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ANNUAL REPORT 2016 Smith TB, Ennis RS, Kadison E, Nemeth RS, Henderson LM 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 Special Thanks To: Beasley V, Brandt ME, Brandtneris VB, Brewer RS, Byrne I, Groves S, Holstein DM, Jobsis P, Prosterman S, Taylor M, Tonge R, Jones Sailing School, INDEX i © 2016 Cite As: Smith TB, Ennis R, Kadison E, Nemeth RS, Henderson L (2016) The United States Virgin Islands Territorial Coral Reef Monitoring Program. 2016 Annual Report. University of the Virgin Islands, United States Virgin Islands 286pp INDEX ii INDEX OF TABLES XIII MISSION 14 OUR VISION 14 OBJECTIVES 14 EXECUTIVE SUMMARY 15 CORAL REEFS OF THE VIRGIN ISLANDS: MANGEMENT ACTIONS NEEDED 15 CORAL REEFS OF THE VIRGIN ISLANDS: POSITIVE SIGNS 17 UPDATE: INVASION OF THE INDO-PACIFIC RED LIONFISH 21 NASSAU GROUPER 25 EMERGENCE OF THE RED ALGAE RAMICRUSTA SP. 30 INTRODUCTION 35 OBJECTIVES FOR MONITORING CORAL REEFS 38 METHODS 42 BENTHIC ASSESSMENTS 42 FISH CENSUS 48 TERRITORIAL CORAL REEF MONITORING SUMMARY 49 BENTHIC COMMUNITIES AND CORAL REEF HEALTH 50 CORAL COVER 50 EPILITHIC ALGAL COMMUNITY COVER 54 MACROALGAL COVER 56 FILAMENTOUS CYANOBACTERIA 58 GORGONIAN AND ANTIPATHARIAN COVER 60 SPONGE COVER 62 INDEX iii FISH COMMUNITIES 64 FISH ABUNDANCE 67 FISH BIOMASS 69 BLACK SPINY SEA URCHIN DIADEMA ANTILLARUM 71 SITE SUMMARIES 73 RATIONALE 73 SITE SUMMMARY ELEMENTS 73 ST. CROIX 77 BUCK ISLAND, ST. CROIX 79 CANE BAY 85 CANE BAY DEEP 91 CASTLE 97 EAGLE RAY 103 GREAT POND 109 JACKS BAY 115 KINGS CORNER 121 LANG BANK EAST END MARINE PARK 127 LANG BANK RED HIND FISH SPAWNING AGGREGATION 133 MUTTON SNAPPER 139 SALT RIVER WEST 145 SALT RIVER DEEP 151 SPRAT HOLE 157 ST. JOHN 163 CORAL BAY 165 FISH BAY 171 MERI SHOAL 177 INDEX iv ST. THOMAS 183 BLACK POINT 185 BOTANY BAY 192 BREWERS BAY 198 BUCK ISLAND, ST. THOMAS 204 COCULUS ROCK 210 COLLEGE SHOAL 216 FLAT CAY 222 GINSBURGS FRINGE 228 GRAMMANIK TIGER 234 HIND BANK 240 LITTLE SAINT JAMES 246 MAGENS BAY 252 SAVANA ISLAND 259 SEAHORSE COTTAGE SHOAL 265 SOUTH CAPELLA 271 SOUTH WATER 277 LITERATURE CITED 283 INDEX v Index of Figures Figure 1. Partially bleached and recovering colony of Siderastrea siderea at Flat Cay, St. Thomas (Nov. 12, 2005). ............................................................................................................................................................................................................ 16 Figure 2. Indo-Pacific red lionfish (Pterois volitans) at the Grammanik Bank, St. Thomas, April 14, 2017; depth 40m. (photo credit: Viktor W. Brandtneris) ................................................................................................................................... 21 Figure 3. Nassau grouper on the Grammanik Bank, St. Thomas during spawning season. ........................................ 25 Figure 4. Nassau grouper observed across all sites on belt transects, conducted annually from 2003-2016. ... 26 Figure 5. Total number of Nassau grouper observed by site in the northern USVI, in 2015 and 2016. ................ 27 Figure 6. Maximum number of Nassau grouper observed on a single point count during the spawning season (January- April) on the Grammanik Bank from 2002 through 2017. .................................................................................. 29 Figure 7. Representative photos of Ramicrusta spp. overgrowing Orbicella faveolata (A), Orbicella annularis (B), Orbicella annularis (C), and Millepora alcicornis (D) at the TCRMP location Savana. ........................................ 31 Figure 8. Abundance of Ramicrusta sp. presence in non-overlapping video clips at TCRMP locations in 2016. 32 Figure 9. Benthic cover (±SEM) of Ramicrusta sp., coral, epilithic algae community, and fleshy macroalgae at Savana from 2003-2016. ....................................................................................................................................................................... 33 Figure 10. Locations of Territorial Coral Reef Monitoring Sites in the US Virgin Islands. Boundaries indicate federal and territorial marine protected areas. ........................................................................................................................... 40 Figure 11. A screen grab of benthic video used for the determination of percent cover of coral reef organisms and non-living substrate. ....................................................................................................................................................................... 44 Figure 12. Coral cover (±SE) across TCRMP monitoring sites over time. .......................................................................... 53 Figure 13. Epilithic Algal Community cover (±SE) across TCRMP monitoring sites over time. ................................ 55 Figure 14. Macroalgae cover (±SE) across TCRMP monitoring sites over time. ............................................................. 57 Figure 15. Filamentous cyanobacteria cover (±SE) across TCRMP monitoring sites over time. ............................. 59 Figure 16. Gorgonian and Antipatharian cover (±SE) across TCRMP monitoring sites over time. ......................... 61 Figure 17. Sponge cover (±SE) across TCRMP monitoring sites over time. ...................................................................... 63 Figure 18. Fish abundance (±SE) across TCRMP monitoring sites over time. St. Croix sites are to the left and northern USVI to the right on the x-axis. ......................................................................................................................................... 68 Figure 19. Mean fish biomass (±SE) across TCRMP monitoring sites over time. St. Croix sites are to the left and northern USVI to the right on the x-axis. ......................................................................................................................................... 70 Figure 20. Abundance of the black spiny sea urchin (Diadema antillarum) at TCRMP monitoring sites. Note the log scale. ............................................................................................................................................................................................... 72 INDEX vi Figure 21. The Buck Island, St. Croix. (top) Position in the Buck Island Reef National Monument. (right)A representative photo. .............................................................................................................................................................................. 79 Figure 22. Buck Island, St. Croix benthic temperatures (14 m depth). Data provided by the National Park Service (site BUIS_SFR). ......................................................................................................................................................................... 80 Figure 23. Buck Island, St. Croix. (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. ................................................... 81 Figure 24. Buck Island, St. Croix benthic cover and coral health through time (mean ± SE). ................................... 82 Figure 25. The Buck Island, St. Croix fish community by absolute and relative biomass. ........................................... 84 Figure 26. Cane Bay. (top) Location. (right) A representative photo of the reef. .......................................................... 85 Figure 27. Cane Bay benthic temperatures (8 m depth) .......................................................................................................... 86 Figure 28. Cane Bay. (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. ................................................................................... 87 Figure 29. Cane Bay benthic cover and coral health through time (mean ± SE). .......................................................... 88 Figure 30. The Cane Bay fish community by absolute and relative biomass. .................................................................. 90 Figure 31. 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. ........................................................................................................... 91 Figure 32. Cane Bay Deep temperature (39 m depth). ............................................................................................................. 92 Figure 33. Cane Bay Deep. (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. ................................................................. 93 Figure 34. Cane Bay Deep benthic cover and coral health through time (mean ± SE). ............................................... 94 Figure 35. The Cane Bay Deep fish community by absolute and relative biomass. ....................................................... 96 Figure 36. Castle. (top) Location. (right) A representative photo of the reef. ................................................................ 97 Figure 37. Castle benthic temperatures (9 m depth). ................................................................................................................ 98 Figure 38. Castle. (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. ................................................................................... 99 Figure 39. Castle benthic cover and coral health through time (mean ± SE). .............................................................. 100 Figure 40. The Castle fish community by absolute and relative biomass. ...................................................................... 102 Figure 41. Eagle Ray. (top) Location. (right) A representative photo of the reef. ...................................................... 103 Figure 42. Eagle Ray benthic temperature at 9 m depth ...................................................................................................... 104 Figure 43. Eagle Ray. (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. ................................................................................ 105 Figure 44. Eagle Ray benthic cover and coral health through time (mean ± SE). ...................................................... 106 Figure 45. The Eagle Ray fish community by absolute and relative biomass. .............................................................. 108 INDEX vii Figure 46. Great Pond. (top) Location. (right) A representative photo of the reef. ................................................... 109 Figure 47. Great Pond benthic temperature (5 m depth). .................................................................................................... 110 Figure 48. Great Pond (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. ................................................................................ 111 Figure 49. Great Pond benthic cover and coral health through time (mean ± SE). .................................................... 112 Figure 50. The Great Pond fish community by absolute and relative biomass. ........................................................... 114 Figure 51. Jacks Bay. (top) Location. (right) A representative photo of the reef........................................................ 115 Figure 52. Jacks Bay benthic temperature at 12 m depth .................................................................................................... 116 Figure 53. Jacks Bay (left) relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. ................................................................................ 117 Figure 54. Jacks Bay benthic cover and coral health through time (mean ± SE). ....................................................... 118 Figure 55. The Jacks Bay fish community by absolute and relative biomass. ............................................................... 120 Figure 56. Kings Corner. (top) Location. (right) A representative photo of the reef with a school of lane snapper (Lutjanus synagris). ............................................................................................................................................................ 121 Figure 57. Kings Corner benthic temperature (17 m depth) ............................................................................................... 122 Figure 58. Kings Corner (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. .............................................................. 123 Figure 59. Kings Corner benthic cover and coral health through time (mean ± SE). ................................................ 124 Figure 60. The Kings Corner fish community by absolute and relative biomass. ........................................................ 126 Figure 61. Lang Bank EEMP. (top) Location. (right) A representative photo of the reef. ....................................... 127 Figure 62. Lang Bank EEMP benthic temperature (28 m depth) ...................................................................................... 128 Figure 63. 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. ...................... 129 Figure 64. Lang Bank EEMP benthic cover and coral health through time (mean ± SE). ....................................... 130 Figure 65. The Lang Bank EEMP fish community by absolute and relative biomass. ............................................... 132 Figure 66. Lang Bank Red Hind FSA. (top) Location. (right) A representative photo of the reef ........................ 133 Figure 67. Lang Bank Hind current speed (left) and benthic temperature (right; 33 m depth) ........................... 134 Figure 68. Lang Bank Red Hind FSA (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. ................................................ 135 Figure 69. Lang Bank Red HindFSA benthic cover and coral health through time (mean ± SE). ......................... 136 Figure 70. The Lang Bank Red Hind FSA fish community by absolute and relative biomass. ................................ 138 Figure 71. Mutton Snapper. (top) Location. (right) A representative photo of the reef taken in 2014. ............ 139 Figure 72. Mutton Snapper benthic temperature record at 23 m (left) and 39 m depth (right). ......................... 140 INDEX viii Figure 73. Mutton Snapper (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. .............................................................. 141 Figure 74. Mutton Snapper benthic cover and coral health through time (mean ± SE). ......................................... 142 Figure 75. The Mutton Snapper fish community by absolute and relative biomass. ................................................. 144 Figure 76. Salt River. (top) Location. (right) A representative photo of the reef with TCRMP researcher recording coral health data (Oct. 1, 2015). ................................................................................................................................. 145 Figure 77. Salt River West surface-benthic temperature record 5m depths. Data provided by the NOAA ICON monitoring network. ............................................................................................................................................................................ 146 Figure 78. Salt River West (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. .............................................................. 147 Figure 79. Salt River West benthic cover and coral health through time (mean ± SE). ............................................ 148 Figure 80. The Salt River West fish community by absolute and relative biomass. .................................................... 150 Figure 81. Salt River Deep. (top) Location. (right) A representative photo of the reef with TCRMP team (Oct. 1, 2015). ..................................................................................................................................................................................................... 151 Figure 82. Salt River Deep benthic temperature at 30 m depth (left) and 40 m depth (right). ............................ 152 Figure 83. Salt River Deep (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. .............................................................. 153 Figure 84. Salt River Deep benthic cover and coral health through time (mean ± SE). ........................................... 154 Figure 85. The Salt River Deep fish community by absolute and relative biomass. ................................................... 156 Figure 86. Sprat Hole. (top) Location. (right) A representative photo of the reef. .................................................... 157 Figure 87. Sprat Hole benthic temperature (7 m depth). ..................................................................................................... 158 Figure 88. Sprat Hole (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. ................................................................................ 159 Figure 89. Sprat Hole benthic cover and coral health through time (mean ± SE). ..................................................... 160 Figure 90. The Sprat Hole fish community by absolute and relative biomass. ............................................................. 162 Figure 91. Coral Bay. (top) Location. (right) A representative photo of the reef. ...................................................... 165 Figure 92. Coral Bay benthic temperature (9 m depth) ........................................................................................................ 166 Figure 93. Coral Bay (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. ................................................................................ 167 Figure 94. Coral Bay benthic cover and coral health through time (mean ± SE). ....................................................... 168 Figure 95. The Coral Bay fish community by absolute and relative biomass................................................................ 170 Figure 96. Fish Bay. (top) Location. (right) A representative photo of the reef. ......................................................... 171 Figure 97. Fish Bay benthic temperature record (6 m depth). ........................................................................................... 172 INDEX ix Figure 98. Fish Bay (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. ................................................................................ 173 Figure 99. Fish Bay benthic cover and coral health through time (mean ± SE). ......................................................... 174 Figure 100. The Fish Bay fish community by absolute and relative biomass. .............................................................. 176 Figure 101. 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 1.8 m wide. .................................................... 177 Figure 102. Meri Shoal benthic temperature record (30 m depth). ................................................................................. 178 Figure 103. Meri Shoal (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. .............................................................. 179 Figure 104. Meri Shoal benthic cover and coral health through time (mean ± SE). .................................................. 180 Figure 105. The Meri Shoal fish community by absolute and relative biomass. .......................................................... 182 Figure 106. Black Point. (top) Location. (right) A representative photo of the reef. ................................................ 185 Figure 107. Black point current speed and benthic temperature record (8 m depth). ............................................. 186 Figure 108. Black Point chlorophyll (left) and turbidity (right) record (16 m depth). ............................................. 187 Figure 109. Black Point. (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. .............................................................. 188 Figure 110. Black Point benthic cover and coral health through time (mean ± SE). ................................................. 189 Figure 111. The Black Point fish community by absolute and relative biomass. ........................................................ 191 Figure 112. Botany Bay. (top) Location. (right) A representative photo of the reef. ................................................ 192 Figure 113. Botany Bay benthic temperature record (11 m depth). ................................................................................ 193 Figure 114. A large colony of pillar coral (Dendrogyra cylindricus) dislodge, toppled, and diseased after the 2009 swell event (Botany Bay, June 25, 2009). .......................................................................................................................... 193 Figure 115. Botany Bay. (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. .............................................................. 194 Figure 116. Botany Bay benthic cover and coral health through time (mean ± SE). ................................................ 195 Figure 117. The Botany Bay fish community by absolute and relative biomass. ........................................................ 197 Figure 118. Brewers Bay. (top) Location. (right) A representative photo of the reef. .............................................. 198 Figure 119. Brewers Bay. (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. .............................................................. 200 Figure 120. Brewers Bay benthic cover and coral health through time (mean ± SE) ............................................... 201 Figure 121. The Brewers Bay fish community by absolute and relative biomass. ...................................................... 203 Figure 122. Buck Island, St. Thomas. (top) Location. (right) A representative photo of the reef. ....................... 204 Figure 123. Buck Island, St. Thomas benthic temperature record (12 m depth). ....................................................... 205 INDEX x Figure 124. Buck Island, St. Thomas. (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. ................................................ 206 Figure 125. Buck Island, St. Thomas benthic cover and coral health through time (mean ± SE). ........................ 207 Figure 126. The Buck Island, St. Thomas fish community by absolute and relative biomass................................. 209 Figure 127. Coculus Rock. (top) Location. (right) A representative photo of the reef showing the aggregation of redfin parrotfish. ............................................................................................................................................................................... 210 Figure 128. Coculus Rock benthic temperature record (7 m depth). ............................................................................... 211 Figure 129. Coculus Rock. (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. .............................................................. 212 Figure 130. Coculus Rock benthic cover and coral health through time (mean ± SE). ............................................. 213 Figure 131. The Coculus Rock fish community by absolute and relative biomass. ..................................................... 215 Figure 132. College Shoal. (top) Location. (right) A representative photo of the reef. ............................................ 216 Figure 133. College Shoal benthic temperature record (29 m depth). ............................................................................ 217 Figure 134. College Shoal (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. .............................................................. 218 Figure 135. College Shoal benthic cover and coral health through time (mean ±SE). .............................................. 219 Figure 136. The College Shoal fish community by absolute and relative biomass. ..................................................... 221 Figure 137. Flat Cay. (top) Location. (right) A representative photo of the reef. ....................................................... 222 Figure 138. Flat Cay benthic current speed (left) and temperature record (right) (14 m depth). ....................... 223 Figure 139. Flat Cay (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. ................................................................................ 224 Figure 140. Flat Cay benthic cover and coral health through time (mean ± SE). ....................................................... 225 Figure 141. The Flat Cay fish community by absolute and relative biomass. ............................................................... 227 Figure 142. Ginsburgs Fringe. (top) Location. (right) A representative photo of the reef showing whorled lettuce coral colonies up to 7m in width and research diver filming permanent transect in background (Nov. 13, 2015). .................................................................................................................................................................................................. 228 Figure 143. Ginsburgs Fringe current speed (50 m depth) and benthic temperature (63 m depth). BT = bleaching threshold ; DHW = degree heating weeks . ............................................................................................................. 229 Figure 144. Ginsburgs Fringe. (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. .............................................................. 230 Figure 145. Ginsburgs Fringe benthic cover through time (mean ± SE). ........................................................................ 231 Figure 146. The Ginsburgs Fringe fish community by absolute and relative biomass. .............................................. 233 Figure 147. Grammanik Tiger (top) Location. (right) A representative photo of the reef. ................................... 234 INDEX xi Figure 148. Grammanik Tiger benthic currents speed and temperature record (38 m depth). ........................... 235 Figure 149. Grammanik Tiger FSA. (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. ................................................ 236 Figure 150. Grammanik Tiger benthic cover and coral health through time (mean ± SE)..................................... 237 Figure 151. The Grammanik Tiger fish community by absolute and relative biomass. ........................................... 239 Figure 152. Hind Bank (top) Location. (right) A representative photo of the reef. ................................................ 240 Figure 153. (top) Hind Bank benthic current speed (40m depth). (bottom) Benthic temperature record at 40 m depth. ..................................................................................................................................................................................................... 241 Figure 154. Hind Bank. (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. .............................................................. 242 Figure 155. Hind Bank benthic cover and coral health through time (mean ± SE). .................................................. 243 Figure 156. The Hind Bank East fish community by absolute and relative biomass. ................................................ 245 Figure 157. Little St. James. (top) Location. (right) A representative photo of the reef with derelict fish trap ...................................................................................................................................................................................................................... 246 Figure 158. Little St. James benthic temperature record (19 m depth). ......................................................................... 247 Figure 159. Little St. James. (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. .............................................................. 248 Figure 160. Little St. James benthic cover and coral health through time (mean ± SE). .......................................... 249 Figure 161. The Little St. James fish community by absolute and relative biomass. .................................................. 251 Figure 162. Magens Bay. (top) Location. (right) A representative photo of the reef. .............................................. 252 Figure 163. Magens Bay current speed and benthic temperature record (9 m depth)............................................. 253 Figure 164. Magens Bay chlorophyll (left) and turbidity (right) record (16 m depth). ........................................... 254 Figure 165. Magens Bay. (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. .............................................................. 255 Figure 166. Magens Bay benthic cover and coral health through time (mean ± SE). ............................................... 256 Figure 167. The Magens Bay fish community by absolute and relative biomass. ....................................................... 258 Figure 168. Savana. (top) Location. (right) A representative photo of the reef showing large colonies of Orbicella faveolata (Nov. 17, 2015). ............................................................................................................................................... 259 Figure 169. Savana benthic temperature record (10 m depth). ........................................................................................ 260 Figure 170. Savana Island. (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. .............................................................. 261 Figure 171. Savana Island benthic cover and coral health through time (mean ± SE). ........................................... 262 Figure 172. The Savana Island fish community by absolute and relative biomass. .................................................. 264 INDEX xii Figure 173. Seahorse Cottage Shoal. (top) Location. (right) A representative photo of the reef. ....................... 265 Figure 174. Seahorse benthic temperature record (21 m depth). ..................................................................................... 266 Figure 175. Seahorse Cottage Shoal. (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. ................................................ 267 Figure 176. Seahorse Cottage Shoal benthic cover and coral health through time (mean ± SE). ........................ 268 Figure 177. The Seahorse Cottage Shoal fish community by absolute and relative biomass. ................................ 270 Figure 178. South Capella. (top) Location. (right) The reef with a derelict Antillean fish trap in Transect #1. ...................................................................................................................................................................................................................... 271 Figure 179. South Capella benthic temperature record (24 m depth). ........................................................................... 272 Figure 180. South Capella. (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. .............................................................. 273 Figure 181. South Capella benthic cover and coral health through time (mean ± SE). ............................................ 274 Figure 182. The South Capella fish community by absolute and relative biomass. .................................................... 276 Figure 183.South Water. (top) Location. (right) A representative photo of the reef. ............................................... 277 Figure 184. South Water benthic temperature record (24 m depth) ............................................................................... 278 Figure 185. South Water. (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. .............................................................. 279 Figure 186. South Water benthic cover and coral health through time (mean ± SE). .............................................. 280 Figure 187. The South Water fish community by absolute and relative biomass. ...................................................... 282 INDEX xiii Index of Tables Table 2. TCRMP site reef complex type, location coordinates (decimal degrees; WGS 1984), and depths. FSA = Fish Spawning Aggregation. EEMP = East End Marine Park. ................................................................................................ 45 Table 3. TCRMP site sampling data (benthic/health) and type of sampling. .................................................................. 46 Table 4. The 2016 species richness for belt transects and roving diver surveys (RDS). Sites are divided into nearshore, offshore, and mesophotic sites as described in the text. ..................................................................................... 66 MISSION 14 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 15 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 about 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 16 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 17 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 stocks 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 Pollution. 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 altered through human activity, 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 of 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 18 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 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 listed as threatened on the United States Endangered Species List (NOAA 2014), 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. The lower MCE consists mostly of lettuce corals (primarily Agaricia undata) and form a semi-continuous ring on steep slopes and walls at depths between 50-70m. These reef are isolated from some local impacts, but may be susceptible to global climate change (see below). 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 been increasing numbers of Nassau grouper present for annual spawning (Kadison et al. EXECUTIVE SUMMARY 19 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.). In 2015 there was a recruitment pulse of juvenile Nassau grouper to shallow nearshore environments of St. Thomas and St. John in 2015. In Brewers Bay, St. Thomas over 70 juvenile Nassau grouper were recorded (R. Nemeth, unpub. data), increasing evidence that the reproductive population is contributing to the recovery of the species. 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. 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 pollution. 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 EXECUTIVE SUMMARY 20 project “USVI Coastal Habitat Restoration Through Watershed Stabilization” showed promising results (Virgin Islands Resource Conservation and Development Council; P.I. M. Taylor). This report presents results of the 15th year of monitoring on reefs surrounding St. Croix, St. John, and St. Thomas (years 2001-2015). 