Boat \•leek end At-1 5 8.8 19.7 7 61.6 91.4 Pr1 3 0.0 7 0.0 \o!eekday At1 3 0.4 22.1 17 6.8 22.1 Pt1 7 0.4 13.7 17 6.8 .... 13.7

Total 80.5 90.3 123

APPENDIX L Estimates (%) of total annual mortality (A), annual expectation of death b,)t_natural causes (v), and annual exploitation rates (u) for largemouth r bass, northern pike, bluegill, pumpkinseed, and yellow perch from several lakes and location.

lake and Location A v u Source

largemouth bass Fort Smith, Ark. 38 6 32 Cole 1966 Sutherland, Calif. 70 34 36 La Faunce et. al. 1964 Merle Collins, Calif. 71-92 11-56 36-65 Rawstron & Hashagen 1972 Folsom, Calif. 89 49 40 Rawstron 1967 Ridge, Ill. 35-40 5-11 25-30 Bennett 1954 Gordy, Ind. 60 24 36 Gerking 1952 Whitmore, Mich. 42 20 22 Cooper & Shafer 1954 Sugarloaf, Mich. 70 35 35 Cooper & Latta 1954 Dollar, Mich. 36 Patriarche 1959 Gladstone, Minn. 61 47 14 Maloney et. al. 1962 Murphy Flowage, WI. 48 21 27 Snow 1978 Northern pike Bucks, WI. 64 37 9 Snow &· Beard 1972 Escanaba, WI.~ 60 14 46 Kempinger .& Carline 1978 Escanaba, WI. 82 76 9 Kempi nge·r & Ca Y-1 in 1978 Murphy Flowage, 59-77 21-74 3-39 Snow 1974 Murphy Flowage, 38-90 24-84 6-14 Snow 1974 Bluegill Muskellunge, Ind. 60 41 19 Ricker 1945 Shoe, Ind. 71 46 24 Ricker 1945 Spear, Ind. 77 41 36 Ricker 1955 Gordy, Ind. 82 . 47 35 Gerking 195 Sugarloaf, Mich. 66 41 25 Cooper & Latta 1954 Dollar, f4ich. 36 Patriarche 1959 Escabana, WI. 33 Kempinger et. al. 1975 Pumpkinseed Spear, Ind. 88 Ricker 1955 Muskellunge, Ind 80 Ricker 1945 Dollar, Mich. 20 Patriarche 1959 · Escanaba, WI. 13-41 Kempinger et. al. 1975 fwturphy Flowage, WI. 59-87 Snow 1978 Yellow perch Oneida, N.Y. 44 Clady 1977 Dollar, Mich. 49 Patriarche 1959 Murphy Flowage, WI. 34-90 28-86 2-6 Snow 1978 Windermere, Great Britaine 31 McCormack 1965 a bBefore a 22 inch length limit was placed on northern pike. After a 22 inch length limit was enforced for northern pike. cEstimates for native northern pike. dEstimates for stocked northern pike. eFor European perch, f. fluviatilis. APPENDIX M1 Back-calculated lengths for pumpkinseed in Mid Lake before (1974-75-76) angling. lge Number CALCULATED MEAN LENGTH AT EACH ANNULUS Mean S.D. fish I II III IV V VI VII VIII IX X 1ength

1 11 51.7 48.73 10.0 2 73 42.3 76.1 81.05 11.7 3 67 43.7 75.2 123.2 118.79 14.4 4 29 45.2 75.6 116.5 165.4 165.10 19.1 ..... 5 30 42.9 71.9 111.6 158.2 188.0 193.67 7.6 1'\) ~ 6 24 44.9 73.0 110.0 146.7 180.5 197.2 200.67 11.5 7 6 40.4 69.3 104.0 149.5 188.5 204.5 213.8 212.17 5.3

8 5 39.6 69.4 96.2 123.9 154.6 183.8 194.3 208.0 207.00 2o.a 9 0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.00 0.0 0 1 36.2 59.5 89.3 118.1 156.3 188.9 201.0 214.0 221.4 230.7 248.00 0.0

olumn Means 43.0 71.2 107.3 143.6 173.6 193.6 203.0 211.0 221.4 230.7 tand. Dev. 4.3 5.4 11.7 18.8 16.9 9.1 9.9 4.2 0.0 0.0 ncrement 43.0 28.2 36.0 36.4 30.0 20.0 . 9.4 8.0 10.4 9.3 eighted Mean 43.6 74.5 116.1 154.7 182.3 196.3 204.6 209.0 221.4 230.7 tand. Dev. 2.2 2.1 7.3 11.0 9.4 6.0 9.8 2.4 221.4 230.7 APPENDIX M2 Back-calculated lengths for pumpkinseed in Mid Lake after (1977-78) angling.

