USVI Public Records

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SITE SUMMARIES 151 St. John SITE SUMMARIES: FISH BAY 152 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. Coral Bay may also be threatened by maritime activities within Coral Harbor. Turbidity at the site is usually very high, with underwater visibility usually <4 m. Proximity to land makes this site in territorial waters potentially vulnerable to fishing. Figure 89. Coral Bay. (top) Location. (right) A representative photo of the reef. SITE SUMMARIES: FISH BAY 153 Figure 90. 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. There is no empirically established bleaching threshold and the modeled bleaching threshold (Smith et al. 2016a) is likely too low, given high DHW values with limited observed bleaching, especially in 2019. Other. This site and the wider Coral Bay area have been under investigation for land-based sources of pollution impacts since 2009 (Smith et al. 2013a). SITE SUMMARIES: FISH BAY 154 Benthic Community. Coral Bay has a very diverse coral community, with no clear dominance of cover. In contrast to many sites, the mustard hill coral Porites astreoides has the greatest cover among coral species. Coral cover has been declining since 2015, with a precipitous decline in the year 2018. Increasing impacts of land-based sources of pollution may be contributing to the degradation. Sponges and gorgonians are also very common at this site, following a possible island-wide trend for St. John (Tsounis and Edmunds 2017). Epilithic algae and a high abundance of crustose coralline algae dominate the algal community, with very low abundance of macroalgae until recent years. 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 2019. In 2019 there was an increase in bleaching prevalence and extent, but to a low level. This bleaching was not evident in February 2020, when the site was resurveyed. Bleaching was, however, highly prevalent during the 2023 bleaching event when 78% of corals bleached ~70% of the colony surface. The arrival of SCTLD to Coral Bay seemed to be delayed relative to other sites around St. John, but was present during the 2021 sampling period and disease prevalence (both Dark Spot Disease and white disease) rose during the 2022 sampling period. SITE SUMMARIES: FISH BAY 155 Figure 91. Coral Bay benthic cover and coral health through time (mean ± SE). SITE SUMMARIES: FISH BAY 156 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 abundance and juvenile striped and redband parrotfish in biomass. Acanthurids are present but only in the juvenile phase. Planktivores commonly observed in this high turbidity habitat are limited to a few juvenile yellowtail snapper and bicolor damselfish. Although benthic invertivores are more prolific and diverse, only a few individuals comprise each species group and most fish are juveniles. Likewise, piscivores have a very low biomass and are limited to a very few individuals that appear to be moving across the reef rather than residing there. SITE SUMMARIES: FISH BAY 157 Figure 92. The 2023 Coral Bay fish community as (A-D) average biomass per trophic group with the most common species shown in order on the x-axis, (E) species richness, and (F) relative community composition by total biomass. Note that biomass is a log scale. SITE SUMMARIES: FISH BAY 158 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). The site lies just outside the southwestern boundary of the Virgin Islands National Park. 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 93. Fish Bay. (top) Location. (right) A representative photo of the reef (photo credit: S. Kadison). SITE SUMMARIES: FISH BAY 159 Figure 94. 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 a high bleaching threshold. In 2023, extensive bleaching occurred as the model predicted a maximum of 17 DHW in late October. SITE SUMMARIES: FISH BAY 160 Benthic Community. The coral community of Fish Bay is dominated by the boulder star coral Orbicella spp. 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. The site lost an additional 14% relative cover following the 2023 bleaching event, most of which occurred in the seward transects (4-6). Gorgonians are also very common on the wave-washed outer transects. Gorgonians have been increasing in cover at this site, following a possible island-wide trend for St. John (Tsounis and Edmunds 2017). 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 bleaching event with 100% of corals showing almost 100% bleaching. In 2019 bleaching prevalence stayed consistent, but thermal stress evidently increased bleaching extent. In 2023, bleaching prevalence was very high (78.%) as was extent of bleaching across colonies (70%). 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. SCTLD affected corals in 2020, particularly on the outer transects with a more abundant and diverse coral community. This site has been the focus of SCTLD treatment with antibiotic pastes, which has likely rescued many of the large O. faveolata colonies in the near term. 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.). SITE SUMMARIES: FISH BAY 161 Figure 95. Fish Bay benthic cover and coral health through time (mean ± SE). SITE SUMMARIES: FISH BAY 162 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 the common Caribbean parrotfishes, large schools of mixed acanthurids, and herbivorous pomacentrids. The common planktivores in the turbid water are limited to juvenile yellowtail snapper, a few small pomacentrids, and the occasional creole wrasse. Benthic invertivores and piscivores are more diverse and have a higher biomass, but generally fish are juveniles or subadults; large fish are rare in the bay. Invertivores are comprised primarily of grunts, goatfish and wrasses, and piscivore biomass is dominated annually by jacks. Large serranids and lutjanids are generally absent from Fish Bay although in 2018 a dog snapper was recorded and in 2022 a large cubera snapper a was seen. Both Caribbean reef sharks and lemon sharks are known to pup in Fish Bay, and juvenile lemon sharks are sometimes seen in the murky water. SITE SUMMARIES: FISH BAY 163 Figure 96. The 2023 Fish Bay fish community as (A-D) average biomass per trophic group with the most common species shown in order on the x-axis, (E) species richness, and (F) relative community composition by total biomass. Note that biomass is a log scale. SITE SUMMARIES: MERI SHOAL 164 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. In recent years however, this coverage has dropped precipitously. 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 97. Meri Shoal. (top) Location. (right) A photo of the reef taken during the bleaching of 2023 (photo credit: N. Krampitz). SITE SUMMARIES: MERI SHOAL 165 Figure 98. 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. However, in 2023 it did experience severe bleaching and reach almost 18 predicted DHW. SITE SUMMARIES: MERI SHOAL 166 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 has not recovered any cover. Since 2005, it has steadily declined in cover, dropping to ~8% in 2024. Losses of coral cover from 2019-2022 were likely driven by the impact of SCTLD or other white plagues to O. franksi, which dominates the reef. Losses since that can largely be attributed to the 2023 bleaching event, in which 80% of corals bleached over 80% of the colony area. A year later, coverage dropped a staggering 66%, representing a 15% loss in absolute coverage. Surprisingly, given the history of 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 and 2019. In 2023, both bleaching and extent were extensive, even in the post-bleaching survey that occurred ~7 months after peak heat stress. 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, 2011, and especially 2023. SCTLD was recorded in transect in 2020 and had reached nearly 10% prevalence. 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, peaking in the spring of 2024 after severe bleaching and concurrent with high disease prevalence. SITE SUMMARIES: MERI SHOAL 167 Figure 99. Meri Shoal benthic cover and coral health through time (mean ± SE). SITE SUMMARIES: MERI SHOAL 168 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 occasional black durgeon, primarily a zooplankton feeder. Herbivores commonly observed on the site include large stoplight parrotfish, as well as the three common smaller Caribbean parrotfish (redband, striped and princess), and all three acanthurids. Ocean surgeonfish are especially in relative high abundance. Queen triggerfish and red hind are both common at Meri Shoal. In 2012 and 2018 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 rare but exciting encounters as the site is not protected from traps or any bottom fishing. Large jacks, mackerels, and barracuda are also regularly observed in the water column at Meri Shoal. SITE SUMMARIES: MERI SHOAL 169 Figure 100. The 2023 Meri Shoal fish community as (A-D) average biomass per trophic group with the most common species shown in order on the x-axis, (E) species richness, and (F) relative community composition by total biomass. Note that biomass is a log scale. SITE SUMMARIES 170 St. Thomas SITE SUMMARIES: BLACK POINT 171 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 occurred with monthly to quarterly sampling from 2009-2022. 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 101. Black Point. (top) Location. (right) A representative photo of the reef in 2019 (photo credit: V. Brandteneris). SITE SUMMARIES: BLACK POINT 172 Figure 102. 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. In 2023, an estimated 16 DHW was reached during sampling in October. ! !!" !" "!" " "#" #" ##" # ##$ #$ $#$ $ $!$ !$ !!$ % C'EE)*+%#,))-%./%0 N23 %45S%N%457 %458%N%45S %459%N%458 %45W%N%459 %452%N%45W %454%N%452 SITE SUMMARIES: BLACK POINT 173 Figure 103. Black Point chlorophyll (left) and turbidity (right) record (16 m depth). Chlorophyll & Turbidity. Chlorophyll tends to be high at Black Point, likely due to inputs of land-based nutrients that fuel pelagic productivity. There are also exists a very prominent tidal signature that reflects switching source currents at the reef. SITE SUMMARIES: BLACK POINT 174 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 appearance of SCTLD in 2019 and a thermal stress event caused about a 30% decline in coral cover. After the 2023 bleaching event, the coral community at Black Point experienced a further ~35% reduction in coverage. The sponge community was damaged, and cover lost in the major hurricanes of 2017 (Gochfeld et al. 2020), with slow recovery thereafter. 