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Virgin Islands National Park: Coral Reef: Population Dynamics: Scleractinian corals

These data are evidence of the the long-term dynamics of shallow coral reefs along the south coast of St. John from as early as 1987. These data describe coral reef community structure as percent cover based on the analysis of color photographs. All of these data originate from color images of photoquadrats recorded annually (usually in the summer) from as early as 1987. The data falls into three groups. The two groups that are contained in this data package are (1) Tektite & Yawzi and (2) Random sites. The juvenile coral density is packaged separately. Tektite – this is at 14 m depth on the eastern side of Great Lameshur Bay and is the original site of the Tektite man-in-the sea project in 1969; this project marked the birth of the Virgin Islands Ecological Research Station (later the Virgin Islands Environmental Resource Station) that hosts the field component of the project. The reef in this location consists of a single buttress that has remained dominated by Montastraea anularis since the start of the research (1987). These surveys consist of 30 photoquadrats (1 x 1 m) distributed along three, 10 m transects. Yawzi – this is at 9 m depth and is on the western side of Great Lameshur Bay and has been recorded photographically since 1987. This reef also started the study period dominated by Montastraea annularis, but has degraded much more rapidly that the Tektite site. These surveys consist of 30 photoquadrats (1 x 1 m) distributed along three, 10 m transects. Random sites – were added in 1992 to address the concern that the original sites (Yawzi and Tektite) were selected on “good” areas of reef and, therefore, could only decline in condition. The Random sites were selected using random coordinates in 1992, and consist of 6 sites (at 7-9 m depth) scattered between Cabritte Point and White Point. All lie a little shoreward of Yawzi and Tektite, and have always been characterized by low coral cover (< 10% cover). The surveys consist of 18-40 photoquadrats (0.5 x 0

Virgin Islands National Park: Coral Reef: Recruitment Tiles

In this study, coral recruitment was measured on a kilometer-wide scale on shallow (5–6 m depth) fringing reefs in St. John, US Virgin Islands, with the objective of determining the extent to which variation in recruitment was affected by biophysical coupling involving temperature and flow. Coral recruitment was measured using settlement tiles deployed at 10 sites along 10 km of shore. The tiles were first deployed in August 2006, and thereafter replaced every ≈6 months to sample from either August to January, or January to August over 2 years. Seawater temperature was recorded at the 10 sites using logging thermistors, and flow was quantified using drogues. Overall, corals recruited at a rate equivalent to 76 corals m− 2 6 months− 1, and were represented mostly by poritids (43% of recruits), agaricids (29%), faviids (17%) and siderastreids (7%). Although the density of recruits differed among sites in a pattern that varied among periods and years, there was a consistent trend for mean density to decline from ≈ 4 corals tile− 1 at eastern sites, to ≤ 1 coral tile− 1 at western sites. One aspect of seawater temperature – the daily range – differed among sites and was greater at western compared to eastern sites, and while it was related inversely to recruitment over one of the sampling periods, it was equivocal as a physical process affecting recruitment. Instead, our results are consistent with biophysical coupling involving patch depletion and downstream filtering, whereby patches of coral larvae are delivered to the south shore of St. John and depleted of larvae through settlement as the water progresses westward.

Virgin Islands National Park: Coral Reef: Juvenile Coral

Coral larvae are selective with regards to the surfaces upon which they settle, but little is known about the outcome of these choices. In this study, we explored the implications for juvenile scleractinians (less than 40-mm diameter) of growing on igneous versus carbonate rock on the shallow reefs (5-m depth) of St. John, US Virgin Islands. Surveys revealed that juvenile corals occurred at densities of 16 colonies m− 2 and were distributed on igneous and carbonate rocks in proportion to the abundance of these surfaces, suggesting that larvae do not discriminate between rock types at settlement. Repeated surveys demonstrated that all juvenile corals (i.e., pooled among taxa) grew 41% slower on igneous versus carbonate rock between January and August, but not between August and January when the growth was statistically indistinguishable between rock types. Although the growth of the most common juvenile coral, Porites astreoides, was similar on both substrata, the photophysiology of this species was affected by the type of rock. The maximum relative electron transfer rate (rETR, a proxy for photosynthesis) of P. astreoides was down-regulated 30% on igneous compared to carbonate rock. Phylogenetic analyses of the Symbiodinium community sequence profiles within P. astreoides revealed significant differences between substrata, with a greater diversity of co-occurring ITS-2 sequences in corals growing on carbonate compared to igneous rock. While substratum-dependent patterns in the characteristics of juvenile corals suggested there is selective value to the settlement choices made by larvae, these trends did not translate into differences in survival, at least over the time scale investigated. It remains uncertain what features of the rocks affected coral performance, but differences in the temperature of the rock may be an important feature during the warmest period of the year.