Age Number CALCULATED MEAN LENGTH AT EACH ANNULUS Mean S.D. Fish I II III IV V length

1 6 36.8 53.00 1.8 2 42 35.2 68.2 74.40 9.8

3 81 32.6 66.8 106.9 120.42 20.0 ..... N 4 9 31.2 70.4 113.1 152.2 146.89 18.9 U1 5 1 34.7 72.9 106.6 138.1 166.2 159.00 0.0

Column Means 34.1 69.6 108.9 145.2 166.2 Stand. Dev. 2.2 2.7 3.7 10.0 0.0 Increment 34.1 35.5 39.3 36.3 21.0 Weighted Mean 33.5 67.6 107.5 150.8 166.2 Stand. Dev. 1.5 ' 1.1 1.9 4.5 166.2 Increment 33.5 34.1 39.9 43.3 15.4 APPENDIX M3 Back·calculated lengths for pumpkinseed in Allen Lake in the years 1974, 75, and 76 combined.

Age Number CALCULATED MEAN LENGTH AT EACH ANNULUS Mean S.D. fish I II III IV V length

1 1 46.1 47.00 0.0 2 12 40.5 68.9 70.67 6.1

3 51 39.1 68.9 104.4 115.18 22.0 ...... N 4 30 40.9 63.0 96.3 126.5 131.80 16.1 ())

5 3 36.2 61.5 98.2 125.7 145.8 142.00 17.4

Column Means 40.6 65.6 99.6 126.1 145.8 Stand. Dev. 3.6 3.9 4.2 0.5 0.0 Increment 40.6 25.0 34.1 26.5 19.7 Weighted Mean 39.8 66.8 101.3 126.4 145.8 Stand. Dev. 1.3 2.9 3.9 0.2 0.1 Increment 39.8 27.0 34.4 25.1' 19.4 APPENDIX M4 Back-calculated lengths for pumpkinseed in Allen Lake in the years 1977 and 78 combined.

Age Number CALCULATED MEAN LENGTH AT EACH ANNULUS Mean S.D. fish I II III IV V 1ength

1 0 0.0 0.00 0.0 2 26 47.8 74.8 75.69 5.4 3 10 43.1 69.6 90.7 90.90 7.5 4 7 41.6 65.6 95.1 130.0 129.86 11.7 5 13 46.0 67.6 101.1 129.9 150.6 145.00 9.6

Column Means 44.6 69.4 95.6 129.9 150.6 Stand. Dev. 2.8 4.0 5.2 . 0.1 0.0 Increment 44.6 24.7 26.2 34.3 20.7 Weighted Mean 45.8 71.0 96.2 129.9 150.6 Stand. Dev. 2.4 3.7 4.6 0.0 0.0 Increment 45.8 25.3 25.2 33.7 20.7 APPENDIX M5 Back-calculated lengths for bluegill in Mid Lake before (1974-75-76) angling.

Age Number CALCULATED MEAN LENGTH AT EACH ANNULUS ~1ean S.D. fish I II III IV V VI VII VIII IX X length

1 24 45.3 42.96 7.9 2 29. 37.2 81.9 82.86 12.0 3 89 36.7 80.6 142.7 140.19 17.1 4 24 36.8 71.9 120.3 178.5 171.17 21.6 ..... 5 22 34.4 62.8 102.7 148.3 183.1 191.23 26.1 N (X) 6 38 37.2 70.3 110.9 154.4 193.2 217.8 214.34 12.1 7 36 34.5 62.6 101.8 142.2 177.2 199.2 212.6 227.78 21.1 8 25 34.2 62.8 102.9 146.6 189.1 215.5 230.8 242.7 234.20 13.8 9 4 42.8 77.4 109.7 158.9 194.6 219.2 230.9 242.1 251.5 248.00 9.1 10 4 41.9 67.4 101.1 138.9 176.6 196.9 . 208.9 223.2 233.2 248.1 258.00 7.3

