TCRMP 2012: annual report, part 1

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Date: 2012
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ANNUAL REPORT 2012 Smith TB, Kadison E, Henderson L, Gyory J, Brandt ME, Wright V, Nemeth RS, Rothenberger P The United States Virgin Islands TERRITORIAL CORAL REEF MONITORING PROGRAM A collaboration between: The Center for Marine and Environmental Studies, University of the Virgin Islands The Division of Coastal Zone Management, USVI Department of Planning and Natural Resources The Coral Reef Conservation Program, National Oceanic and Atmospheric Administration INDEX i © 2012 Cite As: Smith TB, Kadison E, Henderson L, Gyory J, Brandt ME, Wright V, Nemeth RS, Rothenberger P (2012) The United States Virgin Islands Territorial Coral Reef Monitoring Program. Year 12 Annual Report. Version 1 267 pp INDEX ii INDEX OF TABLES XII MISSION 13 OUR VISION 13 OBJECTIVES 13 EXECUTIVE SUMMARY 14 CORAL REEFS OF THE VIRGIN ISLANDS: MANGEMENT ACTIONS NEEDED 14 CORAL REEFS OF THE VIRGIN ISLANDS: POSITIVE SIGNS 16 RESEARCH HIGHLIGHTS 20 BLEACHING RESISTANT SPECIES IN THE CARIBBEAN AND IMPLICATIONS FOR CORAL REEF MANAGEMENT 21 RECOMMENDATIONS 23 INTRODUCTION 25 OBJECTIVES FOR MONITORING CORAL REEFS 28 METHODS 30 BENTHIC ASSESSMENTS 30 FISH CENSUS 36 TERRITORIAL CORAL REEF MONITORING SUMMARY 37 BENTHIC COMMUNITIES AND CORAL REEF HEALTH 38 CORAL COVER 38 EPILITHIC ALGAL COMMUNITY COVER 40 MACROALGAL COVER 42 FILAMENTOUS CYANOBACTERIA 44 GORGONIAN AND ANTIPATHARIAN COVER 46 INDEX iii SPONGE COVER 48 FISH COMMUNITIES 50 FISH ABUNDANCE 52 FISH BIOMASS 54 BLACK SPINY SEA URCHIN DIADEMA ANTILLARUM 56 SITE SUMMARIES 58 RATIONALE 58 SITE SUMMMARY ELEMENTS 58 ST. CROIX 61 BUCK ISLAND, ST. CROIX 63 CANE BAY 69 CANE BAY DEEP 75 CASTLE 81 EAGLE RAY 87 GREAT POND 93 JACKS BAY 99 KINGS CORNER 105 LANG BANK EAST END MARINE PARK 111 LANG BANK RED HIND FISH SPAWNING AGGREGATION 117 MUTTON SNAPPER 123 SALT RIVER WEST 129 SALT RIVER DEEP 135 SPRAT HOLE 141 ST. JOHN 147 CORAL BAY 149 FISH BAY 155 MERI SHOAL 161 INDEX iv ST. THOMAS 167 BLACK POINT 169 BOTANY BAY 175 BREWERS BAY 181 BUCK ISLAND, ST. THOMAS 187 COCULUS ROCK 193 COLLEGE SHOAL 199 FLAT CAY 205 GINSBURGS FRINGE 211 GRAMMANIK TIGER 215 HIND BANK 221 LITTLE SAINT JAMES 227 MAGENS BAY 233 SAVANA ISLAND 239 SEAHORSE COTTAGE SHOAL 245 SOUTH CAPELLA 251 SOUTH WATER 257 LITERATURE CITED 263 INDEX v Index of Figures Figure 1. Partially bleached and recovering colony of Siderastrea siderea at Flat Cay, St. Thomas (Nov. 12, 2005). ................................................................................................................................................................................................................. 15 Figure 2. Bleaching of Orbicella faveolata and O. annularis at Flat Cay, St. Thomas (Nov. 12, 2005). .................. 21 Figure 3. The multi-‐faceted response of Orbicella spp. to the 2005 bleaching event. .................................................... 24 Figure 4. Locations of Territorial Coral Reef Monitoring Sites in the US Virgin Islands, 2008-‐2010.Boundaries indicate federal and territorial marine protected areas. ............................................................................................................ 29 Figure 5. A screen grab of benthic video used for the determination of percent cover of coral reef organisms and non-‐living substrate. ........................................................................................................................................................................... 32 Figure 6. Coral cover (±SE) across TCRMP monitoring sites over time. .............................................................................. 39 Figure 7. Epilithic algal community cover (±SE) across TCRMP monitoring sites over time. .................................... 41 Figure 8. Macroalgae cover (±SE) across TCRMP monitoring sites over time. ................................................................. 43 Figure 9. Filamentous cyanobacteria cover (±SE) across TCRMP monitoring sites over time. ................................. 45 Figure 10. Gorgonian and Antipatharian cover (±SE) across TCRMP monitoring sites over time. ......................... 47 Figure 11. Sponge cover (±SE) across TCRMP monitoring sites over time. ........................................................................ 49 Figure 12. Fish abundance (±SE) across TCRMP monitoring sites over time. Dotted line separates St. Croix sites (left) from St. Thomas (right). ...................................................................................................................................................... 53 Figure 13. Mean fish biomass (±SE) across TCRMP monitoring sites over time. Dotted line separates St. Croix sites (left) from St. Thomas (right). ...................................................................................................................................................... 55 Figure 14. Abundance of the black spiny sea urchin (Diadema antillarum) at TCRMP monitoring sites. Note the log scale. .................................................................................................................................................................................................... 57 Figure 15. The Buck Island, St. Croix. (top) Position in the Buck Island Reef National Monument. (right)A representative photo. .................................................................................................................................................................................. 63 Figure 16. Buck Island, St. Croix benthic temperatures (14 m depth). Data provided by the National Park Service (site BUIS_SFR). ............................................................................................................................................................................. 64 Figure 17. Buck Island, St. Croix. (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. .................................................... 65 Figure 18. Buck Island, St. Croix benthic cover and coral health through time (mean ±SE). ..................................... 66 Figure 19. The Buck Island, St. Croix fish community by absolute and relative biomass. ............................................ 68 Figure 20. Cane Bay. (top) Location. (right) A representative photo of the reef. ........................................................... 69 Figure 21. Cane Bay benthic temperatures (8 m depth) ............................................................................................................ 70 INDEX vi Figure 22. Cane Bay. (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. ..................................................................................... 71 Figure 23. Cane Bay benthic cover and coral health through time (mean ±SE). ............................................................. 72 Figure 24. The Cane Bay fish community by absolute and relative biomass. .................................................................... 