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. In 2019 and 2023, bleaching prevalence and extent was elevated. Prior to the appearance of stony coral tissue loss disease, 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. SITE SUMMARIES: BLACK POINT 175 Figure 104. Black Point benthic cover and coral health through time (mean ± SE). SITE SUMMARIES: BLACK POINT 176 Fish Community. Black Point fish abundance is highly dominated by herbivores and invertivores. Juvenile parrotfish, wrasse and damselfish are numerous. Chromis and schools of creole wrasse are equally abundant in the turbid, plankton filled water. In 2018 a very large school of southern sennets shared the water column with these planktivores. The site holds very few large fish, although cubera snapper, Nassau grouper, and yellowfin grouper have been recorded in TCRMP surveys over the years. These rare fish are normally observed near the eastern edge of the site where the reef is undercut and caves have formed. A manta ray was even observed cruising that edge in the past survey year. Mutton snapper are seen regularly on roving dives, cruising the bottom of the reef where it meets the sand/hardbottom plain. Hamlets are especially diverse and numerous on Black Point. In the mid to late afternoon, striped parrotfish (Scarus iserti) spawn at the western end of the site. They can be seen swimming along the reef edge in large groups beginning in the early afternoon. Spawning goes into the late afternoon and involves tens of fish. Black Point is close to shore and is not fished by commercial traps often; however, like Brewers Bay reef, divers can swim to the site from the public beach to spearfish. It is notably lacking resident large fish. SITE SUMMARIES: BLACK POINT 177 Figure 105. The 2023 Black Point fish community as (A-D) average biomass per trophic group with the most common species shown in order on the x-axis, (E) species richness, and (F) relative community composition by total biomass. Note that biomass is a log scale. SITE SUMMARIES: BOTANY BAY 178 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 prettier 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 106. Botany Bay. (top) Location. (right) A representative photo of the reef. SITE SUMMARIES: BOTANY BAY 179 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. In 2019-2022, Botany Bay surpassed the bleaching threshold each year, though bleaching extent was been minimal. Even in 2023, bleaching was moderate as DHW reached 16. Figure 107. Botany Bay benthic temperature record (11 m depth). Figure 108. A large colony of pillar coral (Dendrogyra cylindrus) dislodge, toppled, and diseased after the 2009 swell event (Botany Bay, June 25, 2009). SITE SUMMARIES: BOTANY BAY 180 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. However, beginning in 2015 coral cover began to decline at this site for unknown reasons, but potentially related to sediment impacts from development. Botany Bay was heavily impacted by the passage of Hurricane Irma just to the north of St. Thomas on September 6th, 2017. The P. porites fields were stripped and Orbicella spp. colonies were dislodged or removed. SCTLD was first encountered here in 2019 and has continued to impact coral cover. 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, in 2010 at a low extent, and elevated prevalence and extent of bleaching in 2019, and again in 2023. 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. SCTLD and lesions likely associated with SCTLD reached over 10% prevalence in 2019 and 2020. 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). SITE SUMMARIES: BOTANY BAY 181 Figure 109. Botany Bay benthic cover and coral health through time (mean ± SE). SITE SUMMARIES: BOTANY BAY 182 Fish Community. The fish community at Botany Bay is fairly typical of well-developed nearshore reefs around St. Thomas. The site is dominated by herbivores, equally split between the four common nearshore parrotfish species (stoplight, queen, redband and striped). In recent years, fish diversity and biomass has declined in Botany Bay, probably due to the continued degradation of the reef. In 2017, however, Nassau grouper were recorded at the site. Historically red hind and dog snapper contributed to the piscivore trophic guild; however, in recent years the major piscivores have been limited to graysby, coney and bar jacks—coney are especially numerous in Botany Bay. The abundance of yellowtail snapper has also declined, and planktivores are now limited primarily to small chromis and damselfishes. Grunts and wrasses are numerous and diverse at the site, utilizing the variety of resources available for invertivores. Like most of the nearshore reefs in the northern USVI’s, large jacks and mackerels are nearly absent from the site. SITE SUMMARIES: BOTANY BAY 183 Figure 110. The 2023 Botany Bay fish community as (A-D) average biomass per trophic group with the most common species shown in order on the x-axis, (E) species richness, and (F) relative community composition by total biomass. Note that biomass is a log scale. SITE SUMMARIES: BREWERS BAY 184 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 was one of the best preserved O. annularis reefs around St. Thomas, until SCTLD introduction in 2019. 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. 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. Increased cruising boats in the bay since 2019 have led to anchor damage and parts of the reef. Figure 111. Brewers Bay. (top) Location. (right) A representative photo of the reef in 2024. (photo: S. Parr) SITE SUMMARIES: BREWERS BAY 185 Figure 112. Brewers Bay benthic temperature record (8 m depth). 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 began to be recorded in 2018, but previous records from Black Point are an decent proxy for historical temperatures. The site is also co-located with a physical oceanography monitoring station of the National Coral Reef Monitoring Program. SITE SUMMARIES: BREWERS BAY 186 Benthic Community. The Brewers Bay site is highly dominated by the boulder coral Orbicella annularis and exhibited 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. Recently coral cover has declined dramatically with the arrival of SCTLD and bleaching in 2019. This disease has already caused a catastrophic decline in coral cover from 30% in 2018 to 10.6% by 2021. In 2022, cover appeared to rebound somewhat, reaching ~12%. However, cover then decline further following the 2023 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 2019 there was high prevalence of high extent bleaching, comparable to the bleaching event in 2023. In other years, bleaching prevalence is often high, with a low extent. Yellow band disease outbreaks were severe and affected the O. annularis community in 2002 and 2003. The 2019 monitoring period saw the emergence of SCTLD at the Brewers Bay reef and impacts at the monitoring site were extremely severe. The prevalence of lesions likely associated with SCTLD and recovery from heat stress surpassed 35%. 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). SITE SUMMARIES: BREWERS BAY 187 Figure 113. Brewers Bay benthic cover and coral health through time (mean ± SE). SITE SUMMARIES: BREWERS BAY 188 Fish Community. Brewers Bay is characterized by a high fish abundance dominated by herbivores. The site holds large numbers of parrotfish and damselfish. Numerically, the herbivores are dominated by juvenile striped parrotfish that swim over the reef in groups of mixed parrotfish, acanthurids 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 the occasional 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 sightings are becoming more and 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, Nassau and yellowfin grouper are rarely seen at the reefs today; the other species are no longer observed. SITE SUMMARIES: BREWERS BAY 189 Figure 114. The 2023 Brewers Bay fish community as (A-D) average biomass per trophic group with the most common species shown in order on the x-axis, (E) species richness, and (F) relative community composition by total biomass. Note that biomass is a log scale. SITE SUMMARIES: BUCK ISLAND STT 190 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 (Fig. 97). In addition, derelict traps are common around the site. Figure 115. Buck Island, St. Thomas. (top) Location. (right) A representative photo of the reef in 2024 (photo credit: T. Smith). SITE SUMMARIES: BUCK ISLAND STT 191 Figure 116. 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, causing a gap in data. In 2023, temperatures reached recorded highs for the site, accumulating almost 15 DHW. SITE SUMMARIES: BUCK ISLAND STT 192 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. Coral cover again dipped with the arrival of SCTLD in 2019, but not as severely as at other sites. Among sessile epibenthic animals a high proportion of the community is composed of sponges. The algal community is dominated by epilithic the macroalgae Dictyota spp. and Lobophora variegata, which are in very high abundance. Typical macroalgal cover is about 50%, but it reached 70% after Hurricane Irma on September 6, 2017, largely the result of increases in Dictyota. Filamentous cyanobacteria can also be abundant at times. 