Karl-Franzens-Universitaet Graz Geobiological Aspects of the Southeast Florida Continental Reef Tract By Kenneth Banks A thesis Submitted to the Faculty of Graduate Studies and Research in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy Institut fuer Erdwissenschaften Graz, Austria 2007 Table of Contents LIST OF FIGURES .......................................................................................................... 5 LIST OF TABLES .......................................................................................................... 11 LIST OF APPENDICES ................................................................................................ 13 ABSTRACT..................................................................................................................... 14 1 INTRODUCTION....................................................................................................... 16 INTRODUCTION........................................................................................................... 16 RATIONALE FOR THE STUDY OF THE SOUTHEAST FLORIDA REEF TRACT.................................................. 17 GEOBIOLOGICAL APPROACH TO REEF STUDIES ......................................................................................... 18 THESIS OBJECTIVES.................................................................................................. 18 REFERENCES................................................................................................................ 19 2 ACTIVE OPTICAL AND ACOUSTIC REMOTE SENSING METHODS OF CORAL REEF GEOMORPHOLOGY ........................................................................ 21 INTRODUCTION........................................................................................................... 21 REEF MAPPING............................................................................................................ 23 SIDESCAN SONAR...................................................................................................................................... 24 ACOUSTIC ECHO ANALYSIS....................................................................................................................... 28 RoxAann.............................................................................................................................................. 30 QTC View............................................................................................................................................ 33 Echoplus.............................................................................................................................................. 35 BATHYMETRIC MAPPING........................................................................................ 36 SINGLE-BEAM ECHOSOUNDERS................................................................................................................. 37 MULTI-BEAM ECHOSOUNDERS.................................................................................................................. 38 ACTIVE OPTICAL METHODS (LASER) ......................................................................................................... 42 COMBINED METHODS............................................................................................... 45 CONCLUSIONS ............................................................................................................. 45 REFERENCES................................................................................................................ 46 3 GEOMORPHOLOGY OF THE SOUTHEAST FLORIDA CONTINENTAL REEF TRACT (MIAMI-DADE, BROWARD, AND PALM BEACH COUNTIES, USA) ................................................................................................................................. 52 INTRODUCTION........................................................................................................... 52 MATERIALS AND METHODS ................................................................................... 54 2 BATHYMETRIC DATA COLLECTION AND ANALYSIS ................................................................................... 55 SUBBOTTOM PROFILING............................................................................................................................ 56 CORING .................................................................................................................................................... 56 ANALYSIS OF GEOMORPHOLOGY .............................................................................................................. 57 RESULTS ........................................................................................................................ 57 OVERALL MORPHOLOGY .......................................................................................................................... 58 THE OUTER REEF ...................................................................................................................................... 60 THE MIDDLE REEF..................................................................................................................................... 65 THE INNER REEF ....................................................................................................................................... 70 RIDGE COMPLEX....................................................................................................................................... 74 DISCUSSION .................................................................................................................. 75 SURFICIAL GEOLOGY ................................................................................................................................75 DEPOSITIONAL FRAMEWORK .................................................................................................................... 78 RECONSTRUCTED GROWTH HISTORY ........................................................................................................ 79 ACKNOWLEDGMENTS .............................................................................................. 82 REFERENCES................................................................................................................ 82 4 ENVIRONMENTAL GEOLOGY OF THE CONTINENTAL SOUTHEAST FLORIDA REEF TRACT (MIAMI-DADE, BROWARD AND PALM BEACH COUNTIES, USA) .......................................................................................................... 86 INTRODUCTION........................................................................................................... 86 REGIONAL SETTING .................................................................................................................................. 90 Climatology......................................................................................................................................... 91 Hurricanes .......................................................................................................................................... 93 Regional Physical Oceanographic Processes..................................................................................... 95 HOLOCENE CLIMATE.............................................................................................................................. 100 ENVIRONMENTAL RECORDS IN CORAL SKELETONS ................................. 106 CHARACTERIZATION OF SOUTHEAST FLORIDA REEFS ............................ 110 GEOMORPHOLOGY.................................................................................................................................. 110 BENTHIC HABITAT MAPPING.................................................................................................................. 115 BIOGEOGRAPHY OF SOUTHEAST FLORIDA REEFS...................................... 120 PATTERNS IN REEF COMMUNITY STRUCTURE............................................. 126 REGION-WIDE BENTHIC COMMUNITY STRUCTURE .................................................................................. 126 CROSS-SHELF PATTERNS IN BENTHIC COMMUNITY STRUCTURE.............................................................. 131 FISH COMMUNITY STRUCTURE................................................................................................................ 137 Miami-Dade and Broward Counties.................................................................................................137 Palm Beach County........................................................................................................................... 143 HUMAN IMPACTS AND CONSERVATION ISSUES ........................................... 147 WATER QUALITY.................................................................................................................................... 148 COASTAL CONSTRUCTION ...................................................................................................................... 149 SHIP GROUNDINGS AND ANCHOR DAMAGE ON REEFS ........................................................................... 152 CLIMATE CHANGE.................................................................................................................................. 154 PRESENT STATUS OF REEF HEALTH ................................................................. 155 3 CONCLUSIONS ..........................................................................................................