74 Figure 25. Cane Bay Deep. (top) Location. (right) A representative photo of the reef during the 2005 bleaching event. Bleached colonies are 0.5 – 3 m wide. .............................................................................................................. 75 Figure 26. Cane Bay Deep temperature (39 m depth). ................................................................................................................ 76 Figure 27. Cane Bay Deep. (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. ................................................................... 77 Figure 28. Cane Bay Deep benthic cover and coral health through time (mean ±SE). ................................................. 78 Figure 29. The Cane Bay Deep fish community by absolute and relative biomass. ........................................................ 80 Figure 30. Castle. (top) Location. (right) A representative photo of the reef. .................................................................. 81 Figure 31. Castle benthic temperatures (9 m depth). .................................................................................................................. 82 Figure 32. Castle. (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. ..................................................................................... 83 Figure 33. Castle benthic cover and coral health through time (mean ±SE). .................................................................... 84 Figure 34. The Castle fish community by absolute and relative biomass. ........................................................................... 86 Figure 35. Eagle Ray. (top) Location. (right) A representative photo of the reef. .......................................................... 87 Figure 36. Eagle Ray benthic temperature at 9 m depth ........................................................................................................... 88 Figure 37. Eagle Ray. (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. ..................................................................................... 89 Figure 38. Eagle Ray benthic cover and coral health through time (mean ±SE). ............................................................ 90 Figure 39. The Eagle Ray fish community by absolute and relative biomass. ................................................................... 92 Figure 40. Great Pond. (top) Location. (right) A representative photo of the reef. ....................................................... 93 Figure 41. Great Pond benthic temperature (5 m depth). ......................................................................................................... 94 Figure 42. Great Pond (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. ..................................................................................... 95 Figure 43. Great Pond benthic cover and coral health through time (mean ±SE). ......................................................... 96 Figure 44. The Great Pond fish community by absolute and relative biomass. ................................................................ 98 Figure 45. Jacks Bay. (top) Location. (right) A representative photo of the reef. ........................................................... 99 Figure 46. Jacks Bay benthic temperature at 12 m depth ....................................................................................................... 100 Figure 47. Jacks Bay (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. .................................................................................. 101 INDEX vii Figure 48. Jacks Bay benthic cover and coral health through time (mean ±SE). ......................................................... 102 Figure 49. The Jacks Bay fish community by absolute and relative biomass. ................................................................ 104 Figure 50. Kings Corner. (top) Location. (right) A representative photo of the reef with a school of lane snapper (Lutjaus synagris). ................................................................................................................................................................... 105 Figure 51. Kings Corner benthic temperature (17 m depth) ................................................................................................. 106 Figure 52. Kings Corner (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. ................................................................ 107 Figure 53. Kings Corner benthic cover and coral health through time (mean ±SE). .................................................. 108 Figure 54. The Kings Corner fish community by absolute and relative biomass. ......................................................... 110 Figure 55. Lang Bank EEMP. (top) Location. (right) A representative photo of the reef. ........................................ 111 Figure 56. Lang Bank EEMP benthic temperature (28 m depth) ........................................................................................ 112 Figure 57. Lang Bank East End Marine Park (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. ...................... 113 Figure 58. Lang Bank EEMP benthic cover and coral health through time (mean ±SE). ......................................... 114 Figure 59. The Lang Bank EEMP fish community by absolute and relative biomass. ................................................ 116 Figure 60. Lang Bank Red Hind FSA. (top) Location. (right) A representative photo of the reef. ........................ 117 Figure 61. Lang Bank Hind current speed (left) and benthic temperature (right; 33m depth) ............................ 118 Figure 62. Lang Bank Red Hind FSA (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. ................................................. 119 Figure 63. Lang Bank Red HindFSA benthic cover and coral health through time (mean ±SE). ........................... 120 Figure 64. The Lang Bank Red Hind FSA fish community by absolute and relative biomass. ................................. 122 Figure 65. Mutton Snapper. (top) Location. (right) A representative photo of the reef. .......................................... 123 Figure 66. Mutton Snapper benthic temperature record at 23 m (left) and 39 m depth (right). ......................... 124 Figure 67. Mutton Snapper (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. ................................................................ 125 Figure 68. Mutton Snapper benthic cover and coral health through time (mean ±SE). ........................................... 126 Figure 69. The Mutton Snapper fish community by absolute and relative biomass. .................................................. 128 Figure 70. Salt River. (top) Location. (right) A representative photo of the reef. ....................................................... 129 Figure 71. Salt River West surface-‐benthic temperature record (1 and 5m depths). Data provided by the NOAA ICON monitoring network. ....................................................................................................................................................... 