Brookinskarl1995
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AN ABSTRACT OF THE DISSERTATION OF Karl G. Brookins for the degree of Doctor of Philosophyin Fisheries Science presented on March 3, 1995. Title: Population Dynamics and Reproductive Ecology of the Redtail Surfperch Amphistichus rhodoterus (Embiotocidae) Redacted for privacy Abstract approved: Howard F. Horton Redtail surfperch (Amphistichus rhodoterus) catch has declined throughout their central California to Washington range. Research objectives determining if temperature affected reproduction, if recreational catch-per-hour (CPH) indexed abundance, if angler catch and effort data from the 1979 to 1986 Marine Recreational Fisheries Statistics Survey (MRFSS) were detailed enough to resolve CPH differences; and developing a population model based on MRFSS angler interview data; correlating abundance and recruitment with environmental factors; and making fishery management recommendations for redtail surfperch. In the laboratory, 30- to 40-day exposure of gestating fish to ambient and ambient plus 3°C temperature affected offspring size and parturition timing. Horsefall Beach catches were recorded to the minute to determine the following: if handling time, inter-species hook competition, recording only successful anglers, rounding effort to 0.5 hrs., combining angler catches, or angling skill invalidated use of the total ratio estimate of CPH (TCPH)to index abundance; to determine if the Poisson Distribution was appropriate when modeling catch accumulation; and to estimate CPH resolution. Annual Horsefall Beach mortality was estimated from MRFSS catch-length andsize at age data, and then combined with predicted gravidity to form a population model. Beards Hollow, Columbia River North Jetty, and Horsefall Beach recruit and abundance indexes were formed using MRFSS TCPH and length measurements; these indexes were correlated with annual catch, effort, and harbor seal abundance and with monthly wave height, wave period, sea surface temperature, and upwelling. TCPH can be used to index abundance and confidence intervals of + 1 TCPH are estimated for A.rhodoterussurf fisheries at TCPH <3.3. Kalaloch Beach, Damon Point, Westport Beach, Beards Hollow, Columbia River North Jetty, Jetty Sands, Freshwater Lagoons, and King Salmon (Buhne Point) fisheries were sustainable, but decreasing length of fish was common. Horsefall Beach fisheries captured prereproductive sizes extensively, and offspring production was below population replacement. Horsefall Beach recruitment correlated positively with June upwelling from when recruits were embryos, but not with catch or effort. Columbia River North Jetty abundance correlated with spring and fall environmental conditions of the previous 18-months. Female harvest restrictions are recommended when offspring production is below replacement levels. ©Copyright by Karl G. Brookins March 3, 1995 All Rights Reserved Population Dynamics and Reproductive Ecology of the Redtail Surfperch Amphistichus rhodoterus (Embiotocidae) by Karl G. Brookins A DISSERTATION submitted to Oregon State University in partial fulfillment of the requirements for the degree of Doctor of Philosophy Completed March 3, 1995 Commencement June 1995 Doctor of Philosophy dissertation of Karl G. Brookins presented on March 3, 1995 APPROVED: Redacted for privacy MajoProfessorepresenting Fisheries Redacted for privacy ead of Department0Fisheries and Wildlife Redacted for privacy I understand that my dissertation will become part of the permanent collection of Oregon State University libraries. My signature below authorizes release of my dissertation to any reader upon request. Redacted for privacy Karl G. Brookins, Author DEDICATION To the fish. ACKNOWLEDGEMENTS I thank Dr. Howard F. Horton for being my major professor and providing direction, editing support, background information, and above all, an ear upon which to bounce ideas. Without his help this research, may have been abandoned long ago. I thank the other members of my committee, Dr. J.D. Hall, Dr. D.F. Markle, Dr. W.C. Pearcy, Dr. C.D. McIntire, Dr. Z. Holmes, and Dr. P.J. Brown for providing guidance, education, and answers in spite of busy schedules. I thank the American Fishing Tackle Manufacturers Association; Mr. W. Wick, Oregon Sea Grant Director; the Lylian Brucefield Renolds Scholarship donors, the Hatfield Marine Science Center, and the Oregon State University Department of Fish and Wildlife for financial support. I thank Russell Porter of the Pacific States Marine Fisheries Commission, and Elaine Stewart of the Oregon Department of Fish and Wildlife for providing the Marine Recreational Fishery Statistics Survey data. I thank Jerry Butler of the Oregon Department of Fish and Wildlife, Wayne Paulson of the Washington