Variation and plasticity and their interaction with urbanization in Guadalupe Bass populations on and off the Edwards Plateau by Jessica E. Pease A Dissertation In Wildlife, Aquatic, and Wildlands Science and Management Submitted to the Graduate Faculty of Texas Tech University in Partial Fulfillment of the Requirements for the Degree of DOCTORAL OF PHILOSOPHY Approved Dr. Timothy Grabowski Co-Chair of Committee Dr. Allison Pease Co-Chair of Committee Dr. Preston Bean Dr. Adam Kaeser Mark Sheridan Dean of the Graduate School August 2018 Copyright 2018, Jessica E. Pease Texas Tech University, Jessica E. Pease, August 2018 ACKNOWLEDGEMENTS I want to express my extreme gratitude to my advisors Dr. Tim Grabowski and Dr. Allison Pease for their continued efforts, mentorship, and support throughout this project. This research and the completion of my dissertation would not have been possible without their guidance and contributions. I would also like to thank my committee members Dr. Preston Bean and Dr. Adam Kaeser for their continued support and guidance throughout this project. Additionally, I want to thank all the individuals that have helped with both field and lab work over the past five years. A. Adams, C. Alejandrez, K. Aziz, P. Bean, M. Berlin, T. Birdsong, S. Boles, J. Botros, D. Bradsby, C. Carter, M. Casarez, D. Chilleri, A. Cohen, B. Cook, G. Cummings, M. DeJesus, J. East, S. Fritts, K. Garmany, D. Geeslin, M. Gilbert, D. Gossett, A. Grubh, R. Hawkenson, D. Hendrickson, S. Hill, A. Horn, F. Howell, L. Howell, M. Kelly, G. Kilcrease, K. Kolodziejcyk, T. Lane, D. Leavitt, K. Linner, C. Loeffler, D. Lutz- Carillo, S. Magnelia, K. Mayes, S. McClanahan, A. Nobles, C. Pavliska, S. Robinson, J. Salazar, S. San-Francisco, A. Stevens, C. Vaughan, and E. Verwys, thank you. I want to thank I want to express my sincerest thanks to my lab mates Q. Chen, J. East, J. Taylor, W. Massure, B. Roesler for their time and camaraderie. I want to especially thank my fellow lab mates M. Acre and H. Williams for their advice, support, and friendship for which I am forever grateful. I want to also thank R. Vickory and the staff of the Lower Colorado River Authority McKinney Roughs Nature Park, and T. Arsuffi, R. Stubblefield and K. Lopez at the Texas Tech University- Junction Campus ii Texas Tech University, Jessica E. Pease, August 2018 and Llano River Field Station provided accommodations and lab facilities while in the field. All Water Guides and their clients assisted with capturing Guadalupe Bass in the Lower Colorado River. D. Lutz-Carrilo and the staff at the A.E. Wood Lab for performing all genetic analyses. I also want to thank R. Katz for her efforts and guidance with my analyses in Chapter 4, as well as her assistance in R. R. Edwards and S. Magnelia who provided comments and suggestions on earlier revisions of this dissertation. I want to thank the U.S. Fish and Wildlife Service State Wildlife Grant, Texas Parks and Wildlife, and the Department of Natural Resources at Texas Tech University for funding this project. I also want to thank the entire staff and faculty of the Department of Natural Resources Management and the Texas Cooperative Fish and Wildlife Research Unit at Texas Tech University for all of their support and assistance. Finally, I cannot express how grateful for my friends and family who have showed continued encouragement and unwavering support throughout this entire process. iii Texas Tech University, Jessica E. Pease, August 2018 TABLE OF CONTENTS Acknowledgements ........................................................................................................ ii Abstract ........................................................................................................................ vii List of Tables.................................................................................................................. x List of Figures .............................................................................................................. xii Chapter 1: Introduction .................................................................................................. 1 References .................................................................................................................. 9 Chapter 2: Changing environmental gradients over forty years alter ecomorphological variation in Guadalupe Bass Micropterus treculii throughout a river basin ................ 15 Abstract .................................................................................................................... 15 Introduction .............................................................................................................. 16 Methods .................................................................................................................... 22 Study Area ............................................................................................................ 22 Environmental datasets ........................................................................................ 24 Morphometric measurements ............................................................................... 27 Data Analysis ....................................................................................................... 30 Results ...................................................................................................................... 33 Historical and present-day landcover and land use in central Texas ................... 33 Hydrologic regime changes.................................................................................. 34 Spatial and temporal morphological variation ..................................................... 35 Environment and morphological divergence ....................................................... 37 Disscussion ............................................................................................................... 42 References ................................................................................................................ 51 iv Texas Tech University, Jessica E. Pease, August 2018 Chapter 3: Variation in growth and recruitment of Guadalupe Bass Micropterus treculii across gradients of flow within a basin ........................................................... 64 Abstract .................................................................................................................... 64 Introduction .............................................................................................................. 65 Methods .................................................................................................................... 69 Study Area ............................................................................................................ 69 Fish Collection ..................................................................................................... 72 Hydrologic Analysis ............................................................................................ 73 Data Analysis ....................................................................................................... 74 Results ...................................................................................................................... 76 Annual Stream Flow Metrics ............................................................................... 76 Growth ................................................................................................................. 81 Mortality and Recruitment ................................................................................... 85 Discussion ................................................................................................................ 87 References ................................................................................................................ 94 Chapter 4: Movement patterns and habitat associations of Guadalupe Bass Micropterus treculii in the lower Colorado River...................................................... 103 Abstract .................................................................................................................. 103 Introduction ............................................................................................................ 104 Methods .................................................................................................................. 109 Study area ........................................................................................................... 109 Radio tagging and tracking ................................................................................ 110 Characterizing instream habitat availability....................................................... 115 Habitat use and availability ................................................................................ 117 v Texas Tech University, Jessica E. Pease, August 2018 Data analysis ...................................................................................................... 117 Habitat model development ............................................................................... 119 Results .................................................................................................................... 122 Seasonal movement and habitat use ................................................................... 123 Home range .......................................................................................................