130 Figure 72. Salt River West (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. ................................................................ 131 Figure 73. Salt River West benthic cover and coral health through time (mean ±SE). .............................................. 132 INDEX viii Figure 74. The Salt River West fish community by absolute and relative biomass. ..................................................... 134 Figure 75. Salt River Deep. (top) Location. (right) A representative photo of the reef. ............................................ 135 Figure 76. Salt River Deep benthic temperature at 30 m depth (left) and 40 m depth (right). ............................. 136 Figure 77. Salt River Deep (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. ................................................................ 137 Figure 78. Salt River Deep benthic cover and coral health through time (mean ±SE). ............................................. 138 Figure 79. The Salt River Deep fish community by absolute and relative biomass. .................................................... 140 Figure 80. Sprat Hole. (top) Location. (right) A representative photo of the reef. ..................................................... 141 Figure 81. Sprat Hole benthic temperature (7 m depth). ........................................................................................................ 142 Figure 82. Sprat Hole (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. .................................................................................. 143 Figure 83. Sprat Hole benthic cover and coral health through time (mean ±SE). ....................................................... 144 Figure 84. The Sprat Hole fish community by absolute and relative biomass. .............................................................. 146 Figure 85. Coral Bay. (top) Location. (right) A representative photo of the reef. ....................................................... 149 Figure 86. Coral Bay benthic temperature (9 m depth) .......................................................................................................... 150 Figure 87. Coral Bay (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. .................................................................................. 151 Figure 88. Coral Bay benthic cover and coral health through time (mean ±SE). ......................................................... 152 Figure 89. Coral Bay. (top) Location. (right) A representative photo of the reef. ....................................................... 155 Figure 90. Fish Bay benthic temperature record (6m depth). .............................................................................................. 156 Figure 91. Fish Bay (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. .................................................................................. 157 Figure 92. Fish Bay benthic cover and coral health through time (mean ±SE). ............................................................ 158 Figure 93. Meri Shoal. (top) Location. (right) A representative photo of the reef during the 2005 coral bleaching event (Oct. 6, 2005). The brain coral in the foreground is 1.8m wide. ....................................................... 161 Figure 94. Meri Shoal benthic temperature record (30m depth). ....................................................................................... 162 Figure 95. Meri Shoal (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. .................................................................................. 163 Figure 96. Meri Shoal benthic cover and coral health through time (mean ±SE). ....................................................... 164 Figure 97. Black Point. (top) Location. (right) A representative photo of the reef. ................................................... 169 Figure 98. Black point current speed and benthic temperature record (8 m depth). ................................................. 170 Figure 99. Black Point chlorophyll (left) and turbidity (right) record (16 m depth) ................................................. 170 INDEX ix Figure 100. Black Point. (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. ................................................................ 171 Figure 101. Black Point benthic cover and coral health through time (mean ±SE). ................................................... 172 Figure 102. The Black Point fish community by absolute and relative biomass. .......................................................... 174 Figure 103. Botany Bay. (top) Location. (right) A representative photo of the reef. ................................................. 175 Figure 104. Botany Bay benthic temperature record (11 m depth). .................................................................................. 176 Figure 105. A large colony of pillar coral (Dendrogyra cylindricus) dislodge, toppled, and diseased after the 2009 swell event (Botany Bay, June 25, 2009). ............................................................................................................................. 176 Figure 106. Botany Bay. (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. ................................................................ 177 Figure 107. Botany Bay benthic cover and coral health through time (mean ±SE). ................................................... 178 Figure 108. Brewers Bay. (top) Location. (right) A representative photo of the reef. ............................................... 181 Figure 109. Brewers Bay. (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. ................................................................ 183 Figure 110. Brewers Bay benthic cover and coral health through time (mean ±SE) ................................................. 184 Figure 111. The Brewers Bay fish community by absolute and relative biomass. ....................................................... 186 Figure 112. Buck Island, St. Thomas. (top) Location. (right) A representative photo of the reef. ....................... 187 Figure 113. Buck Island, St. Thomas benthic temperature record (12 m depth). ........................................................ 188 Figure 114. Buck Island, St. Thomas. (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. ................................................. 189 Figure 115. Buck Island, St. Thomas benthic cover and coral health through time (mean ±SE). ......................... 190 Figure 116. Coculus Rock. (top) Location. (right) A representative photo of the reef showing the aggregation of redfin parrotfish. ................................................................................................................................................................................... 193 Figure 117. Coculus Rock benthic temperature record (7m depth). .................................................................................. 