Virgin Islands National Park: Coral Reef: Physical Measurements

These data have been utilized for several publications analyzing different aspects of seawater temperature, including Edmunds: Royal Society 2006, Green et al: Journal of Experimental Marine Biology and Ecology 2010, Green and Edmunds: Journal of Experimental Marine Biology and Ecology 2011, and Edmunds: Marine Ecology Project Series 2013. Temperatures were averaged by day and month and used to calculate annual mean and range using monthly mean temperatures. Daily temperatures were used to categorize days as hot (> 29.3°C) or cold (≤ 26.0°C), with hot days exceeding the coral bleaching threshold for St. John (http://coralreefwatch.noaa.gov/satellite), and ‘cold days’ less than or equal to the lower 12th percentile of daily seawater temperatures in Great Lameshur Bay between 1989-2005 (Edmunds 2006).This dataset cotains data annually updated data ongoing since July 1999.

Virgin Islands National Park: Coral Reef: Population Dynamics: Diadema antillarum

A potential consequence of individuals compensating for density-dependent processes is that rare or infrequent events can produce profound and long-term shifts in species abundance. In 1983–1984 a mass mortality event reduced the numbers of the abundant sea urchin Diadema antillarum by 95–99% throughout the caribbean and western atlantic. Following this event, the abundance of macroalgae increased and the few surviving D. antillarum responded by increasing in body size and fecundity. these initial observations suggested that populations of D. antillarum could recover rapidly following release from food limitation. In contrast, published studies of field manipulations indicate that this species had traits making it resistant to density-dependent effects on offspring production and adult mortality; this evidence raises the possibility that density-independent processes might keep populations at a diminished level. Decadal scale (1983–2011) monitoring of recruitment, mortality, population density and size structure of D. antillarum from st John, us Virgin Islands, indicates that population density has remained relatively stable and more than an order of magnitude lower than that before the mortality event of 1983–1984. We detected no evidence of density-dependent mortality or recruitment since this mortality event. In this location, model estimates of equilibrium population density, assuming density-independent processes and based on parameters generated over the first decade following the mortality event, accurately predict the low population density 20 years later (2011). We find no evidence to support the notion that this historically dominant species will rebound from this temporally brief, but spatially widespread, perturbation.

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Virgin Islands National Park: Coral Reef: Population Dynamics: Scleractinian corals (Reformatted to the ecocomDP Design Pattern)

This data package is formatted as an ecocomDP (Ecological Community Data Pattern). For more information on ecocomDP see https://github.com/EDIorg/ecocomDP. This Level 1 data package was derived from the Level 0 data package found here: https://pasta.lternet.edu/package/metadata/eml/edi/291/2. The abstract below was extracted from the Level 0 data package and is included for context: These data are evidence of the the long-term dynamics of shallow coral reefs along the south coast of St. John from as early as 1987. These data describe coral reef community structure as percent cover based on the analysis of color photographs. All of these data originate from color images of photoquadrats recorded annually (usually in the summer) from as early as 1987. The data falls into three groups. The two groups that are contained in this data package are (1) Tektite & Yawzi and (2) Random sites. The juvenile coral density is packaged separately. Tektite – this is at 14 m depth on the eastern side of Great Lameshur Bay and is the original site of the Tektite man-in-the sea project in 1969; this project marked the birth of the Virgin Islands Ecological Research Station (later the Virgin Islands Environmental Resource Station) that hosts the field component of the project. The reef in this location consists of a single buttress that has remained dominated by Montastraea anularis since the start of the research (1987). These surveys consist of 30 photoquadrats (1 x 1 m) distributed along three, 10 m transects. Yawzi – this is at 9 m depth and is on the western side of Great Lameshur Bay and has been recorded photographically since 1987. This reef also started the study period dominated by Montastraea annularis, but has degraded much more rapidly that the Tektite site. These surveys consist of 30 photoquadrats (1 x 1 m) distributed along three, 10 m transects. Random sites – were added in 1992 to address the concern that the original sites (Yawzi and Tektite) were selected on “good” a