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 2019 bleaching event, but at a lower prevalence. A similar prevalence of bleaching was evident in 2023, but at a higher 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, and in 2019 when SCTLD reached the monitoring site. Old partial mortality increased rapidly after the 2005 bleaching event and then declined steadily in following years. SITE SUMMARIES: BUCK ISLAND STT 193 Figure 117. Buck Island, St. Thomas benthic cover and coral health through time (mean ± SE). SITE SUMMARIES: BUCK ISLAND STT 194 Fish Community. The fish community at Buck Island, St. Thomas is very diverse and represents the utilization of many habitats and resources. The site is abundant with planktivores, primarily yellowtail snapper and creole wrasse. Tourists and commercial dive operators feed fish at Buck Island and gregarious yellowtail snapper are large and numerous. Herbivores are represented by large stoplight parrotfish as well as the other common parrotfish species, blue tang, and ocean surgeonfish. Invertivores are diverse and very common. Both spotted and yellow goatfish frequently 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, including French, white, bluestriped, Ceasar, tomtate, and cottonwick. Schoolmaster, grey and mahogany snapper dominate the piscivores community on the site. Occasional pelagic jacks (yellow, almaco and bar) swim in the water column above. Seaward of Buck Island the reef has a steep 10m drop to a sand plain below and numerous species of fish can be seen swimming this deep reef edge including porgies, mutton snapper, margates, and Caribbean reef sharks. Two Nassau grouper were observed in belt transects in 2018. No other large groupers have been observed at Buck Island. Although a Territorial Park on land, the area is fished with hook and line, traps, and speargun. Two Nassau grouper were noted in fish traps just off the site in 2008 (Fig. 97). It is also a very heavily dove SCUBA and snorkel site. Figure 118. A threatened Nassau grouper in an Antillean fish trap just of the Buck Island, St. Thomas TCRMP site. A second Nassau grouper was in another trap nearby. Aug. 12, 2008 (credit: T. Smith) SITE SUMMARIES: BUCK ISLAND STT 195 Figure 119. The 2023 Buck Island, St. Thomas fish community as (A-D) average biomass per trophic group with the most common species shown in order on the x-axis, (E) species richness, and (F) relative community composition by total biomass. Note that biomass is a log scale. SITE SUMMARIES: COCULUS ROCK 196 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 was conducted from 2009 - 2017. Outstanding Feature. Coculus Rock is in the St. Thomas East End Reserve (STEER) and is closed to fishing. The site supports a fish spawning aggregation of yellowtail parrotfish (Sparisoma rubripinne). These 100+ fish engage in daily afternoon mating at southeast reef corner. 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 120. Coculus Rock. (top) Location. (right) A representative photo of the reef showing the aggregation of yellowfin parrotfish. SITE SUMMARIES: COCULUS ROCK 197 Figure 121. 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. The site sensor was lost in September 2017 hurricanes causing a gap in the record. In 2023, accumulated temperature stress peaked at 15 DHW, inciting substantial bleaching on the reef. SITE SUMMARIES: COCULUS ROCK 198 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 current dominance by any species, though for many years Siderastrea siderea was considered dominant. 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. This location has lost about 44% relative coral cover (2019 – 2021) since the arrival of Stony Coral Tissue Loss Disease. 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 and 2023 coral bleaching event in both prevalence and extent on colonies. This may be due to a coral species assemblage composed of small, massive-morphology 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, whereas in 2019 the bleaching response was indistinguishable from years without heat stress. 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. SCTLD reached the site in 2020 but the impacts are ongoing. 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. SITE SUMMARIES: COCULUS ROCK 199 Figure 122. Coculus Rock benthic cover and coral health through time (mean ± SE). SITE SUMMARIES: COCULUS ROCK 200 Fish Community. The Coculus Rock fish community is interesting in several ways. It represents an inshore promontory that serves as an aggregation and spawning site for yellowtail parrotfish (Sparisoma rubripinne) in the afternoon, apparently year-round. The top of the bedrock reef, emergent at points, is turbid and rough with breaking waves, but large parrotfish, jacks, doctorfish, and damselfishes often swim in the milky, turbulent water. At the bottom of the rock promontory, where coral and bedrock meet the sand, small ledges run along the southeast edge of the reef. Red hind and an occasional Nassau grouper have been observed hiding in the dark of the undercut. There are generally a dozen or more juvenile lobster using the ledges as well. Juvenile grunts can be particularly common at Coculus Rock, “hanging” in large schools on and under limestone rocks and ledges on the western side of the site. Otherwise, the fish community inhabiting the steep walled rock and algae covered limestone site is primarily wrasses, juvenile parrotfishes, and acanthurids. Except for the occasional red hind or Nassau grouper, piscivores are limited to juvenile schoolmaster, mahogany and gray snappers. The planktivore guild is dominated in biomass by juvenile yellowtail snapper and the invertivore guild is made up of juvenile grunts and a variety of small wrasses. Coculus Rock is part of the territorial Saint Thomas East End Reserve (STEER) and fishes are protected from all harvest year-round. SITE SUMMARIES: COCULUS ROCK 201 Figure 123. The 2023 Coculus Rock fish community as (A-D) average biomass per trophic group with the most common species shown in order on the x-axis, (E) species richness, and (F) relative community composition by total biomass. Note that biomass is a log scale. SITE SUMMARIES: COLLEGE SHOAL EAST 202 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 historically), 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 high coral and 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 124. College Shoal. (top) Location. (right) A representative photo of the reef in 2024 (photo: T. Smtih). SITE SUMMARIES: COLLEGE SHOAL EAST 203 Figure 125. College Shoal benthic temperature record (29 m depth). Physical Characteristics. Currents. 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 were missed at this site. In 2023, College Shoal reached a predicted 12 DHW in late October. SITE SUMMARIES: COLLEGE SHOAL EAST 204 Benthic Community. College Shoal is among the TCRMP sites with the highest coral cover (38.2% in 2011) and, like 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; however, these estimates have some additional error since transects were not made permanent until 2007. SCTLD arrived at this site in 2019 and contributed to a decline in coral cover from 33% to below 16% by 2022. The 2023 bleaching event further declined coverage, reducing it by 28%. 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. Prevalence during the 2023 thermal event was very high (88%), with colonies bleaching more than 70% of their surface. 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. Similarly, disease rose again following the 2023 bleaching event. The impacts of SCTLD were very severe in 2019, with about 25% of colonies displaying disease signs. Old partial mortality was elevated on corals after the mortality from the 2005 bleaching event, and this level has remained stable until 2023, when it rose after the thermal stress event. Recent partial mortality is always relatively high at this site, much of which is attributable to fish bites. SITE SUMMARIES: COLLEGE SHOAL EAST 205 Figure 126. College Shoal benthic cover and coral health through time (mean ±SE). SITE SUMMARIES: COLLEGE SHOAL EAST 206 Fish Community. College Shoal is characterized by a high overall fish abundance and diversity, and an especially high planktivore biomass. Large planktivorous species including ocean triggerfish, black durgon, Atlantic spadefish, black jacks, and yellowtail snapper often contribute to this biomass, as well as large schools of the smaller creole wrasse and boga. The mesophotic, high coral cover reef supports more herbivores than the deeper Hind Bank FSA and Grammanik Bank FSA sites. The herbivore guild is usually split equally between the common parrotfish species (princess, striped, redband, stoplight and queen) and the blue tang and ocean surgeonfish. Piscivores have a relatively high relative biomass as well, made up primarily of jacks (bar, black, and horse-eye), mackerels, barracuda and large snappers. Invertivores are diverse but often contribute less biomass to the community composition. 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 and tiger grouper are seen there regularly. However, no grouper species were seen during the most recent sampling period (2023). SITE SUMMARIES: COLLEGE SHOAL EAST 207 Figure 127. The 2023 College Shoal fish community as (A-D) average biomass per trophic group with the most common species shown in order on the x-axis, (E) species richness, and (F) relative community composition by total biomass. Note that biomass is a log scale. SITE SUMMARIES: FLAT CAY 208 FLAT CAY Description. This monitoring site wraps around the northwest corner 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 to quarterly sampling occurred from 2009-2022. 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. This site was the first location where SCTLD was discovered in the USVI (December 2018). Figure 128. Flat Cay. (top) Location. (right) A representative photo of the reef in 2018. (photo: E. Kadison) SITE SUMMARIES: FLAT CAY 209 Figure 129. 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. Persistent high temperatures in 2023 led to a predicted ~15 DHW. ! !!" !" "!" " "#" #" ##" # ##$ #$ $#$ $ $!$ !$ !!$ % C'EE)*+%,)-./0+N%23%4 5S7 %89W%5%89; %89S%5%89W %898%5%89S SITE SUMMARIES: FLAT CAY 210 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. The impact of SCTLD in 2019 was catastrophic, with a decline in coral cover from 23% in 2018 to 7% in February 2020. Effects were particularly severe for Orbicella spp.. Since then, coverage at Flat Cay has remained stable at ~7%, even following the 2023 bleaching event. 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 relatively severe in 2019, and this may relate to thermal stress combined with SCTLD stress. Bleaching prevalence in 2023 was slightly higher than that in 2019, with extent being nearly identical. 