194 Figure 118. Coculus Rock. (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. ................................................................ 195 Figure 119. Coculus Rock benthic cover and coral health through time (mean ±SE). ............................................... 196 Figure 120. College Shoal. (top) Location. (right) A representative photo of the reef. ............................................. 199 Figure 121.College Shoal benthic temperature record (29m depth). ................................................................................. 200 Figure 122. College Shoal (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. ................................................................ 201 Figure 123. College Shoal benthic cover and coral health through time (mean ±SE). ............................................... 202 Figure 124. The College Shoal fish community by absolute and relative biomass. ...................................................... 204 INDEX x Figure 125. Flat Cay. (top) Location. (right) A representative photo of the reef. ........................................................ 205 Figure 126. Flat Cay benthic current speed (left) and temperature record (right) (14m depth). ........................ 206 Figure 127. Flat Cay (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. .................................................................................. 207 Figure 128. Flat Cay benthic cover and coral health through time (mean ±SE). ......................................................... 208 Figure 129. The Flat Cay fish community by absolute and relative biomass. ................................................................ 210 Figure 130. Ginsburgs Fringe. (top) Location. (right) A representative photo of the reef showing whorled lettuce coral colonies up to 7m in width. ......................................................................................................................................... 211 Figure 131. Ginsburgs Fringe current speed (50m depth). .................................................................................................... 212 Figure 132. Ginsburgs Fringe. (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. ................................................................ 213 Figure 133. Ginsburgs Fringe benthic cover through time (mean ±SE). .......................................................................... 214 Figure 134. Grammanik Tiger (top) Location. (right) A representative photo of the reef. .................................... 215 Figure 135. Grammanik Tiger benthic currents speed and temperature record (38 m depth). ............................ 216 Figure 136. Grammanik Tiger FSA. (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. ................................................. 217 Figure 137. Grammanik Tiger benthic cover and coral health through time (mean ±SE). ..................................... 218 Figure 138. The Grammanik Tiger fish community by absolute and relative biomass. ............................................ 220 Figure 139. Hind Bank (top) Location. (right) A representative photo of the reef. ................................................. 221 Figure 140. Hind Bank benthic current speed (40m depth). Benthic temperature record at 20, 30, and 40 m depth. ............................................................................................................................................................................................................... 222 Figure 141. Hind Bank. (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. ................................................................ 223 Figure 142. Hind Bank benthic cover and coral health through time (mean ±SE). ..................................................... 224 Figure 143. The Hind Bank East fish community by absolute and relative biomass. ................................................. 226 Figure 144. Little St. James. (top) Location. (right) A representative photo of the reef. ......................................... 227 Figure 145. Little St. James benthic temperature record (19m depth). ............................................................................ 228 Figure 146. Little St. James. (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. ................................................................ 229 Figure 147. Little St. James benthic cover and coral health through time (mean ±SE). ............................................ 230 Figure 148. Magens Bay. (top) Location. (right) A representative photo of the reef. ............................................... 233 Figure 149. Magens Bay current speed and benthic temperature record (9 m depth). ............................................ 234 Figure 150. Magens Bay chlorophyll (left) and turbidity (right) record (16 m depth). ............................................ 234 INDEX xi Figure 151. Magens Bay. (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. ................................................................ 235 Figure 152. Magens Bay benthic cover and coral health through time (mean ±SE). ................................................. 236 Figure 153. Savana. (top) Location. (right) A representative photo of the reef during the 2005 coral bleaching event. The dog snapper Lutjanus jocu) is approximately 50cm in length. ................................................. 239 Figure 154. Savana benthic temperature record (10m depth). ........................................................................................... 240 Figure 155. Savana Island. (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. ................................................................ 241 Figure 156. Savana Island benthic cover and coral health through time (mean ±SE). ............................................. 242 Figure 157. Seahorse Cottage Shoal. (top) Location. (right) A representative photo of the reef. ........................ 245 Figure 158. Seahorse benthic temperature record (21m depth). ........................................................................................ 246 Figure 159. Seahorse Cottage Shoal. (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. ................................................. 247 Figure 160. Seahorse Cottage Shoal benthic cover and coral health through time (mean ±SE). .......................... 248 Figure 161. The Seahorse Cottage Shoal fish community by absolute and relative biomass. ................................. 250 Figure 162. South Capella. (top) Location. (right) A representative photo of the reef. ........................................... 251 Figure 163. South Capella benthic temperature record (24m depth). .............................................................................. 252 Figure 164. South Capella. (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. ................................................................ 253 Figure 165. South Capella benthic cover and coral health through time (mean ±SE). .............................................. 