Virgin Islands National Park: Coral Reef: Population Dynamics: Landscape-scale Variation in Scleractinian Corals

This study provides a landscape-scale context to a decadal-scale analysis of community structure on shallow reefs along 4 km of the south shore of St. John, US Virgin Islands. By focusing on 12-14 sites along ~100 km of the shores of St. John and St. Thomas, surveys conducted in 2011 were used to contrast: (1) a local-scale with a landscape-scale analysis on two islands, (2) reefs around St. John and St. Thomas, and (3) reefs on north and south shores. Reefs were censused using photoquadrats that were analyzed for percentage cover first by functional groups (coral, macraolagae and CTB), and then by coral genus. In general, among-site variation for the coarse-resolution analysis eclipsed shore and island effects, but the fine-resolution analysis revealed strong site-specific differences for multiple coral genera that could be the product of priority effects in community succession. Over the next decade these differences probably will create unique community trajectories at each site.

Virgin Islands National Park: Coral Reef: Decadal-scale changes in community structure from 1987 to 2011

These time series data sample percent cover of Scleractinian corals by genus measured from photo quadrats. Percent cover is given for each quadrat, each site, each year from 1987 to 2011. Counts of juvenile corals conducted in situ and small colonies less than 4 cm diameter are pooled from all sites. Supplementary data include in situ seawater temperature daily mean from 1989 to 2011. These data were used to create the figures in Edmunds, P.J., 2013, Decadal-scale changes in the community structure of coral reefs in St. John, US Virgin Islands, Marine ecology Progress Series. doi:10.3354/meps10424

Virgin Islands National Park: Coral Reef: Populations Dynamics: Population Projections

In this study, size-based matrix models for the reef-building coral Orbicella annularis at 14-m depth on the Tektite reef in St. John, U.S. Virgin Islands, were used to: (1) explore the demography of changing coral cover over 25 yr, (2) test for spatial homogeneity in demographic properties through a contrast with a previous study (at Yawzi Point, Edmunds and Elahi 2007), and (3) evaluate the potential for future population stability. During three, five year intervals from 1988 to 2002, St. John was affected by hurricanes and bleaching, yet coral cover at Tektite increased from 33% to 49%; from 2002 to 2007, it declined to 27%; and from 2010 to 2013, it stabilized at ∼ 28%. Over a quarter-century, colonies > 50 cm2 became rare, the abundance of colonies ≤ 50 cm2 increased from 58% (1988) to 92% (2013), and population density doubled to 67 colonies m-2 by 2013. Population growth (λ) was greater at Tektite (1.152 ≥ λ ≥ 1.018) than Yawzi Point (0.679 ≥ λ ≥ 0.586), and while population size at Tektite declined due to bleaching and disease in 2005 (λ = 0.753 over 2003–2008), it recovered between 2008 and 2013 (λ = 0.966); the population at Yawzi Point declined from 1988 to 2003 without signs of recovery. Projections suggest a continuation of recent conditions could allow O. annularis at Tektite to retain ∼ 9% cover after 100 yr, but with a return to the rates of growth and survival of 1993–1998, it could attain coverage similar to that of 1988 (33%) in ∼ 15 yr.