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 the Flat Cay site. White disease was somewhat prevalent after the 2005 bleaching. SCTLD and related lesions had a relatively high prevalence in 2019. 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. SITE SUMMARIES: FLAT CAY 211 Figure 130. Flat Cay benthic cover and coral health through time (mean ± SE). SITE SUMMARIES: FLAT CAY 212 Fish Community. Flat Cay is characterized by a large diversity of fish, though it is dominated in biomass by invertivores and herbivores. There is generally a high biomass of planktivores due to relatively high densities of yellowtail snapper and large schools of chromis and creole wrasse. Invertivores are very diverse and common, reflecting the huge variety of resources available in the sand and hard bottom bordered reef community. Herbivores are equally represented by the common parrotfishes and acanthurid species. Schools of tiny juvenile parrotfish are prevalent mixed with yellowhead wrasse and juvenile acanthurids across the reef. A variety of jacks frequent the site and dominate the piscivore trophic guild. Very occasional large groupers (Nassau, yellowfin, black) have been observed on Flat Cay over the past nine years. The occurrence of black grouper in 2017 is notable; this species is extremely rare throughout the territory. In 2018 three subadult Nassau grouper were found on the site. Where the reef meets the seaward sand plain, large schools of white, French and blue-striped grunts, as well as gray snapper, squirrelfish, and goatfish swim. Small reef sharks are seen out over the sand regularly and in 2018 a hammerhead was observed cruising the edge of the reef. The Flat Cay reef is heavily used as a recreational dive site and spearfishing occurs there regularly. SITE SUMMARIES: FLAT CAY 213 Figure 131. The 2023 Flat Cay fish community as (A-D) average biomass per trophic group with the most common species shown in order on the x-axis, (E) species richness, and (F) relative community composition by total biomass. Note that biomass is a log scale. SITE SUMMARIES: GINSBURGS FRINGE 214 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. Coverage has declined dramatically since then however, dropping over 85%. In 2022, total coral cover was estimated to be only around 5%. 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 132. Ginsburgs Fringe. (top) Location. (right) A representative photo of the reef showing whorled lettuce coral colonies up to 7m in width in 2018 (Photo: V. Brandtneris). SITE SUMMARIES: GINSBURGS FRINGE 215 Figure 133. 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. There is no established empirical bleaching threshold for Ginsburgs Fringe. The site showed bleaching in 2012 (Smith et al. 2016a), suggesting it was above at least 4 DHW. Since this is not reflected in the modeled DHW, it suggests that the bleaching threshold is lower than predicted. ! !!" !" "!" " "#" #" ##" # ##$ #$ $#$ $ $!$ !$ !!$ % C'EE)*+%#,))-%./%0 N23 %45S%N%457 %458%N%45S %459%N%458 %452%N%459 %454%N%452 SITE SUMMARIES: GINSBURGS FRINGE 216 Benthic Community. The coral community at Ginsburgs Fringe is almost exclusively lettuce corals of the genus Agaricia; in particular, Agaricia undata comprises > 90% of the coral cover. A. grahamae and A. lamarcki are also commonly found at this site, while A. agaricites and A. fragilis have not been recorded on the transects. These species identifications are tentative however, 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 site has experienced extreme loss of 88% of its relative coral cover, likely due to anchoring (Smith et al. 2019b) but also more recently potentially from bleaching and disease. The algal community is dominated by epilithic algae and the macroalga Lobophora variegata, which is surprising for these depths. Crustose coralline algae are also in high abundance, as well as a variety of unidentified algal species, including what appears to be Peyssonnelia iradescens (Ballantine and Ruiz 2010). 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. What appears to be warm season bleaching has been observed in some years (Smith et al. 2016a; Smith et al. 2019b). 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. SITE SUMMARIES: GINSBURGS FRINGE 217 Figure 134. Ginsburg Fringe coral and benthic cover (±SE) over time. SITE SUMMARIES: GINSBURGS FRINGE 218 Fish Community. Fish abundance, biomass and diversity are low on Ginsburgs fringe, the deep mesophotic lettuce coral reef. Herbivores are in notably low abundance and piscivores make up the bulk of fish biomass encountered. Blackfin snapper, a deeper water species, are the most common piscivore. Dog snapper are occasionally observed, and in 2018 a yellowmouth grouper was seen on a transect. A deeper water silk snapper (Lutjanus vivanus) was even seen at the site in 2022. In 2016 lionfish were abundant on the deep-water shelf edge site. They were not observed in the following two years, however only four transects were completed each year. Deep-water fishes, including cherubfish and sunshinefish are regularly found on Ginsburgs Fringe, in addition to the blackfin snapper. 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 25 years (Edmond Bryan, commercial fishermen). SITE SUMMARIES: GINSBURGS FRINGE 219 Figure 135. The Ginsburgs Fringe fish community in 2019 as (A-D) average biomass per trophic group with the most common species shown in order on the x-axis, (E) species richness, and (F) relative community composition by total biomass. Note that biomass is a log scale. SITE SUMMARIES: GRAMMANIK 220 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. A ciguatera fish poisoning sampling study occurred with quarterly sampling between 2018-2022. 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). As of early 2024, this site maintains the highest coral coverage across all of TCRMP (17%). Threats. Although the Grammanik Tiger site and surrounding dense reefs are somewhat buffered from high thermal stress, 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 136. Grammanik Tiger (top) Location. (right) A representative photo of the reef in 2019. (photo: V. Brandtneris) SITE SUMMARIES: GRAMMANIK 221 Figure 137. Grammanik Tiger benthic currents speed (2005-2009) 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. 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). Nonetheless, Grammanik Tiger still experienced moderately high thermal stress during the 2023 bleaching event. ! !!" !" "!" " "#" #" ##" # ##$ #$ $#$ $ $!$ !$ !!$ % C'EE)*+%#,))-%./%0 N23 %45S%N%457 %458%N%45S %459%N%458 %45W%N%459 %45;%N%45W %452%N%45; %454%N%452 SITE SUMMARIES: GRAMMANIK 222 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. SCTLD first appeared in February 2020 and relative coral coverage has dropped 28% since then. Following the 2023 bleaching event, coverage dropped another ~18.5%. However, at ~17% coverage in 2024, Grammanik is now considered the highest coral cover site in TCRMP. 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 (Smith et al. 2016a). In 2019 and 2023 bleaching prevalence was very high (~80%), but extent was much lower in 2019 (8%) compared to 2023 (52%). 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. SCTLD and lesions likely associated with SCTLD appeared at the site by February 2020 and had reached almost 20% prevalence by October 2020. While disease subsided in 2021, it rose again in 2022 and 2023, for reasons unknown. Old partial mortality was low but increased rapidly after the 2005 coral bleaching event. Recent partial mortality is relatively high and is caused by disease lesions, predations, and fish bites. SITE SUMMARIES: GRAMMANIK 223 Figure 138. Grammanik Tiger benthic cover and coral health through time (mean ± SE). SITE SUMMARIES: GRAMMANIK 224 Fish Community. The Grammanik Tiger site supports less herbivores and a greater number of piscivores than the shallower sites in the TCRMP. It is a staging area for the spawning site of several species of grouper and snapper and is within 0.5 km of that aggregation area. Given the annual range of spawning across multiple species on the site, surveys often coincide with the occurrence of fish aggregations, particularly 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 are pelagic jacks as well as resident large grouper and snapper that are rarely found on near or offshore reefs of the USVI. Nassau, yellowfin, yellowmouth, and tiger grouper can also be present and even abundant during non-spawning periods at the Grammanik Bank. This reef is protected from traps year-round, and from all fishing gear from February through April. Sitting on the Puerto Rican shelf edge, with upwelling and strong tidal flow, planktivores dominate the relative community composition. Huge schools of creole wrasse and boga contribute to the large planktivore biomass. Black durgeon and yellowtail snapper are also very common on this shelf edge site. The herbivore guild is generally dominated by large adult stoplight parrotfish. During some years the chub is found in small schools on the site, grazing on Lobophora and contributing significantly to herbivore biomass. Juvenile parrotfish and doctorfish are relatively uncommon on this and all the northern USVI mesophotic sites. Wrasse are also notably uncommon. In recent years the invasive red lionfish has become very prolific at the Grammanik Bank, with individuals commonly observed on any given dive. Although fishing pressure is low, potential lionfish predators are in relatively high abundance at the site, however they do not appear to be controlling the invasive fish. As well as large groupers and snappers, lemon, Caribbean reef and bull sharks are seen frequently on the reef. Nurse sharks and Nassau grouper have been observed killing and eating lionfish that had been collected to be tagged and were caged under clear nets on the bottom. Predators overturned the nets and ate the lionfish, so there is hope that this behavior occurs without the aid of divers. SITE SUMMARIES: GRAMMANIK 225 Figure 139. The 2023 Grammanik Tiger fish community as (A-D) average biomass per trophic group with the most common species shown in order on the x-axis, (E) species richness, and (F) relative community composition by total biomass. Note that biomass is a log scale. SITE SUMMARIES: HIND BANK EAST 226 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. A ciguatera fish poisoning sampling study occurred with quarterly sampling between 2018-2022. 