Department of Fisheries, and Wade Van Buskirk of the California Department of Fish and Game for assisting with the MRFSS data. I thank Dr. David Sampson for his assistance with population and fisheries questions, Dr. Michael Davis for his assistance in providing laboratory space at the Hatfield Marine Science Center, and Dr. C. Epifanio, University of Delaware for advising me to work with earlier life stages because they are so easy to obtain (ha!). I acknowledge the support of my family and friends who have tolerated my eccentricities, given me couches to sleep on, helped with experiments, caught fish, made editing suggestions, and helped maintain my sanity. The Fords, my Austrailan host parents and family, fueled my excitement for discovery. My parents, Francis and Jack Brookins, provided me with everything I could not obtain elsewhere. Vivian Viar gave me reason to look beyond graduate school and encouraged my getting there. TABLE OF CONTENTS CHAPTER PAGE 1. GENERAL INTRODUCTION 1 THE EFFECT OF TEMPERATURE ON BROOD DEVELOPMENT AND PARTURITION IN REDTAIL SURFPERCH Introduction 7 Methods 9 Gestation Experiments 10 Parturition Experiment 11 Results 12 Gestation Experiments 12 Parturition Experiment 13 Discussion 17 Gestation Experiments 17 Parturition Experiment 20 Conclusion 24 ANALYSIS OF SURF ANGLING CATCHES Introduction 26 Methods 29 Monte Carlo Simulations 30 Results 33 Fishery Description 33 Monte Carlo Simulations 39 Discussion 41 Fishery Description 41 Handling Time And Gear Saturation 42 Competition For Hooks 43 Monte Carlo Simulations 44 Catch Model 47 Resolution 47 Conclusion 48 4. POPULATION AND FISHERY STATUS OF REDTAIL SURFPERCH, Amphistichus rhodoterus,BASED ON RECREATIONAL CATCH Introduction 49 Marine Recreational Fishery Statistics Survey 49 Offspring Production 51 Length Frequencies 52 TCPH 53 Methods 55 MRFSS Angler Interview Data 55 Computer Simulation 58 Age At Length 61 Gravidity 63 Population Models 64 Age Structured 64 Average Mortality Model 65 Fishery Recruitment 67 Environmental Correlations 68 Results 70 MRFSS Length Frequency Distributions 70 Kalaloch Beach 70 Damon Point 70 Westport Beach 75 Beards Hollow 75 Columbia River North Jetty 78 Jetty Sands 78 Horsefall Beach 81 Freshwater Lagoon 81 King Salmon 85 MRFSS BLUE Estimator 85 Computer Simulations 88 Length Frequencies 88 TCPH Bias 88 TCPH Variance 90 Length At Age 92 Gravidity 92 Population Models 97 Age Structured Model 97 Average Mortality Model 97 Fishery Recruitment 98 Environmental Correlations 101 Recruit Index 102 Abundance Index 105 Discussion 108 CPUE and Abundance 108 Marine Recreational Fishery Statistics Survey 111 Interstate Comparison 111 Intrastate Comparison 112 TCPH and Population Age Changes 113 Kalaloch Beach 114 Damon Point 115 Westport Beach 116 Beards Hollow 116 Columbia River North Jetty 117 Jetty Sands 117 Horsefall Beach 118 Freshwater Lagoon 118 King Salmon 119 BLUE Estimator 120 Estuaries 120 Gravidity 121 Offspring Production 124 Population Models 126 Environmental Correlations 131 El Nino Southern Oscillation 134 Fishery Recommendations 135 Conclusion 139 REFERENCES 141 APPENDIXES 150 LIST OF FIGURES FIGURE PAGE 1 2 Estimated redtail surfperch catch plus or minus 1 standard error (USDC 1984a, 1984b, 1985, 1986, 1987, 1992a). 2 16 Daily water temperature measurements of ambient and heated tanks during parturition experiment with redtail surf perch 3 32 Distributions of the total ratio estimate of catch per hour (TCPH) generated by Monte Carlo simulation for a single angler on different days, and for six anglers catching 6, 7, 8, 9, 10, and 11 fish in 147 min (6 skill levels). 4 36 Frequency distribution of minutes per catch for the three most commonly caught species at Horsefall Beach, Oregon during 1987. 5 37 Catch per hour of Amphistichus rhodoterus at Horsefall Beach, Oregon for 1987. 6 40 Distributions of total ratio estimate of catch per hour (TCPH) generated by Monte Carlo simulation for all angler trips with trip duration recorded as minutes angling and trip duration rounded to the next higher one-half hour. 7 57 Amphistichus rhodoterus sample locations from the Marine Recreational Fishery Statistics Survey for which data were analyzed. 8 71 Relative catch per hour of redtail surf perch sampled at Kalaloch Beach, Washington. 9 74 Relative catch per hour of redtail surfperch sampled at Damon Point, Washington. 10 76 Relative catch per hour of redtail surfperch sampled at Westport Beach, Washington. FIGURE PAGE 11 77 Relative catch per hour of redtail surfperch sampled at Beards Hollow, Washington. 12 79 Relative catch per hour of redtail surfperch sampled at Columbia River North Jetty. 13 80 Relative catch per hour of redtail surfperch sampled at Jetty Sands, Oregon. 14 82 Relative catch per hour of redtail surfperch sampled at Horsefall