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. All data is now available at the TCRMP website and updated annually after quality control: https://sites.google.com/site/usvitcrmp/home RESEARCH HIGHLIGHTS 21 Update: Invasion of the Indo-Pacific Red Lionfish The first Indo-Pacific lionfish (Fig. 2) reported in USVI waters was found in 2009 on the west end of St. Croix under the Frederiksted pier. The species had been rapidly spreading throughout the Caribbean from the believed introduction point of Florida, and was already common in the Bahamas, Jamaica, and Hispanola. Several more of the fish were seen over the next few weeks; however, it was not until early 2010 that the first lionfish was reported in St. Thomas. By early 2011, divers and fishermen from around the territory were finding lionfish commonly, and although a concerted effort was made to eradicate the fish the population continued to increase. Today, the invasive species is quite prevalent throughout the territory and Caribbean region; however, both divers and fishermen say they are seeing fewer fish than 2011-2013, and they are smaller in general. Figure 2. Indo-Pacific red lionfish (Pterois volitans) at the Grammanik Bank, St. Thomas, April 14, 2017; depth 40m. (photo credit: Viktor W. Brandtneris) INTRODUCTION 22 There continues to be an effort to control the lionfish through fishing. A growing market for the species as a food fish exists on all three islands, it is selling in an increasing number of restaurants, and fillets fetch a high market price. Ciguatoxin that causes Ciguatera Fish Poisoning is present in in about 12% of fishes from toxic areas, such as the south coast of St. Thomas and St. John (Robertson et al. 2013); however, poisonings are not known suggesting the threat to human health is not large. The lionfish invasion is particularly important because of the ability of lionfish to consume large quantities of native reef fish. Lionfish are gape-limited stalking predators capable of consuming prey that are almost half their total length, yet lionfish are themselves largely protected from predation by venomous fin spines (Morris and Whitfield 2009). Lionfish have rapidly spread over more than 4,000,000 km2 of marine habitat across the Western Atlantic, Caribbean and Gulf of Mexico, and are now undergoing exponential increases in abundance at many locations (Betancur-R et al. 2011; REEF 2012). Invasive lionfish occupy a range of habitat types and depths, where they consume an array of native fishes and crustaceans at very high rates (Schofield 2009; Green et al. 2011). There is growing concern that predation by lionfish will nullify efforts to protect vulnerable fish populations from anthropogenic threats in the region. Lionfish were first observed in the TCRMP data on roving dives at only two sites in 2010, Lang Bank and Kings Corner, both located off St. Croix. By 2011, seven sites out of 32 held lionfish, including four sites off St. Thomas. Note that this report is not updated with 2016 data, but is left in the 2016 report for reference. By visual inspection of the data there had not been a large change in lionfish abundance between 2015 and 2016. Fish were recorded in 2011 transects as well as roving dive surveys (Fig. 3). One year later, lionfish were recorded on transects at over half of all monitoring sites. On roving dives, they were observed on 20 out of 32 sites (data not shown). In the latest year of sampling (2015) lionfish were observed during roving dives on twelve out of 14 sites off St. Croix, RESEARCH HIGHLIGHTS 23 and eight out of 18 on St Thomas. Lionfish encounters in 2015 were higher overall than in 2014 around the northern USVI (112 in 2015 and 81 in 2014); however, this was primarily due to a very large number observed on the mesophotic Hind Bank FSA and Ginsburgs Fringe1 sites. Around St. Croix numbers observed on transects were nearly the same in the last two years of monitoring (20 in 2015 and 18 in 2014). Mesophotic sites off St. Thomas continue to have the highest abundances of lionfish, and two of these sites (Hind Bank FSA and Ginsburgs Fringe) had large increases in 2015. The Grammanik Bank had a notable decrease in lionfish in 2015, possibly due predation by the spawning aggregations of large piscivorous fish. Lionfish across the territory ranged in estimated size from 6 to 40cm TL and the majority (~45%) of fish were between 11 and 20cm TL. In 2014, the majority of fish (41%) were estimated to be between 20 and 30cm TL. Only seventeen lionfish (13%) were recorded over 30 cm TL in 2015. This number was down 7% from 2014 data. Little data has been collected and analyzed regarding preferential habitat for lionfish in the western Atlantic; however, based on the TCRMP data and many other dives conducted across the USVI shelves by the authors, it appears that the species utilizes a variety of habitats and uses any available structure within the area. They are common on hard bottom areas (generally associated with the largest rock /coral around) as well as coral reefs, and are found to be particularly abundant on submerged man-made structures. They may be somewhat limited from turbulent or high current environments by their large fins. It is unknown if their high densities on mesophotic reefs represent a preference for deepwater habitats, or a reduced fishing pressure. The Grammanik Bank and Hind Bank are marine reserves where bottom fishing is prohibited and large snappers, groupers, and sharks are observed regularly. Predation by large piscivores 1 Note: Ginsburgs Fringe fish data is not formally incorporated into the TCRMP and is not presented in this summary, but is now included in the site summaries section. INTRODUCTION 24 could partially control the recruitment or growth of lionfish at the Grammanik Bank, but the data is equivocal. Figure 3. The abundance (±SEM) of red lionfish on TCRMP transects from 2011 to 2015. Kings Corner Castle Sprat Hole Black Point Brewers Bay Fish Bay Buck Island STT Mutton Snapper Eagle Ray Seahorse Cottage Shoal South Capella St. James Savana Meri Shoal Lang Bank EEMP Lang Bank FSA Salt River Deep College Shoal Grammanik Hind Bank Mean lionfish observed in 100m2 0 1 2 3 4 5 6 7 2011 2012 2013 2014 2015 Mesophotic Near Shore Offshore RESEARCH HIGHLIGHTS 25 Improved Signs for the Threatened Nassau Grouper The once prolific Nassau grouper (Epinephelus striatus; Fig. 3), is today commercially extinct over much of its range. Historically this species has been dominant both culturally and economically in Caribbean fisheries. Although protected in federal waters of the United States since the 1990’s, the Nassau is still considered to be one of the most threatened groupers worldwide, is listed as endangered on the IUCN Red List, and is a candidate for the US Endangered Species Act. The fish was at one time the most common grouper on reefs of the US Virgin Islands. The Nassau fishery collapsed in the 1980’s, shortly after a large Nassau grouper spawning aggregation site located south of St. Thomas was extirpated by overfishing in the 1980’s and as a possible consequence the fishery collapsed shortly afterwards. The territorial government of the USVI protected the Nassau grouper from all fishing in 2006. The Caribbean Fisheries Management Council closed the south St. Thomas Grammanik Bank yellowfin grouper spawning aggregation site (Fig .3) in 2005, inadvertently protecting a small spawning aggregation Figure 3. Nassau grouper on the Grammanik Bank, St. Thomas during spawning season. INTRODUCTION 26 of Nassau grouper. These fish may have relocated from the extirpated historic Nassau aggregation located on a few kilometers to the west. There is some evidence that these management measures may be positively affecting Nassau grouper populations in the US Virgin Islands. Over the past two years there have been reports by divers of the fish being seen commonly on reefs around the territory, and fishermen are reporting regular occurrences of Nassau grouper in their fish traps. In TCRMP survey data from 2015 and 2016, substantially more Nassau grouper were observed than in earlier years (Figure 4). The fish was seen on nine sites in the northern USVI during those years (Figure 5). On St. Croix, five Nassau grouper were recorded on transects in 2015-16. Additionally, juvenille young-of-the-year Nassau were commonly seen in nearshore areas of St. Thomas and St. John in 2006, 2014, 2015, and 2016 (R. Nemeth, unpub data). Figure 4. Nassau grouper observed across all sites on belt transects, conducted annually from 2003-2016. 0 2 4 6 8 10 12 14 16 18 20 Northern USVI Sites St. Croix Sites Fish Encountered RESEARCH HIGHLIGHTS 27 Figure 5. Total number of Nassau grouper observed by site in the northern USVI, in 2015 and 2016. Nassau grouper in the northern USVI may be recovering in part because of a growing spawning aggregation at the Grammanik Bank. The Grammanik Bank, located approximately 4 km east of the historic Nassau grouper spawning site, is a multi-species aggregation area hosting spawning of several species of fish including yellowfin grouper (Mycteroperca venenosa), tiger grouper (Mycteroperca tigris), dog snapper (Lutjanus jocu), cubera snapper (Lutjanus cyanopterus), and Bermuda chub (Kyphosis sectatrix). Nassau grouper also aggregate on the site and spawn there shortly after dark in the months of January through April. The bank is closed seasonally to fishing from February 1 to April 31 and is closed to bottom tending gear year-round, thus providing partial protection for the aggregating Nassau grouper. Nassau may have shifted to spawning at the Grammanik bank after fishing down of their nearby historic aggregation. The Nassau grouper spawning aggregation site at the Grammanik Bank is of disputed age, and some local fishermen claim that the bank is not a historical location for Nassau spawning, whereas others suggest that a small number of Nassau have always spawned in that location (anon). The historic Nassau grouper aggregation sites is 4 km to the west, but no fish have been observed to aggregate in this area after over a decade of observation (R. Nemeth, unpub. obs.). One hypothesis is that Black Point College Shoal Grammanik Bank Hind Bank East South Water St. James 2015 Black Point Buck Island Coculus Rock Flat Cay Grammanik Bank Hind Bank East South Water 2016 INTRODUCTION 28 the Nassau grouper now utilizing the Grammanik Bank are a small sub-population of that original spawning group from the historic bank. The Nassau grouper has increased in numbers on the Grammanik Bank during the week after the full moon of January through April since 2002 (Figure 6). In both January and February 2017, nearly 200 fish were observed on single dives on the western end of the bank. This represents over a 200% increase from the number of fish observed during the early and mid-2000’s. The early and tentative recovery of the Nassau grouper in the northern USVI is indeed positive, but is far from complete. While fisheries closures have helped, targeted conservation actions may also be important for locking in and building on these gains for this threatened fish. Nassau grouper caught incidentally from deeper water (>20m deep) usually need to have their swim bladders deflated to allow them to submerge and survive when released. Thus, avoiding incidental capture even with release is important. In the northern USVI, a more complete fishing closure of the Grammanik Bank that encompasses the full seasonal cycle of Nassau grouper spawning activities (December to May) would ensure minimal incidental capture. Additionally, creating a migratory corridor between the nearby Hind Bank Marine Conservation District, a no-take closure that appears to support a relative high adult population on Nassau, would also limit fisheries impacts. In St. Croix, where a struggling small population of Nassau grouper are present, closing an area at the tip of the Lang Bank where there is a small aggregation of about 10 individuals would help to ensure that they are not taken incidentally or poached. In all of the USVI more education on Nassau grouper and their protected status would be very helpful. The early life cycle of Nassau grouper typically involves settling in shallow, nearshore structures surrounded by seagrass. These juveniles are vulnerable to recreation line fishing and spearfishing before they migrate to more offshore locations. Education and citizen science to get the community behind the recovery of Nassau would RESEARCH HIGHLIGHTS 29 greatly enhance the protections already in place by encouraging compliance. Nowhere else in US waters is the chance to protect and recover the Nassau as strong as in the USVI and the territory could lead a huge conservation success story for ailing fish populations. Figure 6. Maximum number of Nassau grouper observed on a single point count during the spawning season (January- April) on the Grammanik Bank from 2002 through 2017. 0 50 100 150 200 250 Max Fish /survey INTRODUCTION 30 Emergence of the Invasive Red Algae Ramicrusta spp. Many nearshore coral reefs throughout the Caribbean region have been experiencing increases in macroalgae cover. This increase in macroalgae has been linked with negative impacts to living stony corals through abrasion, shading, and chemical release. While the majority of macroalgae cover at TCRMP locations is dominated by Dictyota spp. and Lobophora spp., several have experienced relatively rapid increases in an encrusting red algae Ramicrusta spp (hereafter Ramicrusta). The genus Ramicrusta is present in multiple locations in the Pacific Ocean (Dixon and Saunders 2013), but was not reported in the Caribbean until 2009 at Discovery Bay, Jamaica (Pueschel and Saunders 2009). The genus has since been documented in Bonaire (Eckrich and Engel 2013) and Puerto Rico (Ballantine David et al. 2016). At present, three Ramicrusta species have been identified: Ramicrusta textilis (Pueschel and Saunders 2009) in Jamaica and Puerto Rico, Ramicrusta bonairensis (Ballantine, Ruiz, Lozada-Troche & Norris 2016) in Bonaire, and Ramicrusta monensis (Ballantine, Ruiz, Lozada-Troche & Norris 2016) in Puerto Rico. The TCRMP believes this genus has now become established in the USVI but exact ID is pending judgment of specialists. Until then this summary assumes the species is/are of the genus Ramicrusta. There is very little known about the biology of Ramicrusta and the environmental factors that determine its presence. Ramicrusta ranges in color from red to brown and primarily forms thin crusts, though frondose edges may be present (Fig. 7). Ramicrusta appears to be a strong competitor relative to most other benthic organisms, rapidly colonizing and expanding on open substrate. It has been observed overgrowing live coral tissue, sponges, gorgonians, zoanthids, and other kinds of macroalgae. Interactions with live coral colonies appear to be indiscriminate, and often cause bleaching and partial, if not complete, colony mortality. Successful recruitment of coral larvae or other benthic organisms has not been recorded on Ramicrusta substrate with the exceptions of occasional short fronds of RESEARCH HIGHL Dictyota spp. (Ennis, pers. obs to be particularly devastating environmental conditions. Figure 7. Representative phot Orbicella annularis (B), Orbice location Savana. A preliminary investigation in TCRMP benthic cover dataset locations in 2016, but abunda IGHTS 31 s. 8 Dec 2016). This combination of factors ha to reef ecosystems that are already under str os of Ramicrusta spp. overgrowing Orbicella f ella annularis (C), and Millepora alcicornis (D) nto Ramicrusta presence, abundance, and imp has revealed its presence at nearly 60% of TC ance seems to be variable (Fig. 8). While the m as the potential ress from other faveolata (A), at the TCRMP acts in the CRMP majority of INTRODUCTION 32 locations had less than 25% presence of Ramicrusta in TCRMP non-overlapping video images, College Shoal East and Savana had prevalence of Ramicrusta in benthic cover clips of 87.3% and 98.25%, respectively. Figure 8. Abundance of Ramicrusta sp. presence in non-overlapping video clips at TCRMP locations in 2016. Further analysis of benthic cover at Savana, which is an offshore site with little apparent human impacts, has shown that Ramicrusta has been present at low cover since the location’s first sampling in 2003 (Fig. 9). Ramicrusta cover at Savana was less than 10% until the 2005 bleaching event, after which cover increased nearly five-fold by 2008 and RESEARCH HIGHLIGHTS 33 is currently about 60% of the total benthic cover (Fig. 9). The increase in Ramicrusta cover after the 2005 bleaching suggests a tipping point was reached when coral cover declined from 20% to 10%. Ramicrusta initially took over this space by 2006, but has since increased linearly and by 2016 occupied 60% of the substrate, depressing all other benthic categories. Corals are in high contact with the algae and are being overgrown on the margins. Ramicrusta is likely driving the decline in coral cover since 2010. Figure 9. Benthic cover (±SEM) of Ramicrusta sp., coral, epilithic algae community, and fleshy macroalgae at Savana from 2003-2016. INTRODUCTION 34 Although the change in Ramicrusta benthic cover at Savana is an extreme case relative to all other TCRMP locations, it demonstrates the need for continued monitoring of changes in the cover of this algae. This is especially relevant given the potential devastation of overgrowth and the general lack of information regarding the life history of the genus in the Caribbean. Further examination of the long-term TCRMP dataset could provide valuable insight into the factors driving or controlling Ramicrusta sp. abundance. Future work by TCRMP and UVI will attempt to experimentally determine the mechanisms of impacts on corals and factors controlling the growth of Ramicrusta, such as productivity and impacts of herbivores. It is not clear if Ramicrusta was introduced to the Atlantic Ocean or has always been present in low abundance. However, it is clear that Ramicrusta is rapidly increasing in abundance at the expense of stony corals. RESEARCH HIGHLIGHTS 35 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. 10). 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. St. Croix lies on an isolated platform sixty-five kilometers to the south of St. Thomas and St. John and separated by the 4000m deep Anegada Passage and the Virgin Islands Trough. This forms an effective barrier to the migration of adult 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. The economy of the US Virgin Islands is reliant to a large extent on maintenance of vibrant marine ecosystems. Tourism drives the economy of the Virgin Islands, famous for white sand beaches that give way to clean, clear marine waters. The diverse marine life of the coral reefs and other habitats attracts thousands of skin and scuba divers each year. Sport fishing on charter boats and private vessels also makes an important contribution to the economy. In addition, 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 work in territorial and federal waters surrounding all three islands (Tobias 1997). In tough economic times and after 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, mass coral reef bleaching, and invasive species introductions have caused extensive coral mortality to the INTRODUCTION 36 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; Smith et al. 2013b). Recovery from these 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; Sabine et al. 2015; Ennis et al. 2016). 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). In addition, the invasive red algae Ramicrusta has increased in abundance at some locations and is killing coral tissue through competitive overgrowth (Eckrich and Engel 2013; Ballantine David et al. 2016). High thermal stress and coral bleaching events affected the northeastern Caribbean in 2005, 2010, and 2012, but these events had contrasting signatures in the United States Virgin Islands. These events and the species-specific responses of Caribbean corals are summarized in Smith et al. (2013) for shallow corals and Smith et al. (2016) for shallow and mesophotic corals. 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 RESEARCH HIGHLIGHTS 37 Islands a peak of 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. Recent research developed bleaching threshold temperatures for 24 of 33 TCRMP monitoring sites dominated by star corals of the genus Orbicella (Smith et al. 2016a). This research showed that mesophotic reefs bleached in 2005 with shallow reefs and then bleached again during a mesophotic coral reef bleaching event in 2012, when shallow reefs were unaffected. The study concluded that mesophotic reefs of the USVI are unlikely to be long-term climate change refugia because they are not immune to high temperature thermal stress. 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. 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. 2010b; Smith et al. INTRODUCTION 38 2016b). 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; Sabine et al. 2015; Ennis et al. 2016). 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 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 RESEARCH HIGHLIGHTS 39 ecosystems. The TCRMP is complimentary to the National Coral Reef Monitoring Program (NCRMP) that started in 2013 and is co-coordinated in the USVI by the University of the Virgin Islands. TCRMP focuses on fixed sites and repeatedly samples the same corals to generate the most in-depth metrics of change over time. NCRMP used a stratified-random sampling design to spread out samples and gain an understanding of change through time, with predictions that can be applied spatially. NCRMP does not sample reefs below 30m at this point, and therefore misses the dominant habitat in the northern USVI, which is only sampled in the TCRMP. This report presents monitoring results from 2001-2016 in St. Croix and from 2003-2016 in St. Thomas and St. John. For both islands, temporal changes from year to year in the conditions of the reef communities are assessed. INTRODUCTION 40 Figure 10. Locations of Territorial Coral Reef Monitoring Sites in the US Virgin Islands. Boundaries indicate federal and territorial marine protected areas. METHODS 41 A TCRMP research diver (T. Smith) on closed circuit rebreather records a fish transect at the lower mesophotic coral reef site Ginsburgs Fringe at 63m/220’ depth (April 20, 2017; photo credit: V.W. Brandtneris) METHODS 42 Methods BENTHIC ASSESSMENTS The University of the Virgin Islands determined the benthic composition at 33 long-term monitoring sites between 2001 and 2015 (Fig. 14). All data is now available at the TCRMP website and updated annually after quality control: https://sites.google.com/site/usvitcrmp/home Around St. Croix the following 14 sites were assessed: Buck Island-St. Croix, Cane Bay, Cane Bay Deep, Castle, Eagle Ray, Great Pond, Jacks/Isaacs Bay, Kings Corner, Lang Bank East End Marine Park (Lang EEMP), Lang Bank Red Hind Fish Spawning Aggregation (Lang Hind), Mutton Snapper, Salt River, Salt River Deep, and Sprat Hole. Four of these sites are within the St. Croix East End Marine Park boundary (Castle, Great Pond, Jacks Bay, Lang EEMP), three sites are within National Park Service boundaries (Buck Island-St. Croix, Salt River West, and Salt River Deep), two sites are within federal fisheries marine protected areas (Lang Hind, Mutton Snapper), and four sites can be considered mesophotic coral reefs (Cane Bay Deep, Lang Bank EEMP, Lang Hind, Salt River Deep; sensu Ginsburg 2007) . Salt River Deep transects 1-4 established at 40 m depth in April 2009 sampling were relocated upslope to 30 m in the January 2010 sampling due to low coral cover in the deeper transects. Around St. John-St. Thomas the following 19 sites were assessed: Black Point, Botany Bay, Brewers Bay, Buck Island-St. Thomas, Coculus Rock, College Shoal East, Coral Bay, Fish Bay, Flat Cay, Ginsburgs Fringe, Grammanik Tiger FSA, Hind Bank FSA, Little St. James, Magens Bay, Savana Island, Seahorse Cottage Shoal (Seahorse), Meri Shoal, South Capella, and South Water Island. One site is the within the St. Thomas East End Reserve (Coculus Rock), four sites are within federal fisheries marine protected areas (College Shoal, Ginsburgs Fringe, Grammanik Tiger, Hind Bank), and five sites can be considered mesophotic coral reefs METHODS 43 (College Shoal, Ginsburgs Fringe, Grammanik Tiger, Hind Bank, Meri Shoal). Four sites were also part of the Ciguatera Fish Poisoning Monitoring Program and were surveyed monthly for benthic structure and coral health from 2010-2016 (Black Point, Coculus Rock, Flat Cay, Seahorse). Because of its deep depth, Ginsburgs Fringe at 60-66m was only sampled for benthic cover and some fish transects. Benthic Cover. At each site benthic cover and coral health surveys were conducted along six 10 m long permanent transects marked with steel or brass rods. In 2016 video sampling consisted of one diver traversing each transect videotaping the benthic cover using a high definition video cassette recorder (Sony FX-7 in Light and Motion housing) or an HD digital video recorder with wide angle lens (Canon XF in Light and Motion housing). The diver swam at a uniform speed, pointing the camera down and keeping the lens approximately 0.4 m above the substrate at all times. A guide wand or dropper weight attached to the camera housing was used to help the diver maintain the camera a constant distance above the reef. After taping, approximately 20 - 50 non-overlapping images per transect were captured and saved as JPEG files (Fig. 11). Captured images represented an area of reef approximately 0.31 m2 (0.64 m x 0.48 m). Coral Point Count with Excel Extension software (Kohler and Gil 2006) was used to superimpose randomly located dots on each image. The number of points varied with the evolution of the video camera systems and was 10 points from 2001-2011, 15 points from 2012-2013, and 20 points from 2014 onwards. The substrate type located under each of the dots was then identified to the most descriptive level possible and entered into a database. Where multiple benthic cover categories fell under a single point, for example macroalgae over bedrock, the upper benthic category was assessed. For each transect, the percent cover of coral, epilithic algae (formerly called dead coral with turf algae), macroalgae, sponges, gorgonians, and sand/sediment were calculated by dividing the number of random dots falling on that substrate type by the total number of dots for that transect. Epilithic algae (sensu Hatcher and Larkum 1983) are diminutive turfs and filamentous algae without thallus structure that cover all rock surfaces METHODS 44 of coral reefs not occupied by larger epibenthic organisms. They can also be considered to be grazed surfaces and are often an indicator of healthy grazing communities and high sessile animal cover. Figure 11. A screen grab of benthic video used for the determination of percent cover of coral reef organisms and non-living substrate. METHODS 45 Table 1. TCRMP site reef complex type, location coordinates (decimal degrees; WGS 1984), and depths. FSA = Fish Spawning Aggregation. EEMP = East End Marine Park. Island Site Reef Complex Lat Long Depth (m) St. Croix Buck Island-St. Croix Offshore-Shallow 17.78500 -64.60917 15 Cane Bay Nearshore 17.77388 -64.81350 10 Cane Bay Deep Offshore-MCE 17.77661 -64.81522 38 Castle Offshore-Shallow 17.76278 -64.59743 7 Eagle Ray Offshore-Shallow 17.76150 -64.69880 10 Great Pond Nearshore 17.71097 -64.65221 6 Jacks Bay Nearshore 17.74337 -64.57160 14 Kings Corner Nearshore 17.69116 -64.90008 17 Lang Bank EEMP Offshore-MCE 17.72145 -64.54706 27 Lang Bank Red Hind FSA Offshore-MCE 17.82372 -64.44943 33 Mutton Snapper FSA Offshore-Shallow 17.63660 -64.86240 24 Salt River Deep Offshore-MCE 17.78523 -64.75917 30 Salt River West Nearshore 17.78530 -64.75940 11 Sprat Hole Nearshore 17.73400 -64.89540 8 St. John Coral Bay Nearshore 18.33797 -64.70402 9 Fish Bay Nearshore 18.31417 -64.76408 6 Meri Shoal Offshore-MCE 18.24433 -64.75832 30 St. Thomas Black Point Nearshore 18.34450 -64.98595 9 Botany Bay Nearshore 18.35845 -65.03330 8 Brewers Bay Nearshore 18.34403 -64.98435 6 Buck Island-St. Thomas Offshore-Shallow 18.27883 -64.89833 14 Coculus Rock Nearshore 18.31257 -64.86058 7 College Shoal East Offshore-MCE 18.18568 -65.07677 30 Flat Cay Offshore-Shallow 18.31822 -64.99104 12 Ginsburgs Fringe Offshore-MCE 18.18770 -64.95998 63 Grammanik Tiger FSA Offshore-MCE 18.18885 -64.95659 38 Hind Bank East FSA Offshore-MCE 18.20217 -65.00158 39 Magens Bay Nearshore 18.37425 -64.93438 7 Savana Offshore-Shallow 18.34064 -65.08205 9 Seahorse Cottage Shoal Offshore-Shallow 18.29467 -64.86750 20 South Capella Offshore-Shallow 18.26267 -64.87237 20 South Water Offshore-Shallow 18.28068 -64.94592 20 St James Offshore-Shallow 18.29459 -64.83238 15 METHODS 46 Table 2. TCRMP site sampling data (benthic/health) and type of sampling. Island Site Date Sampled Benthic Health Fish/Urchin St. Croix Buck Island STX 10/11/16 x x x Cane Bay 10/12/16 x x x Cane Bay Deep 10/12/16 x x x Castle 10/11/16 x x x Eagle Ray 10/14/16 x x x Great Pond 10/13/16 x x x Jacks Bay 10/13/16 x x x Kings Corner 10/15/16 x x x Lang Bank EEMP 10/13/16 x x x Lang Bank Red Hind FSA 10/11/16 x x x Mutton Snapper FSA 10/15/16 x x x Salt River Deep 10/14/16 x x x Salt River West 10/14/16 x x x Sprat Hole 10/12/16 x x x St. John Coral Bay 10/24/16 x x x Fish Bay 10/24/16 x x x Meri Shoal 10/24/16 x x x St. Thomas Black Point 10/03/16 x x x Botany Bay 12/08/16 x x x Brewers Bay 10/20/16 x x x Buck Island STT 11/23/16 x x x Coculus Rock 10/06/16 x x x College Shoal East 12/06/16 x x x Flat Cay 10/04/16 x x x Ginsburgs Fringe 04/20/17 x x Grammanik Tiger FSA 12/01/16 x x x Hind Bank East FSA 12/01/16 x x x Magens Bay 12/08/16 x x x Savana 12/08/16 x x x Seahorse Cottage Shoal 10/06/16 x x x South Capella 12/09/16 x x x South Water 12/09/16 x x x St James 11/23/16 x x x METHODS 47 Coral Health. Coral health assessments followed methodologies outlined in (Calnan et al. 2008), Smith et al. 2008, and Smith et al. 2013 and are briefly described here. All coral colonies located directly under the transect lines were assessed in situ for signs of mortality and disease following a modified Atlantic and Gulf Rapid Reef Assessment protocol (Kramer et al. 2005). Starting in 2008 all colonies were assessed, regardless of size, in contrast to previous years where only colonies greater than 10 cm in maximum linear dimension were assessed. Partial mortality of coral colonies was broken into two categories. Recent partial mortality was characterized visually as skeleton not eroded (fine corallite structure still intact) and bare or with a thin veneer of sheeting or filamentous algae. Recent partial mortality is typically visible for up to three months following tissue loss. Old partial mortality was characterized as skeleton eroded and covered with turf or macroalgae. Old partial mortality is a transition from recent mortality and typically lasts up to 1–6 years (Smith et al. 2008, also see http://www.agrra.org/method/methodcor.html). Diseases were conservatively categorized into recognized Caribbean scleractinian diseases and syndromes that included bleaching, black band disease, dark spots disease, white plague, and yellow band (blotch) disease (following Bruckner 2007). Acroporid corals were extremely rare at the study sites; thus, their associated diseases (white band and white pox) are not presented. Bleaching was assessed as abnormal paling of the colony, and, when present, the severity of the bleaching (paling or total whitening) and the area of the colony affected were assessed. A major bleaching event occurred between September and December 2005 affecting all sites monitored that year, a mild bleaching event occurred September and October 2010 affecting only shallow sites, and a mild bleaching event occurred in October and November 2012 and affected only mesophotic sites (Smith et al. 2013b; Smith et al. 2016a). On St. Croix, a subset of sites were assessed during the 2010 coral bleaching event, and included Cane Bay, Cane Bay Deep, and Jacks Bay. METHODS 48 For each transect, the prevalence of coral impairment categories was calculated as the number of colonies with partial mortality, disease, or bleaching divided by the number of colonies assessed. Also, for affected colonies in each transect the average three- dimensional surface area (%) of the colony affected was also estimated for each impairment category. FISH CENSUS Fish surveys were conducted at 14 sites around St. Croix and 19 sites around St. Thomas, including a subset of two transects completed at Ginsburgs Fringe (Table 2). Ten replicate belt transects and three replicate roving dive surveys (RDS) were conducted at each site. Belt transects were 25m x 4m and conducted in 15 minutes per replicate following protocols established by the NOAA Biogeography Branch (Menza et al. 2006; Friedlander et al. 2013). All transects were begun at a random location on the site, and were swum in a random direction. RDS replicates were 15 min in duration. In previous years 30 minute RDS surveys were conducted in depths less than 20m. Because almost all diversity was captured in the first 15 minutes, for easier diving logistics, and to make deeper sites comparable, the methods were switched to 15 RDS at all sites in 2016. In addition to relative abundance data, specific total length estimates were made for each large grouper, large snapper, or hogfish (Lachnolaimus maximus) encountered. In all surveys, all species encountered were recorded except blennies and gobies. Data were transcribed to Microsoft Excel and Access spreadsheets, and were analyzed for descriptive statistics of reef fish assemblage structure. Divers also counted the number of Diadema antillarum sea urchins within 1 m on either side of a transect. From 2001 – 2008 this occurred along the 6 – 10 m long benthic transects. Starting in 2009, urchins were assessed along 25x2m belt transects corresponding to the return of the 10 fish transects. The mean number of sea urchins per 100 m2 was calculated for each site. TCRMP MONITORING SUMMARY 49 Territorial Coral Reef Monitoring Summary BENTHIC COVER & CORAL HEALTH 50 BENTHIC COMMUNITIES AND CORAL REEF HEALTH Benthic cover was monitored at 33 monitoring sites and coral health was monitored at 32 sites in 2016. Benthic cover raw data is presented in electronic Appendix I. Coral health raw data is presented in electronic Appendix II. In addition, updated benthic cover for each site individually is presented in the “Site Summaries” section. Coral Cover The cover of hard corals decreased at most sites immediately after the 2005 coral bleaching event, but showed little or no change as the results of the 2010 and 2012 coral bleaching events (Fig. 12). Shallow (<25 m depth), nearshore and offshore sites with greater than about 20% coral cover showed declines in cover, but there was extreme variability in the degree of cover change. For example, the relative loss in coral cover of shallow Orbicella spp.2 dominated reefs ranged from 87% at the Mutton Snapper site to less than 20% at the Brewers Bay site. Mesophotic coral monitoring sites that were sampled before and after the 2005 coral bleaching event showed lower relative losses of coral cover compared with shallow site. Losses ranged from 5.4% (Grammanik Tiger) to 36.0% (Meri Shoal). Sites that had low coral cover prior to 2005 lost far less relative cover as the result of bleaching. While part of this may be due to detectability at coral cover values nearer to 0, and that these