Column Means 38.1 70.8 111.5 152.5 185.6 209.7 220.8 236.0 242.4 248.1 Stand. Dev. 3.9 7.7 14.2 )3.3 7.9 10.8 11.7 11.1 12.9 0.0 Increment 38.1 32.8 40.7 41.0 33.1 24.1 11.1 15.2 6.4 5.7 Weighted Mean 37.0 72.8 120.4 152.9 185.8 210.3 220.0 240.3 242.4 248.1 Stand. Dev. 2.9 7.9 17.8 12.1 6.7 8.8 9.2 6.4 9.8 0.1 Increment 37.0 35.8 47.6 32.4 32.9 24.6 9.7 20.3 2.1 5.7 APPENDIX M6 Back-calculated lengths for bluegill in Mid Lake after (1977-78) angling.

Age Number CALCULATED MEAN LENGTH AT EACH ANNULUS Mean S.D. fish I II III IV V VI VII VIII 1ength

1 18 35.0 48.94 5.1 2 37 26.6 75.1 82.16 13.3 3 86 21.1 67.0 119.5 137.22 22.6

4 23 22.3 66.7 130.4 187.9 186.00 20.2 ..... N 5 13 13.1 45.4 95.5 154.6 192.6 213.38 7.5 1.0 6 10 22.8 58.8 105.5 154.5 196.8 226.0 235.10 10.7 7 21 21.3 48.7 87.7 134.5 176.3 201.1 221.5 243.95 7.3 8 4 22.9 58.9 109.7 156.5 193.7 218.4 238.0 254.4 261.00 6.5

Column Means 23.1 60.1 108.0 157.6 189.8 215.2 229.8 254.4 Stand. Dev. 6.1 10.5 15.6 19.2 9.2 12.8 11.7 0.0 Increment 23.1 36.9 48.0 49.6 32.2 25.4 14.6 24.6 Weighted Mean 23.0 64.5 113.7 159.5 186.4 210.2 224.2 254.4 Stand. Dev. 4.7 8.9 13.5 21.5 9.1 11.5 6.2 0.1 Increment 23.0 41.5 49.2 45.8 26.9 23.8 14.0 30.2 APPENDIX M7 Back-calculated lengths for bluegill in Allen Lake in the years 1974, 75, and 76 combined.

Age Number CALCULATED MEAN LENGTH AT EACH ANNULUS Mean S.D. fish I II III IV V VI VII VIII length

1 8 56.3 ' 49.88 7.6 2 15 45.0 65.9 67.13 9.6 3 45 39.4 58.7 81.2 85.84 13.6 ...... w 4 53 39.7 56.7 78.2 100.3 98.70 12.1 0 5 65 38.6 59.5 82.9 109.5 134.6 133.02 17.4 6 33 37.8 58.4 84.0 110.2 136.3 153.1 157.79 17.2 7 20 40.0 63.5 90.2 117.8 139.3 162.3 183.5 188.20 12.7 8 10 37 ... 5 65.9 85.1 115.7 137.1 156.6 177.6 192.4 195.10 18.1

Column Means 41.8 61.2 83.6 110.7 136.8 157.3 180.5 192.4 Stand. Dev. 6.3 3.8 4.0 6.8 1.9 4.6 4.2 0.0 Increment 41.8 19.4 22.4 27.1 26.1 20.5 23.2 11.9 Weighted Mean 39.9 59.6 82.4 108.2 136.0 156.6 181.5 192.4 Stand. Dev. 3.4 2.8 3.2 5.7 1.7 4.1 2.8 0.0 Increment 39.9 19.7 22.8 25.8 27.8 20.6 24.9 10.9 APPENDIX M8 Back-calculated lengths for bluegill in Allen Lake in the years 1977 and 78 combined.

Age Number CALCULATED MEAN LENGTH AT EACH ANNULUS Mean S.D. fish I II III IV V VI VII length

1 0 0.0 0.00 0.0 2 34 43.1 70.8 74.79 5.1 3 8 43.7 67.8 89.6 96.50 5.8 4 12 39.3 54.7 74.2 89.5 96.25 6.0 5 47 38.5 54.0 74.1 92.9 108.3 117.96 ...... 14.0 ...... w 6 42 40.6 58.0 79.2 99.5 116.8 133.9 142.07 14.6 7 2 40.8 63.8 8.4.3 111.7 133.5 150.2 172.6 171.50 2.1

Column Means 41.0 61.5 80.3 98.4 119.5 142.1 172.6 Stand. Dev. 2.1 7.0 6.7 9.8 12.8 11.6 0.0 Increment 41.0 20.5 18.7 18.1 21.1 22.5 30.6 Weighted Mean 40.6 60.1 77.3 95.6 112.8 134.6 172.6 Stand. Dev. 1.9 6.8 4.3 4.4 5.3 3.5 0.1 Increment 40.6 19.5 17.3 18.2 17.2 21.8. 38.0 APPENDIX M9

Back-cal~ulated lengths for yellow perch in Mid Lake before (1974-75-76} angling.

