National Park Service U.S. Department of the Interior Natural Resource Stewardship and Science Assessment of Natural Resource Condition in and Adjacent to the Dry Tortugas National Park Natural Resource Report NPS/DRTO/NRR—2012/558 ON THE COVER Sergeant majors (Abudefduf saxatilis) in Dry Tortugas National Park. Photograph by NOAA/NOS/NCCOS/CCMA Biogeography Branch Assessment of Natural Resource Conditions In and Adjacent to Dry Tortugas National Park Natural Resource Report NPS/DRTO/NRR—2012/558 Christopher F. G. Jeffrey1,2 ,Sarah D. Hile1,2, Christine Addison3, Jerald S. Ault4, Carolyn Currin3, Don Field3, Nicole Fogarty5, Jiangang Luo4, Vanessa McDonough6, Doug Morrison7, Greg Piniak1, Varis Ransibrahmanakul1, Steve G. Smith4, Shay Viehman3 Editor: Christopher F. G. Jeffrey1,2 1National Oceanic and Atmospheric 4University of Miami Administration Rosenstiel School of Marine and National Ocean Service, National Centers Atmospheric Science for Coastal Ocean Science 4600 Rickenbacker Causeway Center for Coastal Monitoring and Miami, FL 33149-1098 Assessment, Biogeography Branch 1305 East West Highway, SSMC4, N/SCI-1 5Nova Southeastern University Silver Spring, MD 20910 Oceanographic Center 8000 N. Ocean Drive 2Consolidated Safety Services, Inc. Dania Beach, Florida 10301 Democracy Lane, Suite 300 Fairfax, VA 22030 6National Park Service Biscayne National Park 3National Oceanic and Atmospheric 9700 SW 328 Street Administration Homestead, Florida 33033 National Ocean Service, National Centers for Coastal Ocean Science 7National Park Service Center for Coastal Fisheries and Habitat Everglades and Dry Tortugas National Parks Research 40001 State Road 9336 101 Pivers Island Rd Homestead, Florida 33034-6733 Beaufort NC 28516-9722 July 2012 U.S. Department of the Interior National Park Service Natural Resource Stewardship and Science Fort Collins, Colorado The National Park Service, Natural Resource Stewardship and Science office in Fort Collins, Colorado publishes a range of reports that address natural resource topics of interest and app licability to a broad audience in the National Park Service and others in natural resource management, including scientists, conservation and environmental constituencies, and the public. The Natural Resource Report Series is used to disseminate high-priority, current natural resource management information with managerial application. The series targets a general, diverse audience, and may contain NPS policy considerations or address sensitive issues of management applicability. All manuscripts in the series receive the appropriate level of peer review to ensure that the information is scientifically credible, technically accurate, appropriately written for the intended audience, and designed and published in a professional manner. This report received formal peer review by subject-matter experts who were not directly involved in the collection, analysis, or reporting of the data, and whose background and expertise put them on par technically and scientifically with the authors of the information. Views, statements, findings, conclusions, recommendations, and data in this report do not necessarily reflect views and policies of the National Park Service, U.S. Department of the Interior. Mention of trade names or commercial products does not constitute endorsement or recommendation for use by the U.S. Government. This report is available from the Ocean and Coastal Resources Branch (Water Resource Division) of the National Park Service and the Natural Resource Publications Management website (http://www.nature.nps.gov/publications/nrpm/). Please cite this publication as: Jeffrey, C. F. G., S. D. Hile, C. Addison, J. S. Ault, C. Currin, D. Field, N. Fogarty, J. Luo, V. McDonough, D. Morrison, G. Piniak, V. Ransibrahmanakul, S. G. Smith, S. Viehman. 2012. Assessment of natural resource conditions in and adjacent to Dry Tortugas National Park. Natural Resource Report NPS/DRTO/NRR—2012/558. National Park Service, Fort Collins, Colorado. NPS 364/115932, July 2012 ii Contents Page Contents ......................................................................................................................................... iii Figures........................................................................................................................................... vii Tables ............................................................................................................................................. xi Executive Summary ..................................................................................................................... xiii Acknowledgements .................................................................................................................... xxvi Acronyms .................................................................................................................................. xxvii Chapter 1: Introduction ................................................................................................................... 1 Chapter 2: History of Dry Tortugas National Park ......................................................................... 5 2.1. History of Research, 1852−1990 ......................................................................................... 5 2.2. Recent Multi-year Research and Monitoring, 1990−2007 .................................................. 6 2.3. Current Research and Monitoring, 2007 to Present ............................................................. 6 Chapter 3: Climate and Oceanography ......................................................................................... 17 3.1. Climate ............................................................................................................................... 17 3.2. Geologic and Bathymetric Features ................................................................................... 17 3.3. Oceanography and Currents ............................................................................................... 18 3.4. Climate Change versus Variability in Ocean Temperature ............................................... 20 3.3.1. Sea Surface Temperature ............................................................................................ 20 3.3.2. Sea Level Rise ............................................................................................................. 21 3.3.3. Ocean Acidification .................................................................................................... 21 3.3.4. Cyclonic Storms .......................................................................................................... 22 3.4. Water Quality ..................................................................................................................... 23 3.5. Summary ............................................................................................................................ 26 Chapter 4: Distribution and Condition of Coral Reef and Benthic Communities ........................ 37 4.1. Spatial Distribution of Coral Reefs, 1882−1990s .............................................................. 37 4.2. Characterization of Benthic Communities at the Sand-reef Interface ............................... 39 4.2.1. Data Collection and Statistical Analyses .................................................................... 39 4.2.2. Results and Discussion ............................................................................................... 40 4.3. Multi-scale Mapping, Benthic Cover, and Fish Surveys ................................................... 45 4.4. Long-term Monitoring of Coral Cover .............................................................................. 45 iii Contents (continued) Page 4.5. Long-term Monitoring of Coral Disease and Bleaching .................................................... 46 4.6. South Florida/Caribbean Inventory and Monitoring Network ........................................... 47 4.7. Summary ............................................................................................................................ 48 Chapter 5: Distribution and Condition of Seagrass, Algal, and Sand Communities .................... 63 5.1. Importance of Seagrass and Algal Communities to Coral Reef Ecosystems .................... 63 5.2. Types and Spatial Distribution of Submerged Aquatic Vegetation ................................... 63 5.3. Monitoring of Seagrasses and Algae ................................................................................. 65 5.3.1. South Florida/Caribbean Monitoring Network ........................................................... 65 5.3.2. Monitoring of Seagrasses ............................................................................................ 65 5.3.3. Methods ....................................................................................................................... 66 5.3.4. Results and Discussion ............................................................................................... 66 5.4. Summary ............................................................................................................................ 67 Chapter 6: Condition of Reef Fishes and Macroinvertebrates ...................................................... 81 6.1. Reef Fishes, Fisheries, and Resource Management ........................................................... 81 6.2. Trends and Patterns in Fisheries Landings and