Virgin Islands National Park: Coral Reef: Population Dynamics: Octocorals

These data are evidence of the the long-term dynamics of shallow coral reefs along the south coast of St. John from as early as 1987. These data describe coral reef community structure by density based on the analysis of color photographs. All of these data originate from color images of photoquadrats recorded annually (usually in the summer) from as early as 1987. The data falls into three groups. The two groups that are contained in this data package are (1) Tektite & Yawzi and (2) Random sites. Tektite – this is at 14 m depth on the eastern side of Great Lameshur Bay and is the original site of the Tektite man-in-the sea project in 1969; this project marked the birth of the Virgin Islands Ecological Research Station (later the Virgin Islands Environmental Resource Station) that hosts the field component of the project. The reef in this location consists of a single buttress that has remained dominated by Montastraea anularis since the start of the research (1987). These surveys consist of 30 photoquadrats (1 x 1 m) distributed along three, 10 m transects. Yawzi – this is at 9 m depth and is on the western side of Great Lameshur Bay and has been recorded photographically since 1987. This reef also started the study period dominated by Montastraea annularis, but has degraded much more rapidly that the Tektite site. These surveys consist of 30 photoquadrats (1 x 1 m) distributed along three, 10 m transects. Random sites – were added in 1992 to address the concern that the original sites (Yawzi and Tektite) were selected on “good” areas of reef and, therefore, could only decline in condition. The Random sites were selected using random coordinates in 1992, and consist of 6 sites (at 7-9 m depth) scattered between Cabritte Point and White Point. All lie a little shoreward of Yawzi and Tektite, and have always been characterized by low coral cover (< 10% cover). The surveys consist of 18-40 photoquadrats (0.5 x 0.5 m; with sample size determined by the exposures on a 3

Virgin Islands National Park: Coral Reef: Reference: Taxonomy

In early years photos were analyzed with less refined taxonomic classsification. This reference table may be used to aggregate taxa to align with coarse analysis. Use this table to define sub-categories and super-categories such as the M. annularis complex. This is a reference dataset containing the taxonomic classifications, groupings of taxonomic classifications, and functional groups. It has been updated in accordance with Budd, et al., 2012.

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Virgin Islands National Park: Coral Reef: Population Dynamics: Scleractinian corals (Reformatted to a Darwin Core Archive)

This data package is formatted as a Darwin Core Archive (DwC-A, event core). For more information on Darwin Core see https://www.tdwg.org/standards/dwc/. This Level 2 data package was derived from the Level 1 data package found here: https://pasta.lternet.edu/package/metadata/eml/edi/357/2, which was derived from the Level 0 data package found here: https://pasta.lternet.edu/package/metadata/eml/edi/291/2. The abstract below was extracted from the Level 0 data package and is included for context: These data are evidence of the the long-term dynamics of shallow coral reefs along the south coast of St. John from as early as 1987. These data describe coral reef community structure as percent cover based on the analysis of color photographs. All of these data originate from color images of photoquadrats recorded annually (usually in the summer) from as early as 1987. The data falls into three groups. The two groups that are contained in this data package are (1) Tektite & Yawzi and (2) Random sites. The juvenile coral density is packaged separately. Tektite – this is at 14 m depth on the eastern side of Great Lameshur Bay and is the original site of the Tektite man-in-the sea project in 1969; this project marked the birth of the Virgin Islands Ecological Research Station (later the Virgin Islands Environmental Resource Station) that hosts the field component of the project. The reef in this location consists of a single buttress that has remained dominated by Montastraea anularis since the start of the research (1987). These surveys consist of 30 photoquadrats (1 x 1 m) distributed along three, 10 m transects. Yawzi – this is at 9 m depth and is on the western side of Great Lameshur Bay and has been recorded photographically since 1987. This reef also started the study period dominated by Montastraea annularis, but has degraded much more rapidly that the Tektite site. These surveys consist of 30 photoquadrats (1 x 1 m) distributed along three, 10 m transects. Random sit

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Virgin Islands National Park: Coral Reef: Reference: Geography

This is a reference dataset containing the site locations, year established, and types of surveys.