W&M ScholarWorks Dissertations, Theses, and Masters Projects Theses, Dissertations, & Master Projects Spring 2017 Juvenile Blue Crab (Callinectes Sapidus) Response to Altered Nursery Habitat Megan Wood College of William and Mary - Virginia Institute of Marine Science, [email protected] Follow this and additional works at: https://scholarworks.wm.edu/etd Part of the Aquaculture and Fisheries Commons, Marine Biology Commons, and the Terrestrial and Aquatic Ecology Commons Recommended Citation Wood, Megan, "Juvenile Blue Crab (Callinectes Sapidus) Response to Altered Nursery Habitat" (2017). Dissertations, Theses, and Masters Projects. Paper 1499449868. http://dx.doi.org/10.21220/M2GD1Q This Dissertation is brought to you for free and open access by the Theses, Dissertations, & Master Projects at W&M ScholarWorks. It has been accepted for inclusion in Dissertations, Theses, and Masters Projects by an authorized administrator of W&M ScholarWorks. For more information, please contact [email protected]. Juvenile blue crab (Callinectes sapidus) response to altered nursery habitat ____________________ A Dissertation Presented to The Faculty of the School of Marine Science The College of William and Mary in Virginia In Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy ____________________ by Megan A. Wood May 2017 APPROVAL SHEET This dissertation is submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy _________________________________ Megan A. Wood Approved, by the Committee, April, 2017 _________________________________ Romuald N. Lipcius, Ph.D. Committee Chairman/ Advisor _________________________________ Rochelle D. Seitz, Ph.D. _________________________________ Kenneth A. Moore, Ph.D. _________________________________ Carl T. Friedrichs, Ph.D. _________________________________ Sarah L. Day, Ph.D. College of William and Mary Williamsburg, VA _________________________________ Karen J. McGlathery, Ph.D. University of Virginia Charlottesville, VA ii DEDICATION For my mom, who made sure her kids knew how to swim because she couldn’t. I miss you every day. iii TABLE OF CONTENTS ACKNOWLEDGEMENTS ............................................................................................ vi LIST OF TABLES .......................................................................................................... vii LIST OF FIGURES ......................................................................................................... ix LIST OF APPENDICES ................................................................................................. xi DISSERTATION ABSTRACT...................................................................................... xii CHAPTER 1 Dissertation Introduction.......................................................................... 2 LITERATURE CITED ................................................................................................... 5 CHAPTER 2 Exotic red alga Gracilaria vermiculophylla substitutes for seagrass as blue crab nursery habitat in the emerging Chesapeake Bay ecosystem ...................... 7 ABSTRACT .................................................................................................................... 8 INTRODUCTION ........................................................................................................ 10 MATERIALS AND METHODS .................................................................................. 14 Study area.............................................................................................................................. 14 Survey .................................................................................................................................... 15 Analysis ................................................................................................................................. 16 RESULTS ..................................................................................................................... 17 Spatial distribution ................................................................................................................ 17 Seasonal and annual distribution patterns ............................................................................ 17 DISCUSSION ............................................................................................................... 19 Gracilaria distribution and biomass patterns ....................................................................... 19 Interactions with native seagrasses ....................................................................................... 21 Implications for juvenile blue crabs ...................................................................................... 22 LITERATURE CITED ................................................................................................. 24 TABLES ....................................................................................................................... 30 FIGURES ...................................................................................................................... 33 CHAPTER 3 Utilization of native seagrass and exotic algae by juvenile blue crabs and macrofaunal prey communities .............................................................................. 39 ABSTRACT .................................................................................................................. 40 INTRODUCTION ........................................................................................................ 41 MATERIALS AND METHODS .................................................................................. 44 Epifaunal communities .......................................................................................................... 45 Infaunal communities ............................................................................................................ 45 Analysis ................................................................................................................................. 46 RESULTS ..................................................................................................................... 47 Juvenile blue crab density and size ....................................................................................... 47 Epifaunal communities .......................................................................................................... 48 Infaunal communities ............................................................................................................ 48 DISCUSSION ............................................................................................................... 50 LITERATURE CITED ................................................................................................. 52 TABLES ....................................................................................................................... 55 FIGURES ...................................................................................................................... 61 iv CHAPTER 4 In situ growth of juvenile blue crabs in native seagrass and the exotic alga Gracilaria vermiculophylla in lower Chesapeake Bay .......................................... 65 ABSTRACT .................................................................................................................. 66 INTRODUCTION ........................................................................................................ 67 MATERIALS AND METHODS .................................................................................. 70 RESULTS ..................................................................................................................... 72 Physical variables ................................................................................................................. 72 Growth................................................................................................................................... 73 DISCUSSION ............................................................................................................... 73 LITERATURE CITED ................................................................................................. 75 TABLES ....................................................................................................................... 81 FIGURES ...................................................................................................................... 85 APPENDIX I ................................................................................................................. 88 CHAPTER 5 Simulated effects of benthic habitat on juvenile blue crab recruitment in the York River ............................................................................................................ 91 ABSTRACT .................................................................................................................. 92 INTRODUCTION ........................................................................................................ 93 MATERIALS AND METHODS .................................................................................. 97 Blue crab nursery habitat model ........................................................................................... 97 Numerical simulations .........................................................................................................