254 Figure 166. The South Capella fish community by absolute and relative biomass. ..................................................... 256 Figure 167.South Water. (top) Location. (right) A representative photo of the reef. ................................................ 257 Figure 168. South Water benthic temperature record (24m depth) .................................................................................. 258 Figure 169. South Water. (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. ................................................................ 259 Figure 170. South Water benthic cover and coral health through time (mean ±SE). ................................................ 260 Figure 171. The South Water fish community by absolute and relative biomass. ....................................................... 262 INDEX xii Index of Tables Table 1. TCRMP site reef complex type, location coordinates, and depths. FSA = Fish Spawning Aggregation. EEMP = East End Marine Park. ............................................................................................................................................................... 33 Table 2. TCRMP site date sampled (benthic/health) and type of sampling. ...................................................................... 34 Table 3. Species richness across sites in belt transects and roving diver surveys (RDS). Sites are divided into nearshore, offshore and mesophotic sites as described in the text above. ........................................................................... 51 MISSION STATEMENT 13 Mission OUR VISION To provide critical information on the status and threats to all Virgin Islands coral reef ecosystems in order to increase management effectiveness and improve basic and applied coral reef research OBJECTIVES • Monitor the status and trajectories of coral reefs across a majority of habitats and threats, including land-‐based sources of pollution & thermal stress • Link changes in coral reef health with specific stressors, indicating specific management interventions most effective for preserving reefs • Integrate assessments of understudied mesophotic coral reef ecosystems and threatened species in the USVI • Provide data, outputs, and advice to stakeholders and create a nexus of information for reef research EXECUTIVE SUMMARY 14 Executive Summary Coral reefs in the Caribbean are facing a dramatic decline and are at a crossroads. Management decisions made today will affect the goods and services that reefs provide for decades to come. The government of the United States Virgin Islands (USVI), in coordination with the NOAA Coral Reef Conservation Program and the University of the Virgin Islands, implemented the Territorial Coral Reef Monitoring Program (TCRMP). The TCRMP has established baseline conditions and temporal trends of coral reefs and fish populations and has identified threats that will influence the future reef health and development. A major focus of the TCRMP is to provide information that can lead to more effective management strategies that balance the immediate needs of the Virgin Island’s population with preservation and sustainability of coral reefs and the renewable goods and services they provide. The intent of this report is to distill monitoring data into actionable information that can guide management decisions and inform the public and policy-‐makers on areas that need further effort. This executive summary presents information on threats to USVI reefs that require management intervention/action as well as positive signs that can inform our understanding of sustainability. CORAL REEFS OF THE VIRGIN ISLANDS: MANGEMENT ACTIONS NEEDED The TCRMP data has identified threats to USVI coral reef ecosystems that need increased management attention if reef corals are to persist in a condition that is equal to or better than current conditions. Coral Reef Bleaching. High thermal stress caused by climate change is currently the greatest threat to USVI coral reef ecosystems. The 2005 coral bleaching event caused the EXECUTIVE SUMMARY 15 largest loss of coral in the documented history of the USVI, with a 50% decline in coral cover in shallow waters less than 25m/85’ deep. This event surpassed all known modern impacts from physical damage (storms and anchoring), ecosystem changes (fishing and disease), and pollution (terrestrial sediments and toxins). These events are predicted to increase with a warming planet, troubling news for the USVI While local management actions cannot remove impacts to reefs from global warming, reefs that are otherwise less stressed by land-‐based sources of pollution, fishing, and/or physical damage are known to recover more quickly from bleaching. Hence, local management actions that promote seascape-‐wide coral reef health offer the best strategy for sustainable reefs. We can also identify areas that are naturally more resistant to thermal stress and offer these areas further protection, since they offer insurance against the worst possible future outcomes for USVI reefs. Figure 1. Partially bleached and recovering colony of Siderastrea siderea at Flat Cay, St. Thomas (Nov. 12, 2005). EXECUTIVE SUMMARY 16 Overﬁshing. There are clear indications that reefs of the USVI are suffering the effects of overexploitation of reef resources, although there are also positive signs. The entire district of St. Croix has an extremely low abundance of commercially important grouper species, including the threatened Nassau grouper. In St. John and St. Thomas, many common species have completely or nearly disappeared from nearshore waters in the last 30 years. For example, a study conducted by Rogers et al. (1982) on the southwest coast of St. Thomas during the airport runway expansion (1979-‐1981) found a variety of species that are no longer encountered or are rare, including the black, Nassau, tiger, and yellowfin groupers, as well as the federally protected parrotfish species blue, midnight, and rainbow. A study by Randall (1963) also found high relative abundances of groupers and threatened parrotfish on the south coast of St. John. Rebuilding these fish stock will require comprehensive life-‐history information for target species, a willingness to find strategies to rebuild stocks, and partnerships between commercial and recreational fishers, community stakeholders and managers. Land-‐Based Source of Pollu/on. The steep hillsides of the USVI are natural conduits for run-‐off during heavy rain events and in many instances there is little interception of materials before they reach the sea and impact coral reefs. When tropical soils are naturally disturbed or through the actions of man, they can erode and release fine-‐ grained silt and clay particles. In the USVI, these fine-‐grained particles are quickly transported to coral reefs where they can block sunlight, directly smother corals, or increase the growth organisms that compete with corals for space. There is evidence from the TCRMP that terrestrial sediments