sites tend to be dominated by small massive species that are more resistant to bleaching and disease related mortality (Smith et al. 2013b). A few sites showed no change, and included Buck Island STT, Coculus Rock, Jacks Bay, and South 2 The genus for the species Montastraea annularis, M. faveolata, and M. franksi was changed to Orbicella Budd AF, Fukami H, Smith ND, Knowlton N (2012) Taxonomic reclassification of the coral reef coral family Mussidae (Cnidaria: Anthozoa: Scleractinia). Zoological Journal of the Linnean Society 166:465-529 and the TCRMP recognizes this change. Some figures still use “Montastraea” where they have not been converted from previous reports. Other genus revisions (e.g., Pseudodiploria) have not yet been incorporated. TCRMP MONITORING SUMMARY 51 Water. However, the Buck Island STT site may be anomalous since transects were not permanently placed until 2007 and unprecedented prevalence of white disease was seen at this site in 2006. Recovery since bleaching in 2005 was marginal at most sites. The majority of sites had apparently level coral cover with recovery potentially inhibited by disease and increased interactions with other organisms. However, slow and irregular upward trajectories are notable at some sites, including Black Point, Botany Bay, Cane Bay, Fish Bay, Lang Hind, Salt River West, Salt River Deep, Seahorse, and St. James. Generalities that might indicate why these sites are recovering are difficult, but the coral communities in these reefs are all diverse. This diversity may contribute to recovery as fast growing species, such as Agaricites spp. and Porites porites may lead increases in coral cover. Some sites also showed degradation since 2007, when direct impacts of the 2005 bleaching abated. This was indicated by declines in coral cover and the sites include College Shoal, Ginsburgs Fringe, Grammanik Tiger, Magens Bay, Meri Shoal, and Savana. Four of six sites that were declining are mesophotic coral reefs, which may reflect the impact of generally higher prevalence of white diseases at high coral cover deep sites and a mild bleaching event that occurred in 2012. In addition, the deep Ginsburgs Fringe site lost 50% coral cover between 2011 and 2016, in what appears to be a continuous decline. While lionfish are frequent at this site and there is high cover of the macroalgae Lobophora variegata, the most obvious cause of disturbance is anchoring. A recent derelict reef claw anchor with at least 30m of polypropylene line was seen embedded in the monitoring site in 2014. Since damage has been recurrent it is likely that one or a few people are repeatedly anchoring on the edge to fish the Grammanik Bank. The activities have broken large plates and overturned portions of a large section of the large Agaricia spp. colonies that compose this reef. Ginsburgs Fringe is just along the border of the Grammanik Bank Federal Fisheries BENTHIC COVER & CORAL HEALTH 52 Managed Area and the site of a multi-species spawning aggregation, including Nassau grouper and yellowfin grouper (Kadison et al. 2006; Nemeth et al. 2006; Nemeth and Kadison 2013). Anchoring was likely for the purpose of fishing within the seasonal closed area, as there is little other obvious reason for anchoring at the shelf edge in deep water. Impacts to the corals and other essential fish habitat at this site may indirectly harm fishing in the US Virgin Islands. Two nearshore shallow sites that are degrading since 2007 may be impacted for different reasons. Magens Bay is highly impacted by sedimentation since it is largely enclosed, is surrounded by steep hillsides under constant development (sediment run-off), and is susceptible to strong winter swells (Rothenberger et al. 2008). Degradation at this site may primarily be the result of sediment impacts. On the other hand, Savana is an offshore and uninhabited island next to the typically clear waters of the Virgin Passage. Degradation at this site can be largely attributed to encrusting alga (Ramicrusta sp.), which has been competing for benthic space and slowly decreasing coral cover by overtopping colony margins. TCRMP MONITORING SUMMARY 53 Figure 12. Coral cover (±SE) across TCRMP monitoring sites over time. Nearshore Cover 0% 20% 40% 60% 80% 100% Black Point Botany Bay Brewers Bay Cane Bay Coculus Rock Coral Bay Fish Bay Great Pond Jacks Bay Kings Corner Magens Bay Salt River West Sprat Hole Offshore Cover 0% 20% 40% 60% 80% 100% Buck Island STT Buck Island STX Castle Eagle Ray Flat Cay Mutton Snapper Savana Island Seahorse South Capella South Water St. James Mesophotic 2001 2002 2003 2004 2005 2005 BL 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 Cover 0% 20% 40% 60% 80% 100% Cane Bay Deep College Shoal Ginsburgs Fringe Grammanik Tiger Hind Bank FSA Lang Bank EEMP Lang Bank FSA Meri Shoal Salt River Deep BENTHIC COVER & CORAL HEALTH 54 Epilithic Algal Community Cover Algae show the highest inter-annual variability of any group of benthic organisms (Fig. 13). This is largely due to seasonality. The cover of epilithic algae is no exception, since it tends to negatively covary with more ephemeral macroalgae. Epilithic algae is important as it can indicate substrates grazed by herbivores and therefore open to the settlement of sessile epibenthic animals, including coral. Therefore, declines in the cover of epilithic algae (or increases in the cover of macroalgae and filamentous cyanobacteria) could be an early indication of declining herbivory at sites. Some offshore sites, such as Eagle Ray, Buck Island-St. Croix, and Savana, appear to have a declining abundance of epilithic algae over the extent of the monitoring. Large recent declines in epilithic algae at Savana are due to increases in the “macroalgae” Ramictrusta (see next section). Nearshore and mesophotic sites typically showed little inter-annual trend in epilithic algal cover, although interannual variability was high at many nearshore monitoring sites. TCRMP MONITORING SUMMARY 55 Figure 13. Epilithic Algal Community cover (±SE) across TCRMP monitoring sites over time. Nearshore Cover 0% 20% 40% 60% 80% 100% Black Point Botany Bay Brewers Bay Cane Bay Coculus Rock Coral Bay Fish Bay Great Pond Jacks Bay Kings Corner Magens Bay Salt River West Sprat Hole Offshore Cover 0% 20% 40% 60% 80% 100% Buck Island STT Buck Island STX Castle Eagle Ray Flat Cay Mutton Snapper Savana Island Seahorse South Capella South Water St. James Mesophotic 2001 2002 2003 2004 2005 2005 BL 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 Cover 0% 20% 40% 60% 80% 100% Cane Bay Deep College Shoal Ginsburgs Fringe Grammanik Tiger Hind Bank FSA Lang Bank EEMP Lang Bank FSA Meri Shoal Salt River Deep BENTHIC COVER & CORAL HEALTH 56 Macroalgal Cover Macroalgae have been increasing at many reefs, particularly after the 2005 bleaching event (Fig. 14). At sites where there was no loss of coral cover, increased macroalgae may be due to declining grazing, such as at Eagle Ray. At other sites where coral cover dropped after 2005, space opened for algal colonization by coral die-off may have been taken by macroalgae. This might occur where resident herbivores communities are already at the threshold of maximum grazing rates (Williams et al. 2001). This process could be enhanced where herbivores numbers are falling due to fishing. These reefs include: the Buck Islands (St. Thomas and St. Croix), Cane Bay, Meri Shoal, South Capella, and Sprat Hole. The same explanation may also apply for filamentous cyanobacteria (see following section). At Savana the large increase in macroalgae in 2014 and continuing to 2015 was due to a large increase in encrusting Ramicrusta, which was mentioned above as a cause of declining coral cover (Ramicrusta is classified with macroalgae in TCRMP data summaries despite its largely encrusting habitat). This increase in Ramicrusta sp. was also at the expense of epilithic algae. TCRMP MONITORING SUMMARY 57 Figure 14. Macroalgae cover (±SE) across TCRMP monitoring sites over time. Nearshore Cover 0% 20% 40% 60% 80% 100% Black Point Botany Bay Brewers Bay Cane Bay Coculus Rock Coral Bay Fish Bay Great Pond Jacks Bay Kings Corner Magens Bay Salt River West Sprat Hole Offshore Cover 0% 20% 40% 60% 80% 100% Buck Island STT Buck Island STX Castle Eagle Ray Flat Cay Mutton Snapper Savana Island Seahorse South Capella South Water St. James Mesophotic 2001 2002 2003 2004 2005 2005 BL 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 Cover 0% 20% 40% 60% 80% 100% Cane Bay Deep College Shoal Ginsburgs Fringe Grammanik Tiger Hind Bank FSA Lang Bank EEMP Lang Bank FSA Meri Shoal Salt River Deep BENTHIC COVER & CORAL HEALTH 58 Filamentous Cyanobacteria Filamentous cyanobacteria cover has been increasing at many sites in the TCRMP since the 2005 coral bleaching event (Fig.15). In many cases this was a multi-year peak that has abated, but at some sites high cover relative to baseline has persisted until 2014. This is particularly true at many sites on St. Croix. For example, Salt River West, Jacks Bay, Cane Bay, Sprat Hole, Mutton Snapper, Buck Island-St. Croix, Eagle Ray, Lang Bank EEMP, and Lang Bank Hind have all seen cover of filamentous cyanobacteria from 10 – 60%, with 2009 as a particularly high abundance year for offshore sites. The increased incidence of filamentous cyanobacteria can be an indication of disturbance, increased nutrient inputs, and insufficient grazing (Fong and Paul 2011). In addition, filamentous cyanobacteria can promote increases in palatable macroalgae in coral reefs by coating and protecting algae with secondary metabolites that deter grazing (Fong et al. 2006; Smith et al. 2010a). Filamentous cyanobacteria can inhibit the recruitment of coral larvae (Kuffner et al. 2006) and have been observed interacting at the borders of adult coral (TCRMP, unpub. data). Monitoring the trends of filamentous cyanobacteria in USVI reef systems will be increasingly important in future years in an effort to understand the factors influencing bloom formation and which reefs are most vulnerable. TCRMP MONITORING SUMMARY 59 Figure 15. Filamentous cyanobacteria cover (±SE) across TCRMP monitoring sites over time. Nearshore Cover 0% 20% 40% 60% 80% 100% Black Point Botany Bay Brewers Bay Cane Bay Coculus Rock Coral Bay Fish Bay Great Pond Jacks Bay Kings Corner Magens Bay Salt River West Sprat Hole Offshore Cover 0% 20% 40% 60% 80% 100% Buck Island STT Buck Island STX Castle Eagle Ray Flat Cay Mutton Snapper Savana Island Seahorse South Capella South Water St. James Mesophotic 2001 2002 2003 2004 2005 2005 BL 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 Cover 0% 20% 40% 60% 80% 100% Cane Bay Deep College Shoal Ginsburgs Fringe Grammanik Tiger Hind Bank FSA Lang Bank EEMP Lang Bank FSA Meri Shoal Salt River Deep BENTHIC COVER & CORAL HEALTH 60 Gorgonian and Antipatharian Cover The cover of gorgonians and antipatharians has been fairly constant at most monitoring sites throughout the years of monitoring (Fig. 16). These groups did not seem sensitive to the thermal stress events in 2005, 2010, and 2012. In most cases they are a relatively minor component of cover because of their upright growth form and small branches. At Coral Bay, Fish Bay, and Magens Bay the cover of gorgonians has been increasing through the monitoring time series. These sites are known to have water quality issues and a high influx of terrestrial sediments. It is possible that inputs of nutrients from terrestrial run-off and poor sewage disposal are stimulating pelagic primary productivity (Furnas et al. 2005) and increasing the abundance of gorgonians that can feed heterotrophically on water column resources (De'ath and Fabricius 2010). Note that Black Corals (antipatharians) are rare and when they occur tend to be more prominent in deep monitoring sites. For many gorgonians species their abundance tends to peak in shallow water where there is constant swell (benthic orbital turbulence). TCRMP MONITORING SUMMARY 61 Figure 16. Gorgonian and Antipatharian cover (±SE) across TCRMP monitoring sites over time. Nearshore Cover 0% 5% 10% 15% 20% 25% Black Point Botany Bay Brewers Bay Cane Bay Coculus Rock Coral Bay Fish Bay Great Pond Jacks Bay Kings Corner Magens Bay Salt River West Sprat Hole Offshore Cover 0% 5% 10% 15% 20% 25% Buck Island STT Buck Island STX Castle Eagle Ray Flat Cay Mutton Snapper Savana Island Seahorse South Capella South Water St. James Mesophotic 2001 2002 2003 2004 2005 2005 BL 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 Cover 0% 5% 10% 15% 20% 25% Cane Bay Deep College Shoal Ginsburgs Fringe Grammanik Tiger Hind Bank FSA Lang Bank EEMP Lang Bank FSA Meri Shoal Salt River Deep BENTHIC COVER & CORAL HEALTH 62 Sponge Cover Sponge cover has been constant or variable at many offshore and mesophotic sites, but there is an indication of slightly increasing sponge cover at some nearshore sites (Fig. 17). Nearshore increases were most pronounced at Black Point, Coral Bay, and Magens Bay. This increase in epibenthic and boring sponges may indicate increasing supplies of food, such as bacteria and small eukaryotes, in nearshore environments. This may be a consequence of increasing nearshore nutrient pollution. Further study needs to be done to establish this linkage. TCRMP MONITORING SUMMARY 63 Figure 17. Sponge cover (±SE) across TCRMP monitoring sites over time. Nearshore Cover 0% 5% 10% 15% 20% 25% Black Point Botany Bay Brewers Bay Cane Bay Coculus Rock Coral Bay Fish Bay Great Pond Jacks Bay Kings Corner Magens Bay Salt River West Sprat Hole Offshore Cover 0% 5% 10% 15% 20% 25% Buck Island STT Buck Island STX Castle Eagle Ray Flat Cay Mutton Snapper Savana Island Seahorse South Capella South Water St. James Mesophotic 2001 2002 2003 2004 2005 2005 BL 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 Cover 0% 5% 10% 15% 20% 25% Cane Bay Deep College Shoal Ginsburgs Fringe Grammanik Tiger Hind Bank FSA Lang Bank EEMP Lang Bank FSA Meri Shoal Salt River Deep FISH COMMUNITIES 64 FISH COMMUNITIES In 2016, a total of 57,119 fish representing 143 species and 42 families were recorded over 180 belt transects across 18 sites off the northern USVI. Total calculated biomass on sites of the northern USVI was 1,795.61 kg. An additional 54,855 fish representing 136 species and 42 families were recorded over 140 transects across all 14 sites off St. Croix. The calculated biomass was 1,553.74 kg. Using roving diver surveys (RDS) 127 species representing 35 families were observed in 2016 off the northern USVI and 133 species representing 36 families off St. Croix. Species richness was variable between sites but was similar between survey methods (transects and RDS). No differences in species richness were apparent between nearshore, offshore, and mesophotic sites (Table 3). Sites with notably high species diversity were Hind Bank East FSA and Seahorse Cottage Shoal off St. Thomas (28.5 ±1 .6 and 32.8 ± 1.5 species transect-1, respectively), and Lang Bank EEMP and Kings Corner off St. Croix (28.7 ± 1.7 and 27.8 ± 1.9 species transect- 1, respectively). Two mesophotic sites off St. Croix, Cane Bay Deep and Salt River Deep, had low species richness (18.7 ± 1.4 and 18.9 ± 1.6 species transect-1 , respectively), as well as the nearshore site in Coral Bay, St. John (17.6 ± 1.0 species transect-1) . Overall fish size distribution on both the northern USVI and St. Croix followed trends seen in earlier years. Over 60% of all individuals counted off both the northern USVI and St. Croix were less than 5cm TL and over 82% were less than 10cm TL. Large fish (> 40cm TL) constituted 0.4% of the numeric total in the northern USVI (228 fish), and 0.2% off St. Croix (91 fish). Numerically the most dominant fish across all USVI reefs was the glass goby (Coryopterus personatus), which constituted over 25% of the fish observed. In the northern USVI, striped parrotfish (Scarus iserti), bluehead wrasse (Thalassoma bifaciatum), creole wrasse (Clepticus parrae), and blue chromis (Chromis cyanae) made up an additional 30% of the numeric total. On St Croix reefs, creole wrasse, blue chromis, and bluehead wrasse contributed and additional 35% to the numeric total of all sites. All of these species were ubiquitous and have been observed in relatively high numbers across all sites, and across all TCRMP SITE SUMMARIES 65 years. The exception is the creole wrasse, which was abundant primarily on offshore and mesophotic sites and on nearshore sites adjacent to walls. FISH COMMUNITIES 66 Table 3. The 2016 species richness for belt transects and roving diver surveys (RDS). Sites are divided into nearshore, offshore, and mesophotic sites as described in the text. Belt Transects (25x4) RDS Total Number of Species Mean species per transect (±SE) Total Number of Species Nearshore Cane Bay 56 23.2±1.5 46 Great Pond 54 20.9±1.1 50 Jacks Bay 61 21.9±2.0 64 Kings Corner 68 27.8±1.9 75 Salt River West 50 20.0±1.8 49 Sprat Hole 62 26.4±1.2 63 Coculus Rock 61 22.3±0.9 52 Black Point 53 22.9±1.1 56 Brewers Bay 51 21.2±0.5 56 Botany Bay 62 25.3±3.0 60 Buck Island, St. Thomas 75 32.8±1.5 72 Coral Bay 43 17.6±1.0 38 Fish Bay 56 23.7±0.7 57 Megans Bay 49 22.4±1.3 49 Offshore Eagle Ray 62 25.6±1.4 62 Buck Island, St. Croix 63 22.4±1.4 51 Castle 69 26.3±1.5 52 Mutton Snapper 65 25.0±1.4 61 Seahorse Cottage 58 26.3±0.8 54 South Capella 59 24.6±1.2 55 South Water Island 63 25.1±1.1 57 Flat Cay 65 25.2±1.8 54 Meri Shoal 57 22.9±1.2 48 Savana Cay 59 25.2±1.4 56 Little St. James 66 26.1±1.3 58 Mesophotic Cane Bay Deep 50 18.7±1.4 52 Lang EEMP 71 28.3±1.8 58 Lang Bank 59 24.9±1.4 60 Salt River Deep 60 18.9±1.6 46 College Shoal East 64 25.4±0.5 42 Grammanik Bank FSA 60 26.1±1.5 56 Hind Bank East FSA 70 28.5±1.6 58 TCRMP SITE SUMMARIES 67 Fish Abundance Total fish abundances across nearshore, offshore, and mesophotic sites and years are shown in Fig. 18. Fish abundance across most sites in 2016 was higher than previous years due to a small change in methodology. In 2016 all blennies and gobies encountered were identified and enumerated while in previous years they were not. The glass goby (Coryopterus personatus) is a very abundant fish on Caribbean reefs, and contributed nearly 60,000 individuals to northern USVI sites and almost 55,000 to sites in St. Croix. Glass gobies were found on all reef sites in large numbers. Total fish abundance was highly variable across sites and strata with no obvious patterns over time or space noted. The two nearshore sites in the northern USVI, Coral Bay and Fish Bay, with glass gobies excluded, continued to have lower abundances of fish than other sites. The sites with the highest overall fish abundance over the years have been Cane Bay Shallow, Kings Corner and Sprat Hole on St. Croix, and Flat Cay and College Shoal in the northern USVI. FISH COMMUNITIE Figure 18. Fish abundance (±S are to the left and northern USV ES 68 E) across TCRMP monitoring sites over time. VI to the right on the x-axis. St. Croix sites TCRMP SITE SUMMARIES 69 Fish Biomass Fish biomass across sites is shown in Fig. 19. As with abundance, biomass is highly variable between sites and years. No temporal pattern is evident, and differences in time appear to be seasonal or natural variation. The biomass of fish at mesophotic sites off the northern USVI (Grammanik Bank FSA, Hind Bank FSA, and College Shoal) have had the highest biomass values throughout the TCRMP sampling series. These are protected reefs on the insular shelf edge, and fish spawning occurs on both the Grammanik Bank FSA and Hind Bank FSA. Although TCRMP sampling occurs outside of the spawning season, higher numbers of large fish may inhabit these sites due to their roles as aggregation areas. College Shoal does not host spawning events however, and biomass is also generally high on this site. The St. Croix nearshore site, Kings Corner, continued to have a relatively high biomass in 2016 when compared to the other nearshore and offshore sites, as well as the St. Croix mesophotic sites. Kings Corner also generally has a relatively high fish abundance and species richness, which was also observed in 2016. Northern USVI nearshore sites, Coral Bay, Magens Bay, Fish Bay and Botany Bay, all had notably low fish biomass in 2016. These sites are along shorelines of developing residential areas and sustain high turbidity levels. They are also far from the deeper water near the shelf edge, and so these sites appear to support only juvenile fishes, and small species and at very low abundances. Large-bodied fishes that do colonize these reefs are likely vulnerable to fishing. FISH COMMUNITIE Figure 19. Mean fish biomass ( sites are to the left and norther ES 70 (±SE) across TCRMP monitoring sites over tim rn USVI to the right on the x-axis. me. St. Croix SEA URCHINS 71 BLACK SPINY SEA URCHIN DIADEMA ANTILLARUM The abundance of the black spiny sea urchin Diadema antillarum shows tremendous site- to-site variability (Fig. 24). In general the shallowest sites, e.g., Great Pond, support the greatest abundance of D. antillarum. These sites also tend to have very low macroalgal cover. Trends are not presented here by year, as variability is generally low. At Coral Bay there is a high abundance of Echinometra spp. that has not been quantified. This species seems to be the dominant grazer and effectively removes most macroalgal cover, but also contributes apparently high bioerosion (gnawed coral bases). Future monitoring might considered targeted monitoring of these species at certain sites. FISH COMMUNITIES 72 Figure 20. Abundance of the black spiny sea urchin (Diadema antillarum) at TCRMP monitoring sites. Note the log scale. log (Diadema antillarum/100m2) 0.001 0.01 0.1 1 10 100 Cane Bay Deep College Shoal Ginsburg Fringe Grammanik Kings Corner Lang Bank EEMP Lang Bank FSA Meri Shoal Mutton Snapper Salt River Deep Savana Seahorse South Capella South Water Sprat Hole Hind Bank St James Flat Cay Jacks Bay Buck Island STX Buck Island STT Salt River West Fish Bay Eagle Ray Cane Bay Black Point Magens Bay Coral Bay Brewers Bay Botany Bay Castle Coculus Rock Great Pond SITE SUMMARIES 73 Site Summaries RATIONALE The purpose of this section is to provide a more comprehensive survey of TCRMP site characteristics than can be achieved in the overall data compilations. Each TCRMP monitoring site is unique and has experienced distinctive responses to local and global stressors. Given the increase in sites included under this program and the inclusion of more information at each site, such as physical data, this section is designed to provide a summary that highlights each site’s individual characteristics and serves as a quick reference guide for managers, policy makers, and academics. The duration of surveys at most sites also now provides sufficient data from which to draw conclusions about longer term site dynamics and the processes that might be contributing to recent trajectories of health, development, and degradation. SITE SUMMMARY ELEMENTS TCRMP site information is presented in a few pages that provide a brief description of the setting and the potential susceptibility to local and global stressors and disturbances. Sub- sections include a description of (1) the physical environment, (2) the benthic community and (3) the fish community. The benthic data and coral health are updated in each annual report, whereas the fish summaries and physical data are updated periodically. Benthic community structure is presented as the mean (±SE) cover of coral, macroalgae, cyanobacteria, and epilithic algae. Epilithic algal communities are diminutive turf and filamentous algae that cover hardbottom surfaces, whilst macroalgae have identifiable thallus differentiation and structure. Any open hardbottom space is assumed to host an epilithic algal community even if algae cannot be resolved in video images. The loss of coral cover due to the 2005 bleaching event was calculated as the relative change in coral cover from 2005 to 2007, unless otherwise noted for sites not sampled in these years. In addition, the percent recovery from the 2005 bleaching event was calculated as the amount of coral cover regained by 2011 (Cover2011 - Cover2007)/(Cover2005- Cover2007). Change calculations must be treated with caution for sites where transects where not made permanent until after the 2005 bleaching event or where percent cover is low, since the SITE SUMMARY 74 conditions introduce an unknown amount of error. Trends are shown for all available years of monitoring Benthic community pie charts were constructed from all years of data. The sessile epibenthic animal community includes Agaricia spp., Colpophyllia natans, Diploria strigosa, Orbicella annularis3, Orbicella spp. (O. faveolata, O. fransksi, + unidentified Orbicella spp.), Montastraea cavernosa, Porites astreoides, branching Porites species, Siderastrea siderea, other corals, sponges, and gorgonians. The algae/non-living substrata category includes cyanobacteria, epilithic algae (“DCA”), Lobophora variegata, Dictyota spp., Halimeda spp. crustose coralline algae, and sand/sediment. These figures not are updated every annual report, since relative composition tends to change slowly. Figures are changed every five years or after a major disturbance, such as a coral bleaching event. Coral Health is presented as the mean (±SE) of coral bleaching prevalence (proportion of population affected) and extent (proportion of colony affected), disease prevalence, and partial mortality prevalence. PHYSICAL CHARACTERISTICS. Temperature. Benthic temperatures were recorded at each site with a calibration checked HoboTemp™ thermistor data logger (Onset Computer Corporation, Bourne, Massachusetts). Thermistors were affixed within transects and set to 3 The genus Orbicella was formerly named Montastraea, but changed in 2012 reflecting an earlier precedence and dissimilarity with Montastraea cavernosa (Budd et al. 2012). Some figures in this report may still abbreviate the genus name as “M.” Temperature Figure Guide. Temperatures in degrees Celsius (left axis) and degree heating weeks (right axis). Line color indicates year of record. BT = Bleaching Threshold, calculated empirically or taken from linear relationship shown in Smith et al. (2016). MMM = BT – 1°C, EMMM = Empirical MMM derived from non- bleaching years over period of observation. DHW = Degree Heating Week (NOAA 2006). Dashed DHW line indicates incomplete temperature record; DHW provisional. Colored dot on DHW line indicates the date of annual sampling to put the bleaching observations in context. SITE SUMMARIES 75 record at intervals of 15 minutes. Records are presented as daily averages across months, February 29th excluded. Each temperature figure includes the climatological monthly maximum mean temperature (28.5°C), and the bleaching threshold temperature (29.5°C) established for the region (NOAA 2006). Data for 2005 was taken from current profilers or federal data sources. Currents. Water currents were recorded at a subset of sites and times with Nortek Aquadopp™ Acoustic Doppler Current Profilers (ADCPs). Profilers were set in bases on the seafloor and set to record current speed and direction within predefined depth bins above the substrate. The bin closest to the substrate and closest to the coral reef was selected for display. Compass rose figures were developed that show the frequency of current in magnetic directions 0, 22.5, 45, 67.5, 90, 112.5, 135, 157.5, 180, 202.5, 225, 247.5, 270, 292.5, 315, 337.5, 360°. Within each direction the frequency of current speed within bins of 0.1 m s-1 were plotted. For Flat Cay, current data was retrieved with an Aandaraa 2-D current meter that measured current speed and direction directly over the sensor head. Chlorophyll and Turbidity. Continuous fluorometric measurements of chlorophyll and turbidity were conducted at some sites for short periods (Black Point, Grammanik, Magens Bay). Wetlabs ECOFLNT fluorometers with antifouling bio-wipers were deployed and set to record for one minute at hourly intervals. Water column chlorophyll measurements detect phytoplankton abundance. Fluorometric measurements of chlorophyll are proxies for true chlorophyll concentrations. Direct chlorophyll measurements to calibrate fluorometric measurements have not been conducted at the monitoring sites. SITE SUMMARIES 77 St. Croix SITE SUMMARIES 79 BUCK ISLAND, ST. CROIX Description. The Buck Island, St. Croix site is a seaward extension of the southeast Buck Island barrier reef complex in water depth of 15 m. The reef is a low framework surrounded by a sand plain to the west and a rolling reef/hardbottom to the east. The Buck Island, St. Croix site is largely composed of large living and dead O. annularis heads surrounded by sand. The site has been monitored since 2001, with three permanent benthic transects installed in 2001, and three additional transects installed in 2003. Outstanding Feature. The Buck Island, St. Croix site is within the expanded (2001) Buck Island Reef National Monument. The reef fish populations may show recovery due to the restriction of fishing. Threats. Due to its protected area status and remoteness from land-based pollution Buck Island, St. Croix is primarily threatened by changing climate as its populations of O. annularis were shown to be susceptible during the 2005 bleaching event. Figure 21. The Buck Island, St. Croix. (top) Position in the Buck Island Reef National Monument. (right)A representative photo. BUCK ISLAND, ST. CROIX 80 Figure 22. Buck Island, St. Croix benthic temperatures (14 m depth). Data provided by the National Park Service (site BUIS_SFR). Physical Characteristics Current. Currents have not been recorded at the Buck Island, St. Croix monitoring site. Unidirectional currents have always been light during monitoring. Oscillatory currents occasionally impact the site when swell is from the east. Temperature. Temperatures at the Buck Island, St. Croix monitoring sites can get very warm and surpassed the bleaching threshold at or above 4 Degree Heating Weeks in 2005 and 2010. Month SITE SUMMARIES 81 Benthic Community. The Buck Island, St. Croix hard coral community is dominated by the boulder star coral Orbicella annularis; however, the most abundant sessile epibenthic animals are gorgonians. Epilithic algae dominate the algal community, with a low cover of macroalgae relative to other sites. There is a high proportion of sand. This coral community lost 65.5% of its coral cover in the 2005 bleaching event and had only regained 6% of coral cover by 2011. Filamentous cyanobacteria showed very large increases in cover after the 2005 bleaching event. Coral Health. Buck Island, St. Croix corals were likely severely affected during the 2005 bleaching event; however, bleaching health surveys were not completed until Jan. 13, 2006 when recovery had already commenced. The prevalence of coral diseases was high on O. annularis, with frequent incidence of yellow band disease and white disease following the 2005 bleaching event. Old partial mortality was very prevalent after the 2005 coral bleaching event and then decreased, becoming stable over time in 2011. Figure 23. Buck Island, St. Croix. (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. BUCK ISLAND, ST. CROIX 82 Figure 24. Buck Island, St. Croix benthic cover and coral health through time (mean ± SE). Benthic Community Cover 0% 20% 40% 60% 80% 100% Coral Cyanobacteria Epilithic Algae Macroalgae Bleaching Prevalence/Extent 0% 20% 40% 60% 80% 100% Prevalence Extent Disease Prevalence 0% 5% 10% 15% 20% 25% 30% All disease Black Band Lesion Dark Spots Intercostal White Disease Yellow Band Unknown Partial Mortality 2001 2002 2003 2004 2005 2005 BL 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 Prevalence 0% 20% 40% 60% 80% 100% Old Recent SITE SUMMARIES 83 Fish Community. Buck Island is a low patchy reef community surrounded by and interspersed with sand. The fish community is largely dominated in biomass by herbivores with a very high biomass of stoplight parrotfish. Close to the monitoring site are “the Haystacks”, large Acropora palmata skeletal remains that provide ample grazing area for large parrotfish. In addition, the Buck Island site is within the Buck Island Coral Reef National Monument and the fish inhabitants are theoretically protected from spearfishing and nets. There is also a high biomass of invertivore fishes, which are dominated by the yellowhead wrasse. Invertivores are diverse on the site and include several species of grunts (tomtate, French, Spanish, white, and bluestripe) as well as many wrasses (yellowhead, bluehead, clown, yellowcheek, slippery dick, and creole wrasse). Piscivores are uncommon, and the only serranids observed during transects in 2011 and 2012 were small red hind and graysby. Snapper were limited to schoolmaster and one mahogany snapper. BUCK ISLAND, ST. CROIX 84 Figure 25. The Buck Island, St. Croix fish community by absolute and relative biomass. Herbivores stoplight parrotfish blue tang redband parrotfish striped parrotfish threespot damsel ocean surgeonfish princess parrotfish dusky damsel Beaugregory doctorfish yellowtail damsel queen parrotfish greenblotch parrotfish orangespotted filefish longfin damsel Fish Biomass (g) 0 2000 4000 6000 8000 10000 Invertivores French grunt queen trigger yellowhead wrasse spotted goatfish sand tilefish squirrelfish tomtate yellowfin mojarra saucereye porgy yellow goatfish yellowcheek wrasse clown wrasse butter hamlet slippery dick white grunt red hind yellowtail hamlet harlequin bass southern stingray fairy basselet Fish Biomass (g) 0 500 1000 1500 2000 2500 3000 Plankivores blue chromis bicolor damsel yellowtail snapper creole wrasse brown chromis black durgon Fish Biomass (g) 0 500 1000 1500 2000 2500 Piscivores schoolmaster graysby trumpetfish redspotted hawkfish mahogany snapper bar jack red lionfish Fish Biomass (g) 0 500 1000 1500 2000 2500 3000 3500 SITE SUMMARIES 85 CANE BAY Description. The Cane Bay monitoring site is a nearshore/shelf edge fringing reef on the northwest coast of St. Croix. Transects follow the trend of the leeward spur and groove formations. Cane Bay has been monitored since 2001. Outstanding Feature. Cane Bay is one of the most well developed nearshore reefs on St. Croix. It is also one of the most heavily visited dive sites by both tourists and residents in the Virgin Islands due to its proximity to the wall, considered by some to be the most precipitous submarine drop off in the world. The reef has been under scientific investigation since the 1970’s. Threats. Although the Cane Bay reef is a singular treasure for the Virgin Islands, it is threatened by pollution, fishing, climate change, and recreational overuse. The watershed above Cane Bay has been planned for residential development with potential for the influx of terrestrial sediment. The reef is also fished commercially, and teams of spearfishers on SCUBA have been observed. This reef also lost half its coral cover in the 2005 bleaching event, suggesting it is vulnerable to warming ocean temperatures. Figure 26. Cane Bay. (top) Location. (right) A representative photo of the reef. CANE BAY 86 Figure 27. Cane Bay benthic temperatures (8 m depth) Physical Characteristics Current. Cane Bay currents have not been directly measured by the TCRMP. However, this site typically has moderate unidirectional currents with the occasional exposure to strong north swell. The current at the site may be part of an eddy formed by the dominant westward flowing current wrapping around the eastern point. Its downstream location from the entire north coast of St Croix may also make this site a recruitment sink for larvae, potentially adding to the diversity. Temperature. Cane Bay is a relatively open and clear environment, and the temperatures tend to stay cooler, but the propensity for bleaching may be increased by the high light transmission. Month SITE SUMMARIES 87 Benthic Community. Cane Bay supports a very diverse coral community, with dominance by Orbicella spp. Open substrates were mostly epilithic algal community; however, epilithic algae cover has declined since the 2005 bleaching event with increases in the cover of macroalgae and filamentous cyanobacteria. This indicates that the resident herbivore community was not able to effectively graze substrates opened by coral mortality. This coral community lost 46.8% of coral cover in the 2005 bleaching event and lost 6% more as of 2011, a troubling sign. Coral Health. Cane Bay corals were severely affected during the 2005 bleaching event with nearly all colonies bleached over 80% of the colony surface. The prevalence of bleaching was also high in 2010, yet at a low extent. The prevalence of coral diseases was low before 2005, but outbreaks of white, yellow band, and dark spots disease have occurred more recently, another indication of declining health at this reef. Old and recent partial mortality became very prevalent after the 2005 coral bleaching event and have remained nearly steady or increased since. Figure 28. Cane Bay. (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. CANE BAY 88 Figure 29. Cane Bay benthic cover and coral health through time (mean ± SE). Benthic Community Cover 0% 20% 40% 60% 80% 100% Coral Cyanobacteria Epilithic Algae Macroalgae Bleaching Prevalence/Extent 0% 20% 40% 60% 80% 100% Prevalence Extent Disease Prevalence 0% 5% 10% 15% 20% 25% 30% All disease Black Band Lesion Dark Spots Intercostal White Disease Yellow Band Unknown Partial Mortality 2001 2002 2003 2004 2005 2005 BL 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 Prevalence 0% 20% 40% 60% 80% 100% Old Recent SITE SUMMARIES 89 Fish Community. Cane Bay has a high diversity, abundance, and biomass of fish, reflecting the benthic diversity and high structural complexity. The most dominant fish species in terms of both abundance and biomass is the creole wrasse, zooplankton feeders. Also very common are other planktivorous fishes: the black durgeon, yellowtail snapper, and blue and brown chromis. Large parrotfishes can regularly be observed on the Cane Bay site, including adult queen and stoplight parrotfish. A variety of other herbivores are common, especially princess parrotfish, redband parrotfish, and blue tang. Mahogany snapper and graysby dominate the piscivores group. Other than these, no snapper or grouper were observed on the Cane Bay reef. Nonetheless the site has a high diversity of fish, with several butterflyfish and squirrelfish species present, as well as some deeper water species (sunshinefish, longsnout butterflyfish, and fairy basslet) due to the site’s close proximity to the deep wall drop. CANE BAY 90 Figure 30. The Cane Bay fish community by absolute and relative biomass. Herbivores stoplight parrotfish redband parrotfish blue tang princess parrotfish yellowtail damsel ocean surgeonfish threespot damsel doctorfish longfin damsel dusky damsel striped parrotfish Beaugregory Fish Biomass (g) 0 1000 2000 3000 4000 5000 6000 Invertivores yellow goatfish French grunt squirrelfish blackbar soldierfish striped grunt yellowhead wrasse white grunt Spanish hogfish dusky squirrelfish bluestriped grunt spotted goatfish tomtate yellowcheek wrasse fairy basselet red hind Fish Biomass (g) 0 1000 2000 3000 4000 5000 Plankivores creole wrasse brown chromis blue chromis black durgon bicolor damsel yellowtail snapper sunshinefish Fish Biomass (g) 0 2000 4000 6000 8000 10000 Piscivores mahogany snapper graysby bar jack glasseye snapper cero Fish Biomass (g) 0 200 400 600 800 1000 1200 1400 SITE SUMMARIES 91 CANE BAY DEEP Description. The Cane Bay Deep monitoring site is a mesophotic wall coral reef environment just downslope from the Cane Bay site. The reef is composed of deep spurs of coral interspersed with sediment. Cane Bay Deep was first surveyed during the 2005 coral bleaching event, but a permanent monitoring site was not established until 2009. Outstanding Feature. Cane Bay Deep is one of the most impressive wall environments in the Caribbean and is the crown jewel for St. Croix dive tourism and biodiversity. Threats. Although Cane Bay is economically important via dive tourism, it is under no special protection. Cane Bay Deep is threatened by sediment, fishing, climate change, and recreational overuse. Sediment cascades down from the shallow reef. Fishing occurs even at the deep reef evidenced by the presence of lost gear (monofilament and trap lines). Figure 31. 