Age Number CALCULATED MEAN LENGTH AT EACH ANNULUS Mean S.D. fish I II III IV V VI VII VIII IX X - length

1 1 . 127.2 120.00 0.0 2 30 98.6 141.7 127.77 18.6 3 6 82.9 109.7 152.8 169.83 22.4

4 40. 95.2 131.1 170.1 215.3 206.80 25.7 ..... w 5 14 96.2 135.0 171.7 211.7 249.6 249.57 18.3 N 6 38 92.2 134.8 178.0 216.2 242.4 264.1 278.18 16.6 7 58 93.1 135.2 179.4 2i8.2 244.2 266.4 280.6 291.71 22.1

8 12 95.6 139.8 190.6 229~8 255.6 272.2 285.5 '-295.9 303.08 20.7 9 0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.00 0.0 10 1 118.7 149.7 188.3 223.7 249.4 265.5 279.4 289.1 295.5 306.2 327.00 0.0

Column Means 100.0 134.6 175.8 219.2 248.2 267.0 281.8 292.5 295.5 306.2 Stand. Dev. 13.9 11.6 12.7 6.5 5.2 3.6 3.2 4.8 0.0 0.0 Increment 100.0 34.7 41.2 .43.3 29.1 18.8 14.8 10.6 3.0 10.7 Weighted Mean 94.5 134.8 176.2 217.4 245.4 266.2 281.4 295.3 295.5 306.2 APPENDIX M10 Back-calculated lengths for yellow perch in Mid Lake after (1977-78} angling.

Age Number CALCULATED MEAN LENGTH AT EACH ANNULUS Mean S.D. fish I II III IV V length

1 1 95.4 79.00 0.0 2 17 87.1 129.5 143.00 25.8 ..... 3 4 w 94.0 137.8 181.3 222.00 22.2 w 4 3 128.1 170.3 207.1 259.0 226.00 37.0 5 2 73.4 100.9 137.5 196.8 . 241.6 265.00 0.0

Column Means 95.6 134.6 175.3 227.9 241.6 Stand. Dev. 20.1 28.6 35.2 44.0 0.0 Increment 95.6 39.1 40.6 52.6 13.7 Weighted Mean 91.9 133.3 180.1 234.1 241.6 Stand. Dev. 13.9 . 16.2 27.0 34.1 0.2 Increment 91.9 41.3 46.9 54.0 7.4 APPENDIX ~111 Back-calculated lengths for yellow perch in Allen Lake in the years 1974, 75, and 76 combined.

Age Number CALCULATED MEAN LENGTH AT EACH ANNULUS Mean S. D. fish I II III IV V length

1 4 95.8 92.75 23.6 2 32 83.5 122.0 122.69 15.9 3 19 69.5 95.4 129.0 156.79 19.0 4 38 80.1 110.0 142.8 173.2 164.63 24.8

Column Means 86.4 132.4 177.8 243.8 331.6 Stand. Dev. 13.2 47.8 72.9 99.9 0.0 Increment 86.4 46.0 45.4 66.1 87.8 Weighted Mean 80.0 112.2 140.3 176.8 331.6 Stand. Dev. 6.6 13.7 17.5 22.6 331.6 Increment 80.0 32.2 28.1 36.5 154.8 APPENDIX M12 Back-calculated lengths for yellow perch in Allen Lake in the years 1977 and 78 combined.