are having large negative impacts on nearshore coral reefs by increasing mortality of ecologically important corals. CORAL REEFS OF THE VIRGIN ISLANDS: POSITIVE SIGNS Despite the incredible declines in reef health witnessed since the inception of the TCRMP in 2001, there are many positive signs for the USVI that should be highlighted. These EXECUTIVE SUMMARY 17 successes offer lessons that can be applied to troubled reefs and may indicate refuge areas where we might “double-‐down” on current management strategies. Reef Refuges. The USVI is blessed, perhaps uniquely for the Caribbean, with extensive areas of deep bank and slope reefs that may be buffered from the direct impacts of climate change and local pressures. The mesophotic (pronounced: me-‐zo-‐photik; meaning; “middle-‐light”) reefs of the USVI are the best developed in the Caribbean from what is currently known. Mesophotic Coral Ecosystem (MCE) bank reefs with high populations of star corals (Orbicella spp.), which have recently been proposed for listing as endangered on the United States Endangered Species List (NOAA 2012), form extensive tracts on the south shelf of St. John and St. Thomas, from the British Virgin Islands to Vieques, Puerto Rico. Well-‐formed, but patchier mesophotic boulder coral reefs also form on the Lang Bank, St. Croix and the northern Puerto Rican Shelf. During the 2005 bleaching event, where shallow water reefs lost 50% of coral cover, MCE studied by the TCRMP hardly bleached and lost a more modest 20% coral cover. Thus, there is hope that these reefs will serve as refuges for corals during a time of increasing ocean temperatures. In federal waters some of these areas are wholly or partly protected from fishing of ecologically important species that help maintain reef health. These include the Red Hind Marine Conservation District (est. 1999), the Grammanik Bank Seasonally Closed Area (est. 2005), and the Lang Bank Red Hind Seasonally Closed Area (est. 1993). However, extensively developed mesophotic reef in unprotected territorial waters also exist near the island of French Cap and Sail Rock, St. Thomas District. It is important that these areas are identified, their threats assessed, and they are incorporated into the territorial and federal management planning process. Rebounding Fisheries Species. There are positive signs of recovery for certain fish species in some areas. At the Grammanik Bank grouper spawning aggregation site there have EXECUTIVE SUMMARY 18 been increasing numbers of Nassau grouper present for annual spawning (Kadison et al. 2010, Jackson et al. 2014) and a red hind aggregation in the Red Hind Marine Conservation District (MCD) has dramatically rebounded (Nemeth 2005). Red hind caught in the fishery on the south side of St. Thomas are more numerous and larger (D. Olsen, pers. comm.). It is also the impression of the authors that stocks of grouper and snapper are increasing in the MCD, although TCRMP measurements are confounded to some degree by the rotating array of aggregating fishes. Other territorial and federal closed areas in St. Croix, St. John, and St. Thomas are more recently established and may not show effects for several years. In 2011 the TCRMP recorded the first ever sightings of two Nassau grouper in St. Croix, a positive sign. No Nassau grouper were observed in 2012 unfortunately. For species that are completely protected from fishing (Nassau grouper and blue, midnight, and rainbow parrotfish), educational campaigns for recreational and commercial fisherman are critical, as awareness of regulations appears to be lacking (Authors, unpub. obs.). Land-‐based source of pollu,on. While development of steep island slopes has continued despite current regulations intended to prevent sediments from entering nearshore waters, research has identified key targets for restoration and some effective habitat restoration best-‐management practices. Results from TCRMP research suggest that there are certain levels of silt-‐laden terrestrial run-‐off that are damaging to corals, providing a target for reductions of sediment in the marine environment. Unpaved road segments have been implicated as the worst culprits in the production of sediment-‐laden run-‐off (Ramos-‐Scharrón and MacDonald 2007b) and this provides a clear target for where management can be most effectively applied. Restoration of watersheds has shown that implementation of best-‐management practices and control structures can be effective in reducing sedimentation. For example, the American Recovery and Reinvestment Act project “USVI Coastal Habitat Restoration Through Watershed Stabilization” showed EXECUTIVE SUMMARY 19 promising results (Virgin Islands Resource Conservation and Development Council; P.I. M. Taylor). This report presents results of the 12th year of monitoring on reefs surrounding St. Croix, St. John, and St. Thomas (years 2001-‐2012). Monitoring sites were distributed across the insular platform in depths from 5 to 63 m (16 – 220’) in an effort to capture the diversity of reef types present in the Virgin Islands. Long-‐term data is presented from 33 sites. While not exhaustive, the TCRMP is generally representative of the geographic areas and variety of reef types in the USVI. Digital video and diver surveys were used to quantify benthic cover and coral health at 14 permanent sites surrounding the island of St. Croix and 19 permanent sites on the Puerto Rican Shelf surrounding the island of St. John and St. Thomas. In addition, at 32 of these sites sea urchin density and fish community structure were evaluated. This report presents data from a major expansion of coral reef monitoring sites. RESEARCH HIGHLIGHTS 20 Research Highlights SPECIES-‐SPECIFIC RESPONSES TO BLEACHING 21 Bleaching Resistant Species in the Caribbean and Implications for Coral Reef Management TCRMP research has uncovered new information on the response of Caribbean corals to thermal stress events that has high relevance for management and was recently published in the journal Ecosphere (Smith et al. 2013). Shallow reefs of the USVI were affected by thermal stress in 2005 and 2010 when temperatures exceeded a stress point for many corals known as the bleaching threshold. The longer corals spend above the bleaching threshold and the greater the temperature surpasses the bleaching threshold the more likely corals are to bleach (Fig. 1), or lose the pigmented microalgae that live in their cells and give corals the lion’s share of their nutrition. Weakened corals are susceptible to disease and direct mortality. In 2005 the temperatures were very high for very long and the majority of shallow water corals bleached, with a loss of 50-‐60% of the coverage of reef corals in the USVI (Miller et al. 2009). In 2010 the temperatures were on their way to surpass the heat stress in 2005, but temperatures were cooled by the upwelling of deep water stimulated by the passage of Hurricane Earl (August 30th). Heat stress was less than half that experienced in 2010, with limited bleaching, disease and mortality, often confined to specific areas (Brandt