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. CANE BAY DEEP 92 Figure 32. Cane Bay Deep temperature (39 m depth). Physical Characteristics Current. Cane Bay Deep is a calm wall environment that is buffered from water motion. However, it does receive sediment cascades from particles resuspended from the upper reef terrace. These flows are directed in the depressions between spurs. Temperature. Cane Bay Deep temperatures are buffered in the warmest months by the presence of the thermocline. However, internal tide activity at this site is not as strong as in deep (~40 m) sites on the south shelf of St. Thomas, leading to less diurnal variability in temperatures. This may make the mesophotic wall environments more susceptible to bleaching than other mesophotic sites on the southern Puerto Rican shelf. Month SITE SUMMARIES 93 Benthic Community. Cane Bay Deep is a mesophotic plating coral community dominated by lettuce corals (Agaricia spp.), sponges, gorgonians, and black coral. The algal community is mostly epilithic algae, but there are also quantities of Dictyota spp. and Lobophora variegata. A high proportion of the substrate is soft sediment that flows from the upper shelf to deposit in grooves. Benthic cover was not measured until 2009. Coral Health. Surprisingly for a dim and cooler mesophotic reef, Cane Bay Deep corals bleached heavily in the 2005 coral bleaching event by both prevalence and extent. Low- extent coral bleaching is very prevalent even in years without thermal stress, a likely result of sediment deposition. Unknown diseases and dark spots diseases are prevalent in some years. Old partial mortality increased after 2005, and remained high and steady from 2009- 2011. Figure 33. Cane Bay Deep. (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. CANE BAY DEEP 94 Figure 34. Cane Bay Deep benthic cover and coral health through time (mean ± SE). Benthic Community Cover 0% 20% 40% 60% 80% 100% Coral Cyanobacteria Epilithic Algae Macroalgae Bleaching Prevalence/Extent 0% 20% 40% 60% 80% 100% Prevalence Extent Disease Prevalence 0% 5% 10% 15% 20% 25% 30% All disease Black Band Lesion Dark Spots Intercostal White Disease Yellow Band Unknown Partial Mortality 2001 2002 2003 2004 2005 2005 BL 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 Prevalence 0% 20% 40% 60% 80% 100% Old Recent SITE SUMMARIES 95 Fish Community. Cane Bay Deep has maintained a very low fish biomass compared to both other mesophotic sites and shallow and midshelf sites of St. Croix. The site is dominated by invertivores, primarily planktivorous creole wrasse and blue chromis. This planktivorous community is depauperate compared to that of Salt River Deep. Herbivores present are primarily benthic feeders: sub-adult princess parrotfish, redband parrotfish, and doctorfish. There is very low piscivorous biomass on the reef, generally made up of schoolmaster snapper, mahogany snapper, graysby, and an occasional barracuda. Deepwater reef species such as the bantum bass, fairly basslet, cherubfish, and sunshine fish are common. CANE BAY DEEP 96 Figure 35. The Cane Bay Deep fish community by absolute and relative biomass. Herbivores princess parrotfish redband parrotfish stoplight parrotfish blue tang striped parrotfish doctorfish ocean surgeonfish Beaugregory threespot damsel dusky damsel yellowtail damsel Fish Biomass (g) 0 1000 2000 3000 4000 Invertivores red hind yellow goatfish French grunt yellowhead wrasse bluestriped grunt blackbar soldierfish longsnout butterflyfish dusky squirrelfish fairy basselet Spanish hogfish yellowtail hamlet slippery dick spotted drum clown wrasse Fish Biomass (g) 0 500 1000 1500 2000 2500 3000 Plankivores creole wrasse creolefish blue chromis sunshinefish yellowtail snapper brown chromis chalk bass 0 1000 2000 3000 4000 5000 6000 7000 Piscivores schoolmaster great barracuda mahogany snapper graysby bar jack black hamlet Fish Biomass (g) 0 200 400 600 800 1000 1200 1400 1600 Fish Biomass (g) SITE SUMMARIES 97 CASTLE Description. Castle (aka. West Indies Lab) is part of the seaward northeastern St. Croix barrier reef complex outside Teague Bay. The reef starts at sea level as a relict elkhorn coral reef and is dominated by boulder star corals along the seaward edge. The area around the Castle site was monitored initially in 2003, but permanent transect were not installed until 2008. Outstanding Feature. Castle is part of the once luxurious living elkhorn coral barrier reef that protects the northeastern St. Croix shoreline. It was a research area of the former West Indies Laboratory of Farleigh Dickenson University, which was a seminal area for global coral reef research from the 1970’s and 1980’s. Threats. The barrier reef outside Teague Bay is inside the St. Croix East End Marine Park, but is in the open fishing zone. There is relatively low potential for land-based sources of pollution due to the sites midshelf location in front of a lightly populated area. Clear water and warm temperatures make this an area of potential concern during bleaching events. Figure 36. Castle. (top) Location. (right) A representative photo of the reef. CASTLE 98 Figure 37. Castle benthic temperatures (9 m depth). Physical Characteristics Current. Little is known about the current at the Castle site. It is under the influence of wave-driven oscillatory flow in the shallows, but strong directional currents have not been experienced during monitoring activities. Temperature. Castle has the potential to develop very warm temperatures and spent nearly a month above the bleaching threshold in 2010. Month SITE SUMMARIES 99 Benthic Community. The Castle site is unusual for its dominance of branching Porites corals along the slope and concentrations of Orbicella spp. corals at the outer fringe adjacent to sand. The algal community is dominated by epilithic algae, with lesser abundance of Dictyota spp.. Macroalgae and filamentous cyanobacteria are also common. The impacts of the 2005 bleaching event are not known since monitoring in 2003 was not necessarily in exactly the same spot as the location of permanent transects established in 2008. Coral Health. Bleaching is mild at the site. Corals were assessed prior to but not during the 2010 coral bleaching event. Old partial mortality is high in prevalence and steady. Recent partial mortality is particularly high at the site, and this may be a consequence of numerous damselfish (Stegastes spp.) and predatory snails (Coralliophila spp.) on large Orbicella spp. colonies. Figure 38. Castle. (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. CASTLE 100 Figure 39. Castle benthic cover and coral health through time (mean ± SE). Benthic Community Cover 0% 20% 40% 60% 80% 100% Coral Cyanobacteria Epilithic Algae Macroalgae Bleaching Prevalence/Extent 0% 20% 40% 60% 80% 100% Prevalence Extent Disease Prevalence 0% 5% 10% 15% 20% 25% 30% All disease Black Band Lesion Dark Spots Intercostal White Disease Yellow Band Unknown Partial Mortality 2001 2002 2003 2004 2005 2005 BL 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 Prevalence 0% 20% 40% 60% 80% 100% Old Recent SITE SUMMARIES 101 Fish Community. The Castle fish community is typically lower in overall abundance and biomass than most of the St. Croix offshore sites. It is dominated by herbivores in biomass, driven by a few large stoplight parrotfish. However, sub-adult and juvenile redband, striped, and princess parrotfish are numerically much more common than stoplight. All three acanthurids (ocean surgeonfish, blue tang, and doctorfish) are common, as are many species of damselfish. Invertivores are also fairly high in biomass and are a diverse group; dominated by benthic feeders such as yellow and spotted goatfishes, as well as blackbar soldierfish and squirrelfish. Piscivore biomass in recent years has been heavily dominated by the invasive lionfish. No serranids other than hamlets and tiny basslets have been recorded. CASTLE 102 Figure 40. The Castle fish community by absolute and relative biomass. Herbivores redfin parrotfish stoplight parrotfish doctorfish blue tang yellowtail damsel redband parrotfish threespot damsel ocean surgeonfish queen parrotfish dusky damsel striped parrotfish princess parrotfish Beaugregory cocoa damsel greenblotch parrotfish Fish Biomass (g) 0 2000 4000 6000 8000 10000 12000 14000 16000 18000 20000 Invertivores blackbar soldierfish yellow goatfish squirrelfish French grunt spotted goatfish yellowhead wrasse Spanish hogfish red hind spotted drum harlequin bass striped grunt butter hamlet dusky squirrelfish fairy basselet belted cardinalfish Fish Biomass (g) 0 500 1000 1500 2000 2500 Plankivores blue chromis brown chromis bicolor damsel sunshinefish creole wrasse yellowtail snapper tobaccofish Fish Biomass (g) 0 200 400 600 800 1000 1200 Piscivores red lionfish blue runner gray snapper bar jack graysby mahogany snapper spotted moray schoolmaster trumpetfish black hamlet Fish Biomass (g) 0 200 400 600 800 1000 1200 1400 1600 1800 SITE SUMMARIES 103 EAGLE RAY Description. The Eagle Ray site is a shallow seaward barrier reef located at west dive buoy 1 outside the main Christiansted access channel. The monitoring site is colonized hardbottom to coral reef, with more extensive development of reef at the seaward edge. Eagle Ray has been monitored since 2001. Outstanding Feature. Eagle Ray is one of the most visited dive sites due to its proximity to Christiansted. Threats. Proximity to Christiansted increases the potential for land-based sources of pollution, such as sewage, run-off, and marine debris. The site is frequented by small fishing craft that venture just out of port, likely increasing the fishing pressure. Figure 41. Eagle Ray. (top) Location. (right) A representative photo of the reef. EAGLE RAY 104 Figure 42. Eagle Ray benthic temperature at 9 m depth Physical Characteristics Current. Currents have not been measured at Eagle Ray; however, strong unidirectional currents seem rare. There are increased oscillatory currents near the shallow portion of the site. Temperature. Eagle Ray is shallow but near deep water on two sides, which may potentially help to reduce the temperature relative to sites in more enclosed environments. Month SITE SUMMARIES 105 Benthic Community. Eagle Ray supports a diverse community of small coral colonies, but sponges and gorgonians compose half the sessile epibenthic animal community. Coral cover has been low (less than 10%) throughout the monitoring period. Coral cover decreased only slightly with the 2005 coral bleaching event, 11.7%, but cover has come back and actually increased above pre-bleaching values. The limited response may be partly due to the high relative abundance of more thermally resistant coral species. The site was dominated with epilithic algae; however, this has declined after the 2005 bleaching event with a concomitant increase in macroalgae and filamentous cyanobacteria. Coral Health. Eagle Ray corals were severely affected during the 2005 bleaching event with nearly all colonies bleached over about 80% of the colony surface. Low-level bleaching is also common in years without thermal stress. The site was monitored in 2010 prior to the thermal stress event and bleaching is underestimated for that year. Diseases are a common feature of the site, with black band, yellow band, and dark spots disease having outbreaks in certain years. Lesions were also common during the 2005 coral bleaching event. Old partial mortality became very prevalent after the 2005 coral bleaching event and subsided in the following years. Figure 43. Eagle Ray. (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. EAGLE RAY 106 Figure 44. Eagle Ray benthic cover and coral health through time (mean ± SE). Benthic Community Cover 0% 20% 40% 60% 80% 100% Coral Cyanobacteria Epilithic Algae Macroalgae Bleaching Prevalence/Extent 0% 20% 40% 60% 80% 100% Prevalence Extent Disease Prevalence 0% 5% 10% 15% 20% 25% 30% All disease Black Band Lesion Dark Spots Intercostal White Disease Yellow Band Unknown Partial Mortality 2001 2002 2003 2004 2005 2005 BL 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 Prevalence 0% 20% 40% 60% 80% 100% Old Recent SITE SUMMARIES 107 Fish Community. Eagle Ray is a fairly diverse and rich site, especially considering the fishing and diving pressure it receives, as well as the proximity of Christiansted Harbor. It is dominated by herbivores and invertivores, with a large variety of parrotfishes and benthic feeders such as the blackbar soldierfish. Proximity to open deep water is evidenced by the occurrence of fairly high numbers of planktivorous creole wrasse and a few black durgeon. Yellowtail snapper are large and plentiful, probably due to the divers that frequent the site with fish food. Large jacks are common at the site and generally dominate the piscivores group. Graysbys are the most common serranid; no large serranids are ever observed on Eagle Ray. Overall the fish community, while lacking top predators, remains high in overall biomass and species richness. EAGLE RAY 108 Figure 45. The Eagle Ray fish community by absolute and relative biomass. Herbivores stoplight parrotfish redfin parrotfish blue tang redband parrotfish doctorfish ocean surgeonfish redtail parrotfish princess parrotfish dusky damsel yellowtail damsel striped parrotfish threespot damsel Beaugregory redlip blenny greenblotch parrotfish cocoa damsel Fish Biomass (g) 0 2000 4000 6000 8000 10000 12000 14000 16000 Invertivores blackbar soldierfish bluestriped grunt French grunt squirrelfish red hind spotted goatfish yellowhead wrasse spotted drum tomtate saucereye porgy Spanish hogfish slippery dick harlequin bass white grunt smallmouth grunt fairy basselet striped grunt Fish Biomass (g) 0 2000 4000 6000 8000 10000 12000 14000 16000 Plankivores yellowtail snapper bicolor damsel black durgon creole wrasse brown chromis blue chromis chalk bass Fish Biomass (g) 0 2000 4000 6000 8000 Piscivores blue runner bar jack graysby mahogany snapper redspotted hawkfish spotted moray trumpetfish schoolmaster Fish Biomass (g) 0 2000 4000 6000 8000 10000 12000 SITE SUMMARIES 109 GREAT POND Description. The Great Pond monitoring site is a wave-washed shallow barrier reef that was formerly an elkhorn coral reef in depths of 5-7 m. The reef is part of the barrier reef front surrounded by patch reefs and sand. Great Pond has been monitored since 2003. Outstanding Feature. Great Pond hosts the largest population of the black spiny urchin Diadema antillarum of any TCRMP monitoring site, likely because of its shallow depth. It also hosts an abundance of large- bodied stoplight (Sparisoma virde) and yellowfin parrotfish (Sparisoma rubripinne) that likely spawn near the site. Threats. The Great Pond monitoring site is located in the St. Croix East End Marine Park but outside the no-take fishery zone. If park rules are enforced, this site could see a return of fisheries species by spillover from adjacent protected areas. Because of high turbulence and low watershed development, sediment is not considered a problem; however, large industrial sites operate within 3-10 km westward and could contribute to pollution. Figure 46. Great Pond. (top) Location. (right) A representative photo of the reef. GREAT POND 110 Figure 47. Great Pond benthic temperature (5 m depth). Physical Characteristics Current. Great Pond currents have not been measured directly. Wave-generated oscillatory currents dominate and this is the most regularly swell-influenced site in the TCRMP making work conditions difficult on all but the calmest day. Strong unidirectional currents have not been experienced. Temperature. Great Pond typically experiences very high temperatures in August to October, with temperatures peaking at nearly 31°C in 2010. Month SITE SUMMARIES 111 Benthic Community. The Great Pond site is unusually dominated with the mustard hill coral (Porites astreoides) and Diploria strigosa. It is also the only site with a relatively high abundance of Diploria clivosa. The site lost 55.9% of its coral cover in the 2005 bleaching event, but has regained about half as of 2011. Macroalgal blooms occur occasionally (2007 and 2011), but the site is dominated by epilithic algae. Coral Health. Great Pond corals were moderately affected during the 2005 coral bleaching event, which may be a reflection of the high composition of resistant coral species and the regular exposure to high temperatures. The site was not monitored during the height of the 2010 coral bleaching event. Patchy, low-level bleaching is common in some years. Diseases have been almost non-existent at the monitoring site. Partial mortality is variable and has not shown consistent trends over years. Figure 48. Great Pond (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. GREAT POND 112 Figure 49. Great Pond benthic cover and coral health through time (mean ± SE). Benthic Community Cover 0% 20% 40% 60% 80% 100% Coral Cyanobacteria Epilithic Algae Macroalgae Bleaching Prevalence/Extent 0% 20% 40% 60% 80% 100% Prevalence Extent Disease Prevalence 0% 5% 10% 15% 20% 25% 30% All disease Black Band Lesion Dark Spots Intercostal White Disease Yellow Band Unknown Partial Mortality 2001 2002 2003 2004 2005 2005 BL 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 Prevalence 0% 20% 40% 60% 80% 100% Old Recent SITE SUMMARIES 113 Fish Community. The Great Pond fish community is dominated by herbivores. The primary herbivores at the site are the yellowtail damselfish and blue tang, which swim in foraging schools feeding on algae covering the relict elkhorn coral. Also present are large queen and stoplight parrotfish, which can also be seen foraging in large groups, and a probably spawning in the late afternoon and evening hours at or near the site. These fish concentrate around the skeletal remains of Acropora. Between these areas, fish biomass is low and is primarily made up of yellow goatfish, wrasses, and juvenile parrotfish. Piscivores at Great Pond are limited almost entirely to mahogany snapper and bar jacks. Benthic invertivores are dominated in biomass by yellow goatfish and blackbar soldierfish, however the wrasse diversity is high on the site and includes slippery dick, clown wrasse, yellowhead and bluehead wrasse, rainbow wrasse, puddingwife, and Spanish hogfish. GREAT POND 114 Figure 50. The Great Pond fish community by absolute and relative biomass. Herbivores yellowtail damsel blue tang doctorfish stoplight parrotfish ocean surgeonfish redband parrotfish striped parrotfish dusky damsel queen parrotfish greenblotch parrotfish redtail parrotfish orangespotted filefish redfin parrotfish cocoa damsel threespot damsel redlip blenny Beaugregory princess parrotfish bucktooth parrotfish Fish Biomass (g) 0 2000 4000 6000 8000 Invertivores yellow goatfish blackbar soldierfish slippery dick squirrelfish clown wrasse yellowhead wrasse spotted goatfish bluestriped grunt puddingwife rainbow wrasse dusky squirrelfish Spanish hogfish French grunt Fish Biomass (g) 0 2000 4000 6000 8000 Plankivores blue chromis black durgon bicolor damsel brown chromis Fish Biomass (g) 0 200 400 600 800 1000 Piscivores bar jack glasseye snapper peacock flounder greater soapfish redspotted hawkfish Fish Biomass (g) 0 200 400 600 800 1000 1200 SITE SUMMARIES 115 JACKS BAY Description. The Jacks Bay monitoring site (aka Jacks/Isaacs Bay) is part of fringing reef, colonized hardbottom on the southeast point of St. Croix in water depths of 13-16 m. The monitoring site is just inward from the shelf break and seaward reef slope, which terminates in a sand plain at about 20 m depth. Jacks Bay is largely a carbonate hardbottom with scattered hard coral, although there are some large coral heads seaward of the transects. Permanent transects were installed at Jacks Bay in 2001. Outstanding Feature. Jacks Bay hosts a unique fish community with high abundance of small wrasses and the occasional occurrence of red hind (Epinephelus guttatus). Threats. Jacks Bay is within the St. Croix East End Marine Park but lies just outside the restricted fisheries area and is open to fishing. High turbulence and no watershed development mean there is low threat of land- based sources of pollution at this nearshore site. Figure 51. Jacks Bay. (top) Location. (right) A representative photo of the reef. JACKS BAY 116 Figure 52. Jacks Bay benthic temperature at 12 m depth Physical Characteristics Current. Jacks Bay currents have not been measured directly. There are weak unidirectional currents, but there is a propensity for strong wave-generated oscillatory currents due the open coast southeast exposure. Temperature. Jacks Bay can experience high temperatures during August to October. Month SITE SUMMARIES 117 Benthic Community. The Jacks Bay site has low coral cover (<10%) and is the only TCRMP site dominated by the great star coral Montastraea cavernosa. Jacks Bay lost 44.7% of its coral cover in the 2005 coral bleaching event, but had regained about 32% of the loss by 2011. Over half of the sessile epibenthic community is composed of gorgonians and sponges and the site might be considered more a colonized hardbottom than true coral reef. The algal community is composed of high proportions each of epilithic algae, macroalgae, and filamentous cyanobacteria. The site also shows a high degree of sand intermixed with filamentous algae, an important deterrent for coral larval settlement (Bellwood and Fulton 2008). This site is often colonized by fleshy upright brown algae, such as Turbinaria turbinata and Sargassum hystrix (species unconfirmed). Very large beach wrack of these brown algae can often accumulate on the windward beaches behind the site. Coral Health. The Jacks Bay site was strongly affected during the 2005 bleaching event and was moderately affected during the 2010 bleaching event. Disease prevalence was low and only dark spots disease was present. Recent partial mortality was high during the 2005 bleaching event, likely reflecting the fact that surveys were conducted in November 2005 when mortality had begun. Old partial mortality increased greatly after the 2005 bleaching and then declined to stable levels in 2009-2011. Figure 53. Jacks Bay (left) relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. JACKS BAY 118 Figure 54. Jacks Bay benthic cover and coral health through time (mean ± SE). Benthic Community Cover 0% 20% 40% 60% 80% 100% Coral Cyanobacteria Epilithic Algae Macroalgae Bleaching Prevalence/Extent 0% 20% 40% 60% 80% 100% Prevalence Extent Disease Prevalence 0% 5% 10% 15% 20% 25% 30% All disease Black Band Lesion Dark Spots Intercostal White Disease Yellow Band Unknown Partial Mortality 2001 2002 2003 2004 2005 2005 BL 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 Prevalence 0% 20% 40% 60% 80% 100% Old Recent SITE SUMMARIES 119 Fish Community. The Jacks Bay fish community is characterized by very low fish biomass and abundance but relatively high diversity. The site is primarily hard bottom, adjacent to more developed coral reef on the seaward edge, over which larger fishes are observed. The hardbottom community is highly dominated numerically by blue chromis, yellowhead wrasse, and bicolor damselfish. Juvenile wrasses and parrotfish swim and hover in mixed schools among the rubble and gorgonians. Slippery dicks, clown wrasse, rainbow wrasse, and blackear wrasse are also fairly common. Angelfishes are common across the hardbottom. Piscivores are always rare and limited to schoolmaster, bar jack, glasseye snapper, and redspotted hawkfish. Medium to larger sized species are very rare, and nearly all of these species are seen at Jacks Bay in the juvenile life history stage. JACKS BAY 120 Figure 55. The Jacks Bay fish community by absolute and relative biomass. Herbivores blue tang redband parrotfish ocean surgeonfish princess parrotfish yellowtail damsel stoplight parrotfish doctorfish striped parrotfish redfin parrotfish Beaugregory cocoa damsel dusky damsel greenblotch parrotfish Fish Biomass (g) 0 200 400 600 800 1000 1200 1400 1600 1800 Invertivores queen trigger yellowhead wrasse blackbar soldierfish squirrelfish French grunt slippery dick puddingwife tomtate highhat red hind Spanish hogfish blackear wrasse spotted goatfish yellow goatfish yellowcheek wrasse fairy basselet Fish Biomass (g) 0 500 1000 1500 2000 2500 3000 Plankivores blue chromis bicolor damsel brown chromis Fish Biomass (g) 0 200 400 600 800 1000 1200 1400 1600 Piscivores schoolmaster bar jack glasseye snapper redspotted hawkfish Fish Biomass (g) 0 100 200 300 400 500 600 700 SITE SUMMARIES 121 KINGS CORNER Description. The Kings Corner monitoring site is a part of a patchy reef complex along the steeply sloping west coast of St. Croix in depths of 15-25 m. The reef contains a high diversity of corals and sponges on mounds surrounded by sand. Kings Corner has been monitored since 2006, with permanent transects installed in 2007. Outstanding Feature. Kings Corner is a commercially important recreational dive site. The site supports a high diversity and density of fishes. It is also a very aesthetically pleasing site with high topographic relief. Threats. Kings Corner is open to fishing and is easily accessible as part of the calm lee of western St. Croix near Frederiksted. Derelict fishing lines, fish traps, fish weights, and other marine debris are in evidence in and around the site. Large plumes of sediment that wrap around Sandy Point from the south coast of St. Croix also periodically affect the site. Plumes can drop visibility to near zero and lead to high incidence of sediment on coral and spotty bleaching. Figure 56. Kings Corner. (top) Location. (right) A representative photo of the reef with a school of lane snapper (Lutjanus synagris). KINGS CORNER 122 Figure 57. Kings Corner benthic temperature (17 m depth) Physical Characteristics Current. Kings Corner currents have not been measured directly. The site is protected from wave action, but can experience strong unidirectional currents at times, particularly at shallower depths. Temperature. Kings Corner has moderately high temperatures. Month SITE SUMMARIES 123 Benthic Community. The Kings Corner site supports a diverse community of hard corals dominated by Orbicella spp. The site also has a very abundant population of sponges. This site was not monitored until after the 2005 bleaching event, so the impacts on coral cover are not known. Epilithic algae dominate the algal community at Kings Corner, with very low abundance of macroalgae and filamentous cyanobacteria. Sand is prominently interspersed among the coral banks. Coral Health. Non-thermal bleaching with moderate prevalence but low extent on colonies is a common feature at this site, likely as the result of chronic sedimentation. The prevalence of coral diseases has been low with dark spots disease predominating. Old partial mortality has been very high at this site and may be an indication of impacts from the 2005 coral bleaching event. Old partial mortality has increased lately. Figure 58. Kings Corner (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. KINGS CORNER 124 Figure 59. Kings Corner benthic cover and coral health through time (mean ± SE). Benthic Community Cover 0% 20% 40% 60% 80% 100% Coral Cyanobacteria Epilithic Algae Macroalgae Bleaching Prevalence/Extent 0% 20% 40% 60% 80% 100% Prevalence Extent Disease Prevalence 0% 5% 10% 15% 20% 25% 30% All disease Black Band Lesion Dark Spots Intercostal White Disease Yellow Band Unknown Partial Mortality 2001 2002 2003 2004 2005 2005 BL 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 Prevalence 0% 20% 40% 60% 80% 100% Old Recent SITE SUMMARIES 125 Fish Community. Kings Corner represents the most diverse fish community with the highest fish biomass in the St Croix monitoring program, with a huge variety of resources available for foraging and habitat. The site is dominated by invertivores, influenced highly by the large numbers of the nocturnal feeding blackbar soldierfish, a zooplanktivore, and the tomtate, a more opportunistic benthic feeder of invertebrates, zooplankton and benthic algae. Other common planktonic feeders include the black durgeon, creole wrasse, and yellowtail snapper. Common benthic herbivores include the blue tang and ocean surgeonfish as well as most of the parrotfishes (stoplight, princess, redband, redfin, queen, and striped). Grunts are common on the site and mutton snapper occasional. Piscivores as a group can be relatively high in biomass, primarily as a result of the great barracuda, which is generally observed in relatively high numbers at the site. Other common piscivores are represented by bar jacks (pelagic), glasseye snapper and bigeye (nocturnal feeders), and graysby, lionfish, and small snappers (diurnal bottom feeders). KINGS CORNER 126 Figure 60. The Kings Corner fish community by absolute and relative biomass. Herbivores ocean surgeonfish stoplight parrotfish blue tang princess parrotfish redband parrotfish striped parrotfish redfin parrotfish doctorfish orangespotted filefish threespot damsel Beaugregory queen parrotfish dusky damsel Fish Biomass (g) 0 2000 4000 6000 8000 10000 12000 Invertivores mutton snapper blackbar soldierfish smallmouth grunt porcupine tomtate yellow goatfish lane snapper spotted goatfish French grunt yellowhead wrasse Spanish hogfish white grunt southern stingray yellowfin mojarra fairy basselet harlequin bass clown wrasse spotted drum Fish Biomass (g) 0 2e+4 4e+4 6e+4 8e+4 1e+5 Plankivores yellowtail snapper bicolor damsel brown chromis black durgon blue chromis creole wrasse Fish Biomass (g) 0 1000 2000 3000 4000 5000 6000 7000 Piscivores great barracuda bar jack glasseye snapper graysby red lionfish sand diver bigeye schoolmaster mahogany snapper trumpetfish redspotted hawkfish Fish Biomass (g) 0 10000 20000 30000 40000 SITE SUMMARIES 127 LANG BANK EAST END MARINE PARK Description. The Lang Bank EEMP site is a shelf edge mesophotic coral reef located at a depth of 27 – 30 m. The monitoring site sits just above a steep shelf break and is composed of rolling coral knolls dominated by boulder star corals (Orbicella spp.). This site was established in 2009. Outstanding Feature. The Lang Bank EEMP site appears to be a well- developed mesophotic boulder star coral reef on St. Croix, which may be relatively rare compared to St. Thomas. Large populations of fishes and spiny lobsters are often encountered Threats. The Lang Bank EEMP is in the outer park area and is open to fishing year-round. = Its offshore location protects it from land- based sources of pollution. Figure 61. Lang Bank EEMP. (top) Location. (right) A representative photo of the reef. LANG BANK EEMP 128 Figure 62. Lang Bank EEMP benthic temperature (28 m depth) Physical Characteristics Current. Direct current measurements have not been taken at Lang Bank EEMP. The depth buffers the site from wave-driven oscillatory currents. Only weak unidirectional benthic currents have been experienced at the site during monitoring; however, midwater and surface currents can be moderate to strong (>10cm s-1). Temperature. Lang Bank EEMP has temperature that is reduced relative to shallow water sites. However, the bleaching threshold has not been established and here is based on a relationship between depth. It is likely to low given the degree heating weeks accumulated since 2009, but empirical observations are lacking. Month SITE SUMMARIES 129 Benthic Community. Lang Bank EEMP supports many coral species but is dominated by Orbicella spp.. Sponges are also quite prominent and make up a quarter of the sessile epibenthic animal community. Epilithic algae, Lobophora variegata, and filamentous cyanobacteria near equally represent the algal community. The prominence of filamentous cyanobacteria is quite striking and has reached almost 40% of the substrate in some years. Coral Health. Background, non-thermal bleaching prevalence is quite high at Lang Bank EEMP. White disease showed an outbreak in 2011. Lang Bank EEMP was not initially monitored until well after the 2005 coral bleaching event; however, a high prevalence of old partial mortality suggests that corals were impacted. Many of the large faviids show lesion patterns that are consistent with the large lunate dead areas caused by white diseases following bleaching in 2005. Figure 63. 