Age Number CALCULATED MEAN LENGTH AT EACH ANNULUS Mean S.D. fish I II II I IV V VI length

1 3 77.1 86.67 10.4 2 6 81.9 136.2 161.50 14.9 ...... 80.1 117.9 170.3 189.18 19.8 w 3 11 01 4 8 76.5 116.1 156.0 195.4 218.75 14.3 5 8 85.9 119.9 150.8 187.4 218.0 209.13 29.9 6 1 65.9 83.5 105.9 126.7 145.8 160.2 174.00 0.0

Co 1umn r~eans 77.9 114.7 145.8 169.8 181.9 160.2 Stand. Dev. 6.8 19.2 27.8 37.6 51.0 0.0 Increment 77.9 36.8 31.0 24.1 12.1 -21.7 Weighted Mean 80.2 120.2 158.3 187.6 210.0 160.2 Stand. Dev. 4.1 9.7 13.3 16.2 24.0 160.2 Increment 80.2 39.9 38.2 29.3 22.4 -49.7 APPENDIX M13 Back-calculated mean lengths for largemouth bass in Mid Lake before (1974-75-76) angling.

Age · Number CALCULATED MEAN LENGTH AT EACH ANNULUS ~1ean S.D. fish I II III IV V VI VII VIII 1ength

1 25 82.5 79.20 16.1 2 13 77.6 166.3 157.15 25.3 3 12 75.8 142.9 206.8 213.75 38.0

4 22 79.4 141.2 189.1 278.9 271.50 28.6 ..... w 5 17 74.3 142.5 222.6 293.9 343.6 344.94 21.9 CJ') 6 24 73.8 134.2 191.5 260.9 311.5 354.2 351.92 14.4 7 12 68.9 131.4 180.5 248.1 306.9 343.6 376.5 382.50 51.9 8 1 65.7 104.7 206.6 263.5 319.0 374.5 419.4 441.9 411.00 0.0

Column Means 74.8 137.6 199.5 269.0 320.3 357.4 398.0 441.9 Stand. Dev. 5.5 18.4 15.3 17.7 16.4 15.7 30.4 0.0 Increment 74.8 62.8 61.9 69.5 51.2 37.2 40.5 44.0 Weighted Mean 76.6 141.7 197.7 271.5 320.7 351.3 379.8 441.9 Stand. Dev. 4.2 10.9 14.3 16.0 15.8 6.3 11.9 441.9 Increment 76.6 65.0 56.0 73.8 49.3 30.6 28.5 62.2 APPENDIX M14 Back-calculated lengths for largemouth bass in Mid Lake after (1977-78) angling.

Age Number CALCULATED MEAN LENGTH AT EACH ANNULUS Mean S.D. fish I II III IV V VI VII 1ength

1 5 54.8 137.80 133.3 2 36 41.1 154.3 167.72 16.3 3 25 27.9 124.2 233.5 254.36 16.7 4 5 34.6 139.1 278.6 328.3 321.40 20.3 .._. 7: w 5 59.8 125.7 200.3 294.0 353.7 337.14 35.8 ...... 6 . 2 28.1 78.6 120.0 201.1 275.9 327.2 367.50 14.8 7 1 19.1 96.6 201.1 267.7 321.8 343.4 375.8 401.00 0.0

Column Means 37.9 119.7 206.7 272.8 317.1 335.3 375.8 Stand. Dev. 14.9 27.8 58.0 53.8 39.1 11.5 0.0 Increment 37.9 87.0 87.0 66.1 44.3 18.2 40.5 Weighted Mean 38.5 138.0 226.9 291.3 334.9 332.6 375.8 Stand. Dev. 10.1 17.9 33.2 41.2 32.7 9.4 375.8 Increment 38.5 99.5 88.9 64.4 43.7 -2.3 43.2

\ APPENDIX M15 Back-calculated lengths for largemouth bass in Allen Lake in the years 1974, 75, and 76 combined.

Age Number· CALCULATED MEAN LENGTH AT EACH ANNULUS Mean S.D. fish I II III IV V VI VII length

1 2 87.2 85.50 2.1 2 65 81.2 156.8 153.65 25.6 3 36 76.4 144.0 208.0 215.58 26.8

4 38 95.7 164.3 230.2 278.1 274.79 35.9 w -00 5 10 79.1 148.3 204.0 258.1 314.1 325.80 40.0 6 23 75.6 145.5 192.2 253.7 308.2 352.4 347.48 24.7 7 4 81.8 142.5 177.3 218.6 269.8 307.0 345.1 384.25 29.2

Column Means 82.4 150~2 202.3 252.1 297.4 329.7 345.1 Stand .. Dev. 7.0 8.6 19.6 24.7 24.0 32.1 0.0 Increment 82.4 67.8 52.1 49.8 45.3 32.4 15.3 Weighted Mean 82.5 153.5 210.8 264.8 305.6 345.7 345.1 Stand. Dev. 7.2 7.8 15.8 15.8 12.9 16.4 0.2 Increment 82.5 71.0 57.3 53.9 40.9 40.1 -0.6 APPENDIX M16 · Back-calculated lengths for largemouth bass in Allen Lake in the years 1977 and 78 combined.