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 140. Hind Bank (top) Location. (right) A representative photo of the reef in 2018 (photo: L. Henderson) SITE SUMMARIES: HIND BANK EAST 227 Figure 141. (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 notably cooler than shallow water sites in the upper mixed layer and nearshore embayments. Peaking at 9 DHW in 2023, Hind Bank had one of the lowest predicted DHWs in all the TCRMP sites. ! !!" !" "!" " "#" #" ##" # ##$ #$ $#$ $ $!$ !$ !!$ % C'EE)*+%#,))-%./%0 N23 %45S%N%457 %458%N%45S %459%N%458 %452%N%459 %454%N%452 SITE SUMMARIES: HIND BANK EAST 228 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 arrival of SCTLD in 2019 appeared to initiate a further decline of this site, reducing coverage by almost 50% in three years (2019-2022). This was largely driven by the loss of Orbicella spp. coverage. 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. Neither the 2010 nor 2019 events were detected in sampling. 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. Despite raised temperatures and DHW, bleaching prevalence did not increase during the 2023, although extent was much higher than previous years. Coral diseases are somewhat 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). SCTLD had begun to impact the site in 2019. Old partial mortality increased after the 2005 bleaching event and remained at relatively the same levels since. Recent partial mortality prevalence is often high and reflects the impacts of disease and predation. SITE SUMMARIES: HIND BANK EAST 229 Figure 142. Hind Bank East benthic cover and coral health through time (mean ± SE). SITE SUMMARIES: HIND BANK EAST 230 Fish Community. Like the Grammanik Bank, the Hind Bank is characterized by a high number and biomass 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. It is also a corridor for large snappers and groupers swimming to and from the Grammanik Bank to spawn. Surveys often coincide with the occurrence of schoolmaster snapper, which has a protracted spawning season. Although this drives up the relative piscivore biomass, there are also jacks, large barracuda, and resident groupers and snappers that contribute. Occasional to common large groupers include the Nassau, yellowfin, tiger and yellowmouth. Herbivore biomass is relatively low on the Hind Bank, as on other mesophotic sites. Herbivores are dominated by adult or semi-adult princess, redband, and stoplight parrotfish; queen parrotfish are also commonly observed. Juvenile parrotfish are absent from the site. Benthic invertivores are typically dominated by blackbar soldierfish, queen triggerfish and goatfish. The site is surrounded by sand and hardbottom areas, supporting a variety of benthic resources for invertebrates. Planktivores observed at the Hind Bank vary with tide and current. Creole wrasse or ocean triggerfish can be seen in large schools or may be absent. Large yellowtail snapper are generally present. Other planktivores found at the Hind Bank include the black jack, black durgeon, boga and creolefish. Mesophotic species such as the fairy basslet, sunshinefish, and longsnout butterflyfish are also common. The red lionfish has become a regular resident of the reef and large sharks are seen occasionally. SITE SUMMARIES: HIND BANK EAST 231 Figure 143. The 2023 Hind Bank East fish community as (A-D) average biomass per trophic group with the most common species shown in order on the x-axis, (E) species richness, and (F) relative community composition by total biomass. Note that biomass is a log scale. SITE SUMMARIES: LITTLE ST. JAMES 232 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 144. Little St. James. (top) Location. (right) A representative photo of the reef with derelict fish trap SITE SUMMARIES: LITTLE ST. JAMES 233 Figure 145. 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 2019 and 2023, when the site reached a predicted 15 degree heating weeks. SITE SUMMARIES: LITTLE ST. JAMES 234 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. SCTLD arrived at Little St. James between October 2019 and February 2020 and may be contributing to the gradual decline in cover observed since 2016. 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. About half the corals had moderate prevalence and extent of bleaching in 2019, and about half of the corals had a substantial extent of bleaching in 2023. Low-level bleaching is a common feature of the site, as is low-level disease prevalence. A white disease outbreak preceded the coral bleaching event in June 2005 and dark spots disease can also be common, especially in recent years. Old partial mortality increased rapidly after the 2005 bleaching event, and is highly variable amongst sample years. Recent partial mortality is not very prominent. SITE SUMMARIES: LITTLE ST. JAMES 235 Figure 146. Little St. James benthic cover and coral health through time (mean ± SE). SITE SUMMARIES: LITTLE ST. JAMES 236 Fish Community. The fish community of Little St. James differs from those of the more developed reef habitats, representing both a coral reef and hard bottom fish community. Queen triggerfish and mutton snapper are far more common on Little St. James than on other TCRMP sites. Large, adult hind and goatfish are also very common. These benthic invertivores are indicative of hard bottom/sandy sites. During parts of the year, grunts (French and white) have been observed in huge numbers and may use the site for spawning. The spongivores (angelfish) are well represented as well. Bar jacks, yellow jacks and almaco jacks are very commonly observed swimming in the water column at the Little St. James site, contributing a high overall piscivore biomass. Schoolmaster, gray, and mahogany snapper are also common. All six of these species are considered ciguatoxic in this area and are not targeted by hook and line, trap, or spear fishermen. Herbivores are mostly dominated by the tangs and surgeonfish, which swim and graze the site in large mixed schools. Most notable is the abundant queen triggerfish population that is present across a wide size-spectrum. Lobsters can also be relatively dense, with over 20 individuals being observed under a singular rock outcrop this past sample year. The Little St. James reef is outside of the boundaries of the St. Thomas East End Reserve and fish traps are observed regularly on the site and are presumably targeting lobster and queen triggerfish. SITE SUMMARIES: LITTLE ST. JAMES 237 Figure 147. The 2023 Little St. James fish community as (A-D) average biomass per trophic group with the most common species shown in order on the x-axis, (E) species richness, and (F) relative community composition by total biomass. Note that biomass is a log scale. SITE SUMMARIES: MAGENS BAY 238 MAGENS BAY Description. The Magens Bay site is a nearshore fringing reef located along Peterborg Point in depths of 7 – 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 148. Magens Bay. (top) Location. (right) A representative photo of the reef. SITE SUMMARIES: MAGENS BAY 239 Figure 149. 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. In 2019 and 2023, temperatures surpassed the bleaching threshold and moderate to substantial bleaching was observed. ! !!" !" "!" " "#" #" ##" # ##$ #$ $#$ $ $!$ !$ !!$ % C'EE)*+%#,))-%./%0 N23 %45S%N%457 %458%N%45S %459%N%458 %452%N%459 %454%N%452 SITE SUMMARIES: MAGENS BAY 240 Figure 150. Magens Bay chlorophyll (left) and turbidity (right) record (16 m depth). 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. SITE SUMMARIES: MAGENS BAY 241 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. By contrast, the 2023 bleaching event appeared to have no immediate effect on coral coverage. 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. In 2019 bleaching was moderate to severe in terms of prevalence and extent. Despite no noticeable changes in coverage, this site did show a strong response to the 2023 bleaching event, with about 70% of corals bleaching at a high (68%) extent. Diseases can be high at Magens Bay and are dominated by dark spots disease. SCTLD reached the site between October 2019 and February 2020, but has not spiked to high prevalence and has not had a large impact on the coral cover. 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). SITE SUMMARIES: MAGENS BAY 242 Figure 151. Magens Bay benthic cover and coral health through time (mean ± SE). SITE SUMMARIES: MAGENS BAY 243 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 1963). The days of large, commercially important fish in Magens Bay have been gone since the 1970’s; however, the bay is adjacent to the deep 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 reef 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 on the eastern edge of the bay (the TCRMP monitoring site) large fish are rare, and herbivores make up the bulk of the fish biomass. On the reef edge, mahogany and lane snapper are found, along with grunts, goatfish, and larger parrotfishes. The top of the reef holds schools of wrasse mixed with juvenile parrotfish, along with high densities of damselfish (mainly bicolor) and juvenile yellowtail snapper. In 2017 a juvenile Nassau grouper was seen on a transect in Magens Bay. No other large groupers or snappers have been observed there throughout the survey period, although trap fishing does not occur in the bay anymore. SITE SUMMARIES: MAGENS BAY 244 Figure 152. The 2023 Magens Bay fish community as (A-D) average biomass per trophic group with the most common species shown in order on the x-axis, (E) species richness, and (F) relative community composition by total biomass. Note that biomass is a log scale. SITE SUMMARIES: SAVANA 245 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 very large colonies of boulder star coral (Orbicella faveolata) and a diverse and abundant fish community. Threats. Savana is threatened the invasive algae Ramicrusta textilis (Hollister et al. 2021) 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 153. Savana. (top) Location. (right) A representative photo of the reef showing large colonies of Orbicella faveolata (Nov. 17, 2015). SITE SUMMARIES: SAVANA 246 Figure 154. 