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. LANG BANK EEMP 130 Figure 64. Lang Bank EEMP benthic cover and coral health through time (mean ± SE). Benthic Community Cover 0% 20% 40% 60% 80% 100% Coral Cyanobacteria Epilithic Algae Macroalgae Bleaching Prevalence/Extent 0% 20% 40% 60% 80% 100% Prevalence Extent Disease Prevalence 0% 5% 10% 15% 20% 25% 30% All disease Black Band Lesion Dark Spots Intercostal White Disease Yellow Band Unknown Partial Mortality 2001 2002 2003 2004 2005 2005 BL 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 Prevalence 0% 20% 40% 60% 80% 100% Old Recent SITE SUMMARIES 131 Fish Community. The Lang Bank East End Marine Park site represents a mesophotic reef community that is characterized by a high biomass of planktonic feeders. The high overall biomass of the group was influenced primarily by the black durgeon while numerically creole wrasse are dominant. Queen triggerfish are also common. Benthic herbivores are dominated both numerically and in biomass by the redband parrotfish. Large parrotfish are fairly uncommon, however small parrotfish (striped and princess) as well as the doctorfishes are very abundant. The benthic invertivores at the site are diverse and include nocturnally feeding blackbar soldierfish and squirrelfish, as well as several species of grunt (French, tomtate, white, bluestriped, Caesar, and smallmouth). Piscivores are generally dominated in biomass by barracuda; however, graysby were common numerically. Other piscivores on the site included the horse-eye jack and cero mackerel, indicators of a deep water community. LANG BANK EEMP 132 Figure 65. The Lang Bank EEMP fish community by absolute and relative biomass. Herbivores redband parrotfish stoplight parrotfish striped parrotfish ocean surgeonfish princess parrotfish doctorfish blue tang yellowtail damsel greenblotch parrotfish Fish Biomass (g) 0 1000 2000 3000 4000 5000 6000 Invertivores blackbar soldierfish squirrelfish French grunt longsnout butterflyfish yellowhead wrasse yellow goatfish tomtate smallmouth grunt white grunt puddingwife spotted goatfish queen trigger bluestriped grunt dusky squirrelfish red hind Spanish hogfish clown wrasse Caesar grunt spotted drum harlequin bass yellowtail hamlet fairy basselet Fish Biomass (g) 0 1000 2000 3000 4000 5000 Plankivores black durgon creole wrasse black jack yellowtail snapper blue chromis brown chromis bicolor damsel Fish Biomass (g) 0 2000 4000 6000 8000 10000 12000 14000 Piscivores great barracuda graysby horse-eye jack red lionfish glasseye snapper bigeye mahogany snapper bar jack redspotted hawkfish schoolmaster Fish Biomass (g) 0 2000 4000 6000 8000 SITE SUMMARIES 133 LANG BANK RED HIND FISH SPAWNING AGGREGATION Description. The Lang Bank Red Hind Fish Spawning Aggregation (Lang Hind) monitoring site is a mesophotic reef of antecedent spur and groove structure at a depth of 30 – 35 m. The site is perched on the southeast side of the spur, which is a large finger that rises to 24 m to the west and drops on all other sides to a rhodolith/sand plain at about 50 m. Lang Hind was initially monitored in 2001 at a site on the shallower (24 m) portion of the bank to the west. Monitoring in 2004-2007 occurred along random transects in a deeper portion of the reef (~33 m depth) and benthic transects were made permanent in this area in 2009 Outstanding Feature. Lang Hind supports an annual fish spawning aggregation of the red hind (Epinephelus guttatus). This site also possesses high water clarity. Threats. The Lang Hind site is removed from land-based stressors. Fishing of the red hind aggregation was common prior to closure of the area to fishing in 1993. However, the aggregation is near the closure boundary. Figure 66. Lang Bank Red Hind FSA. (top) Location. (right) A representative photo of the reef LANG BANK RED HIND FSA 134 Figure 67. Lang Bank Hind current speed (left) and benthic temperature (right; 33 m depth) Physical Characteristics Current. Lang Hind had benthic currents recorded with ADCP every 30 minutes from 11/20/05 to 8/20/06, and 12/11/06 to 3/10/07. Bottom currents most typically alternate between north and southeast and can attain strong speeds periodically exceeding 0.4m s-1. Temperature. Lang Hind has temperatures that are reduced due to the depth and proximity of the warm season thermocline. However, temperatures are not as cool or variable as sites on the southern Puerto Rican shelf, indicating that this site may be more susceptible to warming ocean temperatures. N NNE NE ENE E ESE SE SSE S SSW SW WSW W WNW NW NNW Current Speed (m s -1) 0.5 - 0.6 0.4 - 0.5 0.3 - 0.4 0.2 - 0.3 0.1 - 0.2 0.0 - 0.1 Month SITE SUMMARIES 135 Benthic Community. Lang Hind has a diverse sessile epibenthic community dominated by hard corals, predominantly Orbicella spp., gorgonians, and sponges. Coral cover actually increased by 110% between the coral bleaching event and re-monitoring in 2006, but this may reflect the fact that transects were laid in random, rather than permanent, locations prior to 2009. The algal community is largely open epilithic algal communities, but also contains large proportions of Lobophora variegata and filamentous cyanobacteria. The algal community shows high inter-annual variability. Coral Health. Lang Hind FSA was heavily affected during the 2005 coral bleaching event, with a very high prevalence of corals that were 100% bleached over the colony surface. Non-thermal bleaching with moderate prevalence and low extent on colonies also occurred in later years. The site was heavily affected with white diseases after the coral bleaching event and has had high disease prevalence in all years of monitoring. Old partial mortality jumped after the 2005 bleaching event and was variable in later years. Recent partial mortality is unusually high at Lang Hind, largely as the result of fish bites and predation by the corallivorous snail Coralliophila spp. Figure 68. Lang Bank Red Hind FSA (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. LANG BANK RED HIND FSA 136 Figure 69. Lang Bank Red HindFSA benthic cover and coral health through time (mean ± SE). Benthic Community Cover 0% 20% 40% 60% 80% 100% Coral Cyanobacteria Epilithic Algae Macroalgae Bleaching Prevalence/Extent 0% 20% 40% 60% 80% 100% Prevalence Extent Disease Prevalence 0% 5% 10% 15% 20% 25% 30% All disease Black Band Lesion Dark Spots Intercostal White Disease Yellow Band Unknown Partial Mortality 2001 2002 2003 2004 2005 2005 BL 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 Prevalence 0% 20% 40% 60% 80% 100% Old Recent SITE SUMMARIES 137 Fish Community. The fish community at Lang Bank FSA is indicative of a mesophotic reef system. High water column planktonic feeders are abundant and include the black durgeon, creole wrasse, yellowtail snapper, and creolefish. Bicolor damselfish are numerous while herbivorous damselfishes are uncommon. Benthic herbivores are relatively low in diversity, abundance and biomass compared to nearshore sites. Invertivores are diverse and include many planktivores as well as benthic feeders, utilizing the varied resources of the bank. Four species of angelfish were observed on transects reflecting the high sponge cover. Lang Bank FSA supports a red hind spawning site, active during December through February each year, and red hind are occasionally seen on both roving dives and transects. One Nassau grouper was observed on the bank in 2011, a first observation across all St. Croix monitoring sites. There is reportedly a historic Nassau grouper spawning site near the Lang Hind monitoring site, and with the bank now closed to trap fishing there is hope of some re- establishment of the species on St. Croix. Mahogany snapper dominate piscivorous fish on Lang Bank FSA. No other large groupers or snappers are common although occasionally Caribbean reef sharks are observed. LANG BANK RED HIND FSA 138 Figure 70. The Lang Bank Red Hind FSA fish community by absolute and relative biomass. Herbivores redband parrotfish queen parrotfish princess parrotfish stoplight parrotfish ocean surgeonfish blue tang striped parrotfish doctorfish redtail parrotfish yellowtail damsel Fish Biomass (g) 0 1000 2000 3000 4000 5000 6000 Invertivores queen trigger blackbar soldierfish French grunt Spanish hogfish yellowhead wrasse spotted goatfish yellow goatfish clown wrasse harlequin bass fairy basselet longsnout butterflyfish Fish Biomass (g) 0 500 1000 1500 2000 2500 3000 3500 Plankivores black durgon creole wrasse blue chromis creolefish bicolor damsel brown chromis Fish Biomass (g) 0 2000 4000 6000 8000 10000 Piscivores bar jack great barracuda graysby mahogany snapper horse-eye jack red lionfish spotted moray trumpetfish Fish Biomass (g) 0 1000 2000 3000 4000 5000 6000 SITE SUMMARIES 139 MUTTON SNAPPER Description. The Mutton Snapper site is located on the landward side of a shelf edge spur and groove reef on the southwest shelf of St Croix in depths of 22-24 m. The reef was dominated by boulder star coral (primarily Orbicella franksi) until a mass coral die-off following the 2005 bleaching event. Mutton Snapper has been monitored since 2003. Outstanding Feature. The Mutton Snapper site was located in conjunction with the possible proximity of a mutton snapper (Lutjanus analis) spawning aggregation. It is seasonally closed to fishing. The site was devastated by the 2005 coral bleaching event, with an 87% drop in coral cover and a concomitant increase in algae. Threats. The Mutton Snapper site is threatened by fishing pressure as evidenced by the abundance of fishing line and fishing trap debris. This site is offshore and less likely threatened by land-based stressors. The clear waters and warm temperatures make this site vulnerable to long-term seawater warming. Figure 71. Mutton Snapper. (top) Location. (right) A representative photo of the reef taken in 2014. MUTTON SNAPPER 140 Figure 72. Mutton Snapper benthic temperature record at 23 m (left) and 39 m depth (right). Physical Characteristics. Current. Current records have not been taken at Mutton Snapper. There seems to be little wave-driven oscillatory flow. There are often strong unidirectional currents in a westward direction that penetrate to nearly the bottom. Temperature. Benthic temperatures at the Mutton Snapper site (23 m) show warming above the regional bleaching threshold during the 2010 bleaching event. This may be an overestimation of the heat stress since and empirical bleaching threshold has not yet been established for this site. However, coral health was assessed before the accumulation of heat stress in 2010, so a strong response may have occurred and not been detected. Month SITE SUMMARIES 141 Benthic Community. The Mutton Snapper site’s sessile epibenthic animal community is dominated the boulder star coral (Orbicella spp.), with sub-dominance of sponges. This site lost an extreme amount of coral cover (87.0%) in the 2005 coral bleaching event and has not regained any cover (-2.3%) as of 2011. Lobophora variegata, epilithic algae, and filamentous cyanobacteria dominate the algal community. Apparent is the rise in the abundance of macroalgae and filamentous cyanobacteria after 2005. Filamentous cyanobacteria reached extreme cover values (57.7%) in 2009. Current levels of herbivory no longer appear to be able to control algal abundance. Coral Health. Mutton Snapper bleached heavily in the 2005, with 100% of corals bleaching over 90% of the colony surface. Bleaching prevalence has remained high for most years since 2005, but at low colony extent, indicating continued impairment of corals. White disease has been at consistently high values through many years of monitoring. Old partial mortality increased after 2005, and then subsided as whole colonies were lost from the system. Impairment of this site is puzzling as stressors besides fishing appear to be low. Clear water and low genetic diversity of corals may increase susceptibility to environmental stress and white disease. Figure 73. Mutton Snapper (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. MUTTON SNAPPER 142 Figure 74. Mutton Snapper benthic cover and coral health through time (mean ± SE). Benthic Community Cover 0% 20% 40% 60% 80% 100% Coral Cyanobacteria Epilithic Algae Macroalgae Bleaching Prevalence/Extent 0% 20% 40% 60% 80% 100% Prevalence Extent Disease Prevalence 0% 5% 10% 15% 20% 25% 30% All disease Black Band Lesion Dark Spots Intercostal White Disease Yellow Band Unknown Partial Mortality 2001 2002 2003 2004 2005 2005 BL 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 Prevalence 0% 20% 40% 60% 80% 100% Old Recent SITE SUMMARIES 143 Fish Community. The Mutton Snapper site is an offshore, shelf edge site with a fairly diverse and rich fish community. Fish biomass is generally low on the site; however, in 2014 surveys biomass was much higher than in earlier years. Mutton Snapper is reportedly in an area that mutton snapper spawn; however, mutton snapper have been very rare in surveys conducted at the site over the past 5 years. The Mutton Snapper site is very highly dominated in biomass by the black durgeon, a phytoplankton feeder, and numerically dominated by the creole wrasse, a zooplankton feeder. Stoplight parrotfish and doctorfish generally contribute the most biomass to the benthic herbivore group. Many parrotfish species can be found on the Mutton Snapper reef, however sub-adult and juveniles are by far the majority encountered. The invertivore group is also diverse, indicative of the variety of resources available on the reef. Piscivores are not common on Mutton Snapper and in general the biomass of this group was made up of primarily jacks and barracuda. Piscivorous serranids and lutjanids are usually limited to the graysby and mahogany snapper. Red lionfish are observed regularly on Mutton Snapper, probably because the reef is offshore and does not receive the diving and hunting pressure of nearshore sites. MUTTON SNAPPER 144 Figure 75. The Mutton Snapper fish community by absolute and relative biomass. Herbivores stoplight parrotfish doctorfish princess parrotfish striped parrotfish redband parrotfish ocean surgeonfish blue tang redfin parrotfish queen parrotfish Beaugregory orangespotted filefish threespot damsel greenblotch parrotfish cocoa damsel yellowtail damsel dusky damsel Fish Biomass (g) 0 1000 2000 3000 4000 5000 Invertivores blackbar soldierfish French grunt yellowhead wrasse red hind striped grunt fairy basselet butter hamlet Spanish hogfish squirrelfish white grunt highhat dusky squirrelfish clown wrasse harlequin bass longsnout butterflyfish Fish Biomass (g) 0 1000 2000 3000 4000 5000 6000 7000 Plankivores black durgon blue chromis yellowtail snapper bicolor damsel creole wrasse brown chromis sargassum triggerfish Fish Biomass (g) 0 2000 4000 6000 8000 10000 12000 14000 16000 Piscivores bar jack great barracuda graysby mahogany snapper glasseye snapper red lionfish Fish Biomass (g) 0 200 400 600 800 1000 1200 1400 SITE SUMMARIES 145 SALT RIVER WEST Description. Salt River West lies just atop the Salt River Canyon west wall in a depth of 9 m. The reef is a flat colonized hardbottom/coral community atop ancient carbonates. Salt River West has been monitored since 2001. Outstanding Feature. Salt River West is a popular tourist dive site with a unique sharp drop to the wall environment. This area has been under scientific investigation since the 1970s, beginning with the installation of the Hydrolab undersea habitat run by NOAA. Threats. Salt River West is exposed to the outflow from the Salt River Canyon and resuspension of sediment from the Salt River eastern flats. The site is now within in the Salt River National Historic Park and Ecological Preserve. This protection will hopefully increase the fish populations within the reserve in the coming decades. Figure 76. Salt River. (top) Location. (right) A representative photo of the reef with TCRMP researcher recording coral health data (Oct. 1, 2015). SALT RIVER WEST 146 Figure 77. Salt River West surface-benthic temperature record 5m depths. Data provided by the NOAA ICON monitoring network. Physical Characteristics. Current. Currents have not been directly measured by the TCRMP. Due to the northern exposure and shallow depth, Salt River West experiences wave-driven oscillatory flow, which can be strong. Unidirectional benthic currents are typically weak to moderate (<15cm s-1). Temperature. The temperature at Salt River West can be very warm and in 2005 surpassed the bleaching threshold (29.5°C) for approximately 2.5 months between August and October. Month SITE SUMMARIES 147 Benthic Community. The Salt River West epibenthic sessile animal community has a diverse hard coral community of small massive head corals and large proportions of sponges and gorgonians. The site lost an imperceptible amount of coral cover in the 2005 coral bleaching event (-13.6%) and had regained nearly half of that cover by 2011 (37.1%). The algal community shows extreme dominance by epilithic algae and low abundance of macroalgae and filamentous cyanobacteria. However, filamentous cyanobacteria have increased slightly since 2005. Coral Health. Corals were severely bleached during the 2005 coral bleaching event, with over 90% of corals bleached over 80% of the colony surface. Corals were assessed just prior to the 2010 bleaching event in August, but were showing increased prevalence of low colony extent bleaching by then. Diseases are typically low, with the outstanding case of dark spots disease, which attains some of the highest values seen in TCRMP sites. Of note, is the fact that dark spots disease actually decreased following severe bleaching and recovery in 2005 and 2006. Old partial mortality increased rapidly after the 2005 bleaching and then subsided somewhat by 2011. Recent partial mortality can be high and is primarily caused by fish biting, such as from parrotfish. However, extent is quite low (data not shown). Figure 78. Salt River West (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. SALT RIVER WEST 148 Figure 79. Salt River West benthic cover and coral health through time (mean ± SE). Benthic Community Cover 0% 20% 40% 60% 80% 100% Coral Cyanobacteria Epilithic Algae Macroalgae Bleaching Prevalence/Extent 0% 20% 40% 60% 80% 100% Prevalence Extent Disease Prevalence 0% 5% 10% 15% 20% 25% 30% All disease Black Band Lesion Dark Spots Intercostal White Disease Yellow Band Unknown Partial Mortality 2001 2002 2003 2004 2005 2005 BL 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 Prevalence 0% 20% 40% 60% 80% 100% Old Recent SITE SUMMARIES 149 Fish Community. Fish biomass is relatively low on the Salt River West site. More diversity and some larger fishes can be seen close to the edge of the site, near the Salt River wall; however, the top of the reef has little structure for larger fishes, with low lying coral heads, gorgonians, and sponges. Wrasses and damselfishes are both numerous and diverse; the most dominant species on the site is the bluehead wrasse followed closely by the bicolor damselfish. Black durgeon, an opportunistic planktivore that feeds on zooplankton, phytoplankton and algae, dominates the Salt River West site in biomass, followed by the stoplight parrotfish, ocean surgeonfish, and very numerous creole wrasse. Piscivores are nearly non-existent, and include primarily graysby. Occasional red lionfish are seen on a Salt River West. Yellowfin snapper are the only lutjanids regularly encountered on the site, and these are observed only near the shelf edge. SALT RIVER WEST 150 Figure 80. The Salt River West fish community by absolute and relative biomass. Herbivores stoplight parrotfish ocean surgeonfish redband parrotfish princess parrotfish blue tang striped parrotfish redtail parrotfish doctorfish yellowtail damsel queen parrotfish orangespotted filefish dusky damsel Fish Biomass (g) 0 1000 2000 3000 4000 5000 6000 7000 Invertivores French grunt squirrelfish yellowhead wrasse slippery dick sand tilefish red hind smallmouth grunt harlequin bass spotted goatfish bluestriped grunt Spanish hogfish yellowtail hamlet Fish Biomass (g) 0 500 1000 1500 2000 2500 Plankivores black durgon creole wrasse blue chromis sunshinefish bicolor damsel brown chromis chalk bass Fish Biomass (g) 0 2000 4000 6000 8000 10000 12000 14000 16000 Piscivores trumpetfish graysby Fish Biomass (g) 0 50 100 150 200 250 SITE SUMMARIES 151 SALT RIVER DEEP Description. The Salt River Deep site is located on the steep canyon wall just below the Salt River West monitoring site. The reef consists of vertical buttresses surrounded by extensive sand deposits. The reef is largely formed of plating coral at these deep, mesophotic depths. The initial site was deployed in 2009 with two transects at 30 m depth and 4 transects at 40 m. Due to low coral cover at 40 m transects were moved to 30m in 2010. Outstanding Feature. Salt River Deep is a heavily visited recreational dive site. The site has been under scientific investigation since the 1970’s. The underwater HYDROLAB habitat was maintained near the site from 1977 to 1985 and the Aquarius habitat from 1986 to 1989. Threats. Salt River Deep is threatened by land-based sources of pollution due to its proximity to the Salt River Canyon outflow. The site may also be susceptible to warming temperatures. Figure 81. Salt River Deep. (top) Location. (right) A representative photo of the reef with TCRMP team (Oct. 1, 2015). SALT RIVER DEEP 152 Figure 82. Salt River Deep benthic temperature at 30 m depth (left) and 40 m depth (right). Physical Characteristics. Current. Salt River deep currents have not been measured directly by the TCRMP. Only very weak oscillatory and unidirectional currents have been experienced at the site. Temperature. Temperatures on the wall have been measured at two depth levels at 30 m and 40 m. Both sites have temperatures that are much cooler than the shallow site. The 40 m site experiences even greater cooling and experiences more diel variability (not shown) and day-to-day variability due to the influence of internal waves. Despite some interaction with the thermocline, cooling is not as great as at the mesophotic reefs at similar depths on the southern Puerto Rican Shelf. J F M A M J J A S O N D 24 25 26 27 28 29 30 31 2007 2008 2010 2011 Temperature ( oC) Month J F M A M J J A S O N D 24 25 26 27 28 29 30 31 2009 2010 2011 Temperature ( oC) Month SITE SUMMARIES 153 Benthic Community. Hard coral community of the Salt River Deep monitoring site is dominated by plating lettuce corals (Agaricia spp.); however, sponges, gorgonians, and black corals dominate the overall sessile epibenthic animal community. The site was not monitored during the 2005 bleaching event, but as with the Cane Bay Deep site, severe bleaching was observed down to depths of 40m. The algal community is dominated by epilithic algae and unidentified diminutive macroalgae. The site is notable for the high composition of sediment, which cascades from the upper reef between spurs and buttresses. Coral Health. Low extent coral bleaching is typically in moderate to high prevalence at the Salt River Deep site. Interaction data (not shown) indicates that sediment and Lobophora variegata overgrowth are responsible for much of the bleaching. Diseases have not been observed. Old partial mortality is high on corals, which may be a reflection of the 2005 bleaching event and cumulative impacts from interaction with sediment and algae. Figure 83. Salt River Deep (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. SALT RIVER DEEP 154 Figure 84. Salt River Deep benthic cover and coral health through time (mean ± SE). Benthic Community Cover 0% 20% 40% 60% 80% 100% Coral Cyanobacteria Epilithic Algae Macroalgae Bleaching Prevalence/Extent 0% 20% 40% 60% 80% 100% Prevalence Extent Disease Prevalence 0% 5% 10% 15% 20% 25% 30% All disease Black Band Lesion Dark Spots Intercostal White Disease Yellow Band Unknown Partial Mortality 2001 2002 2003 2004 2005 2005 BL 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 Prevalence 0% 20% 40% 60% 80% 100% Old Recent SITE SUMMARIES 155 Fish Community. The relatively high turbidity and high composition of sand and silt bottom, as a consequence of river discharge, influences the fish community of Salt River Deep. The mesophotic reef wall site is characterized by a primarily invertivore fish community, leading in both biomass and species richness. Invertivores are dominated numerically by the functionally planktivorous blue chromis and creole wrasse. The benthic feeding yellow goatfish dominates the invertivore group by biomass, swimming in small schools along the sandy wall. Mahogany snapper and graysby are common piscivores. Sub-adult princess and redband parrotfish are the prominent herbivores. Characteristic deep water fishes observed commonly on Salt Water Deep include the sunshinefish, bantum bass, fairy basslet, and longsnout butterflyfish. As on the Cane Bay Deep site, occasional cubera snapper (Lutjanus cyanopterus), mutton snapper (L. analis), or southern stingrays (Dasyatis americana) are observed during roving dives on the wall, and commonly one or two small, curious Caribbean reef sharks (Carcharhinus perezi) are present. SALT RIVER DEEP 156 Figure 85. The Salt River Deep fish community by absolute and relative biomass. Herbivores redband parrotfish queen parrotfish ocean surgeonfish princess parrotfish redtail parrotfish striped parrotfish doctorfish threespot damsel midnight parrotfish stoplight parrotfish dusky damsel Fish Biomass (g) 0 500 1000 1500 2000 2500 Invertivores yellow goatfish fairy basselet black margate yellowhead wrasse Spanish hogfish French grunt spotted goatfish tomtate longsnout butterflyfish yellowtail hamlet bluestriped grunt white grunt smallmouth grunt butter hamlet Fish Biomass (g) 0 2000 4000 6000 8000 10000 12000 14000 16000 Plankivores yellowtail snapper creole wrasse black durgon blue chromis bicolor damsel sunshinefish tobaccofish chalk bass brown chromis Fish Biomass(g) 0 1000 2000 3000 4000 5000 Piscivores mahogany snapper graysby bar jack schoolmaster trumpetfish Fish Biomass (g) 0 200 400 600 800 1000 1200 1400 1600 1800 2000 SITE SUMMARIES 157 SPRAT HOLE Description. The Sprat Hole site is a nearshore/shelf-edge fringing reef in depths of 7 – 10 m. The site is a rolling boulder star coral (Orbicella annularis) reef. The slope to the west drops off to an attractive mixed coral community with abundant fish where it meets sand at about 25 m. Sprat Hole has been monitored since 2001. Outstanding Feature. Sprat Hole is a heavily visited reef for snorkel and dive tours. It supports a very diverse fish community. Threats. The Sprat Hole reef is vulnerable to land based sources of pollution if there is increased development of the watershed. Low wave action and light currents favor settling of small particles of terrestrial sediment that injure corals. The site is also frequently fished and there is derelict fishing gear in abundance. Recreational overuse may also be a threat. Figure 86. Sprat Hole. (top) Location. (right) A representative photo of the reef. SPRAT HOLE 158 Figure 87. Sprat Hole benthic temperature (7 m depth). Physical Characteristics. Current. Currents have not been measured at Sprat Hole. Oscillatory currents are typically weak on the western lee of St. Croix. Unidirectional currents during monitoring have always been weak (<10cm s-1). Temperature. Sprat Hole temperature has not been monitored over many years due to loss of probes. This is likely due to the high exposure to recreational and commercial fishing divers. Since 2013 temperature probes of the National Coral Reef Monitoring Program have been co-located at this site. In general Sprat Hole appears to be a warm site. Month SITE SUMMARIES 159 Benthic Community. Sprat Hole is a fringing Orbicella annularis dominated reef, with a good diversity of other coral species. There was a 62.3% decline in coral cover due to the 2005 coral bleaching event, with a regain of 11.9% of cover by 2011. Epilithic algae dominate the algal community, with smaller amounts of a diverse group of macroalgae, including Dictyota spp. and Halimeda spp. There has been variable, but increasing cover of filamentous cyanobacteria since 2005. Coral Health. The coral community at Sprat Hole was heavily affected during the 2005 coral bleaching event, with a high prevalence of bleaching at a very high extent. Bleaching prevalence has tended to be higher since the event. Disease prevalence can be quite high, particularly for white disease. Dark spots disease has also been in high prevalence in certain years. Old partial mortality was high on colonies from 2005 to 2011, and low when recorded in 2002. In this case, old partial mortality is a very common feature of O. annularis and it is likely that low values are due to observer bias and a different method for estimating partial mortality. Recent partial mortality is consistently very high at Sprat Hole, due in part to the high abundance of territorial damselfish (Stegastes spp.) forming algal lawns on O. annularis. Figure 88. Sprat Hole (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. SPRAT HOLE 160 Figure 89. Sprat Hole benthic cover and coral health through time (mean ± SE). Benthic Community Cover 0% 20% 40% 60% 80% 100% Coral Cyanobacteria Epilithic Algae Macroalgae Bleaching Prevalence/Extent 0% 20% 40% 60% 80% 100% Prevalence Extent Disease Prevalence 0% 5% 10% 15% 20% 25% 30% All disease Black Band Lesion Dark Spots Intercostal White Disease Yellow Band Unknown Partial Mortality 2001 2002 2003 2004 2005 2005 BL 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 Prevalence 0% 20% 40% 60% 80% 100% Old Recent SITE SUMMARIES 161 Fish Community. Sprat Hole exhibits a fairly typical fish community structure for a nearshore coral reef ecosystem receiving some amount of terrestrial runoff from the watershed. Fish biomass is moderate, and the site is dominated numerically by the creole wrasse and blue chromis, planktivorous invertivores. Benthic herbivores are common and include small parrotfish and all three Caribbean acanthurid species. Invertivores are diverse and include both planktivores and benthic feeders; mostly small fish in small numbers. Mutton snapper have been recorded on the sight sporadically and a juvenile tiger grouper was spotted in 2013 and yellowfin grouper was seen in 2014. Numerically and by biomass the graysby dominate the piscivore group in. Lionfish have been observed on the Sprat Hole site every year since 2012. SPRAT HOLE 162 Figure 90. The Sprat Hole fish community by absolute and relative biomass. Herbivores stoplight parrotfish striped parrotfish threespot damsel redband parrotfish blue tang ocean surgeonfish princess parrotfish dusky damsel doctorfish queen parrotfish redfin parrotfish cocoa damsel greenblotch parrotfish Beaugregory Fish Biomass (g) 0 2000 4000 6000 8000 Invertivores mutton snapper yellowhead wrasse Spanish hogfish French grunt blackbar soldierfish red hind yellow goatfish squirrelfish clown wrasse slippery dick Caesar grunt spotted drum yellowtail hamlet yellowcheek wrasse striped grunt fairy basselet longsnout butterflyfish harlequin bass Fish Biomass (g) 0 500 1000 1500 2000 2500 3000 3500 Plankivores creole wrasse blue chromis brown chromis bicolor damsel yellowtail snapper black durgon Fish Biomass (g) 0 2000 4000 6000 8000 Piscivores graysby redspotted hawkfish spotted moray red lionfish spotted scorpionfish bar jack mahogany snapper schoolmaster nurseshark trumpetfish black hamlet Fish Biomass (g) 0 1000 2000 3000 4000 5000 SITE SUMMARIES 163 St. John ST. JOHN 164 SITE SUMMARIES 165 CORAL BAY Description. The Coral Bay site is atop a patch reef complex at the southeast mouth of Coral Harbor. The reef is a low carbonate build up with high coral diversity. Coral Bay appears to be a true reef with a well-developed carbonate framework over bedrock. Coral Bay monitoring was initiated in 2011. Outstanding Feature. Coral Bay supports a high diversity of coral and an apparent high rate of coral recruitment. Threats. Coral Bay is subject to land- based sources of pollution, primarily as sediment influx from the large and steep Coral Bay watershed. Recent restoration activities in the watershed are expected to decrease the sediment influx. Coral Bay may also be threatened by maritime activities within Coral Harbor. Proximity to land makes this site in territorial waters potentially vulnerable to fishing. Figure 91. Coral Bay. (top) Location. (right) A representative photo of the reef. CORAL BAY 166 Figure 92. Coral Bay benthic temperature (9 m depth) Physical Characteristics. Current. Currents have not been measured by the TCRMP, however, Dr. Sarah Gray (University of San Diego) has measured 2-D near bottom measurements for some years between 2009-2011. Oscillatory currents are expected to be light and only weak unidirectional currents have been experienced. Temperature. Coral Bay may have restricted water circulation and had very high temperatures during the 2010 bleaching event. Other. This site and the wider Coral Bay area have been under investigation for land-based sources of pollution impacts since 2009. Projects have been involved terrestrial sediment measurement/modeling, marine sediment flux, coral demographic plots, and