Age Number CALCULATED MEAN LENGTH AT EACH ANNULUS f4ean S.D. fish I II III IV V VI VII VIII IX 1ength

1 2- 100.4 100.50 23.3 2 23 100.0 209.8 201.52 21.8 3 12 82.6 179.2 260.1 268.83 17.0 w -\0 4 6 84.3 144.6 202.7 270.5 266.83 14.8 . 5 4 77.2 137.0 192.2 250.7 318.4 322.75 16.5 6 5 79.6 139.7 194.6 247.4 306.0 353.9 376.60 13.1 7 2 80.0 148.6 199.7 271.1 316.6 373.2 432.6 433.50 2.1 8 1 68.8 133.8 167.2 232.1 278.5 315.6 352.8 406.6 458.00 0.0 9 1 70.7 126.3 185.7 269.3 343.5 399.2 449.3 484.5 514.2 467.00 0.0

Column Means 82.6 152.4 200.3 256.8 312.6 360.5 411.5 445.6 514.2 Stand. Dev. 11.2 28.1 28.8 16.0 23.5 35.2 51.6 55.1 0.0 Increment 82.6 69.8 47.9 56.5 55.8 47.9 51.1 34.0 68.7 \~ei ghted Mean 89.4 178.7 220.4 258;2 312.2 359.0 416.8 445.6 514.2 Stand. Dev. 10.1 30.8 32.8 12.6 14.4 22.4 43.4 55.1 514.2 Increment 89.4 89.3 41.7 37.8 54.0 46.7 57.8 28.8 '68. 7 APPENDIX N Length increments compared among samples with a paired t-test (Zar 1974; p. 121). Table values of t are at 0.05 level of significance.

Species Samples compared t df Table-t Significant No significant difference difference

Pumpkinseed Mid 1974-75-76 vs Mid 1977-78 2.259 3 3.182 X Allen 1974-75-76 vs Allen 1977-78 0.636 3 3.182 X Allen 1974-75-76 vs Mid 1974-75-76 4.152 3 3.182 X Allen 1977-78 vs Mid 1977-78 2.733 3 3.182 X ...... ~ 0 Bluegill Mid 1974-75-76 vs Mid 1977-78 1.126 6 2.447 X Allen 1974-75-76 vs Allen 1977-78 0.614 5 2.571 X Allen 1974-75-76 vs Mid 1974-75-76 3.579 4 2. 776 X Allen 1977-78 vs Mid 1977-78 3.480 5 2.571 X

Yellow perch Mid 1974-75-76 vs Mid 1977-78 1. 759 3 3.182 X Allen 1975-75-76 vs Allen 1977-78 0.727 3 3.182 X Allen 1974-75-76 vs Mid 1974-75-76 3.271 2 4.303 X Allen 1977-78 vs Mid 1977-78 0.214 3 3.182 X

Largemouth Mid 1974-75-76 vs Mid 1977-78 0.575 5 2.571 X bass Allen 1974-75-76 vs Allen 1977-78 4.302 5 2.571 X Allen 1974-75-76 vs Mid 1974-75-76 1.034 5 2.571 X Allen 1077-78 vs Mid 1977-78 0.383 5 2.571 X '

APPENDIX 0 Instantaneous rates of growth (G) compared among samples with a paired t-test (Zar 1974; p. 121}. Table values of tare at 0.05 level of significance.

Species Samples compared t df Table-t Significant No significant difference difference

Pumpkinseed Mid 1974-75-76 vs Mid 1977-78 0.553 3 3.182 X Allen 1974-75-76 vs Allen 1977-78 2.281 3 3.182 X Allen 1974-75-76 vs Mid 1974-75-76 1.135 3 3.182 X Allen 1977-78 vs Mid 1977-78 1.787 3 3.182 X ...... j:oo...... Bluegill Mid 1974-75-76 vs Mid 1977-78 1.586 6 2.447 X Allen 1974-75-76 vs Allen 1977-78 0.548 5 2.571 X Allen 1974-75-76 vs Mid 1974-75-76 1.624 6 2.447 X Allen 1977-78 vs Mid 1977-78 1.964 5 2.571 X