et al. 2013). Figure 2. Bleaching of Orbicella faveolata and O. annularis at Flat Cay, St. Thomas (Nov. 12, 2005). These corals were affected by disease during recovery in 2006 and lost tissue. Most corals suffered partial mortality that removed over 50% of the living tissue, but left parts of the colony alive and capable of recovery. RESEARCH HIGHLIGHTS 22 The TCRMP was able to use its resources to provide one of the most comprehensive data sets of coral reef response to thermal stress and bleaching in the Caribbean. One central question to ask of the data was were the responses of very different coral species similar over the extreme and mild thermal events? We used data from 18 of our shallow water (<25m/83’ depth) monitoring sites to look at the response of nine coral species for which we had hundreds to thousands of observations. The response was divided in to bleaching (the proportion of corals that bleached and the extent of bleaching on the colonies surface), disease (the proportion of corals that showed white disease signs), and mortality (the proportion of colonies that had partial or total mortality and the change in the reef coverage of the species). We found that there were three distinct groupings of species that we labeled “types”. Type I had high bleaching and initial mortality, no subsequent white disease, and severe losses of cover (exhibited by Agaricia agaricites and branching Porites species); Type II had moderate bleaching and initial mortality, high subsequent white disease prevalence, and severe losses of cover (exhibited by Colpophyllia natans, and Orbicella spp.); Type III had moderate to low bleaching and paling, low to no subsequent white disease, and low to no loss of cover (exhibited by Diploria strigosa, Montastraea cavernosa, Porites astreoides, and Siderastrea siderea). The biggest surprise was that a group of species (Type III) was almost entirely resistant to bleaching induced mortality. These species may become progressively more dominant on coral reefs of the Caribbean with increasing frequency and severity of coral bleaching events. In contrast, the Type II species, including main reef building species in the Caribbean, Orbicella spp., was only moderately affected by bleaching across our sites, but was highly susceptible to disease after the bleaching event. However, for thermally sensitive Type I and II species partial mortality was much more common than whole colony mortality and the surviving tissues may aid in recovery. SPECIES-‐SPECIFIC RESPONSES TO BLEACHING 23 RECOMMENDATIONS The findings of our research have very important implications for localized management with regards to thermal stress that includes which coral species do not need a lot of active management and which corals should be managed and where management might be most effective. Strategy #1. Do not expend a lot of effort to protect Type III species, as they will likely weather future thermal stress events quite well. These species also tend to be ones that are quite resistant to other localized stressors, such as sedimentation. Type III species will persist through at least the first half of the 21st century and will likely become more dominant in reef systems. However, they may not increase in abundance sufficiently to replace the species lost to thermal stress. Hence, even with persistence, ecological roles played by reefs, such as the provision of nursery and adult habitat for fishes will likely degrade. Strategy #2. Stress local management actions that promote the regrowth of surviving coral tissues. These include the usual actions, such as limiting land-‐based sources of pollution and sediments and reducing fishing that affects populations of herbivorous fishes and urchins that consume seaweeds that compete with coral for space. As an example, the highly thermally sensitive Agaricia agaricites is recovering after 2005 from tissue fragments in reefs with low land based sources of pollution and low seaweed abundance (e.g., Flat Cay), but not at reefs that are clearly still being impacted by local stressors (e.g., Fish Bay). Strategy #3. Large Orbicella spp., some many hundreds of years old, were mostly, but not completely, killed in 2005 (Fig. 2). These corals are akin to the giant sequoia trees of central California that are long-‐lived and virtually irreplaceable. The fact that the centuries old genotypes are hanging on in USVI reefs is cause for hope and action. Every effort should be made to protect these recovering ancients, including education and RESEARCH HIGHLIGHTS 24 active restoration. As for the latter, restoration of Orbicella spp. has not yet been attempted in the USVI to our knowledge. However, the fact that un-‐eroded large skeletons still remain intact provides an opportunity for replantation of fragments that could re-‐sheet old skeletons, short-‐circuiting the recovery process and protecting essential habitat. This area is very ripe for research into effective restoration strategies. Figure 3. The multi-‐ faceted response of Orbicella spp. to the 2005 bleaching event. Corals were moderately to severely bleaching in 2005 and then were affected by white disease in 2006. As an example of the potential for active management, a colony at Savana Is., St. Thomas that is hundreds of years old was heavily bleached in 2005 (top left). This colony was not entirely killed (bottom left) and by 2011 small tissue areas (pink coloring in bottom right) were recovering over the skeleton. The process is very slow and might be aided by restoration that targets these ancient corals still extant in USVI reefs. Images taken from Smith et al. 2013. INTRODUCTION 25 Introduction The U.S. Virgin Islands consists of three large islands, St. Thomas, St. John and St. Croix, and numerous smaller islands surrounded by a diverse, tropical marine environment that includes coral reefs, seagrass beds, and mangrove forests (Fig. 4). The islands of St. Thomas and St John lie on the Puerto Rican Shelf, an extensive shallow water platform that connects them to Puerto Rico to the west and the British Virgin Islands to the east. Sixty-‐five kilometers to the south of St. Thomas and St. John and separated by the Anegada Passage and the Virgin Islands Trough (over 3,000 m deep), St. Croix lies on an isolated platform. This forms an effective barrier to the migration of coral reef fishes and invertebrates. The coral reefs of the Virgin Islands represent a wide range of characteristic coral reef habitats of the Caribbean, including patch reefs, fringing reefs, barrier reefs, shelf reefs, and extensive bank and slope mesophotic coral reef ecosystems. Tourism drives the economy of the Virgin Islands, famous for white sand beaches that give way to clean, clear marine waters. The Virgin Islands are ideal for sailing because of the persistent trade winds and the numerous bays that provide protected anchorages. The diverse marine life of the coral reefs and other habitats attracts thousands of skin and scuba divers each year. Sportfishing on charter boats and private vessels also makes an important contribution