UNIVERSITY OF CALIFORNIA, SAN DIEGO Movement patterns, habitat preferences, and fisheries biology of the common thresher shark (Alopias vulpinus) in the Southern California Bight A dissertation submitted in partial satisfaction of the requirements for the degree Doctor of Philosophy in Marine Biology by Daniel Patrick Cartamil Committee in charge: Professor Jeffrey B. Graham, Chair Professor David M. Checkley Professor Philip A. Hastings Professor Cleridy E. Lennert Professor Richard H. Rosenblatt Professor David S. Woodruff 2009 i IGNATURE PAGE The dissertation of Daniel Patrick Cartamil is approved, and it is acceptable in quality and form for publication on microfilm and electronically: ________________________________________ ________________________________________ ________________________________________ ________________________________________ ________________________________________ Chair University of California, San Diego 2009 iii EPIGRAPH “The swordfish swimmes under the whale, and pricketh him upward. The thresher keepeth above him, and with a mighty great thing like unto a flail, hee so bangeth the whale, that hee will roare as though it thundered, and doth give him such blowes with his weapon, that you would think it to be the crake of a great shot” Block Island fisherman, 1609 iv TABLE OF CONTENTS Signature Page .......................................................................................................... iii Epigraph .................................................................................................................... iv Table of Contents ...................................................................................................... v List of Figures............................................................................................................ vii List of Tables............................................................................................................. x Acknowledgements ................................................................................................... xi Dissertation material published, submitted, or in preparation for publication xi Curriculum Vitae....................................................................................................... xiii Abstract of the Dissertation....................................................................................... xv Introduction ............................................................................................................... 1 Literature Cited................................................................................................. 4 Chapter 1: Diel movement patterns and habitat preferences of subadult and adult thresher sharks (Alopias vulpinus) in the Southern California Bight........................ 6 Abstract............................................................................................................. 6 Introduction ...................................................................................................... 7 Methods ............................................................................................................ 8 Results .............................................................................................................. 11 Discussion......................................................................................................... 13 Tables ............................................................................................................... 21 Figures .............................................................................................................. 22 Literature Cited................................................................................................. 26 Acknowledgments ............................................................................................ 29 Chapter 2: Archival tagging of subadult and adult thresher shark (Alopias vulpinus) in the Southern California Bight................................................................................ 31 Abstract............................................................................................................. 31 Introduction ...................................................................................................... 32 Methods ............................................................................................................ 34 Results .............................................................................................................. 36 Discussion......................................................................................................... 39 Tables ............................................................................................................... 48 Figures .............................................................................................................. 50 Literature Cited................................................................................................. 58 v Acknowledgments ............................................................................................ 62 Chapter 3: Movement patterns and nursery habitat of the juvenile thresher shark (Alopias vulpinus) in the Southern California Bight ................................................. 64 Abstract............................................................................................................. 64 Introduction ...................................................................................................... 64 Methods ............................................................................................................ 67 Results .............................................................................................................. 70 Discussion......................................................................................................... 72 Tables ................................................................................................................. 80 Figures ................................................................................................................ 81 Literature Cited................................................................................................... 86 Acknowledgments .............................................................................................. 91 Chapter 4: The artisanal elasmobranch fishery of the Pacific coast of Baja California, Mexico....................................................................................................... 92 Abstract............................................................................................................... 92 Introduction ........................................................................................................ 93 Methods .............................................................................................................. 95 Results ................................................................................................................ 99 Discussion......................................................................................................... 104 Tables ............................................................................................................... 113 Figures .............................................................................................................. 116 Literature Cited................................................................................................. 122 Acknowledgments ............................................................................................ 126 Chapter 5: Movement patterns, habitat preferences, distribution, and fisheries biology of the thresher shark (Alopias vulpinus) in the SCB and beyond: current status of knowledge and future directions................................................................. 128 Abstract............................................................................................................. 128 Introduction ...................................................................................................... 128 Figures .............................................................................................................. 141 Literature Cited................................................................................................. 144 vi LIST OF FIGURES Chapter 1 Figure 1.1: Latitude and longitude movement data for eight common thresher sharks tracked by acoustic telemetry off San Diego County, California ................... 22 Figure 1.2: Open triangles: hourly rates of movement (ROM; km h-1, mean ± s.e.) of thresher sharks tracked over the diel cycle. Gray shaded areas are nocturnal hours, unshaded areas are daylight hours. B. Open triangles: corresponding hourly angular concentration (r) values................................................................................. 23 Figure 1.3: Dive profiles of common thresher sharks 1 through 8............................ 24 Figure 1.4: Pooled depth distributions (% frequency) for all tracked common thresher sharks in 10 m bins, during night (shaded bars) and day (unshaded bars)... 25 Chapter 2 Figure 2.1: Tag and recapture locations of five thresher sharks in the SCB.............. 50 Figure 2.2: Dive profiles of four archivally tagged thresher sharks in 2004.............. 51 Figure 2.3: A representative five day section of archival data from Shark 1, showing the abrupt transition from