W&M ScholarWorks Dissertations, Theses, and Masters Projects Theses, Dissertations, & Master Projects 2005 Physiological Ecology of the Cultured Hard Clam, Mercenaria mercenaria: A Case Study in Cherrystone Inlet, Virginia Elizabeth Darrow Condon College of William and Mary - Virginia Institute of Marine Science Follow this and additional works at: https://scholarworks.wm.edu/etd Part of the Fresh Water Studies Commons, Oceanography Commons, and the Physiology Commons Recommended Citation Condon, Elizabeth Darrow, "Physiological Ecology of the Cultured Hard Clam, Mercenaria mercenaria: A Case Study in Cherrystone Inlet, Virginia" (2005). Dissertations, Theses, and Masters Projects. Paper 1539617838. https://dx.doi.org/doi:10.25773/v5-rw55-2r98 This Thesis 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]. PHYSIOLOGICAL ECOLOGY OF THE CULTURED HARD CLAM, MERCENAR1A MERCENAR1A: A CASE STUDY IN CHERRYSTONE INLET, VIRGINIA A Thesis 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 Master of Science by Elizabeth Darrow Condon 2005 APPROVAL SHEET This thesis is submitted in partial fulfillment of the requirements for the degree of Master of Science izabeth Darrdw Condon Approved, July 2005 ? % / Lor%f Mark W. Luckenbach, Ph.D. Committee Chairman/Advisor (L Roger L. Mapn, Ph.D. Advisor Iris <fc. Anderson, Ph.D. Harry1V.' Wang, Ph.D. T DEDICATION To Rob, who spent many long nights with me in the lab; and to Ian, who spent many long days with me in the field: I love you both. TABLE OF CONTENTS ACKNOWLEDGMENTS..................................................................................................... vi LIST OF TABLES............................................................................................................... viii LIST OF FIGURES................................................................................................................ix ABSTRACT..........................................................................................................................xiii THESIS INTRODUCTION.................................................................................................... 2 The hard clam.................................................................................................................2 Hard clam aquaculture.................................................................................................. 4 Physiology ......................................................................................................... 7 Ecology......................................................................................................................... 11 Modeling .................................... 15 Study site ............................................................... 17 Objectives...................................................................................................................... 19 CHAPTER ONE: Laboratory Studies on the Physiology of the Cultured Clam, Mercenaria mercenaria...............................................................................................20 INTRODUCTION.................... 21 Laboratory feeding studies....................................................................................21 Laboratory biodeposition studies.............................................................. ,.........31 Laboratory respiration studies............................................................................. 32 Laboratory excretion studies............................................ 35 Objectives................................................................................................................38 MATERIALS AND METHODS................................................................................ 39 Feeding ...................................................................................................................39 Respiration and Excretion.....................................................................................42 Analytical methods............................................................................... 43 Data analysis......................................................................................................... 44 RESULTS.....................................................................................................................47 Feeding ...........................................................................................................47 Biodeposition..........................................................................................................63 Respiration..............................................................................................................66 Excretion.................................................................................................................73 DISCUSSION........................................................................ 81 Feeding ...................................................................................................................81 Biodeposition..........................................................................................................87 Respiration..............................................................................................................89 Excretion ...............................................................................................................93 CONCLUSIONS .................................................................................................... 95 CHAPTER TWO: Field-based Studies on Feeding of the Cultured Clam, Mercenaria mercenaria.................................................. 100 INTRODUCTION..................................................................................... 101 Experimental approach........................................................................................106 Objectives.............................................................................................................. 108 METHODS................................................................................................................. 110 RESULTS................................................................................. 118 Net effects on clearance rates..............................................................................126 Tidal stage effects on food availability...............................................................130 DISCUSSION............................................................................................................. 133 Clearance rates.....................................................................................................133 Environmental parameters...................................................................................133 Influence of tidal stage......................................................................................... 134 Influence o f nets and interacting effects .............................. 135 CHAPTER THREE: Estimated ecosytem impacts of Mercenaria mercenaria............. 150 INTRODUCTION.................................................................................... 141 OBJECTIVES.............................................................................................................143 METHODS...................................................................................................... 143 Clam population data........................ 143 Clam feeding rates...................... 146 Carbon energy budget estimates ......................................................................... 148 Nitrogen uptake and release................................................................................149 RESULTS...................................................................................:............................... 151 Clam population data.......................................................................................... 151 Clam filtration rates............................................................................................. 151 Carbon requirements ........................................................................................... 158 Nitrogen uptake and release.............................. 162 DISCUSSION.......................................................... 167 THESIS SUMMARY..........................................................................................................174 APPENDIX 1: CLAM POPULATION DATA ASSUMPTIONS..................................178 APPENDIX 2: CHERRYSTONE INLET DATA............................................................180 APPENDIX 3: CLAM MORPHOMETRICS................................................................... 181 LITERATURE CITED........................................................................................................185 v ACKNOWLEDGMENTS Thanks go to my major advisor, Dr. Mark Luckenbach, for allowing me to think and work independently, providing the resources for me to try out some of my crazy ideas, and being flexible enough to accommodate my changing plans and unforeseen problems that come with conducting experiments in the field. 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