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. In most years, Savana has temperatures cooler than other shallow TCRMP sites, likely due to the proximity of the open Atlantic Ocean. In 2023 however, it still faced significant heat stress and accumulated an estimate 16 DHW. SITE SUMMARIES: SAVANA 247 Benthic Community. Boulder star corals, predominately large (>2m wide) colonies of Orbicella faveolata, dominated the coral community at the Savana monitoring site in early years; however, in the past decade or so, many of these larger corals have died. 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 textilis to over 60% cover (this is responsible for the spike in “macroalgae” in benthic cover after 2005). This alga overtops coral edges leading a slow, creeping mortality. In addition, SCTLD appeared in 2019 and has also contributed to a decline in coral cover. This has especially impacted the remaining Orbicella spp., which have declined dramatically. 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 relatively moderate during the 2023 event, with just over 50% of colonies bleached at a high extent. Coral diseases can reach high prevalence and are diversely represented at this site. 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 slightly. The cause of the sudden decline of old mortality after 2019 is not quite known, but may be related to entire colonies disappearing after SCTLD introduction or Ramicrusta overgrowing and obscuring old mortality. Recent partial mortality after the 2005 coral bleaching event was unprecedented for any site, and remains relatively high during each sample year. SITE SUMMARIES: SAVANA 248 Figure 155. Savana Island benthic cover and coral health through time (mean ± SE). SITE SUMMARIES: SAVANA 249 Fish Community. The Savana Island fish community is low in biomass, but is quite diverse, and highlights the variety of benthic resources available to fishes in the area. The site is dominated by numerically herbivores, but it also supports a diverse invertivore community and is dominated in biomass by them. The quiet, relatively protected bay receives circulation and resulting plankton loads during parts of the tidal period, supporting large yellowtail snapper and schools of creole wrasse. Jacks and mackerels are commonly seen circling anchovies and other small bait fish. At other times, when the current is less favorable, planktivores are limited to small pomacentrids. Herbivore biomass is evenly split between the common parrotfish species and Acanthurids. Schools of mixed blue tang and surgeonfish are observed grazing the reef commonly. The most numerous piscivore observed at Savana is often the coney. They are numerous near the bedrock periphery of the site along the island shoreline. One small yellowmouth grouper (11-20 cm) was observed on a belt transect in 2012, the first seen on a shallow site. Otherwise, no large snappers and groupers have been seen in the bay, although a small Nassau grouper was observed in 2018 and 2023. The area is highly fished with fish traps. SITE SUMMARIES: SAVANA 250 Figure 156. The 2023 Savana Island fish community as (A-D) average biomass per trophic group with the most common species shown in order on the x-axis, (E) species richness, and (F) relative community composition by total biomass. Note that biomass is a log scale. SITE SUMMARIES: SEAHORSE 251 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 to quarterly sampling occurred from 2009-2022. 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 157. Seahorse Cottage Shoal. (top) Location. (right) A representative photo of the reef. SITE SUMMARIES: SEAHORSE 252 Figure 158. 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. Seahorse spent over four months above the bleaching threshold in 2023. SITE SUMMARIES: SEAHORSE 253 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. SCTLD appeared in 2019 and caused a decline in coral cover from 16% in October 2018 to 5% in October 2020. Despite record-breaking temperatures and observations of substantial bleaching in 2023, coral coverage remained relatively unchanged at this site. 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. In 2019 and 2023 bleaching was moderate to severe in terms of prevalence and extent. Coral diseases are common and diverse at Seahorse. White disease was also prevalent in 2004, which is rare for a site this shallow. SCTLD appeared in early 2020 and reached very high prevalence. Dark spots disease is also ubiquitous. Old partial mortality increased to a very high prevalence after the 2005 bleaching event and has very slowly declined ever since. Recent partial mortality peaked in 2020 and 2021, likely due to the impacts of SCTLD. SITE SUMMARIES: SEAHORSE 254 Figure 159. Seahorse Cottage Shoal benthic cover and coral health through time (mean ± SE). SITE SUMMARIES: SEAHORSE 255 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 and invertivores, with piscivores nearly as high in biomass during some years. This reflects the heterogeneity of reef substrate and the availability of unconsolidated sand and rhodolith habitat surrounding the reef. The orientation on the circular offshore reef determines the number and species of fish observed. On the western edge of the reef, schools of snapper and porgies can be found. Mutton snapper and queen triggerfish are also relatively common on this edge of the reef. The top of the low spur and groove reef on the other hand holds mainly glasseye snapper, wrasses, and parrotfish. Adult stoplight and redband parrotfish dominate herbivore biomass while glasseye snapper and graysby dominate the benthic piscivore trophic guild. Jacks and mackerels are common on the site. Seahorse Cottage Shoal is well known to fishermen and is heavily fished. Traps on the reef are common during surveys. Large groupers are occasional, including one sub-adult goliath grouper spotted in 2012. 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. SITE SUMMARIES: SEAHORSE 256 Figure 160. The 2023 Seahorse Cottage Shoal fish community as (A-D) average biomass per trophic group with the most common species shown in order on the x-axis, (E) species richness, and (F) relative community composition by total biomass. Note that biomass is a log scale. SITE SUMMARIES: SOUTH CAPELLA 257 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. A ciguatera fish poisoning sampling study occurred with quarterly sampling between 2018-2022. 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 and 2023 coral bleaching event, suggesting a susceptibility to rising sea surface temperatures. Figure 161. South Capella. (top) Location. (right) Representative photo of the reef (photo: V. Brandtneris). SITE SUMMARIES: SOUTH CAPELLA 258 Figure 162. South Capella benthic temperature record (Top left: 24 m depth, top right: 35 m depth). Physical Characteristics. Current. 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. Currents were directly measured at South Capella and this data is available upon request Temperature. The thermistor deployed for 2018-2019 failed to record data at the 24 m site. South Capella has relatively cool benthic temperatures for a shallow site during warm years, which may reflect its moderately deep depth and proximity to deep water to the south. The exception to this may be in 2023, when degree heating weeks were predicted to almost reach 20. SITE SUMMARIES: SOUTH CAPELLA 259 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 and the arrival of Stony Coral Tissue Loss Disease. The site lost 56.4% of its cover following the 2005 bleaching event and had not regained any cover by 2011 (-3.7% recovery). SCTLD appeared in 2019 and caused a further sharp decline (44.1%) in coral cover. An additional ~30% of relative coverage is estimated to have been lost following the 2023 bleaching event. 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 to heavily affected by the 2005 bleaching event, with a prevalence of 80%, but an extent on colonies of only about 50%. In 2019 and 2023 bleaching prevalence and extent was relatively severe. 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. SCTLD appeared at the site in 2019. Old partial mortality increased after the 2005 bleaching event and declined slightly thereafter. Recent partial mortality was prevalent in most years of monitoring. In years not following thermal stress or disease outbreaks, the highest identifiable source of recent partial mortality was biting from territorial damselfish (Stegastes spp.). SITE SUMMARIES: SOUTH CAPELLA 260 Figure 163. South Capella benthic cover and coral health through time (mean ± SE). SITE SUMMARIES: SOUTH CAPELLA 261 Fish Community. South Capella is characterized by a diverse fish community that is well split between trophic levels. Schools of schoolmaster snapper are observed regularly and usually dominate the piscivore biomass, however these schools may be small spawning aggregations 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 and variety of invertivores. Grunts and goatfish comprise most of the invertivore biomass. Planktivores include the yellowtail snapper, as well as creole wrasse and black durgeon, generally seen on shelf edge reefs. Benthic herbivores are dominated in biomass by striped parrotfish with redband, stoplight and yellowtail parrotfish also common. The South Capella reef is a highly fished area and traps are commonly seen during our survey events. The rich, complex reef is noticeably bare of large snappers and groupers. However, a mid-sized Nassau grouper was observed at this site in 2018 and 2019. The serranid group is represented only by the graysby, coney, and small hamlets, with an occasional red hind observed. Conversely, red lionfish continue to occur more commonly at the South Capella reef than any other mid-depth offshore site. SITE SUMMARIES: SOUTH CAPELLA 262 Figure 164. The 2023 South Capella fish community as (A-D) average biomass per trophic group with the most common species shown in order on the x-axis, (E) species richness, and (F) relative community composition by total biomass. Note that biomass is a log scale. SITE SUMMARIES: SOUTH WATER 263 SOUTH WATER Description. South Water is a hardbottom coral community along the sharp break of a midshelf hardbottom 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 165. South Water. (top) Location. (right) A representative photo of the reef (Photo: J. Quetel). SITE SUMMARIES: SOUTH WATER 264 Figure 166. 