to the economy. In addition to their tourist appeal, the coral reefs and other habitats in the Virgin Islands are essential to the lives of hundreds of thousands of species including economically important queen conch, whelk, spiny lobster, snapper and grouper. Over three hundred full-‐time or part-‐time commercial fishermen fish in territorial and federal waters surrounding all three islands (Tobias 1997). Recreational and artisanal fishing is a frequent activity and is likely to have a significant impact on nearshore fish populations, but there exists very limited data on species composition and spatial distribution of annual catches (Authors, personal observation). In tough economic times and after INTRODUCTION 26 natural disasters, fishing is an important means of supplemental income or extra protein for many people. Over the last few decades, major hurricanes, coral disease outbreaks and mass coral reef bleaching have caused extensive coral mortality to the coral reefs surrounding the Virgin Islands (Gladfelter 1982, Edmunds and Witman 1991, Rogers et al. 1991, Rothenberger et al. 2008, Woody et al. 2008, Miller et al. 2009). Recovery from these natural disturbances is hindered by a multitude of human impacts that affect coral reefs, such as overfishing of ecologically important species, physical damage to reef structure, and pollution (Hatcher 1984, Pastorok and Bilyard 1985, Rogers and Garrison 2001, Mumby 2006, Mumby et al. 2006, Mumby and Harborne 2010). Moreover, rapid development of steep island slopes has dramatically increased soil erosion and sedimentation into nearshore waters (Brooks et al. 2007, Gray et al. 2008, Smith et al. 2008), particularly below unpaved road surfaces (Anderson and Macdonald 1998, Ramos-‐Scharrón and MacDonald 2007a). Chronic sedimentation affects the abundance and diversity of corals and other reef organisms, increases coral stress and susceptibility to diseases and bleaching, and reduces the ability of corals and other reef organisms to recover and regenerate after natural disturbances such as hurricanes (Acevedo and Morelock 1988, Rogers 1990, Nemeth and Sladeck Nowlis 2001, Fabricius 2005). The first sightings of the invasive Indo-‐Pacific lionfish (Pterois volitans) occurred in the US Virgin Islands in 2009. This predator has the ability to dramatically alter coral reef fish community structure (Cote and Maljkovic 2010) and these alterations may have additional, indirect impacts on benthic communities (Albins and Hixon 2011). High thermal stress and coral bleaching events affected the northeastern Caribbean in 2005 and 2010, but these events had contrasting signatures in the United States Virgin Islands. The year 2005 was the most severe high sea surface temperature (SST) event on record for the northeastern Caribbean (Eakin et al. 2010). In the Virgin Islands a peak of INTRODUCTION 27 10.25 Degree Heating Weeks (DHW) was registered from satellite SST records (NOAA 2012) and a period of approximately 59 days above the local bleaching threshold of 29.5°C (Aug. 20 – Oct. 18); a level of thermal stress accumulation associated with severe coral bleaching and some mortality. The warm season of 2010 started as warm or warmer than 2005, with the bleaching threshold surpassed for 21 days between August 12 and September 2. In a clear example of ameliorative storm cooling (Manzello et al. 2007), the passing of the storm center of Hurricane Earl on August 30th, approximately 100 km to the northeast of the St. Thomas-‐St. John, caused a rapid decline in SST’s below the bleaching threshold to 29.3°C, and then from October 5 -‐ 8, the passage of Hurricane Otto caused windy and cloudy weather that further reduced SST below 29.1°C. Total DHW accumulated in 2010 began to decrease after the beginning of October, when it had reached 5.1 DHW, a level associated with some bleaching and limited mortality. Most research around the Virgin Islands has focused on fringing reefs (5 – 30 m depth) located along the shoreline of the three main islands, St. Thomas, St. John, and St. Croix. In contrast, very little information exists for offshore and deeper reef systems, which can be quite extensive. Surrounding St. Thomas and St. John, these other reef systems include mid-‐shelf reefs (5 – 30 m depth) located 2 to 10 km from the shore of the main islands and mesophotic reefs (>30 m depth) located from 0.5 to 15 km offshore along the edge of the insular platform (Armstrong et al. 2002, Herzlieb et al. 2005, Armstrong et al. 2006, Armstrong 2007, Menza et al. 2007, Menza et al. 2008, Nemeth et al. 2008, Smith et al. 2010a). Distance from shore may be a factor in the historical degeneration of coral reef systems in the Virgin Islands (Herzlieb et al. 2005, Calnan et al. 2008, Smith et al. 2008). A systematic approach to investigating these cross-‐shelf coral reef systems allows us to evaluate the variable impacts and synergistic effects of natural impacts and human-‐ induced stress that influence the decline or recovery of Caribbean coral reef systems. The first two years of this project (2001 and 2002) concentrated on the fringing reefs surrounding St. Croix. In 2003, monitoring continued at St. Croix reefs and began at reef INTRODUCTION 28 systems distributed across the insular platform surrounding St. Thomas. In 2004, 2005 and 2006 monitoring continued at reefs surrounding both islands, with additional reefs surrounding St. Thomas added in 2004, 2005, and 2011. Mesophotic coral reef monitoring sites were added to St. Croix during the 2008 and 2009 monitoring, as well as an additional monitoring site in the St. Croix East End Marine Park. In 2011, the TCRMP also expanded to include sites established under separate funding that will be continued in the core TCRMP monitoring activities funded by USVI DPNR and NOAA CRCP. OBJECTIVES FOR MONITORING CORAL REEFS Effective management is necessary to maintain the resources in the territorial and federal waters of the Virgin Islands in an ecologically and economically sustainable manner. Monitoring programs are essential for successful management because they provide managers with fundamental information with which to make and reinforce decisions. Standards for resource protection can be measured by comparison to baseline data established by monitoring. Monitoring also provides the means to assess the status and trends of ecological resources, allowing managers to determine the effectiveness of current management and to develop effective management plans for the future. The Territorial Coral Reef Monitoring Program monitors the condition of coral reefs throughout the U.S. Virgin Islands and provides key information to better manage these ecosystems. This report presents monitoring results from 2001-‐2012 in St. Croix and from 2003-‐2012 in St. Thomas. For both islands, temporal changes from year to year in the conditions of the reef communities were assessed. INTRODUCTION 29 Figure 4. Locations of Territorial Coral Reef Monitoring Sites in the US Virgin Islands, 2008-‐ 2010.Boundaries indicate federal and territorial marine protected areas.