W&M ScholarWorks Dissertations, Theses, and Masters Projects Theses, Dissertations, & Master Projects 2010 Effects of habitat quality on secondary production in shallow estuarine waters and the consequences for the benthic-pelagic food web David James Gillett College of William and Mary - Virginia Institute of Marine Science Follow this and additional works at: https://scholarworks.wm.edu/etd Part of the Ecology and Evolutionary Biology Commons, Environmental Sciences Commons, and the Oceanography Commons Recommended Citation Gillett, David James, "Effects of habitat quality on secondary production in shallow estuarine waters and the consequences for the benthic-pelagic food web" (2010). Dissertations, Theses, and Masters Projects. Paper 1539616666. https://dx.doi.org/doi:10.25773/v5-7ybd-6034 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]. EFFECTS OF HABITAT QUALITY ON SECONDARY PRODUCTION IN SHALLOW ESTUARINE WATERS AND THE CONSEQUENCES FOR THE BENTHIC-PELAGIC FOOD WEB A Dissertation Presented to The Faculty of the School ofMarine Science The College of William and Mary in Virginia In Partial Fulfillment Of the Requirements for the Degree of Doctor of Philosophy by David James Gillett 2010 APPROVAL SHEET This dissertation is submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy Approved, by the Committee, January, 2010 ~c. Linda C. Scha fner, PJ/1. Committee Chairperson I Advisor c~OQ_~, Iris C. Anderson, Ph.D . .~A.~ ' . ;, ~ Ehz~h A. Canuel, Ph.D. Walter R. Boyn n, Ph.D. Chesapeake Biological Laboratory University of Maryland Center for Environmental Science TABLE OF CONTENTS DEDICATION .................................................................................................................. v ACKNOWLEDGEMENTS ............................................................................................ vi LIST OF TABLES ......................................................................................................... vii LIST OF FIGURES ...................................................................................................... viii ABSTRACT .................................................................................................................... ix CHAPTER I. ASSESSMENT OF HABITAT DEGRADATION IN THE COASTAL ZONE AND THE CONSEQUENCES FOR RESIDENT BlOTA .................................. .2 Introduction .............................................................................................................. 3 Motivations and Investigative Approach ............................................................... 12 Literature Cited ...................................................................................................... 15 CHAPTER II. THE INFLUENCE OF HABIT AT QUALITY ON SECONDARY PRODUCTION IN SHALLOW ESTUARINE WATERS ............................................ 28 Abstract .................................................................................................................. 29 Introduction ............................................................................................................ 30 Materials and Methods ........................................................................................... 33 Site Selection ................................................................................................... 33 Data Collection ..................................................................... , .......................... 34 Analysis ............................................................................................................ 37 Results .................................................................................................................... 39 Discussion .............................................................................................................. 41 Interpreting the Saline Estuary ........................................................................ .42 Interpreting the Tidal Freshwater .................................................................... .46 Some Comments on Biodiversity and Productivity ........................................ .47 Conclusions ............................................................................................................ 49 Literature Cited ...................................................................................................... 50 CHAPTER Ill. THE INFLUENCE OF HABIT AT QUALITY AND MACROBENTHIC COMMUNITY COMPOSITION ON NEKTON UTILIZATION OF SECONDARY PRODUCTION AS A FOOD SOURCE ........................................................................ 68 Abstract .................................................................................................................. 69 Introduction ............................................................................................................ 70 Materials and Methods ........................................................................................... 74 Site Selection ................................................................................................... 74 Data Collection ................................................................................................ 74 Analysis ............................................................................................................ 77 Results .................................................................................................................... 80 Site Characterization ........................................................................................ 80 111 Caging Artifacts and Environmental Parameters ............................................. 80 Production ........................................................................................................ 82 Discussion ....................................................................... : ...................................... 89 Predation Patterns Among Sites ....................................................................... 90 Predation Patterns Among Faunal Groups ....................................................... 95 Conclusions ..................................................................................................................... 97 Literature Cited ...................................................................................................... 99 Appendices ........................................................................................................... l24 Appendix 1..................................................................................................... 124 Appendix 2 ..................................................................................................... 125 , Appendix 3 ..................................................................................................... 126 Appendix 4 ..................................................................................................... 127 CHAPTER IV. NATURAL ABUNDANCE 13C AND 15N ISOTOPES OF SHALLOW, SUBTIDAL ESTUARINE MACROBENTHOS AND THEIR RELATION TO HABITAT QUALITY .................................................................................................. 128 Abstract ................................................................................................................ 129 Introduction .......................................................................................................... l30 Materials and Methods ......................................................................................... 134 Study Sites ..................................................................................................... 134 Sample Collection .... :..................................................................................... 134 Data Analysis ................................................................................................. 136 Results .................................................................................................................. l39 Spatial and Temporal Comparisons ............................................................... 139 Organic Matter.:consumer Relationships ...................................................... 140 Discussion ................................................. ~ .......................................................... 144 The Contribution of Salt Marsh Detritus ....................................................... 146 The Contribution of Phytoplankton ............................................................... 147 The Influence ofHabitat Quality ................................................................... 147 Conclusions .......................................................................................................... 150 Literature Cited .................................................................................................... 152 Appendix .............................................................................................................. 168 CHAPTER V. OVERALL CONCLUSIONS AND IMPLICATIONS ....................... 169 VITA ............................................................................................................................. l75 IV DEDICATION