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. SITE SUMMARIES: SOUTH WATER 265 Benthic Community. The sparse coral community at South Water is very diverse. Contrary to almost every other site, coral cover increased by 21.3% over the 2005 bleaching event and continued to increase (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, 2019, and 2023 bleaching event. Though, bleaching at this site 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. SCTLD appeared at the site in 2019. 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, except in years following disease events. SITE SUMMARIES: SOUTH WATER 266 Figure 167. South Water benthic cover and coral health through time (mean ± SE). SITE SUMMARIES: SOUTH WATER 267 Fish Community. South Water Island is a hard bottom reef crossed by sand channels that supports primarily invertivores and herbivores. Fish biomass is lower on this site than most other offshore and mesophotic sites of St. Thomas. The invertivore biomass is dominated by queen triggerfish, long-spine squirrelfish, and grunts. Mutton snapper and sharks are occasional off the southern edge of the reef. Stoplight and redband parrotfish dominate the herbivore biomass, and many juvenile and sub-adults of these species as well as striped and princess parrotfish occur across the site. Piscivores generally make up a very small percentage of the biomass on the South Water Island site; small mackerels and jacks are commonly observed, driving up average biomass, but the guild is primarily composed of graysby, coney and medium-sized snappers that school along the reef edge. The site lies several miles from the shelf edge, and planktivores are in general limited to yellowtail snapper and small chromis, although schools of creole wrasse have been noted in some years. 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 lining the sand channels. Apart from mutton snapper, the reef is devoid of large snappers and groupers. SITE SUMMARIES: SOUTH WATER 268 Figure 168. The South Water fish community as (A-D) average biomass per trophic group with the most common species shown in order on the x-axis, (E) species richness, and (F) relative community composition by total biomass. Note that biomass is a log scale. 2023 ANNUAL TCRMP REPORT 269 Literature Cited Acevedo R, Morelock J (1988) Effects of terrigenous sediment influx on coral zonation in southwestern Puerto Rico. Proceedings of the Sixth International Coral Reef Symposium 2:189-194 Acevedo R, Morelock J (1988) Effects of terrigenous sediment influx on coral zonation in southwestern Puerto Rico. Proceedings of the Sixth International Coral Reef Symposium 2:189-194 Albins M, Hixon M (2011) Worst case scenario: potential long-term effects of invasive predatory lionfish (Pterois volitans) on Atlantic and Caribbean coral-reef communities. Environmental Biology of Fishes:1-7 Anderson D, Macdonald L (1998) Modelling road surface sediment production using a vector geographic information system. Earth Surface Processes and Landforms 23:95-107 Armstrong R, Singh H, Torres J (2002) Benthic survey of insular slope coral reefs using the Seabed AUV. Backscatter 13:22-25 Armstrong RA (2007) Deep zooxanthellate coral reefs of the Puerto Rico: US Virgin Islands insular platform. Coral Reefs 26:945 Armstrong RA, Singh H, Torres J, Nemeth RS, Can A, Roman C, Eustice R, Riggs L, Garcia-Moliner G (2006) Characterizing the deep insular shelf coral reef habitat of the Hind Bank marine conservation district (US Virgin Islands) using the Seabed autonomous underwater vehicle. Continental Shelf Research 26:194-205 Ballantine David, L. and H. Ruiz. 2010. Two new deep water Peyssonnelia species, Peyssonnelia iridescens and Peyssonnelia gigaspora (Peyssonneliaceae, Rhodophyta) from Puerto Rico, Caribbean Sea. Phycologia 49:537-544. Bellwood DR, Fulton CJ (2008) Sediment-mediated suppression of herbivory on coral reefs: decreasing resilience to rising sea-levels and climate change? Limnology and Oceanography 53:2695-2701 Biggs CR, Nemeth RS (2016) Spatial and temporal movement patterns of two snapper species at a multi-species spawning aggregation. Marine Ecology Progress Series 558:129–142 Bramanti L, Lasker HR, Edmunds PJ (2017) An encrusting peyssonnelid preempts vacant space and overgrows corals in St. John, US Virgin Islands. Reef Encounter 32:68-70 Brandt ME, Ennis RS, Meiling SS, Townsend J, Cobleigh K, Glahn A, Quetel J, Brandtneris V, Henderson LM, Smith TB (2021) The Emergence and Initial Impact of Stony Coral Tissue Loss Disease (SCTLD) in the United States Virgin Islands. Frontiers in Marine Science 8:1105 Bright AJ, Rogers C, Brandt M, Muller E, Smith T (2016) Disease prevalence and snail predation associated with swell-generated damage on the threatened coral, Acropora palmata (Lamarck). Frontiers in Marine Science 3:77 Brooks GR, Devine B, Larson RA, Rood BP (2007) Sedimentary development of Coral Bay, St. John, USVI: a shift from natural to anthropogenic influences. Caribbean Journal of Science 43:226-243 Bruckner AW (2007) Field Guide to Western Atlantic Coral Diseases and Other Causes of Coral Mortality. NOAA, UNEP-WCMC, PADI Calnan J, Smith T, Nemeth R, Kadison E, Blondeau J (2008) Coral disease prevalence and host susceptibility on mid-depth and deep reefs in the US Virgin Islands. Revista Biologia Tropical 56 (suppl. 1):223-224 Cote IM, Maljkovic A (2010) Predation rates of Indo-Pacific lionfish on Bahamian coral reefs. Marine Ecology Progress Series 404:219-225 De'ath G, Fabricius K (2010) Water quality as a regional driver of coral biodiversity and macroalgae on the Great Barrier Reef. Ecological Applications 20:840-850 Edmunds PJ, Witman JD (1991) Effect of Hurricane Hugo on the primary framework of a reef along the south shore of St. John, US Virgin Islands. Marine Ecology Progress Series 78:201-204 Edmunds PJ, Zimmermann SA, Bramanti L (2019) A spatially aggressive peyssonnelid algal crust (PAC) threatens shallow coral reefs in St. John, US Virgin Islands. Coral Reefs 38:1329-1341 Ennis RS, Brandt ME, Wilson Grimes KR, Smith TB (2016) Coral reef health response to chronic and acute changes in water quality in St. Thomas, United States Virgin Islands. Marine Pollution Bulletin 111:418-427 Fabricius K (2005) The effects of terrestrial runoff on the ecology of corals and coral reefs: a review and synthesis. Marine Pollution Bulletin 50:125-146 2023 ANNUAL TCRMP REPORT 270 Fong P, Paul VJ (2011) Coral Reef Algae. In: Dubinsky Z, Stambler N (eds) Coral Reefs: An Ecosystem in Transition. Springer Science, pp241-272 Fong P, Smith TB, Wartian MJ (2006) Epiphytic cyanobacteria maintain shifts to macroalgal dominance on coral reefs following ENSO disturbance. Ecology 87:1162-1168 Friedlander AM, Jeffrey CFG, Hile SD, Pittman SJ, M.E. M, Caldow C (2013) Coral reef ecosystems of St. John, U.S. Virgin Islands: Spatial and temporal patterns in fish and benthic communities (2001-2009). NOAA Technical Memorandum 152. NOAA, Silver Spring, MD 150pp Furnas M, Mitchell A, Skuza M, Brodie J (2005) in the other 90%: phytoplankton responses to enhanced nutrient availability in the Great Barrier Reef Lagoon. Marine Pollution Bulletin 51:235-265 Gladfelter WB (1982) White-band disease in Acropora palmata - implications for the structure of shallow reefs. Bulletin of Marine Science 32:639-643 Gochfeld DJ, Olson JB, Chaves-Fonnegra A, Smith TB, Ennis RS, Brandt ME (2020) Impacts of Hurricanes Irma and Maria on Coral Reef Sponge Communities in St. Thomas, U.S. Virgin Islands. Estuaries and Coasts 43:1235-1247 Gray SC, Gobbi KL, Narwold PV (2008) Comparison of sedimentation in bays and reefs below developed versus undeveloped watersheds on St. John, US Virgin Islands. Proceedings of the 11th International Coral Reef Symposium 1:345-349 Grove, L. J. W., Blondeau, J., Swanson, D. W., Heidmann, S. L., Smith, S. G., Johnson, M. W., ... & Smith, T. B. (2024). Expansion of an established fishery-independent survey into the US Virgin Islands' upper mesophotic zone: feasibility and management implications. Bulletin of Marine Science, 100(2), 113-132 Hatcher BG (1984) A maritime accident provides evidence for alternate stable states in benthic communities on coral reefs. Coral Reefs 3:199-204 Hatcher BG, Larkum AWD (1983) An experimental analysis of factors controlling the standing crop of the epilithic algal community on a coral reef. Journal of Experimental Marine Biology and Ecology 69:61-84 Heidmann, S. L., Olinger, L. K., Brandtneris, V. W., Ennis, R. S., Blondeau, J., Grove, L. J. W., & Smith, T. B. (2024). Depth and structure as environmental drivers of fish communities across a shallow to mesophotic gradient in the northern US Virgin Islands. Bulletin of Marine Science, 100(2), 133-154 Henderson LM, Blondeau J, Taylor M, Nemeth RS, Smith TB (in review) Terrestrial and silt-clay sediment flux affect stony coral health in the nearshore US Virgin Islands. Herzlieb S, Kadison E, Blondeau J, Nemeth RS (2005) Comparative assessment of coral reef systems located along the insular platform south of St. Thomas, US Virgin Islands and the relative effects of natural and human impacts. Proc 10th Int Coral Reef Symp 4-2:1144-1151 Hewson I, Ritchie IT, Evans JS, Altera A, Behringer D, Bowman E, Brandt M, Budd KA, Camacho RA, Cornwell TO, Countway PD, Croquer A, Delgado GA, DeRito C, Duermit-Moreau E, Francis-Floyd R, Gittens S, Henderson L, Hylkema A, Kellogg CA, Kiryu Y, Kitson-Walters KA, Kramer P, Lang JC, Lessios H, Liddy L, Marancik D, Nimrod S, Patterson JT, Pistor M, Romero IC, Sellares-Blasco R, Sevier MLB, Sharp WC, Souza M, Valdez-Trinidad A, van der Laan M, Vilanova-Cuevas B, Villalpando M, Von Hoene SD, Warham M, Wijers T, Williams SM, Work TM, Yanong RP, Zambrano S, Zimmermann A, Breitbart M A scuticociliate causes mass mortality of Diadema antillarum in the Caribbean Sea. Science Advances 9:eadg3200 Hollister KJ, Ennis RS, Spalding HL, Gabrielson PW, Smith TB (2021) Caribbean corals exhibit species-specific differences in competitive abilities with an aggressive encrusting alga, Ramicrusta textilis. Coral Reefs Hylkema A, Kitson-Walters K, Kramer PR, Patterson JT, Roth L, Sevier MLB, Vega-Rodriguez M, Warham MM, Williams SM, Lang JC (2023) The 2022 Diadema antillarum die-off event: Comparisons with the 1983- 1984 mass mortality. Frontiers in Marine Science 9 Jackson A, Semmens BX, Sadovy Y, Nemeth RS, Heppell S, Chapman R, Aguilar-Perera A, Claydon J, Calosso M, Sealey K, Sharer M, Bernardi G (2014) Population structure and phylogeography in Nassau grouper (Epinephelus striatus), a mass-aggregating marine fish. PLoS ONE in press Kadison E, Nemeth R, Herzlieb S, Blondeau J (2006) Temporal and spatial dynamics of Lutjanus cyanopterus and L. jocu (Pisces: Lutjanidae) spawning aggregations on a multi-species spawning site in the USVI. Revista Biologia Tropical 54(suppl. 