biological monitoring. The area has also been involved in water quality monitoring (Smith et al. 2013a). Month SITE SUMMARIES 167 Benthic Community. Coral Bay has a very diverse coral community, with no clear dominance of cover. In contrast to most sites, the mustard hill coral Porites astreoides has the greatest cover among coral species. Sponges and gorgonians are also very common at this site. Epilithic algae and a high abundance of crustose coralline algae dominate the algal community, with very low abundance of macroalgae. This is surprising at this turbid reef site that likely receives high inputs of particulate and dissolved nutrient sources, and indicates that grazing is quite high. There is not a high abundance of herbivorous fish and only the occasional occurrence of Diadema antillarum. However, there is a great abundance of the rock boring urchin Echinometra spp. that appears to be the dominant grazer. This genus is not monitored in TCRMP protocols, but perhaps should be included in future years. Coral Health. It is not known how corals were affected by bleaching in 2005. There was a low prevalence of low extent bleaching in 2011. Diseases were not recorded in 2011. Old partial mortality prevalence was low in 2011, but this may partly be explained by the high abundance of small coral colonies that are less prone old partial mortality. Recent mortality had low prevalence in 2011. Figure 93. Coral Bay (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. CORAL BAY 168 Figure 94. Coral Bay benthic cover and coral health through time (mean ± SE). Benthic Community Cover 0% 20% 40% 60% 80% 100% Coral Cyanobacteria Epilithic Algae Macroalgae Bleaching Prevalence/Extent 0% 20% 40% 60% 80% 100% Prevalence Extent Disease Prevalence 0% 5% 10% 15% 20% 25% 30% All disease Black Band Lesion Dark Spots Intercostal White Disease Yellow Band Unknown Partial Mortality 2001 2002 2003 2004 2005 2005 BL 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 Prevalence 0% 20% 40% 60% 80% 100% Old Recent SITE SUMMARIES 169 Fish Community. The Coral Bay site is low in fish diversity, biomass and abundance. Although epilithic algae are prolific, large grazers are nearly absent. Three spot damselfish dominate the group in both abundance and biomass. Planktivores in the high turbidity habitat are limited to a few juvenile yellowtail snapper and pomacentrids. Although benthic invertivores were more prolific and diverse, only a few individuals comprise each species group. Likewise piscivores had a very low biomass and have been limited to a few individuals during monitoring surveys, most notably the schoolmaster snapper. CORAL BAY 170 Figure 95. The Coral Bay fish community by absolute and relative biomass. Herbivores threespot damsel striped parrotfish redband parrotfish stoplight parrotfish princess parrotfish blue tang doctorfish dusky damsel queen parrotfish Beaugregory cocoa damsel Fish Biomass (g) 0 2000 4000 6000 8000 10000 Invertivores mutton snapper tomtate French grunt blackbar soldierfish yellowhead wrasse lane snapper shy hamlet squirrelfish butter hamlet yellowbelly hamlet indigo hamlet harlequin bass striped grunt Fish Biomass (g) 0 200 400 600 800 1000 1200 1400 1600 1800 Planktivores yellowtail snapper bicolor damsel blue chromis Fish Biomass (g) 0 200 400 600 800 1000 Piscivores schoolmaster sand diver graysby black hamlet bar jack Fish Biomass (g) 0 100 200 300 400 SITE SUMMARIES 171 FISH BAY Description. Fish Bay is a nearshore Fringing Reef in territorial waters. The monitoring site is a sharp edge of a shallow water coral community dropping to sand at 7 m depth. The site has been monitored since 2001. Outstanding Feature. Fish Bay inner transects (1 – 3) are heavily sediment impacted, while outer transects (4-6) support large boulder star corals (Orbicella faveolata). Threats. Fish Bay is subjected to land-based sources of pollution. Inner bay transects tend to have turbid water and overgrowth by macroalgae. This site may also be vulnerable to fishing impacts. Figure 96. Fish Bay. (top) Location. (right) A representative photo of the reef. FISH BAY 172 Figure 97. Fish Bay benthic temperature record (6 m depth). Physical Characteristics. Current. Fish Bay currents have not been measured directly by the TCRMP. Unidirectional currents are mild to slack. Because of the southeast exposure, wave driven oscillatory currents can be quite intense, particularly on the outer transects. Temperature. Fish Bay has relatively high mean temperatures and was very far over the regional bleaching threshold in 2010. Month SITE SUMMARIES 173 Benthic Community. The coral community of Fish Bay is dominated by the boulder star coral Orbicella spp.. In particular, large (>2m wide) colonies of O. faveolata are common on the seaward transects (4-6). The inner transects (1-3) are mostly depauperate of coral (< 4% cover as of 2011). The site lost 37.1% of its cover due to the 2005 coral bleaching event, but had regained 136.1% of cover by 2011. Gorgonians are also very common on the wave- washed outer transects. Equal parts epilithic algae and the macroalgae Dictyota spp. dominate the algal community. The site also has a high abundance of Halimeda opuntia, which can smother coral on inner bay transects closest to land-based sources of pollution. Coral Health. Fish Bay corals were very severely affected in the 2005 with 100% of corals showing almost 100% bleaching. Bleaching is also normally high at this site even in years without thermal stress, a likely consequence of sediment and macroalgal interactions. Diseases, particularly dark spots disease and white disease, can have very high prevalence at Fish Bay. Old partial mortality did increase after the 2005 coral bleaching event, with a decline in 2010 and resurgence in 2011. Recent partial mortality can also be relatively high compared with other sites, largely as the results of bites from site-attached damselfish (Stegastes spp.). Figure 98. Fish Bay (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. FISH BAY 174 Figure 99. Fish Bay benthic cover and coral health through time (mean ± SE). Benthic Community Cover 0% 20% 40% 60% 80% 100% Coral Cyanobacteria Epilithic Algae Macroalgae Bleaching Prevalence/Extent 0% 20% 40% 60% 80% 100% Prevalence Extent Disease Prevalence 0% 5% 10% 15% 20% 25% 30% All disease Black Band Lesion Dark Spots Intercostal White Disease Yellow Band Unknown Partial Mortality 2001 2002 2003 2004 2005 2005 BL 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 Prevalence 0% 20% 40% 60% 80% 100% Old Recent SITE SUMMARIES 175 Fish Community. The Fish Bay fish community is typical of a nearshore reef habitat that receives moderate to heavy sedimentation. The site is dominated by herbivores that include all of the common Caribbean parrotfishes, large schools of mixed acanthurids, and herbivorous pomacentrids. Planktivores in the turbid water are limited to juvenile yellowtail snapper and a few small pomacentrids. Benthic invertivores and piscivores are more diverse and abundant but are dominated by wrasses and jacks, respectively. Large serranids and lutjanids are absent from Fish Bay although occasional juvenile lemon sharks are seen in the murky water, where adult females are known to pup. FISH BAY 176 Figure 100. The Fish Bay fish community by absolute and relative biomass. Herbivores stoplight parrotfish redband parrotfish doctorfish blue tang striped parrotfish yellowtail damsel princess parrotfish ocean surgeonfish redfin parrotfish dusky damsel threespot damsel redtail parrotfish greenblotch parrotfish queen parrotfish Beaugregory cocoa damsel Fish Biomass (g) 0 2000 4000 6000 8000 10000 Invertivores Spanish hogfish yellowhead wrasse slippery dick French grunt spotted goatfish clown wrasse saucereye porgy yellowfin mojarra puddingwife tomtate Fish Biomass (g) 0 200 400 600 800 1000 1200 Planktivores yellowtail snapper bicolor damsel blue chromis Fish Biomass (g) 0 100 200 300 400 500 600 Piscivores bar jack schoolmaster trumpetfish blue runner redspotted hawkfish black hamlet Fish Biomass (g) 0 1000 2000 3000 4000 5000 SITE SUMMARIES 177 MERI SHOAL Description. Meri Shoal is an offshore mesophotic coral bank 30 m depth. The reef is located four miles south of St. John and is on the southernmost of two impressive midshelf coral banks. The reef is dominated by interlocking colonies of boulder star corals (Orbicella spp.). The reef top is very flat coral plain. The site is named for Dr. Meri Whitaker, former director of the VI EPSCoR Program who passed away in 2009. Meri Shoal has been monitored since 2005. Outstanding Feature. Meri Shoal has the highest star coral abundance of any site in the TCRMP and is bathed in clear, clean water. Threats. Meri Shoal is vulnerable to fishing impacts, as it is outside any marine protected area. The high density of corals may also make this site vulnerable to disease impacts. Figure 101. 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 1.8 m wide. MERI SHOAL 178 Figure 102. Meri Shoal benthic temperature record (30 m depth). Physical Characteristics. Current. Currents have not been measured directly at the Meri Shoal site, although the Caribbean Regional Association buoy VI 1 is located within 700 m and its downward focused ADCP has been recording data since April 2011. Temperature. Meri Shoal has relatively low temperatures that are more similar to other mesophotic sites. Month SITE SUMMARIES 179 Benthic Community. The Meri Shoal site is exceptional for its dominance by boulder star corals (Orbicella spp.). Cover of this and other coral species was exceptionally high when the site was first monitored during the 2005 coral bleaching event, but declined by 36.0% after bleaching and had not recovered any cover as of 2011 (-9.6%). Surprisingly, given the high coral cover, Lobophora variegata, and not epilithic algae, dominate the algal community and there has been a trend of increasing macroalgal cover since 2008. Coral Health. Coral bleaching was relatively high for a mesophotic site during the coral bleaching event in 2005. Bleaching was again at high prevalence, but low extent in the thermal stress of 2010. However, low-extent bleaching at moderate prevalence is a persistent feature of Meri Shoal. Disease, particularly white disease and lesions that are likely the remnants of white disease, are highly prevalent, particularly in years following high thermal anomalies, such as 2006 and 2011. Old partial mortality climbed steeply from the 2005 coral bleaching event onwards and reached very high levels by 2006. Recent partial mortality has also been consistently high as the result of white disease and disease lesions. Figure 103. Meri Shoal (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. MERI SHOAL 180 Figure 104. Meri Shoal benthic cover and coral health through time (mean ± SE). Benthic Community Cover 0% 20% 40% 60% 80% 100% Coral Cyanobacteria Epilithic Algae Macroalgae Bleaching Prevalence/Extent 0% 20% 40% 60% 80% 100% Prevalence Extent Disease Prevalence 0% 5% 10% 15% 20% 25% 30% All disease Black Band Lesion Dark Spots Intercostal White Disease Yellow Band Unknown Partial Mortality 2001 2002 2003 2004 2005 2005 BL 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 Prevalence 0% 20% 40% 60% 80% 100% Old Recent SITE SUMMARIES 181 Fish Community. Meri Shoal is a beautiful site in relatively deep water and holds a dynamic fish community of high biomass. Important planktivores include the very prolific creole wrasse, feeding on tiny jellyfish, invertivore larvae and phytoplankton, and the black durgeon, primarily a zooplankton feeder. Herbivores observed on the site include large stoplight parrotfish, all of the common smaller parrotfish, and all three acanthurids in fairly large numbers. Queen triggerfish and red hind are both common. In 2012 a tiger grouper was observed on a belt transect and another on a roving dive. A Nassau grouper was also observed on a roving dive in 2013. These are exciting encounters as the site is not near a spawning aggregation area and is not protected from traps or any type of fishing. Jacks, mackerels, and barracuda are also regularly observed in the water column at Meri Shoal. MERI SHOAL 182 Figure 105. The Meri Shoal fish community by absolute and relative biomass. Herbivores stoplight parrotfish princess parrotfish redband parrotfish striped parrotfish queen parrotfish doctorfish blue tang ocean surgeonfish threespot damsel orangespotted filefish dusky damsel Beaugregory Fish Biomass (g) 0 5000 10000 15000 20000 25000 30000 Invertivores queen trigger red hind saucereye porgy Spanish hogfish blackbar soldierfish French grunt spotted goatfish bluestriped grunt yellowhead wrasse yellowtail hamlet longsnout butterflyfish fairy basselet Fish Biomass (g) 0 2000 4000 6000 8000 10000 12000 Planktivores creole wrasse black durgon creolefish bicolor damsel blue chromis yellowtail snapper brown chromis Fish Biomass (g) 0 2000 4000 6000 8000 10000 12000 14000 16000 18000 Piscivores tiger grouper cero graysby great barracuda schoolmaster trumpetfish bar jack red lionfish redspotted hawkfish Fish Biomass (g) 0 500 1000 1500 2000 2500 3000 SITE SUMMARIES 183 St. Thomas SITE SUMMARIES 185 BLACK POINT Description. Black Point is a nearshore fringing reef located at the mouth of Brewers Bay along the southwest coast of St. Thomas in water depths of 7 – 17 m. The reef has a sharp break in slope leading to a steep escarpment that terminates in a sediment plain at the reef base. Black Point appears to be a true reef with a well-developed carbonate framework over bedrock. Black Point has been monitored since 2003, with permanent benthic transects installed in 2007. A ciguatera fish poisoning study with monthly sampling has been ongoing since 2009. Outstanding Feature. Black Point supports a fish spawning aggregation of striped parrotfish (Scarus iserti) with daily afternoon mating at the edge of the upper reef break. Threats. Black Point is subjected to land-based sources of pollution and tends to have turbid water and overgrowth by heterotrophic organisms, such as sponges. Recreational/artisanal fishers with handline and spear frequently fish this site. Figure 106. Black Point. (top) Location. (right) A representative photo of the reef. BLACK POINT 186 Figure 107. Black point current speed and benthic temperature record (8 m depth). Physical Characteristics. Current. Black Point has restricted water flow dominated by weak currents running counter or orthogonally to the left of the dominant wind direction. This may indicate that there is a counter flowing eddy from Perseverance Bay to the west that impinges on the headland. Current data are based on average data taken every 30 min. (11/29/06 to 3/1/2007) and hourly (4/19/07 to 9/5/07). Temperature. Black Point has low circulation and relatively high mean temperatures with very low day-to-day variability. N NNE NE ENE E ESE SE SSE S SSW SW WSW W WNW NW NNW Current Speed (m s -1) 0.5 - 0.6 0.4 - 0.5 0.3 - 0.4 0.2 - 0.3 0.1 - 0.2 0.0 - 0.1 Month SITE SUMMARIES Chlorophyll & Turbidity. Chlo of land-based nutrients that fue prominent tidal signature that Figure 108. Black Point chloro 187 orophyll tends to be high at Black Point, likely el pelagic productivity. There are also exists a reflects switching source currents at the reef. phyll (left) and turbidity (right) record (16 m y due to inputs a very . m depth). BLACK POINT 188 Benthic Community. Black Point supports a very diverse coral community with very equal representation by many coral species. However, large colonies (> 100 cm diameter) of Orbicella annularis and Orbicella faveolata occur on the eastern edge of the site, with a few occurring within transects. This coral community lost 40.5% of its coral cover in the 2005 bleaching event; however, by 2011 it had regained 103.5% of its coral cover. The algal community at Black Point is co-dominated by epilithic algae and the macroalga Dictyota spp.. Coral Health. Black Point corals were severely affected during the 2005 bleaching event with nearly all colonies bleached over 100% of the colony surface. The prevalence of coral diseases was moderate with dark spots disease predominating. However, white disease outbreaks occurred at least twice over the sampling period. Old partial mortality became very prevalent after the 2005 coral bleaching event and subsided in the following two years. Figure 109. Black Point. (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. SITE SUMMARIES 189 Figure 110. Black Point benthic cover and coral health through time (mean ± SE). Benthic Community Cover 0% 20% 40% 60% 80% 100% Coral Cyanobacteria Epilithic Algae Macroalgae Bleaching Prevalence/Extent 0% 20% 40% 60% 80% 100% Prevalence Extent Disease Prevalence 0% 5% 10% 15% 20% 25% 30% All disease Black Band Lesion Dark Spots Intercostal White Disease Yellow Band Unknown Partial Mortality 2001 2002 2003 2004 2005 2005 BL 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 Prevalence 0% 20% 40% 60% 80% 100% Old Recent BLACK POINT 190 Fish Community. Black Point is highly dominated by herbivores. Juvenile parrotfish and damselfish are numerous. Brown chromis are equally abundant. The site is turbid and holds very few large fish, although the very occasional cubera snapper, Nassau grouper, or yellowfin grouper can be spotted, a rarity for nearshore areas of the USVI. These individuals are always observed near the eastern edge of the site where the reef is undercut and caves have formed. A resident mutton snapper (or two) is regularly observed cruising the sand line at the bottom of the reef. Hamlets are diverse and common. The black hamlet is especially abundant. In the mid to late afternoon, striped parrotfish (Scarus iserti) spawn at Black Point. They can be seen swimming along the reef edge in large groups beginning in the early afternoon. Spawning goes in to the late afternoon and involves tens of fish. Black Point is close to shore and is not fished by commercial traps often; however, divers can swim to the reef from the beach to spearfish. It is notably lacking of resident large edible fish. SITE SUMMARIES 191 Figure 111. The Black Point fish community by absolute and relative biomass. Herbivores striped parrotfish stoplight parrotfish redband parrotfish threespot damsel princess parrotfish dusky damsel blue tang Beaugregory queen parrotfish doctorfish cocoa damsel bucktooth parrotfish Fish Biomass (g) 0 2000 4000 6000 8000 10000 12000 Invertivores creole wrasse yellowtail snapper brown chromis blue chromis tobaccofish bicolor damsel Fish Biomass (g) 0 5000 10000 15000 20000 25000 Planktivores spotted goatfish French grunt tomtate spotted drum squirrelfish yellowhead wrasse Spanish hogfish butter hamlet shy hamlet yellowbelly hamlet yellowtail hamlet indigo hamlet harlequin bass slippery dick rainbow wrasse clown wrasse Fish Biomass (g) 0 500 1000 1500 2000 2500 Piscivores graysby glasseye snapper bar jack red lionfish black hamlet trumpetfish Fish Biomass (g) 0 200 400 600 800 1000 1200 1400 1600 1800 BOTANY BAY 192 BOTANY BAY Description. The Botany Bay site is located on the fore slope of a nearshore fringing reef in water depths of 5 – 17 m. The reef crest is a distinct spur-and- groove, with a sharp break in slope leading to an escarpment that terminates in a sand/sediment plain at the reef base. Botany Bay has been monitored since 2002. Outstanding Feature. Botany Bay supports a diverse and productive reef that is one of the prettiest nearshore reefs in the Virgin Islands. Threats. Botany Bay is threatened by development of the previously fully vegetated watershed and increased land-based sources of pollution. Cuts in the hillsides for construction of roads for luxury homes has left large areas without vegetation. The area is open to fishing. Increased residential development in the watershed may lead to increased recreational use of the reef, including fishing and collecting. The area is also occasionally impacted by large Atlantic swells, causing breakage of corals. Figure 112. Botany Bay. (top) Location. (right) A representative photo of the reef. SITE SUMMARIES 193 Figure 113. Botany Bay benthic temperature record (11 m depth). Physical Characteristics. Current. Currents have not been measured directly at Botany Bay. Unidirectional currents do not tend to be strong. Wave-driven oscillatory currents can impact the reef crest and fore reef. The site is vulnerable to impacts from large Atlantic swells. Many corals were broken and toppled during the 2009 March swell event when offshore swells reached heights to 4 m (Bright et al. 2016). Temperature. Botany Bay tends to have slightly cooler temperatures than other nearshore sites, likely owing to its open position facing the Atlantic. Figure 114. A large colony of pillar coral (Dendrogyra cylindricus) dislodge, toppled, and diseased after the 2009 swell event (Botany Bay, June 25, 2009). Month BOTANY BAY 194 Benthic Community. The Botany Bay site coral community is unique for the dominance of branching Porites porites. The site lost 38.9% of its coral cover in the 2005 bleaching event and had regained 10.6% by 2011. There is a high abundance of gorgonians on the seaward slope exposed to wave swell. The Botany Bay algal community is co-dominated by epilithic algae and the macroalga Dictyota spp., which tend to negatively covary. Coral Health. Bleaching was extremely severe during 2005, with nearly 100% of corals bleached or pale over 100% of their surface. There was also a high prevalence of bleaching in 2002 at an unknown extent and in 2010 at a low extent. Non-thermal stress years have seen variable bleaching. Coral diseases can be high at Botany Bay, with a preponderance of white and dark spots diseases, and lesions that are likely related to white disease. Old partial mortality shows a pattern that is difficult to explain before 2005. During bleaching and afterwards consistent observers have done partial mortality assessments and this data is valid. There was a large increase in old partial mortality after the 2005 bleaching event, then some subsidence and leveling off after 2008. Recent partial mortality was high through most years of monitoring, largely due to biting by territorial damselfish (Stegastes planifrons and S. adustus; data not shown). Figure 115. Botany Bay. (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. SITE SUMMARIES 195 Figure 116. Botany Bay benthic cover and coral health through time (mean ± SE). Benthic Community Cover 0% 20% 40% 60% 80% 100% Coral Cyanobacteria Epilithic Algae Macroalgae Bleaching Prevalence/Extent 0% 20% 40% 60% 80% 100% Prevalence Extent Disease Prevalence 0% 5% 10% 15% 20% 25% 30% All disease Black Band Lesion Dark Spots Intercostal White Disease Yellow Band Unknown Partial Mortality 2001 2002 2003 2004 2005 2005 BL 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 Prevalence 0% 20% 40% 60% 80% 100% Old Recent BOTANY BAY 196 Fish Community. The fish community at Botany Bay is typical of well-developed nearshore reefs around St. Thomas. The site is dominated by herbivores, primarily large stoplight parrotfish. Large habitat diversity at the site supports fish species richness and all trophic groups are well represented. Botany has a highly diverse fish community, similarly to Cane Bay, St. Croix. These sites may each be recruitment sinks owing to their position on the northwest sides of the islands where eddies tend to circulate. Generally, red hind, dog snapper, and yellowtail snapper are recorded in fish transects. In 2014, a rainbow parrotfish was observed. On roving dives, spiny lobsters are nearly always encountered. Grunts and wrasses are especially numerous and diverse at the site. Like most nearshore reefs, large jacks and balistids are nearly absent, and the planktivore community is comprised mainly of blue and brown chromis. SITE SUMMARIES 197 Figure 117. The Botany Bay fish community by absolute and relative biomass. Herbivores stoplight parrotfish yellowtail damsel queen parrotfish redband parrotfish redfin parrotfish striped parrotfish threespot damsel dusky damsel blue tang Beaugregory princess parrotfish ocean surgeonfish doctorfish redlip blenny Fish Biomass 0 2000 4000 6000 8000 10000 12000 14000 16000 18000 Invertivores smallmouth grunt red hind French grunt yellowhead wrasse tomtate spotted drum striped grunt spotted goatfish dusky squirrelfish fairy basselet harlequin bass butter hamlet yellowtail hamlet clown wrasse puddingwife Spanish hogfish Fish Biomass 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Planktivores brown chromis yellowtail snapper blue chromis creole wrasse bicolor damsel chalk bass Fish Biomass 0 1000 2000 3000 4000 Piscivores dog snapper great barracuda bar jack trumpetfish spotted moray glasseye snapper graysby black hamlet Fish Biomass 0 1000 2000 3000 4000 5000 BREWERS BAY 198 BREWERS BAY Description. Brewers Bay is a nearshore fringing reef located along the southwest coast of St. Thomas in water depths of 7 – 17 m. Brewers Bay is a very well developed boulder star coral (Orbicella annularis) dominated reef. Brewers Bay was initially monitored in 2002/2003, but was abandoned due to its proximity to the Black Point site. It was restarted in 2008 because it was resistant to the 2005 bleaching is one of the best preserved O. annularis reefs around St. Thomas. Outstanding Feature. Brewers Bay is very good example of a nearshore boulder star coral fringing reef and has fared better than other reefs of this type over the 2005 mass coral bleaching event. Threats. Brewers Bay is subjected to land-based sources of pollution and tends to have turbid water and overgrowth by heterotrophic organisms, such as sponges. Recreational/artisanal fishers frequently fish Brewers Bay with hand line and spear. The site has a great deal of marine debris, including boat hulls, rope, and metal pieces. Figure 118. Brewers Bay. (top) Location. (right) A representative photo of the reef. SITE SUMMARIES 199 Physical Characteristics. Current. Brewers Bay currents have not been measured directly, but both unidirectional and oscillatory currents are usually very low in magnitude. See also the Black Point physical data, which was taken within 500 m distance. Temperature. Brewers Bay temperatures have not been recorded directly, but see the Black Point temperature data from less than 300 m horizontal distance. The site has restricted flow and should develop high warm season temperatures. BREWERS BAY 200 Benthic Community. The Brewers Bay site is highly dominated by the boulder coral Orbicella annularis and exhibits the highest coral cover of any nearshore site in the TCRMP, with a coral cover of 32% in 2013. Coral cover was not monitored between 2003 and 2008; however there was a 28.4% decline in cover that could largely be attributed to the 2005 coral bleaching event. The algal community at Brewers Bay is dominated by epilithic algae, with lesser amounts of the macroalga Dictyota spp.. Coral Health. Corals at the Brewers Bay site were not monitored for health over the 2005 bleaching event. However, corals exhibited some of the highest prevalence of bleaching during the 2010 coral bleaching event, albeit at a low extent. In other years, bleaching prevalence remained high, with a low extent. Yellow band disease outbreaks were severe and affected the O. annularis community in 2002 and 2003. Old partial mortality is a prominent and persistent feature of the large O. annularis colonies. Recent mortality is very high and largely attributable to the biting of large populations of the territorial three-spot damselfish (Stegastes planifrons; data not shown). Figure 119. Brewers Bay. (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. SITE SUMMARIES 201 Figure 120. Brewers Bay benthic cover and coral health through time (mean ± SE) Benthic Community Cover 0% 20% 40% 60% 80% 100% Coral Cyanobacteria Epilithic Algae Macroalgae Bleaching Prevalence/Extent 0% 20% 40% 60% 80% 100% Prevalence Extent Disease Prevalence 0% 5% 10% 15% 20% 25% 30% All disease Black Band Lesion Dark Spots Intercostal White Disease Yellow Band Unknown Partial Mortality 2001 2002 2003 2004 2005 2005 BL 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 Prevalence 0% 20% 40% 60% 80% 100% Old Recent BREWERS BAY 202 Fish Community. Brewers Bay is characterized by a high fish abundance dominated by herbivores. The site holds large numbers of parrotfish. Numerically, the herbivores are dominated by juvenile striped parrotfish that swim over the reef in groups of mixed parrotfish and wrasse. Both yellowhead and bluehead wrasse are prolific and school with the juvenile parrotfish. There are also larger stoplights and queen parrotfish grazing the reef. Piscivores are limited in biomass but are fairly diverse and generally include inshore pelagics such as cero mackerel and bar jacks or yellow jacks. Hamlets (Hypoplectrus) are very common and diverse, represented by 6 to 7 species in each annual survey. The occasional large snapper (schoolmaster, dog, mutton, and cubera) are sighted on the reef periphery or around large coral heads. The reef is spearfished regularly, so these sighting are becoming more rare. Nassau, black, and yellowfin grouper and the now rare blue and rainbow parrotfish were present in Brewers Bay forty years ago (Rogers 1982); however, only Nassau and yellowfin grouper are rarely seen at the reefs today, whereas the other species are no longer observed. SITE SUMMARIES 203 Figure 121. The Brewers Bay fish community by absolute and relative biomass. Herbivores stoplight parrotfish striped parrotfish threespot damsel redband parrotfish blue tang princess parrotfish Beaugregory dusky damsel yellowtail damsel cocoa damsel orangespotted filefish ocean surgeonfish queen parrotfish Fish Biomass (g) 0 2000 4000 6000 8000 10000 Invertivores mutton snapper yellow goatfish bluestriped grunt French grunt sailors choice spotted drum butter hamlet yellowhead wrasse spotted goatfish slippery dick yellowtail hamlet shy hamlet clown wrasse indigo hamlet harlequin bass fairy basselet striped grunt yellowbelly hamlet Fish Biomass (g) 0 200 400 600 800 1000 1200 1400 1600 1800 Planktivores creole wrasse yellowtail snapper brown chromis blue chromis bicolor damsel tobaccofish Fish Biomass (g) 0 1000 2000 3000 4000 5000 6000 7000 Piscivores schoolmaster red lionfish graysby tiger grouper cero glasseye snapper black hamlet mahogany snapper bigeye bar jack sand diver trumpetfish Fish Biomass (g) 0 1000 2000 3000 4000 BUCK ISLAND, ST. THOMAS 204 BUCK ISLAND, ST. THOMAS Description. Buck Island, St. Thomas is a midshelf reef fringing the northwest coast of an uninhabited offshore island in water depths of 7 – 20 m. The reef has a sharp break in slope leading to a steep escarpment that terminates in a sand/sediment plain at the reef base. The monitoring site is located on that slope. Buck Island, St. Thomas has been monitored since 2005, with permanent benthic transects installed in 2007. Outstanding Feature. Buck Island, St. Thomas is one of the most important tourist sites in the Virgin Islands, with frequent visitation by cruise ship passengers on day boats. Threats. Buck Island, St. Thomas is very heavily used as a recreational dive site with the potential for cumulative impacts. The water surrounding Buck Island, St. Thomas is open to fishing. Commercial trap fishermen frequently target this site, and trap strings have been laid over the monitoring transects. Federally protected Nassau Grouper (Epinephelus striatus) have been observed within traps at the monitoring site. In addition, derelict traps are common around the site. Figure 122. Buck Island, St. Thomas. (top) Location. (right) A representative photo of the reef. SITE SUMMARIES 205 Figure 123. Buck Island, St. Thomas benthic temperature record (12 m depth). Physical Characteristics. Current. Buck Island, St. Thomas currents have not been measured directly. Moderately strong unidirectional currents occasionally influence the site; however, in general currents are very weak. Temperature. Buck Island, St. Thomas may develop high temperatures. Unfortunately, the temperature probe placed during the 2010 coral bleaching event was lost. Month BUCK ISLAND, ST. THOMAS 206 Benthic Community. The Buck Island, St. Thomas site coral community is dominated by the boulder star coral (Orbicella spp.), but shows high and even representation of other species. Coral cover declined by 23.4% due to the 2005 coral bleaching event and the site had regained 13.4% of this cover by 2011. Among sessile epibenthic animals a high proportion of the community is composed of sponges. The algal community is co-dominated by epilithic algae and the macroalgae Dictyota spp. and Lobophora variegata. Filamentous cyanobacteria were also abundant in 2008. Coral Health. The Buck Island, St. Thomas site was severely bleached in the 2005 coral bleaching event, with over 80% of colonies bleached over 100% of the colony surface. Bleaching was also high during the 2010 bleaching event, but at a low extent on colonies. Low prevalence of low-extent bleaching was common in other years of study. Coral diseases were usually low, in prevalence with the striking exception of 2006, when white diseases and lesions consistent with recent white disease reached extremely high prevalence. Old partial mortality increased rapidly after the 2005 bleaching event and then declined steadily in following years. Figure 124. Buck Island, St. Thomas. (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. SITE SUMMARIES 207 Figure 125. Buck Island, St. Thomas benthic cover and coral health through time (mean ± SE). Benthic Community Cover 0% 20% 40% 60% 80% 100% Coral Cyanobacteria Epilithic Algae Macroalgae Bleaching Prevalence/Extent 0% 20% 40% 60% 80% 100% Prevalence Extent Disease Prevalence 0% 5% 10% 15% 20% 25% 30% All disease Black Band Lesion Dark Spots Intercostal White Disease Yellow Band Unknown Partial Mortality 2001 2002 2003 2004 2005 2005 BL 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 Prevalence 0% 20% 40% 60% 80% 100% Old Recent BUCK ISLAND, ST. THOMAS 208 Fish Community. The fish community at Buck Island, St. Thomas is very diverse and represents the utilization of many habitats and resources. Herbivores, especially parrotfishes, dominate the site. Invertivores, however, are also diverse and very common. Both spotted and yellow goatfish roam the top of the reef and large wrasses, including the Spanish hogfish and puddingwife, are prolific. In addition to goatfish and wrasses, a variety of grunts inhabit the Buck Island Reef, and large schools of both jolthead and saucereye porgies are observed there. Tourists and commercial dive operators are known to feed fish at Buck Island and gregarious yellowtail snapper are large and numerous. Mutton snapper are occasionally observed. Schoolmaster snapper dominate the piscivores community on the site. No large grouper or snapper have been observed in belt transects or roving dives; however, small Caribbean reef sharks are generally sighted. Although a Territorial Park on land, the area is fished with hook and line, traps, and speargun. It is also a very heavily dove SCUBA and snorkel site. SITE SUMMARIES 209 Figure 126. The Buck Island, St. Thomas fish community by absolute and relative biomass. Herbivores stoplight parrotfish striped