Yellow perch Mid 1974-75-76 vs Mid 1977-78 2.186 4 2. 776 X Allen 1974-75-76 vs Allen 1977-78 ' 1.120 2 4.303 X Allen 1974-75-76 vs Mid 1974-75-76 0.122 2 4.303 X Allen 1977-78 . vs Mid 1977-78 1.819 3 3.182 X

Largemouth Mid 1974-75-76 vs Hid 1977-78 0.947 5 2.571 X bass Allen 1974-75-76 vs Allen 1977-78 2.763 5 2.571 X Allen 1974-75-75 vs Mid 1974-75-76 1.057 5 2.571 X Allen 1977-78 vs Mid 1977-78 0.967 5 2.571 X APPENDIX p ' Mean total length (mm) at each age for pumpkinseed, bluegill, yellow perch, and large- mou'th bass from Mid and Allen Lakes and the Wisconsin state average (Snow 1960).

Species Lake Combined ~~ samples 1 2 3 4 5 6 7 8 9 10

Pumpkinseed M1d 1974-75-76 49 81 119 165 19~ 201 212 207 248 n 11 73 67 29 30 24 6 5 0 1 so 10.0 11.7 14.4 19.1 7.6 11.5 5.3 20.8 0 0

Mid 1977-78 53 74 120 147 159 n 6 42 81 9 1 so 1.8 9.8 20.0 18.9 0

Allen 1974-75-76 47 71 115 132 142 n 1 12 51 30 3 so 0 6.1 22.0 16.1 17.4

Allen 1977-78 76 91 130 145 n 0 26 10 7 13 so 0 5.4 7.5 11.7 9.6 ...... State ..j:::o average 1qss- b7 46 73 114 127 155 168 N

Bluegill 11ld 1974-75-76 43 83 140 171 191 214 228 234 248 258 n 24 29 1\9 24 22 38 36 25 4 4 so 7.9 12.0 17.1 21.6 26.1 12.1 21.1 13.8 9.1 7.3

I~ I d 1977-78 49 82 137 186 213 235 244 261 n 18 37 1\6 23 13 10 21 4 so 5.1 13.3 22.6 20.2 7.5 10.7 7.3 6.5

All en 1974-75-76 50 67 86 99 133 153 183 195 n 8 15 45 53 65 33 20 10 so 7.6 9.6 13.6 12.1 17.4 17.2 12.7 18.1

Allen 1977-78 75 97 96 118 142 172 n 0 34 0 12 47 t\?. 2 so 0 5.1 5.8 6.0 14.0 14.6 2.1 ; ! . I . I APPENDIX. P continued

Spedes Lake Combined ~~ samples 1 2 3 4 5 6 7 8 9 10

Yellow perch Mfd 1974-75-76 120 128 170 207 250 278 292 303 327 n 1 30 6 40 14 38 58 12 0 1 so 0 18.6 22.4 25.7 18.3 16.6 22.1 20.7 0 0

l~fd 1977-78 79 143 2?.2 226 265 n 1 17 4 3 2 so 0 25.8 22.2 37.0 0

Allen 1974-75-76 93 123 157 165 n 4 32 19 38 so 23.6 15.9 19.0 24.8

Allen 1977..;78 87 162 189 219 209 174 n 3 6 11 8 8 1 so 10.4 '14.9 19.8 14.3 29.~ 0 ..... w~ State Ill ss·c,7 average 68 109 140 180 201 236

Largemouth Mfd 1974-75-76 79 157 214 269 344 352 383 411 bass n 25 13 12 21 18 24 12 1 so 16.1 25.3 38.0 25.5 21.9 14.4 51.9 0

Mfd 1977-78 138 168 254 321 337 368 401 n 5 36 25 5 7 2' 1 so 133.3 16.3 16.7 20.3 35.8 14.8 0

Allen 1974-75-76 86 154 216 275 326 348 384 n 2 65 36 38 10 23 4 so 2.1 25.6 26.8 35.9 40.0 24.7 29.2

Allen 1977-78 101 202 269 267 323 377 434 458 467 n 2 23 12 6 4 5 2 1 1 so 23.3 21.8 17.0 14.8 16.5 13.1 2.1 0 0

State ,., $'$'• (,7 average 79 160 231 315 333 373 424 ...- ......