3):69-78 2023 ANNUAL TCRMP REPORT 271 Kadison E, Nemeth RS, Blondeau J, Smith TB, Calnan JM (2010) Nassau grouper (Epinephelus striatus) in St. Thomas, US Virgin Islands, with evidence for a spawning aggregation site recovery. Proceedings of the Gulf and Caribbean Fisheries Institute 62:273-279 Kadison E, Brandt M, Nemeth R, Martens J, Blondeau J, Smith T (2017) Abundance of commercially important reef fish indicates different levels of over-exploitation across shelves of the U.S. Virgin Islands. PLOS ONE 12:e0180063 Kohler K, Gill SM (2006) Coral Point Count with Excel extensions (CPCe): A Visual Basic program for the determination of coral and substrate coverage using random point count methodology. Computers and Geosciences 32:1259-1269 Kramer P, Lang J, Marks K, Garza-Perez R, Ginsburg R (2005) AGRRA Methodology, version 4.0, June 2005. University of Miami, Miami Kuffner I, B., Walters L, J., Becerro M, A., Paul V, J., Ritson-Williams V, J., Beach K, S. (2006) Inhibition of coral recruitment by macroalgae and cyanobacteria. Marine Ecology Progress Series 323:107-117 Menza C, Kendall M, Hile S (2008) The deeper we go the less we know. Revista Biologia Tropical 56:11-24 Menza C, Kendall M, Rogers C, Miller J (2007) A deep reef in deep trouble. Continental Shelf Research 27:2224- 2230 Menza C, Ault J, Beets J, Bohnsack J, Caldow C, Christensen J, Friedlander A, Jeffrey C, Kendall M, Luo J, Monaco M, Smith S, Woody K (2006) A Guide to Monitoring Reef Fish in the National Park Service's South Florida/Caribbean Network. NOAA Technical Memorandum. NOS NCCOS 39 166 Miller J, Muller E, Rogers C, Waara R, Atkinson A, Whelan K, Patterson M, Witcher B (2009) Coral disease following massive bleaching in 2005 causes 60% decline in coral cover on reefs in the US Virgin Islands. Coral Reefs 28:925-937 Mumby PJ (2006) The impact of exploiting grazers (Scaridae) on the dynamics of Caribbean coral reefs. Ecological Applications 16:747-769 Mumby PJ, Harborne AR (2010) Marine reserves enhance the recovery of corals on Caribbean reefs. PLoS ONE 5:e8657 Mumby PJ, Dahlgren CP, Harborne AR, Kappel CV, Micheli F, Brumbaugh DR, Holmes KE, Mendes JM, Broad K, Sanchirico JN, Buch K, Box S, Stoffle RW, Gill AB (2006) Fishing, trophic cascades, and the process of grazing on coral reefs. Science 311:98-101 Nemeth RS (2005) Population characteristics of a recovering US Virgin Islands red hind spawning aggregation following protection. Marine Ecology Progress Series 286:81-97 Nemeth RS, Sladeck Nowlis J (2001) Monitoring the effects of land development on the near-shore reef environment of St. Thomas, USVI. Bulletin of Marine Science 69:759-775 Nemeth RS, Kadison E, Herzlieb S, Blondeau J, Whiteman E (2006) Status of a yellowfin grouper (Mycteroperca venenosa) spawning aggregation in the US Virgin Islands with notes on other species. Proc 57th Gulf Carib Fish Inst 57:543-558 Nemeth RS, Smith TB, Blondeau J, Kadison E, Calnan JM, Gass J (2008) Characterization of deep water reef communities within the marine conservation district, St. Thomas, U.S. Virgin Islands. Submitted to the Caribbean Fisheries Management Council. University of the Virgin Islands, St. Thomas 90 + appendices NOAA (2006) Tropical Ocean Coral Bleaching Indices. National Oceanic and Atmospheric Administration, Silver Springs, Maryland NOAA Coral Reef Watch (2024), updated daily. NOAA Coral Reef Watch Version 3.1 Daily 5km Satellite Regional Virtual Station Time Series Data for Virgin Islands, Jan. 1, 2005-Dec. 11, 2024. College Park, Maryland, USA: NOAA Coral Reef Watch. Data set accessed 2024-12-11 at https://coralreefwatch.noaa.gov/product/vs/data.php. Pastorok R, Bilyard G (1985) Effects of sewage pollution on coral-reef communities. Marine Ecology Progress Series 21:175-189 Ramos-Scharrón CE, MacDonald LH (2007a) Measurement and prediction of natural and anthropogenic sediment sources, St. John, U.S. Virgin Islands. Catena 71:250-266 Ramos-Scharrón CE, MacDonald LH (2007b) Runoff and suspended sediment yields from an unpaved road segment, St John, US Virgin Islands. Hydrological Processes 21:35-50 2023 ANNUAL TCRMP REPORT 272 Randall JE (1963) A fatal attack by the shark Carcharhinus galapagensis at St. Thomas, Virgin Islands. Caribbean Journal of Marine Science 3:201-205 Rogers C, Garrison V (2001) Ten years after the crime: lasting effects of damage from a cruise ship anchor on a coral reef in St. John, U.S. Virgin Islands Bulletin of Marine Science 69:793-803 Rogers CS (1982) The Marine Environments of Brewers Bay, Perserverence Bay, Flat Cay and Saba Island, St. Thomas, U.S.V.I., with Emphasis on Coral Reefs and Seagrass Beds, November 1978-July 1981 181 Rogers CS (1990) Responses of coral reefs and reef organisms to sedimentation. Marine Ecology Progress Series 62:185-202 Rogers CS, McLain LN, Tobias CR (1991) Effects of Hurricane Hugo (1989) on a coral reef in St. John USVI. Marine Ecology Progress Series 78:189-199 Rothenberger J, Blondeau J, Cox C, Curtis S, Fisher B, Garrison G, Hillis-Starr Z, Jeffrey C, Kadison E, Lundgren I, Miller W, Muller E, Nemeth RS, Paterson S, Rogers CS, Smith TB, Spitzack A, Taylor M, Toller W, Wright J, Wusinich-Mendez D (2008) The State of Coral Reef Ecosystems of the U.S. Virgin Islands. In: Waddell JE, Clarke AM (eds) The State of Coral Reef Ecosystems of the United States and Pacific Freely Associated States: 2008. NOAA Center for Coastal Monitoring and Assessment’s Biogeography Team, Silver Spring, MD, pp567 RStudio (2015) RStudio: Integrated development for R. RStudio, Inc., Boston, MA URL http://www.rstudio.com/ Sabine AM, Smith TB, Williams DE, Brandt ME (2015) Environmental conditions influence tissue regeneration rates in scleractinian corals. Marine Pollution Bulletin 95:253-264 Smith TB, Nemeth RS, Blondeau J, Calnan JM, Kadison E, Herzlieb S (2008) Assessing coral reef health across onshore to offshore stress gradients in the US Virgin Islands. Marine Pollution Bulletin 56:1983-1991 Smith TB, Brown K, Ennis R, Honisch B, Martens J, Wright V (2013a) United States Virgin Islands Department of Environmental Protection. Section 106 Research Program. Study of Nutrient Analysis and Distribution and Sedimentation Rate. Final Project Report (GC085DNR11). University of the Virgin Islands 79 Smith TB, Gyory J, Brandt ME, Miller WJ, Jossart J, Nemeth RS (2016a) Caribbean mesophotic coral ecosystems are unlikely climate change refugia. Global Change Biology 22:2756–2765 Smith TB, Blondeau J, Nemeth RS, Pittman SJ, Calnan JM, Kadison E, Gass J (2010b) Benthic structure and cryptic mortality in a Caribbean mesophotic coral reef bank system, the Hind Bank Marine Conservation District, U.S. Virgin Islands. Coral Reefs 29:289-308 Smith TB, Brandt ME, Calnan JM, Nemeth RS, Blondeau J, Kadison E, Taylor M, Rothenberger JP (2013b) Convergent mortality responses of Caribbean coral species to seawater warming. Ecosphere 4:art87 Smith TB, Brandtneris VW, Canals M, Brandt ME, Martens J, Brewer RS, Kadison E, Kammann M, Keller J, Holstein DM (2016b) Potential structuring forces on a shelf edge upper mesophotic coral ecosystem in the US Virgin Islands. Frontiers in Marine Science 3:115 Smith TB, Brandt ME, Brandtneris VW, Ennis RS, Groves SH, Habtes S, Holstein DM, Kadison E, Nemeth RS (2019a) The United States Virgin Islands. In: Loya Y, Puglise KA, Bridge T (eds) Coral Reefs of the World: Mesophotic Coral Ecosystems. Springer, Smith TB, Brandt ME, Brandtneris VW, Ennis RS, Groves SH, Habtes S, Holstein DM, Kadison E, Nemeth RS (2019b) Disturbance in Mesophotic Coral Ecosystems and Linkages to Conservation and Management. In: Loya Y, Puglise KA, Bridge T (eds) Coral Reefs of the World: Mesophotic Coral Ecosystems. Springer, Strand J, Jørgensen A, Tairova Z (2009) TBT pollution and effects in molluscs at US Virgin Islands, Caribbean Sea. Environment International 35:707-711 Tobias W (1997) Three Year Summary Report: Cooperative Fisheries Statistics Program #SF-42 (NA27FT0301-01). Department of Fish and Wildlife, United States Virgin Islands 41 pp Tsounis, G. and P. J. Edmunds. 2017. Three decades of coral reef community dynamics in St. John, USVI: a contrast of scleractinians and octocorals. Ecosphere 8:e01646.Williams ID, Polunin NVC, Hendrick VJ (2001) Limits to grazing by herbivorous fishes and the impact of low coral cover on macroalgal abundance on a coral reef in Belize. Marine Ecology Progress Series 222:187-196 Williams MK, Edmunds PJ (2021) Reconciling slow linear growth and equivocal competitive ability with rapid spread of peyssonnelid algae in the Caribbean. Coral Reefs 10.1007/s00338-021-02052-7 Woody K, Atkinson A, Clark R, Jeffrey C, Lundgren I, Miller J, Monaco M, Muller E, Patterson M, Rogers C, Smith TB, Spitzack T, Waara R, Whelan K, Witcher B, Wright A (2008) Coral Bleaching in the U.S. Virgin 2023 ANNUAL TCRMP REPORT 273 Islands in 2005 and 2006. In: Wilkinson C, Souter D (eds) Status of Caribbean Coral Reefs After Bleaching and Hurricanes in 2005. Global Coral Reef Monitoring Network, and Reef and Rainforest Research Center, Townsville, pp152