parrotfish redband parrotfish princess parrotfish doctorfish threespot damsel Beaugregory dusky damsel ocean surgeonfish blue tang yellowtail damsel redfin parrotfish queen parrotfish redtail parrotfish cocoa damsel greenblotch parrotfish orangespotted filefish bucktooth parrotfish Fish Biomass (g) 0 2000 4000 6000 8000 10000 12000 Invertivores yellowhead wrasse French grunt Spanish hogfish bluestriped grunt saucereye porgy white grunt spotted goatfish yellow goatfish blackbar soldierfish clown wrasse yellowtail hamlet harlequin bass shy hamlet puddingwife tomtate fairy basselet butter hamlet longsnout butterflyfish yellowhead jawfish spotted drum Fish Biomass (g) 0 200 400 600 800 1000 Planktivores creole wrasse blue chromis bicolor damsel yellowtail snapper black durgon brown chromis creolefish Fish Biomass (g) 0 5000 10000 15000 20000 25000 Piscivores schoolmaster bar jack graysby trumpetfish glasseye snapper black hamlet sand diver Fish Biomass (g) 0 2000 4000 6000 8000 10000 12000 COCULUS ROCK 210 COCULUS ROCK Description. The Coculus Rock site is a coral community on bedrock and pavement in depths of 4 – 7 m. The reef is formed between emergent rocks and a sand plain at 7m. Coculus Rock has been monitored since 2001, with fish community assessment starting in 2009. A ciguatera fish poisoning study with monthly sampling has been ongoing since 2009. Outstanding Feature. Coculus Rock is located in the St. Thomas East End Reserve and is closed to taking of reef fishes. The site supports a fish spawning aggregation of redfin parrotfish (Sparisoma rubripinne). These 100+ fish engage in daily afternoon mating at southeast reef corner. A ciguatera study with monthly sampling has been ongoing since 2009. Threats. Coculus Rock is subject to land-based sources of pollution from the large Turpentine Gut drainage of the Tutu watershed and the numerous industrial maritime activities in Benner Bay. Figure 127. Coculus Rock. (top) Location. (right) A representative photo of the reef showing the aggregation of redfin parrotfish. SITE SUMMARIES 211 Figure 128. Coculus Rock benthic temperature record (7 m depth). Physical Characteristics. Current. Coculus Rock currents have not been measured directly. Only weak unidirectional currents have been experienced. Wave-driven oscillatory currents can be intense from swells coming from the southeast. Temperature. Coculus Rock can experience very high temperatures during the peak warm season. Month COCULUS ROCK 212 Benthic Community. The Coculus Rock site is a coral community on bedrock and thin carbonate pavement that supports a very diverse coral community with no dominance by any species. The site lost 10.7% of its coral cover in the 2005 bleaching event, but had regained 76.0% of this lost cover by 2011. Sponges are a very prominent component of the sessile epibenthic animal community. The algal community is co-dominated by epilithic algae and the macroalga Dictyota spp., which tend to covary. Coral Health. Corals at Coculus Rock were relatively moderately impacted by the 2005 coral bleaching event in both prevalence and extent on colonies. This may be due to a coral species assemblage composed of small massive species that tend to be less susceptible to bleaching (Smith et al. 2013b). A modest prevalence of low extent bleaching was also evident in the 2010 coral bleaching event. In years without high thermal stress, there tends to be a relatively high prevalence of bleaching relative to other sites, and prior to 2004 this was at high extent over colonies. Coral diseases, represented almost exclusively by dark spots disease, can be quite high in some years. Old partial mortality has been fairly high and consistent over time, with a slight increase after the 2005 and 2010 bleaching events. Recent partial mortality tends to be quite low in prevalence. Figure 129. Coculus Rock. (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. SITE SUMMARIES 213 Figure 130. Coculus Rock benthic cover and coral health through time (mean ± SE). Benthic Community Cover 0% 20% 40% 60% 80% 100% Coral Cyanobacteria Epilithic Algae Macroalgae Bleaching Prevalence/Extent 0% 20% 40% 60% 80% 100% Prevalence Extent Disease Prevalence 0% 5% 10% 15% 20% 25% 30% All disease Black Band Lesion Dark Spots Intercostal White Disease Yellow Band Unknown Partial Mortality 2001 2002 2003 2004 2005 2005 BL 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 Prevalence 0% 20% 40% 60% 80% 100% Old Recent COCULUS ROCK 214 Fish Community. The Coculus Rock fish community is interesting in several ways and it represents an inshore promontory that aggregates redfin parrotfish (Sparisoma rubripinne) to spawn every afternoon. For that reason, redfin highly dominate the site in biomass. The top of the reef, emergent at points, is turbid and rough with breaking waves, but large parrotfish, jacks, snappers, doctorfish, and damselfishes swim in this area. At the bottom of the reef, where coral and rock meet the sand, a small ledge runs along the southeast edge. Red hind and an occasional Nassau grouper have been observed hiding in the ledge here. There are generally a dozen or more juvenile lobster using the ledge as well. Juvenile grunts can be particularly common at Coculus Rock, schooling on large limestone rocks on the western side of the site. Otherwise the fish community inhabiting the steep walled rock and algae covered limestone site is primarily wrasses, small parrotfishes, and acanthurids. Coculus Rock is part of the territorial Saint Thomas East End Reserve (STEER) and fishes are protected from all harvest year-round. SITE SUMMARIES 215 Figure 131. The Coculus Rock fish community by absolute and relative biomass. Herbivores redfin parrotfish stoplight parrotfish blue tang redband parrotfish ocean surgeonfish doctorfish yellowtail damsel striped parrotfish dusky damsel redtail parrotfish princess parrotfish Beaugregory threespot damsel orangespotted filefish cocoa damsel Fish Biomass (g) 0 5000 10000 15000 20000 25000 Invertivores yellowhead wrasse saucereye porgy bluestriped grunt squirrelfish French grunt puddingwife slippery dick rainbow wrasse clown wrasse harlequin bass hogfish tomtate fairy basselet Fish Biomass (g) 0 200 400 600 800 1000 1200 1400 Planktivores yellowtail snapper bicolor damsel Fish Biomass (g) 0 500 1000 1500 2000 2500 3000 Piscivores gray snapper sand diver schoolmaster graysby black hamlet trumpetfish Fish Biomass 0 200 400 600 800 1000 Fish Biomass COLLEGE SHOAL 216 COLLEGE SHOAL Description. College Shoal is part of a mesophotic bank located in the Red Hind Marine Conservation District (est. 1999) in depths of 28 – 33 m. The densely populated coral reef is surrounded by continuous reef structure dominated by star corals (Orbicella spp.). College Shoal has been monitored since 2003, with permanent benthic transects installed in 2007. Outstanding Feature. College Shoal is notable for possessing high water clarity, relatively strong currents, a high density of corals (>30% coral cover), and a great abundance of fishes, including commercially important groupers and snappers. College Shoal is one of the most aesthetically pleasing reefs for diving due to its relatively pristine condition, high coral abundance, and high fish abundance. Threats. College Shoal has experienced coral white diseases at chronically high levels (> 1% prevalence). This reef also supports a high abundance of the invasive Indo-Pacific Lionfish (Pterois volitans). Figure 132. College Shoal. (top) Location. (right) A representative photo of the reef. SITE SUMMARIES 217 Figure 133. College Shoal benthic temperature record (29 m depth). Physical Characteristics. Currents. Although not measured directly, College Shoal has strong unidirectional driven currents that seem to be tidally driven and follow a pattern of increasing strength during spring tides. Current data has been collected and will be presented in a future report. Temperature. Benthic temperatures are ameliorated in the warm season by the proximity of the thermocline. The presence of the thermocline causes temperatures that are cool and diurnally variable from May to October. Unfortunately, the thermistor re-initialized improperly in 2009 and the 2010 coral bleaching event temperatures where missed at this site. Month COLLEGE SHOAL 218 Benthic Community. College Shoal is among the TCRMP sites with the highest coral cover (38.2% in 2011) and, similar to other bank mesophotic sites south of the St. Thomas, is dominated by the boulder star coral (Orbicella spp.). This site lost only 10.1% of its coral cover in the 2005 bleaching event, but had not regained cover since then (-1.3%); however, these estimates have some additional error since transects were not made permanent until 2007. Sponges and gorgonians are in very low relative abundance. The algal community is dominated by the macroalga Lobophora variegata and lesser representation by epilithic algae. There is also a relatively high proportion of crustose coralline algae. Coral Health. College Shoal bleached at a relatively low prevalence during the 2005 mass coral bleaching event, although corals that were bleached tended to lose color over their entire surface. The 2010 coral bleaching event had no apparent effect above background bleaching levels. Bleaching in years without thermal stress tends to be moderate. Diseases were dominated by white disease, which reached very high prevalence after the 2005 bleaching event, with an outbreak that lasted for two years in 2006 and 2007. This disease was again very prevalent in 2011 after the 2010 bleaching event, even without apparent thermal bleaching. Old partial mortality was elevated on corals after the mortality from the 2005 bleaching event, and this level has remained stable through 2011. Recent partial mortality is always relatively high, much of it attributable to fish bites. Figure 134. College Shoal (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. SITE SUMMARIES 219 Figure 135. College Shoal benthic cover and coral health through time (mean ±SE). Benthic Community Cover 0% 20% 40% 60% 80% 100% Coral Cyanobacteria Epilithic Algae Macroalgae Bleaching Prevalence/Extent 0% 20% 40% 60% 80% 100% Prevalence Extent Disease Prevalence 0% 5% 10% 15% 20% 25% 30% All disease Black Band Lesion Dark Spots Intercostal White Disease Yellow Band Unknown Partial Mortality 2001 2002 2003 2004 2005 2005 BL 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 Prevalence 0% 20% 40% 60% 80% 100% Old Recent COLLEGE SHOAL 220 Fish Community. College Shoal is characterized by a high fish biomass and high species diversity. Large planktivores are also characteristic of College Shoal, including ocean triggerfish, Atlantic spadefish, black jacks, and yellowtail snapper. Numerically, the site is dominated by creole wrasse; however, large jacks, ocean triggerfish, and black durgeon are very common. College Shoal lies within the Marine Conservation District (MCD) and is protected year round from all fishing. Nassau, yellowfin, and yellowmouth grouper are occasionally observed on the site. Tiger grouper are seen there regularly. The mesophotic, high coral cover reef supports less herbivores than the shallower nearshore and offshore sites; however, more herbivores (ocean surgeonfish) are present than on the significantly deeper Hind Bank FSA and Grammanik Bank FSA sites. Diversity is high in all trophic guilds indicating a high variety of niches available for fishes. SITE SUMMARIES 221 Figure 136. The College Shoal fish community by absolute and relative biomass. Herbivores princess parrotfish stoplight parrotfish ocean surgeonfish queen parrotfish redband parrotfish blue tang doctorfish Beaugregory threespot damsel greenblotch parrotfish striped parrotfish Fish Biomass (g) 0 2000 4000 6000 8000 10000 Invertivores saucereye porgy yellow goatfish red hind queen trigger permit white grunt spotted goatfish blackbar soldierfish yellowhead wrasse porkfish French grunt bluestriped grunt dusky squirrelfish Spanish hogfish slippery dick longsnout butterflyfish fairy basselet harlequin bass yellowtail hamlet Fish Biomass (g) 0 5000 10000 15000 20000 25000 Planktivores ocean trigger yellowtail snapper black durgon creole wrasse black jack blue chromis bicolor damsel creolefish boga brown chromis Fish Biomass (g) 0 5e+4 1e+5 2e+5 2e+5 3e+5 3e+5 Piscivores cubera snapper bar jack horse-eye jack schoolmaster great barracuda dog snapper yellowfin grouper cero red lionfish graysby Fish Biomass (g) 0 2000 4000 6000 8000 10000 12000 14000 16000 18000 FLAT CAY 222 FLAT CAY Description. This monitoring site wraps around the northwest corner depths of Flat Cay in depths of 10 – 17 m. Flat Cay has been monitored since 2003, with permanent benthic transects installed in 2007. A ciguatera fish poisoning study with monthly sampling has been ongoing since 2009. Outstanding Feature. Flat Cay supports a lush coral community, including dense populations of the endangered elkhorn and staghorn corals (Acropora spp.) outside the TCRMP monitoring site. The site is a popular tourist dive site and is an important site for research by local and international investigators. Threats. Flat Cay is down current of industrial port activities and a major sewage outfall. Mollusks, including the commercially important queen conch (Strombus gigas) show sterility (imposex) as a likely result of exposure to hormone mimics released from boat hulls coated with marine antifouling paint containing Tributyltin (Strand et al. 2009). The area experiences heavy fishing and damage from anchoring within the reef. Figure 137. Flat Cay. (top) Location. (right) A representative photo of the reef. SITE SUMMARIES 223 Figure 138. Flat Cay benthic current speed (left) and temperature record (right) (14 m depth). Physical Characteristics. Current. The benthic current at the Flat Cay site is weak and dominated by a south- southwesterly flow. This may be an effect of the wrapping of the generally westward and occasionally strong surface current. Currents were measured with an Aandaraa 2-D current meter measuring 1m above the seafloor. Temperature. Flat Cay experiences moderate warming for a shallow water site and rapid cooling with the passage of tropical storms. N NNE NE ENE E ESE SE SSE S SSW SW WSW W WNW NW NNW Current velocity (m s -1) 0.2 - 0.3 0.1 - 0.2 0.0 - 0.1 Month FLAT CAY 224 Benthic Community. Flat Cay supports a diverse coral community with dominance of boulder star corals (Orbicella spp.). The sessile epibenthic animal community also shows a high abundance of sponges. The site lost a moderate 21.9% of cover in the 2005 bleaching event and had regained 159.3% of this cover by 2011. A caveat is that transects were not made permanent until 2007. Epilithic algae and the macroalga Dictyota spp., with lesser amounts of Lobophora variegata, dominate the algal community. Sand in pockets between coral also makes up a fair amount of the non-living substrate. Coral Health. Corals were severely affected during the 2005 coral bleaching event, with over 90% of corals bleached at 100% extent of the colony surface. Bleaching was also moderately prevalent in the 2010 bleaching event, but at low extent. Coral diseases, particularly dark spots disease can be very prevalent at Flat Cay. There was an unusual outbreak of black band disease in 2004. This disease is rare at the depths of Flat Cay. White disease was somewhat prevalent after the 2005 bleaching. Old partial mortality increased rapidly after the 2005 bleaching event and has not decreased in the intervening years. Recent mortality can be moderate and is due to a variety of causes. Figure 139. Flat Cay (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. SITE SUMMARIES 225 Figure 140. Flat Cay benthic cover and coral health through time (mean ± SE). Benthic Community Cover 0% 20% 40% 60% 80% 100% Coral Cyanobacteria Epilithic Algae Macroalgae Bleaching Prevalence/Extent 0% 20% 40% 60% 80% 100% Prevalence Extent Disease Prevalence 0% 5% 10% 15% 20% 25% 30% All disease Black Band Lesion Dark Spots Intercostal White Disease Yellow Band Unknown Partial Mortality 2001 2002 2003 2004 2005 2005 BL 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 Prevalence 0% 20% 40% 60% 80% 100% Old Recent FLAT CAY 226 Fish Community. Flat Cay is characterized by a large diversity of fish evenly distributed across trophic guilds. There is a higher biomass of invertivores than other groups due to the regular occurrence of large schools of creole wrasse. Herbivores are dominated by redband and striped parrotfish; however, there is a diversity of parrotfish species. Juvenile parrotfish are most prevalent. Carangids frequent the reef and dominate the piscivore trophic group. Very occasional large groupers (Nassau, yellowfin, black) have been observed on Flat Cay over the past eight years. The occurrence of black grouper is notable, since this species is absent throughout the majority of monitoring sites. Generally, the serranids are highly dominated by the coney. The Flat Cay reef is highly used as a recreational dive site and spearfishing occurs regularly. Where the reef meets the sand offshore, large schools of grunts, gray snapper, squirrelfish, and goatfish occur. Small reef sharks are seen out over the sand regularly. SITE SUMMARIES 227 Figure 141. The Flat Cay fish community by absolute and relative biomass. Herbivores stoplight parrotfish redband parrotfish striped parrotfish queen parrotfish threespot damsel doctorfish princess parrotfish blue tang Beaugregory dusky damsel greenblotch parrotfish ocean surgeonfish cocoa damsel orangespotted filefish Fish Biomass 0 2000 4000 6000 8000 10000 Invertivores French grunt yellow goatfish squirrelfish bluestriped grunt spotted goatfish tomtate saucereye porgy yellowhead wrasse white grunt Spanish hogfish porcupine indigo hamlet yellowtail hamlet butter hamlet shy hamlet bandtail puffer blackear wrasse harlequin bass striped grunt fairy basselet Fish Biomass 0 1000 2000 3000 4000 Planktivores brown chromis yellowtail snapper creole wrasse bicolor damsel blue chromis black durgon chalk bass tobaccofish Fish Biomass 0 1000 2000 3000 4000 5000 Piscivores bar jack graysby great barracuda schoolmaster trumpetfish dog snapper black hamlet redspotted hawkfish Fish Biomass 0 1000 2000 3000 4000 GINSBURGS FRINGE 228 GINSBURGS FRINGE Description. Ginsburgs Fringe is a lower mesophotic lettuce coral (Agaricia undata.) reef at depths of 60-75 m (established in 2011). The reef is on a steep escarpment dropping into the abyssal Virgin Islands trough. Outstanding Feature. Ginsburgs Fringe had the highest 2011 coral cover among all TCRMP monitoring sites (44%), with living colonies of lettuce corals over 6m (20’) wide. This site is the epicenter of a multispecies fish spawning aggregation, including the threatened Nassau grouper (Epinephelus striatus). The site name honors the father of comparative sedimentology and mesophotic coral studies, Dr. Robert N. Ginsburg. Threats. Although little is known about conditions in deep mesophotic lettuce coral reefs, Lettuce corals at these depths are potato chip thin at edges and fragile. Reef claw-type anchors appear to be responsible for a 50% drop in coral cover in the last few years. The site is being heavily invaded by red lionfish (Pterois volitans). Figure 142. Ginsburgs Fringe. (top) Location. (right) A representative photo of the reef showing whorled lettuce coral colonies up to 7m in width and research diver filming permanent transect in background (Nov. 13, 2015). SITE SUMMARIES 229 Figure 143. Ginsburgs Fringe current speed (50 m depth) and benthic temperature (63 m depth). BT = bleaching threshold ; DHW = degree heating weeks . Physical Characteristics. Current. Currents have been measured above the site in 50 m depth. There is a strong offshelf-downwelling (southward) that occurs just above the site, potentially carrying larvae and heterotrophic food supplies to the site. Temperature. Temperatures are much cooler at Ginsburgs Fringe than any other TCRMP site, but still quite suitable for healthy Caribbean stony corals. The cooler temperatures lead to a lower bleaching threshold temperature. Month N NNE NE ENE E ESE SE SSE S SSW SW WSW W WNW NW NNW Current Speed (m s -1) 0.4 - 0.5 0.3 - 0.4 0.2 - 0.3 0.1 - 0.2 0.0 - 0.1 GINSBURGS FRINGE 230 Benthic Community. The coral community at Ginsburgs Fringe is almost exclusively lettuce corals of the genus Agaricia. Among the agariciid genus, the rank abundance of species is A. undata (30.8% absolute cover), A. grahamae (8.2%), and A. lamarcki (2.3%), with no colonies of A. agaricites and A. fragilis occurring in transects. These species identifications are tentative as voucher specimens have not been collected. Although not well represented in cover, individual colonies of Montastraea cavernosa and Siderastrea siderea also occur at the site. The algal community is dominated by the macroalga Lobophora variegata, which is surprising for these depths, and epilithic algae. Crustose coralline algae are also in high abundance, as well as a variety of unidentified algal species. Coral Health. Coral health is not directly monitored at Ginsburgs Fringe due to the depth and difficulties assessing colonies greater than 3m width. However, some observations have been made. Anchor damage from reef claw type anchors appears to be causing recent extreme losses of coral cover by breakage and dispersal of the reef framework (a 49% decrease between 2011 and 2016). What appears to be warm season bleaching has been observed. Colonies have a fair degree of partial mortality and recent mortality is very common. In some cases it appears that shaded colony portions die back due to lack of light. The corallivorous snail, Coralliophila abbreviata, has been observed feeding on lettuce corals. Figure 144. Ginsburgs Fringe. (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. SITE SUMMARIES 231 Figure 145. Ginsburgs Fringe benthic cover through time (mean ± SE). Benthic Community 2001 2002 2003 2004 2005 2005 BL 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 Cover 0% 20% 40% 60% 80% 100% Coral Cyanobacteria Epilithic Algae Macroalgae GINSBURGS FRINGE 232 Fish Community. Both abundance and biomass of fish are low on this lower mesophotic lettuce coral reef. Deep-water fishes, such as blackfin snapper, small cherubfish, and sunshinefish, are commonly found on Ginsburgs Fringe, but are rare in upper mesophotic and shallow sites. However, despite its depth there is still some overlap with shallow and upper mesophotic coral reef fish communities. Herbivores are in notably low abundance. Piscivores make up the bulk in biomass of fishes encountered, include dog snapper and blackfin snapper. Lionfish are also very abundant and make up much of the biomass within the piscivore group. During the grouper spawning aggregation period in the winter and spring months, large groups of Nassau and yellowfin grouper have been observed spawning over the reef at depths between 46-65 m. Historically, black grouper were caught off this reef in the spawning season, but they have not been observed spawning here in the last 10 years (Edmond Bryan, commercial fishermen). SITE SUMMARIES 233 Figure 146. The Ginsburgs Fringe fish community by absolute and relative biomass. Herbivores redband parrotfish cherubfish striped parrotfish princess parrotfish blue tang stoplight parrotfish Fish Biomass (g) 0 100 200 300 400 500 Invertivores longspine squirrelfish longjaw squirrelfish foureye butterflyfish spotfin butterflyfish reef butterflyfish bluehead w rasse Fish Biomass (g) 0 200 400 600 800 1000 1200 1400 Planktivores creole wrasse sunshinefish creolefish blue chromis brow n chromis Fish Biomass (g) 0 2000 4000 6000 8000 10000 12000 14000 16000 Piscivores dog snapper red lionfish blackfin snapper graysby bar jack m ahogany snapper Fish Biomass (g) 0 2000 4000 6000 8000 Herbivores 6% Invertivores 18% Omnivores 4% Piscivores 38% Planktivores 26% Spongivores 8% GRAMMANIK TIGER 234 GRAMMANIK TIGER Description. The Grammanik Tiger monitoring site is a primary bank mesophotic reef in depths of 37 – 41m. Star corals (Orbicella spp.) dominate the reef structure. Grammanik Tiger has been monitored since 2003, with permanent transects installed in 2007. Outstanding Feature. The Grammanik Tiger monitoring site supports a dense coral community that is a staging area for annual multi-species fish spawning events, including the threatened Nassau grouper (Epinephelus striatus). Threats. Although the Grammanik Tiger site and surrounding dense reefs are somewhat buffered from high thermal stress, but they are susceptible to chronic coral white diseases. Periodic disease outbreaks follow coral bleaching events. The Indo-Pacific lionfish (Pterois volitans) has formed dense populations within the study area and may be affecting native fish populations. Figure 147. Grammanik Tiger (top) Location. (right) A representative photo of the reef. SITE SUMMARIES 235 Figure 148. Grammanik Tiger benthic currents speed and temperature record (38 m depth). Physical Characteristics. Current. Unidirectional benthic currents at the Grammanik Tiger site are generally north- south, with the strongest current from the north-northeast to the northwest. Currents are typically weak to moderate, but occasionally reach strengths greater than 30cm s-1. Current speeds are based on near-continuous ADCP deployments from February 2005 to April 2009, with measurements at 30 or 60 minute intervals. Oscillatory currents are nil at this depth, with the possible exception of long period swells generated by tropical storms, although this has not been measured. Temperature. Benthic temperatures at Grammanik Tiger are ameliorated by the passage of tidally driven internal tides in the warm season (May-November). Inter-annual variability creates temperatures that can be up to 2°C different for the same Julian Day. The Grammanik Tiger site is a prime example of how cooler temperatures at depth decrease the coral bleaching threshold by acclimation and lead to potential bleaching even in moderate temperatures relative to shallow reefs (Smith et al. 2016a). N NNE NE ENE E ESE SE SSE S SSW SW WSW W WNW NW NNW Current Speed (m s -1) 0.6 - 0.7 0.5 - 0.6 0.4 - 0.5 0.3 - 0.4 0.2 - 0.3 0.1 - 0.2 0.0 - 0.1 Month GRAMMANIK TIGER 236 Benthic Community. Boulder star corals (Orbicella spp.) dominate the coral community of the Grammanik Tiger site; however, there is representation by a high number of other species that are also present in shallow water reefs. Grammanik Tiger lost only 5.4% of its coral cover in the 2005 bleaching event, but had not regained any cover (-129.6%) by 2011. A caveat is that transects were not made permanent until 2007. Other prominent members of the sessile epibenthic animal community are sponges. The macroalga Lobophora variegata and epilithic algae dominate the algal community. There are also a relatively high proportion of crustose coralline algae and various other macroalgae species. Coral Health. Corals at Grammanik Tiger were very affected by bleaching in 2005, but were underestimated in surveys conducted when thermal stress was only about half (4 degree heating weeks) what it eventually reached. The 2010 bleaching event was sampled at the peak (4 degree heating week) but was not detectible above background bleaching levels. High prevalence of bleaching in normal years is due largely to granular bleaching of Orbicella spp., where pigmented spots are surrounded by bleached areas. Coral diseases are very prevalent with high representation of white disease. Yellow band disease was reported at high prevalence in the first years of monitoring. Old partial mortality was low, but increased rapidly after the 2005 coral bleaching event. Recent partial mortality is very high and is caused by disease lesions, predations, and fish bites. Figure 149. Grammanik Tiger FSA. (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. SITE SUMMARIES 237 Figure 150. Grammanik Tiger benthic cover and coral health through time (mean ± SE). Benthic Community Cover 0% 20% 40% 60% 80% 100% Coral Cyanobacteria Epilithic Algae Macroalgae Bleaching Prevalence/Extent 0% 20% 40% 60% 80% 100% Prevalence Extent Disease Prevalence 0% 5% 10% 15% 20% 25% 30% All disease Black Band Lesion Dark Spots Intercostal White Disease Yellow Band Unknown Partial Mortality 2001 2002 2003 2004 2005 2005 BL 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 Prevalence 0% 20% 40% 60% 80% 100% Old Recent GRAMMANIK TIGER 238 Fish Community. The Grammanik Tiger site supports less herbivores and a greater number of piscivores than the more shallow sites in the TCRMP. It is within the staging area and near the spawning site of an aggregation of several species of grouper and snapper. Given the range of spawning species encountered, surveys often coincide with the occurrence of aggregations, particularly in those species with protracted spawning seasons (e.g., cubera and schoolmaster snapper). This drives up the relative piscivore biomass; however, on the Grammanik Bank there also commonly occur members of the pelagic jack family (Carangidae) as well as occasional other large non-spawning grouper and snapper that are rarely or never found on other near and offshore reefs. Nassau, yellowfin, yellowmouth, and tiger grouper are present during non-spawning periods. This reef is protected from traps year round, and from all fishing gear from February through April. Creole wrasse highly dominate the invertivores and adult stoplight parrotfish dominate the herbivores. Juvenile parrotfish and doctorfish are relatively uncommon on this and all mesophotic sites. Yellowhead and bluehead wrasse are also notably much less common on the Grammanik Bank than other sites. In recent years the invasive Indo-Pacific lionfish (Pterois volitans) has become very common, with tens of individual commonly observed on any given dive. This is bothersome because, although fishing pressure is low, potential lionfish predators are in relatively high abundance but do not appear to be controlling the lionfish abundance. As well as large groupers and snappers, lemon and bull sharks are seen frequently on the Grammanik Bank reef. SITE SUMMARIES 239 Figure 151. The Grammanik Tiger fish community by absolute and relative biomass. Herbivores princess parrotfish stoplight parrotfish ocean surgeonfish queen parrotfish redband parrotfish blue tang doctorfish Beaugregory threespot damsel greenblotch parrotfish striped parrotfish Fish Biomass (g) 0 2000 4000 6000 8000 10000 Invertivores saucereye porgy yellow goatfish red hind queen trigger permit white grunt spotted goatfish blackbar soldierfish yellowhead wrasse porkfish French grunt bluestriped grunt dusky squirrelfish Spanish hogfish slippery dick longsnout butterflyfish fairy basselet harlequin bass yellowtail hamlet Fish Biomass (g) 0 5000 10000 15000 20000 25000 Planktivores ocean trigger yellowtail snapper black durgon creole wrasse black jack blue chromis bicolor damsel creolefish boga brown chromis Fish Biomass (g) 0 5e+4 1e+5 2e+5 2e+5 3e+5 3e+5 Piscivores cubera snapper bar jack horse-eye jack schoolmaster great barracuda dog snapper yellowfin grouper cero red lionfish graysby Fish Biomass (g) 0 2000 4000 6000 8000 10000 12000 14000 16000 18000 HIND BANK 240 HIND BANK Description. The Hind Bank is a mesophotic tertiary bank in depths of 38 – 42 m. The reef is part of a patchy complex of star coral (Orbicella spp.) dominated reefs that stretch across the eastern Red Hind Marine Conservation District. The Hind Bank has been monitored since 2003, with permanent benthic transects installed in 2007. Outstanding Feature. The Hind Bank is within a no-take marine reserve and fish populations are recovering and robust. The Hind Bank monitoring site hosts a multispecies spawning aggregation, including a recovering population of the commercially important red hind grouper (Epinephelus guttatus). Threats. The Hind Bank and surrounding dense reefs are somewhat buffered from high thermal stress, but they are susceptible to chronic coral white diseases. Periodic disease outbreaks follow high thermal stress. The Indo-Pacific lionfish (Pterois volitans) has formed dense populations within the study area and may be affecting native fish populations. Figure 152. Hind Bank (top) Location. (right) A representative photo of the reef. SITE SUMMARIES 241 Figure 153. (top) Hind Bank benthic current speed (40m depth). (bottom) Benthic temperature record at 40 m depth. Physical Characteristics. Current. Hind Bank has moderately strong unidirectional near-benthic currents that are dominated by a north to south components. Currents can be moderate to strong (>20cm s- 1). Current speeds are based on near-continuous ADCP deployments from February 2005 to May 2012, with measurements at 30 or 60 min. intervals. Oscillatory currents are not known from the Hind Bank. Temperature. Temperatures show much evidence of internal tides in the warm season and are notable cooler than shallow water sites in the upper mixed layer and nearshore embayments. N NNE NE ENE E ESE SE SSE S SSW SW WSW W WNW NW NNW Current Speed (m s -1) 0.4 - 0.5 0.3 - 0.4 0.2 - 0.3 0.1 - 0.2 0.0 - 0.1 Month HIND BANK 242 Benthic Community. The Hind Bank site is dominated by boulder star corals (Orbicella spp.), but also has a high abundance of lettuce corals (Agaricia spp.). The Hind Bank site lost 21.8% of its coral cover in the 2005 bleaching event, but had regained 71.4% of this cover by 2011. The algal community is co-dominated by epilithic algae and the macroalga Lobophora variegata. There is also high representation of crustose coralline algae and other unidentified macroalgal species. Coral Health. Bleaching during the 2005 event was underestimated because sampling occurred before the peak in heat stress. The prevalence of bleaching was higher during the 2010 coral bleaching event. In later years, the high prevalence of moderate prevalence, low colony extent bleaching was often associated with granular bleaching. This bleaching pattern shows pigmented spots surrounded by bleached tissue. Coral diseases are common at the Hind Bank and may be increasing. White disease was the dominant disease, and 2011 showed a peak of disease signs. In 2009 there was a high prevalence of intercostal mortality syndrome, which is only known from mesophotic coral reefs (Smith et al. 2010b). Old partial mortality increased after the 2005 bleaching event and the high prevalence was not reduced until 2011. Recent partial mortality prevalence is often high and reflects the impacts of disease and predation. Figure 154. Hind Bank. (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. SITE SUMMARIES 243 Figure 155. Hind Bank benthic cover and coral health through time (mean ± SE). Benthic Community Cover 0% 20% 40% 60% 80% 100% Coral Cyanobacteria Epilithic Algae Macroalgae Bleaching Prevalence/Extent 0% 20% 40% 60% 80% 100% Prevalence Extent Disease Prevalence 0% 5% 10% 15% 20% 25% 30% All disease Black Band Lesion Dark Spots Intercostal White Disease Yellow Band Unknown Partial Mortality 2001 2002 2003 2004 2005 2005 BL 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 Prevalence 0% 20% 40% 60% 80% 100% Old Recent HIND BANK 244 Fish Community. Like the Grammanik Bank, the Hind Bank is characterized by a high number of piscivorous fish. The site is within the Marine Conservation District (MCD) and is protected year round from all fishing, except surface trolling. It is the spawning site for several species including red hind, mutton snapper, tiger grouper, and schoolmaster snapper. Surveys often coincide with the occurrence of schoolmaster snapper, which has a protracted spawning season. This drives up the relative piscivore biomass; however, there are also commonly members of the pelagic jack family (Carangidae), large barracuda, and resident groupers. Benthic invertivores are dominated by goatfish as the likely result of the proximity of sand areas along the reef. Creole wrasse are not nearly as dominant on the Hind Bank as on other mesophotic sites. Herbivores, as on other mesophotic sites, are less common than on nearshore sites. This group is dominated by adult or semi-adult princess parrotfish and juvenile parrotfish are uncommon. Yellowhead wrasse are fairly common on the Hind Bank, however bluehead wrasse are not. Mesophotic species such as the fairy basslet, sunshinefish, and longsnout butterflyfish are also common. SITE SUMMARIES 245 Figure 156. The Hind Bank East fish community by absolute and relative biomass. Herbivores stoplight parrotfish queen parrotfish ocean surgeonfish redband parrotfish princess parrotfish blue tang striped parrotfish doctorfish Fish Biomass (g) 0 500 1000 1500 2000 2500 3000 Invertivores queen trigger mutton snapper Nassau grouper porkfish blackbar soldierfish permit red hind hogfish clown wrasse French grunt bluestriped grunt white grunt cottonwick squirrelfish Spanish hogfish longsnout butterflyfish yellowhead wrasse yellowtail hamlet dusky squirrelfish spotted goatfish Caesar grunt shy hamlet fairy basselet bandtail puffer Fish Biomass (g) 0 1000 2000 3000 4000 5000 6000 Planktivores yellowtail snapper creole wrasse blue chromis black jack creolefish bicolor damsel sunshinefish Fish Biomass (g) 0 1000 2000 3000 4000 5000 6000 7000 Piscivores horse-eye jack schoolmaster yellowjack bar jack dog snapper red lionfish cero mahogany snapper graysby gray snapper king mackeral black hamlet trumpetfish Fish Biomass (g) 0 2e+4 4e+4 6e+4 8e+4 1e+5 LITTLE SAINT JAMES 246 LITTLE SAINT JAMES Description. The Little St. James site is a midshelf hardbottom reef in depths of 16-22 m. The site is a patch reef surrounded by sand/rhodolith plain. Little St. James has been monitored since 2005, with permanent benthic transects installed in 2007. Outstanding Feature. The Little St. James site is just outside the St. Thomas East End Reserve and supports occasional high densities of snappers, grunts, and queen trigger. Threats. Commercial fisherman target the Little St. James site and active and derelict fish traps are in high abundance. The site is down-current of development on Little St. James Island and is potentially threatened by land-based source of pollution. Figure 157. Little St. James. (top) Location. (right) A representative photo of the reef with derelict fish trap SITE SUMMARIES 247 Figure 158. Little St. James benthic temperature record (19 m depth). Physical Characteristics. Current. Currents have not been directly measured at St. James. Unidirectional benthic currents have only been weak during monitoring. Strong wave-driven oscillatory currents may take place, as evidenced by the high proportion of gorgonians and Sargassum spp. at the site. Temperature. Benthic temperatures at St. James can be high during warm years, such as 2010. Month LITTLE SAINT JAMES 248 Benthic Community. The sparse coral community of the Little St. James site is diverse. There is a high proportion of rare species, such as Eusmilia fastigiatum, Madracis spp., and Mycetophyllia spp.. The site lost 16.5% of coral cover in the 2005 bleaching event but had apparently regained 376.2% of this loss by 2011. This large increase above bleaching losses may be explained by the fact that transects were not made permanent until 2007 and were then sited in areas with the densest coral. The sessile epibenthic community overall is largely composed of sponges and gorgonians. The algal community is dominated by the macroalgae Dictyota spp. and the Sargassum spp.. Lobophora variegata and epilithic algae are also in high proportional abundance. Coral Health. The coral community at Little St. James was highly affected by the 2005 coral bleaching event, with all corals assessed completely bleached. Half the corals were affected by low extent bleaching in 2010. Low-level bleaching is a common feature of the site. Diseases are less common, with the exception of a white disease outbreak that preceded the coral bleaching event in June 2005. Dark spots disease can also be common. Old partial mortality increased rapidly after the 2005 bleaching event. Recent partial mortality is not very prominent. Figure 159. Little St. James. (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. SITE SUMMARIES 249 Figure 160. Little St. James benthic cover and coral health through time (mean ± SE). Benthic Community Cover 0% 20% 40% 60% 80% 100% Coral Cyanobacteria Epilithic Algae Macroalgae Bleaching Prevalence/Extent 0% 20% 40% 60% 80% 100% Prevalence Extent Disease Prevalence 0% 5% 10% 15% 20% 25% 30% All disease Black Band Lesion Dark Spots Intercostal White Disease Yellow Band Unknown Partial Mortality 2001 2002 2003 2004 2005 2005 BL 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 Prevalence 0% 20% 40% 60% 80% 100% Old Recent LITTLE SAINT JAMES 250 Fish Community. The fish community of Little St. James differs slightly from those of the more developed reef habitats, representing both reef and hard bottom fish community. Queen triggerfish and mutton snapper are far more common on Little St. James than on other TCRMP sites. Red hind are also very common. These three benthic invertivores are indicative of sand mixed with hard bottom sites. The Little St. James reef is outside of the boundaries of the St. Thomas East End Reserves, and fish traps are observed regularly on the site. During parts of the year, grunts (French and white) have been observed in huge numbers, and may use the site for spawning. Bar and yellow jacks are very common swimming in the water column above the Little St. James site, and the schoolmaster, gray, and mahogany snapper are all prolific. All of these species are considered ciguatoxic in this area and so are not targeted by hook and line, trap, or spear fishermen. Notably the queen triggerfish is observed in large numbers and sizes at Little St. James. Lobster are generally found during monitoring events on transects or roving dives. SITE SUMMARIES 251 Figure 161. The Little St. James fish community by absolute and relative biomass. Herbivores doctorfish stoplight parrotfish striped parrotfish blue tang redband parrotfish ocean surgeonfish princess parrotfish Beaugregory queen parrotfish yellowtail damsel threespot damsel greenblotch parrotfish dusky damsel Fish Biomass (g) 0 2000 4000 6000 8000 10000 Invertivores queen trigger bluestriped grunt mutton snapper red hind French grunt yellowhead wrasse squirrelfish spotted goatfish harlequin bass saucereye porgy white grunt Spanish hogfish clown wrasse shy hamlet Fish Biomass (g) 0 5000 10000 15000 20000 25000 Planktivores tobaccofish bicolor damsel yellowtail snapper blue chromis creole wrasse ocean trigger brown chromis Fish Biomass (g) 0 1000 2000 3000 4000 5000 Piscivores bar jack schoolmaster gray snapper graysby horse-eye jack red lionfish mahogany snapper trumpetfish sand diver redspotted hawkfish black hamlet Fish Biomass (g) 0 5000 10000 15000 20000 25000 30000 35000 MAGENS BAY 252 MAGENS BAY Description. The Magens Bay site is a nearshore fringing reef located along Peterborg Point in depths of 4 – 14 m. The reef has a sharp break in slope leading to a steep escarpment that terminates in a sand/sediment plain at the reef base. Magens Bay has been monitored since 2001. Outstanding Feature. The Magens Bay site is a well-protected northside St. Thomas reef near one of the most popular tourist beaches in the Caribbean. Threats. Magens Bay is in a highly enclosed embayment receiving a very large and developed watershed. Sediment run-off is high and deposition on reefs is favored by slow current speeds. The turbidity after rain and swell events can be extreme in the bay and water visibility is often less and 3m. In addition, leaky septic systems may impair bay waters. Recreational/artisanal fishers frequently fish this site with hand line and spear. Figure 162. Magens Bay. (top) Location. (right) A representative photo of the reef. SITE SUMMARIES 253 Figure 163. Magens Bay current speed and benthic temperature record (9 m depth). Physical Characteristics. Current. Magens Bay has restricted water flow dominated by weak currents running counter or orthogonally to the left of the dominant wind direction. This may indicate that there is a counter flowing eddy. Current data are based on average data from Dec. 2006-Oct. 2007 7.5 m above the sensor head. Temperature. Magens Bay has low circulation, but temperatures are kept cooler by exposure to the Atlantic. Chlorophyll & Turbidity. Magens Bay is susceptible to very high chlorophyll and turbidity values indicating very high productivity that is likely fueled by terrestrial run-off. Turbidity reduces light penetration and reduces the depth limits for coral growth and water column productivity favors heterotrophic organisms, such as sponges and gorgonians. Month N NNE NE ENE E ESE SE SSE S SSW SW WSW W WNW NW NNW Current Speed (m s -1) 0.4 - 0.5 0.3 - 0.4 0.2 - 0.3 0.1 - 0.2 0.0 - 0.1 MAGENS BAY Figure 164. Magens Bay chloro 254 ophyll (left) and turbidity (right) record (16 m depth). SITE SUMMARIES 255 Benthic Community. The sparse coral community at Magens Bay is very diverse, with no real dominance by any one species. The site lost 12.4% of its coral cover in the 2005 bleaching and has continued to lose coral, with a cover loss of 33.1% from 2005 pre-bleaching to 2011. Gorgonians and then sponges dominate the sessile epibenthic community. Epilithic algae and the macroalga Dictyota spp. dominate the algal community. Filamentous cyanobacteria are also common. There is a high proportion of sand/sediment around corals at the Magens Bay site. Coral Health. Corals were highly affected by the 2005 bleaching event, with about 80% of all corals about 80% affected across the colony surface. This site also showed a strong response to the 2010 bleaching event with about 60% of corals bleached at a low extent. Diseases can be high and are dominated by dark spots disease. Old partial mortality increased after the 2005 bleaching event and then declined, with a slight increase from 2009 to 2011. Recent partial mortality is common at the Magens Bay site, largely as the result of biting by territorial damselfish (Stegastes spp.; data not shown). Figure 165. Magens Bay. (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. MAGENS BAY 256 Figure 166. Magens Bay benthic cover and coral health through time (mean ± SE). Benthic Community Cover 0% 20% 40% 60% 80% 100% Coral Cyanobacteria Epilithic Algae Macroalgae Bleaching Prevalence/Extent 0% 20% 40% 60% 80% 100% Prevalence Extent Disease Prevalence 0% 5% 10% 15% 20% 25% 30% All disease Black Band Lesion Dark Spots Intercostal White Disease Yellow Band Unknown Partial Mortality 2001 2002 2003 2004 2005 2005 BL 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 Prevalence 0% 20% 40% 60% 80% 100% Old Recent SITE SUMMARIES 257 Fish Community. Magens Bay once supported its own rich fishery and was the notorious site of the only fatality by shark attack recorded in St. Thomas (Randall 1963a). The days of large, commercially important fish in Magens Bay have been gone since the 1970’s; however, the bay is connected to the deeper Puerto Rican shelf to the north and large sharks are known to frequent the bay. Tiger sharks are still caught commonly off either point defining the bay to the east or west. Anecdotally, hammerheads mate in the middle of Magens Bay during one moon phase of the year, and along the mile long sandy beach it is not uncommon to see young of the year sharks swimming in the clear water, suggesting that the deep protected bay is the pupping ground for at least one species of shark. Along the reef that is the TCRMP monitoring site, large fish are rare, and herbivores make up the bulk of the fish biomass. The largest fish swim along the reef edge, where occasional mahogany and lane snapper reside, along with grunts, goatfish, and larger parrotfishes. Schools of wrasse, mixed with juvenile parrotfish, and damselfishes occupy the top of the reef. The threespot damselfish is extremely prolific. No large groupers or snappers were observed in Magens Bay from 2012 to 2014, the first three years of fish monitoring. MAGENS BAY 258 Figure 167. The Magens Bay fish community by absolute and relative biomass. Herbivores stoplight parrotfish redband parrotfish threespot damsel striped parrotfish doctorfish princess parrotfish dusky damsel queen parrotfish blue tang yellowtail damsel Beaugregory cocoa damsel ocean surgeonfish redtail parrotfish Fish Biomass (g) 0 2000 4000 6000 8000 10000 Invertivores French grunt red hind Caesar grunt blackbar soldierfish yellow goatfish yellowhead wrasse tomtate bluestriped grunt lane snapper squirrelfish slippery dick clown wrasse reef croaker yellowbelly hamlet dusky squirrelfish yellowtail hamlet checkered puffer Spanish hogfish harlequin bass Fish Biomass (g) 0 1000 2000 3000 4000 5000 6000 Planktivores yellowtail snapper Fish Biomass (g) 0 200 400 600 800 Piscivores bar jack trumpetfish schoolmaster graysby mahogany snapper black hamlet Fish Biomass (g) 0 200 400 600 800 1000 SITE SUMMARIES 259 SAVANA ISLAND Description. The Savana Island site is a midshelf fringing reef facing the Atlantic Ocean to the northwest in depths of 5 – 17 m. The reef is a well-developed coral community atop bedrock, with some insipient carbonate accumulation. Savana has been monitored since 2003, with permanent benthic transects installed in 2007. Outstanding Feature. Savana harbors behemoth colonies of boulder star coral (Orbicella faveolata) and a diverse and abundant fish community. Threats. Savana is threatened the invasive algae Ramicrusta sp. (identification provisional) and by warming ocean temperatures, as O. faveolata can be susceptible to bleaching, disease, and partial mortality. The area is also open to fishing and the occasional accumulation of debris can be seen. Figure 168. Savana. (top) Location. (right) A representative photo of the reef showing large colonies of Orbicella faveolata (Nov. 17, 2015). SAVANA ISLAND 260 Figure 169. Savana benthic temperature record (10 m depth). Physical Characteristics. Current. Currents have not been measured directly at Savana. Strong unidirectional currents can influence the surface near the site. Wave-driven oscillatory currents are common and occasionally strong. Temperature. Savana has temperatures cooler than other shallow sites, likely due to the proximity of the open Atlantic Ocean. Month SITE SUMMARIES 261 Benthic Community. Boulder star corals, predominately large (>2m wide) colonies of Orbicella faveolata, dominate the coral community at the Savana monitoring site. The site lost 45.2% of its coral cover in the 2005 bleaching event. Coral cover has continued to decline, rather than recover, and this is related to a striking increase in the red encrusting algae Ramicrusta sp. to over 60% cover (this is responsible for the spike in “macroalgae” in benthic cover after 2005). This algae overtops coral edges leading a slow, creeping mortality. Gorgonians and sponges are also prominent components of the sessile epibenthic animal community. Coral Health. The coral community at Savana was highly affected in the 2005 bleaching event, with 80% of corals affected on almost 90% of the colony surface. Bleaching was also very prominent in 2006, but at a lower extent. Bleaching was moderate during the 2010 bleaching event, with over 50% of colonies bleached at a low extent. Coral diseases can reach high prevalence and are diversely represented. Particularly noticeable is the dramatic outbreak of white disease in 2006. Dark spots disease has also affected a high proportion of corals from 2008 onwards. Old partial mortality increased markedly after the 2005 coral bleaching event and has declined only slightly. Recent partial mortality after the 2005 coral bleaching event was unprecedented for any site. Figure 170. Savana Island. (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. SAVANA ISLAND 262 Figure 171. Savana Island benthic cover and coral health through time (mean ± SE). Benthic Community Cover 0% 20% 40% 60% 80% 100% Coral Cyanobacteria Epilithic Algae Macroalgae Bleaching Prevalence/Extent 0% 20% 40% 60% 80% 100% Prevalence Extent Disease Prevalence 0% 5% 10% 15% 20% 25% 30% All disease Black Band Lesion Dark Spots Intercostal White Disease Yellow Band Unknown Partial Mortality 2001 2002 2003 2004 2005 2005 BL 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 Prevalence 0% 20% 40% 60% 80% 100% Old Recent SITE SUMMARIES 263 Fish Community. The Savana Island fish community is fairly small in biomass, but is quite diverse, and highlights the variety of benthic resources available to fishes in the area. The site is dominated by herbivores, but it also supports a diverse invertivore community. Planktivores in the quiet protected bay are limited to the smaller pomacentrids and wrasses. However, these fish groups are all quite prolific. The most numerous piscivore observed in the first three years of fish monitoring has been the schoolmaster snapper. One small yellowmouth grouper (11-20 cm) was observed on a belt transect in 2012, the first seen on a site in shallow water located near land. The area is highly fished with fish traps. No large commercially important fish have been seen in the bay. SAVANA ISLAND 264 Figure 172. The Savana Island fish community by absolute and relative biomass. Herbivores stoplight parrotfish princess parrotfish ocean surgeonfish blue tang striped parrotfish redband parrotfish queen parrotfish redfin parrotfish yellowtail damsel dusky damsel doctorfish threespot damsel Beaugregory cocoa damsel orangespotted filefish Fish Biomass (g) 0 1000 2000 3000 4000 5000 Invertivores bluestriped grunt yellow goatfish Spanish hogfish porkfish spotted goatfish French grunt blackbar soldierfish yellowhead wrasse Caesar grunt saucereye porgy striped grunt puddingwife spotted drum smallmouth grunt fairy basselet dusky squirrelfish slippery dick harlequin bass shy hamlet yellowtail hamlet butter hamlet clown wrasse Fish Biomass (g) 0 200 400 600 800 1000 1200 1400 1600 Planktivores blue chromis creole wrasse bicolor damsel brown chromis Fish Biomass (g) 0 200 400 600 800 1000 Piscivores schoolmaster trumpetfish sand diver graysby bar jack yellowmouth grouper black hamlet Fish Biomass (g) 0 200 400 600 800 1000 1200 1400 SITE SUMMARIES 265 SEAHORSE COTTAGE SHOAL Description. The Seahorse Cottage Shoal site is a large patch reef surrounded by sand and rhodolith in depths of 17 – 23m. The isolated reef is flat topped and dominated by Orbicella spp.. Seahorse has been monitored since 2003, with permanent benthic transects installed in 2007. A ciguatera study with monthly sampling has been ongoing since 2009. Outstanding Feature. Seahorse supports a diverse and abundant coral and fish community adjacent to the St. Thomas East End Reserves. Threats. Seahorse is buffered from land-based sources of pollution. The site is a targeted site in the St. Thomas trap fishery and trap strings have been observed over and adjacent to the site. Figure 173. Seahorse Cottage Shoal. (top) Location. (right) A representative photo of the reef. SEAHORSE COTTAGE SHOAL 266 Figure 174. Seahorse benthic temperature record (21 m depth). Physical Characteristics. Current. Currents have not been directly measured at Seahorse Cottage Shoal. Unidirectional benthic currents tend to be slow and wave-driven oscillatory currents only occur during heavy storm activity. Temperature. Benthic temperatures are moderate to high during warming events. Month SITE SUMMARIES 267 Benthic Community. The coral community of the Seahorse site is dominated by the boulder star coral (Orbicella spp.), but hosts a high diversity of other coral species. The site lost 46.6% of its cover in the 2005 bleaching event and had only regained 4.7% of this loss by 2011. Gorgonians and sponges are also common components of the sessile epibenthic animal community. The algal community is co-dominated by epilithic algae and the macroalgae Lobophora variegata and Dictyota spp.. Coral Health. The coral community bleached severely in the 2005 bleaching event with nearly 100% of corals bleaching over about 100% of their surface. Bleaching prevalence after 2005 was slow to decline due to delayed recovery in large Orbicella spp. colonies. The site also had a high prevalence of bleaching in the 2010 event, but at a low extent on colonies. Bleaching was also moderately prevalent in 2011. Coral diseases are common and diverse at Seahorse. White disease was also prevalent in 2004, which is rare for a site at this depth. Dark spots disease is also ubiquitous. Old partial mortality increased to a very high prevalence after the 2005 bleaching event, but had declined by 2011. Figure 175. Seahorse Cottage Shoal. (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. SEAHORSE COTTAGE SHOAL 268 Figure 176. Seahorse Cottage Shoal benthic cover and coral health through time (mean ± SE). Benthic Community Cover 0% 20% 40% 60% 80% 100% Coral Cyanobacteria Epilithic Algae Macroalgae Bleaching Prevalence/Extent 0% 20% 40% 60% 80% 100% Prevalence Extent Disease Prevalence 0% 5% 10% 15% 20% 25% 30% All disease Black Band Lesion Dark Spots Intercostal White Disease Yellow Band Unknown Partial Mortality 2001 2002 2003 2004 2005 2005 BL 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 Prevalence 0% 20% 40% 60% 80% 100% Old Recent SITE SUMMARIES 269 Fish Community. Seahorse Cottage Shoal supports a large variety of reef fish and hosts aggregations of gray snapper and lane snapper during the summer months. The trophic guilds on the offshore reef are split relatively evenly between herbivores, invertivores, and piscivores. This reflects the heterogeneity of reef substrate and the availability of unconsolidated sand and rhodolith habitat surrounding the reef. Mutton snapper and queen triggerfish are relatively common. Adult stoplight and redband parrotfish dominate herbivores, although most of the larger parrotfish species do occur, including both adult and juvenile phase. Glasseye snapper and graysby dominate the piscivores trophic guild. Large groupers have never been seen on the reef. Seahorse Cottage Shoal is well known to fishermen and fairly heavily fished. Traps on the reef are common during surveys. However, schoolmaster, lane, gray, and mahogany snapper are all common. This may reflect the proximity to nursery habitats in the St. Thomas East End Reserves and the mangrove habitats therein. SEAHORSE COTTAGE SHOAL 270 Figure 177. The Seahorse Cottage Shoal fish community by absolute and relative biomass. Herbivores stoplight parrotfish redband parrotfish striped parrotfish princess parrotfish orangespotted filefish queen parrotfish doctorfish blue tang yellowtail damsel threespot damsel redfin parrotfish ocean surgeonfish Beaugregory dusky damsel greenblotch parrotfish Fish Biomass (g) 0 2000 4000 6000 8000 10000 12000 14000 16000 18000 Invertivores queen trigger sailors choice tomtate French grunt blackbar soldierfish yellow goatfish yellowhead wrasse Spanish hogfish red hind bluestriped grunt squirrelfish shy hamlet clown wrasse harlequin bass yellowbelly hamlet spotted goatfish butter hamlet fairy basselet striped grunt slippery dick Fish Biomass (g) 0 1000 2000 3000 4000 5000 6000 7000 Planktivores creole wrasse blue chromis bicolor damsel yellowtail snapper brown chromis tobaccofish Fish Biomass (g) 0 1000 2000 3000 4000 5000 6000 Piscivores blue runner bar jack glasseye snapper mahogany snapper schoolmaster graysby gray snapper sand diver trumpetfish spotted moray red lionfish Fish Biomass (g) 0 1000 2000 3000 4000 5000 6000 7000 SITE SUMMARIES 271 SOUTH CAPELLA Description. The South Capella site is located on a rise of the St. Thomas-St. John midshelf reef complex in depths of 16 - 25 m. The reef is made of rolling ridges of coral and pavement interspersed with sand grooves. South Capella has been monitored since 2003, with permanent benthic transects installed in 2007. Outstanding Feature. The South Capella site is part of an outstanding shallow water midshelf reef system that is essential fish habitat. Threats. The St. Thomas trap fishery heavily targets South Capella. Active and derelict trap strings crisscross the site and a derelict trap appeared in permanent transect 1 in 2008 and has been degrading there since. The trap was still fully intact as of 2016 but not actively trapping. The reef was also highly affected by the 2005 coral bleaching event, suggesting a susceptibility to rising sea surface temperatures. Figure 178. South Capella. (top) Location. (right) The reef with a derelict Antillean fish trap in Transect #1. SOUTH CAPELLA 272 Figure 179. South Capella benthic temperature record (24 m depth). Physical Characteristics. Current. Currents were directly measured at South Capella and this data will be included in a future report. Wave-driven oscillatory currents have not been experienced but are likely during swells and storms. Unidirectional benthic currents are usually weak, but strong currents can develop from the surface to midwater. Temperature. South Capella has relatively cool benthic temperatures for a shallow site during warm years, which may be a reflection of its moderately deep depth and proximity to deep water to the south. Month SITE SUMMARIES 273 Benthic Community. Boulder star corals (Orbicella spp.) dominate the coral community at South Capella. These corals were very heavily affected by mortality due to the 2005 coral bleaching event. The site lost 56.4% of its cover and had not regained any cover by 2011 (- 3.7% recovery). Gorgonians and sponges are also common components of the sessile epibenthic animal community. The macroalga Lobophora variegata dominates the algal community, with epilithic algae and Dictyota spp. comprising the second largest shares. There was also a high abundance of crustose coralline algae and filamentous cyanobacteria. Coral Health. Corals were moderately-heavily affected by the 2005 bleaching event, with a prevalence of 80%, but an extent on colonies of only about 50%. Bleaching prevalence also increased during the 2010 bleaching event, but at a low extent. Bleaching is moderately prevalent at this site even in years without notable thermal stress. Coral diseases are common and diverse at South Capella. White disease was prevalent after the 2005 bleaching event in 2006, and then again in 2009 and 2011. Black band disease was found in 2002, which is unusual for a site at these depths. Dark spots disease was also typically present in most years. Old partial mortality increased after the 2005 bleaching event and has declined to 2011. Recent partial mortality was prevalent in most years of monitoring, particularly in 2006. In years not following thermal stress the highest identifiable source of recent partial mortality was biting from territorial damselfish (Stegastes spp.). Figure 180. South Capella. (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. SOUTH CAPELLA 274 Figure 181. South Capella benthic cover and coral health through time (mean ± SE). Benthic Community Cover 0% 20% 40% 60% 80% 100% Coral Cyanobacteria Epilithic Algae Macroalgae Bleaching Prevalence/Extent 0% 20% 40% 60% 80% 100% Prevalence Extent Disease Prevalence 0% 5% 10% 15% 20% 25% 30% All disease Black Band Lesion Dark Spots Intercostal White Disease Yellow Band Unknown Partial Mortality 2001 2002 2003 2004 2005 2005 BL 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 Prevalence 0% 20% 40% 60% 80% 100% Old Recent SITE SUMMARIES 275 Fish Community. South Capella is characterized by a fairly diverse fish community that is fairly well split between trophic levels. In 2011, a large school of schoolmaster snapper skewed this balance toward piscivores; however, this was probably a spawning event, and not typical of the daily fish community. The reef is spur and groove with complex reef edges and sand channels that support a large number of invertivores and variety of omnivores. Planktivores include yellowtail snapper and black durgeon. Benthic herbivores are dominated in biomass by large stoplight parrotfish. The South Capella reef is highly fished and traps are commonly seen during our survey events. The rich, complex reef is noticeably bare of large snappers and groupers. The serranid group is represented only by the graysby and small hamlets, with an occasional red hind observed. Lionfish are more common on this site than other offshore sites. SOUTH CAPELLA 276 Figure 182. The South Capella fish community by absolute and relative biomass. Herbivores striped parrotfish princess parrotfish stoplight parrotfish doctorfish redband parrotfish blue tang ocean surgeonfish redfin parrotfish queen parrotfish yellowtail damsel Beaugregory threespot damsel Fish Biomass (g) 0 1000 2000 3000 4000 5000 6000 7000 Invertivores saucereye porgy queen trigger red hind spotted goatfish tomtate French grunt yellowhead wrasse longsnout butterflyfish fairy basselet harlequin bass Spanish hogfish yellowbelly hamlet yellowtail hamlet striped grunt clown wrasse Fish Biomass (g) 0 1000 2000 3000 4000 Planktivores blue chromis bicolor damsel brown chromis creole wrasse yellowtail snapper chalk bass tobaccofish Fish Biomass (g) 0 200 400 600 800 1000 Piscivores graysby great barracuda bar jack trumpetfish gray snapper green moray black hamlet Fish Biomass (g) 0 500 1000 1500 2000 2500 SITE SUMMARIES 277 SOUTH WATER Description. South Water is a hardbottom coral community along the sharp break of a midshelf reef complex in depths of 17 – 28 m. The reef has a sharp break in slope leading to a steep escarpment that terminates in a sand/sediment plain at the reef base. South Water has been monitored since 2005, with permanent benthic transects installed in 2007. Outstanding Feature. South Water is a commercially important fishing ground for reef fishes and spiny lobster. Threats. South Water is primarily threatened by fishing and strings of fish and lobster traps are common over the site. Figure 183.South Water. (top) Location. (right) A representative photo of the reef. SOUTH WATER 278 Figure 184. South Water benthic temperature record (24 m depth) Physical Characteristics. Current. Current measurements have not been taken at the South Water site. Unidirectional benthic currents can be moderate on the hardbottom reef top and strong from the surface to midwater. Wave-driven oscillatory currents are likely to be felt on the reef top during swells and storms. Temperature. South Water has relatively moderate temperatures compared with other shallow water sites during warm years. This may be due to the deeper depths of the site and the proximity of deep water. Month SITE SUMMARIES 279 Benthic Community. The sparse coral community at South Water is very diverse. Coral cover increased by 21.3% over the 2005 bleaching event and had increased by 42.6% between 2005 and 2011. However, permanent transects were not installed until 2007 and the low coral cover means that small variations in detection of corals can lead to large apparent year-to-year differences in cover. Sponges and gorgonians dominate the sessile epibenthic animal community. The algal community is nearly equally divided between Lobophora variegata, Dictyota spp., and epilithic algae. Crustose coralline algae and filamentous cyanobacteria are also very common. Coral Health. Corals were severely affected by the 2005 coral bleaching event, with over 80% of corals bleaching over nearly the entire coral surface. Corals were moderately affected in the 2010 bleaching event, with just less than 50% of corals bleaching at a low extent. Bleaching tends to be moderately prevalent even in non-thermal stress years. Coral diseases are not common, although there is a trend of increasing dark spots disease. Old partial mortality increased in prevalence after the 2005 bleaching event, but at a lower prevalence than most other sites. Recent partial mortality is rare. Figure 185. South Water. (left) Relative composition of the sessile epibenthic animal community. (right) Relative composition of the algal community and unconsolidated sediment. SOUTH WATER 280 Figure 186. South Water benthic cover and coral health through time (mean ± SE). Benthic Community Cover 0% 20% 40% 60% 80% 100% Coral Cyanobacteria Epilithic Algae Macroalgae Bleaching Prevalence/Extent 0% 20% 40% 60% 80% 100% Prevalence Extent Disease Prevalence 0% 5% 10% 15% 20% 25% 30% All disease Black Band Lesion Dark Spots Intercostal White Disease Yellow Band Unknown Partial Mortality 2001 2002 2003 2004 2005 2005 BL 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 Prevalence 0% 20% 40% 60% 80% 100% Old Recent SITE SUMMARIES 281 Fish Community. South Water Island is a low lying reef with hard bottom that supports primarily invertivores. Fish biomass is lower on this site than other offshore St. Thomas sites. Queen trigger and red hind dominate invertivore biomass. Mutton snapper are occasional. Stoplight and princess parrotfish dominate herbivores, and many juvenile and sub-adults of these species occur on the site. Piscivores make up only 5% of the biomass on the South Water Island site; the guild is primarily composed of the graysby. South Water Island is highly fished and traps are commonly seen during our survey events. Lobsters are common on this low-lying reef, hiding in the hard bottom ledges that extend across the site. Except for mutton snapper, the reef is bare of large snappers and groupers. SOUTH WATER 282 Figure 187. The South Water fish community by absolute and relative biomass. Herbivores stoplight parrotfish yellowtail damsel queen parrotfish redband parrotfish redfin parrotfish striped parrotfish threespot damsel dusky damsel blue tang Beaugregory princess parrotfish ocean surgeonfish doctorfish redlip blenny Fish Biomass (g) 0 2000 4000 6000 8000 10000 12000 14000 16000 18000 Invertivores smallmouth grunt red hind French grunt yellowhead wrasse tomtate spotted drum striped grunt spotted goatfish dusky squirrelfish fairy basselet harlequin bass butter hamlet yellowtail hamlet clown wrasse puddingwife Spanish hogfish Fish Biomass (g) 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Planktivores brown chromis yellowtail snapper blue chromis creole wrasse bicolor damsel chalk bass Fish Biomass (g) 0 1000 2000 3000 4000 Piscivores dog snapper great barracuda bar jack trumpetfish spotted moray glasseye snapper graysby black hamlet Fish Biomass (g) 0 1000 2000 3000 4000 5000 2016 ANNUAL TCRMP REPORT 283 Literature Cited Acevedo R, Morelock J (1988) Effects of terrigenous sediment influx on coral zonation in southwestern Puerto Rico. 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