Staghorn coral, Acropora cervicornis, is a threatened species and the primary focus of western Atlantic reef-restoration efforts to date. As part of the USGS Coral Reef Ecosystems Studies project (http://coastal.er.usgs.gov/crest/), scientists investigated skeletal characteristics of nursery-grown staghorn coral reared using two commonly used grow-out methods at Mote Tropical Research Laboratory’s offshore nursery. USGS staff compared linear extension, calcification rate, and skeletal density of nursery-raised A. cervicornis branches reared for six months either on blocks attached to substratum or hanging from monofilament line (on PVC “trees”) in the water column. The results demonstrated that branches grown on the substratum had significantly higher skeletal density, measured using computerized tomography (CT), and lower linear extension rates compared to water-column fragments. Calcification rates determined with buoyant weighing were not statistically different between the two grow-out methods, but did vary among coral genotypes. Whereas skeletal density and extension rates were plastic traits that depended on environment, the calcification rate was conserved. Results show that the two rearing methods generate the same amount of calcium-carbonate skeleton but produce colonies with different skeletal characteristics, and suggest that genetically based variability in coral-calcification performance exists. The data resulting from this experiment are provided in this data release and are interpreted in Kuffner et al. (2017).

The USGS Coral Reef Ecosystems Studies project (https://coastal.er.usgs.gov/crest/) provides science that helps resource managers tasked with the stewardship of coral reef resources. This data release contains data on coral-growth rates for Orbicella sp. coral colonies grown at five sites on the Florida Keys reef tract from 2013 to 2015, survey data for census-based carbonate budgeting at Hen and Chickens Reef (Islamorada, Florida) collected in 2017, and time-series photographs taken of permanent markers used to measure reef erosion at Hen and Chickens Reef in 1998 and 2015. The time-series photographs document a loss in coral-reef elevation over 17 years at this site. The data will be used to inform resource managers of the capacity for future growth (or loss) of reefs dominated by genus Orbicella in the Florida Keys so that the reef ecosystem might be better understood and managed. The datasets included here were interpreted in Kuffner and others (2019). Kuffner, I.B., Toth, L.T., Hudson, J.H., Goodwin, W.B., Stathakopoulos, A., Bartlett, L.A. and Whitcher, E.M. (2019), Improving estimates of coral reef construction and erosion with in situ measurements. Limnol Oceanogr. doi:10.1002/lno.11184

The USGS Coral Reef Ecosystems Studies project (https://coastal.er.usgs.gov/crest/) provides science that helps resource managers tasked with the stewardship of coral reef resources. This data release contains data on coral-growth rates and time-series photographs taken of colonies of the elkhorn coral, Acropora palmata, grown at five sites on the Florida Keys reef tract from Spring 2018 to Autumn 2019. The data will be used to inform resource managers of the capacity for restoration and growth of this threatened species of coral along 350 kilometers of the Florida reef tract to aid species recovery throughout the western Atlantic. The datasets included here were interpreted in Kuffner and others (2020). Kuffner, I.B., Stathakopoulos, A., Toth, L.T., and Bartlett, L.A. In press. Reestablishing a stepping-stone population of the threatened coral, Acropora palmata, to aid regional recovery. Endangered Species Research.

To maximize long term (>10yr) survival of nursery raised Acropora cervicornis corals, a map based tool was created that ranks locations in the Florida Acropora Critical Habitat based on climate vulnerability. Climate vulnerability is defined both in terms of exposure to future heat stress and the coral's sensitivity as resilience. Suitable sites are determined by a number of factors, suitable sites must be within the Acropora critical habitat and within the depth range 5-15m, with either hard bottom or coral present. Those possible locations are ranked based on projected climate change impacts and a resilience metric based on seven different indicators: coral cover, macroalgae cover, bleaching resistance, coral diversity, coral disease, herbivore biomass, and temperature variability. The data is presented as a Google Earth tool (zipped), maps, gridded netCDF files and are accompanied by a guidance document and a .csv file ranking all locations. The Google Earth tool contains five major layers: depth, turbidity, resilience, year of annual severe bleaching, and outplanting score. Bleaching projections included here use climate model data from 2006-2099.

Data were collected as part of the CRCP-funded project "Coral restoration in natural ocean acidification refugia." Carbonate chemistry parameters and temperature data describe environmental conditions incident on Acropora cervicornis nursery and outplanting sites throughout the Florida Keys and Dry Tortugas. Growth data are periodic measurement of colony total linear extent (TLE).

Acropora cervicornis fragments of each genotype were evenly and haphazardly assigned to two nutrient treatments: ambient nutrients (Ambient) or elevated ammonium (NH4). Each nutrient treatment was replicated in four independent tanks (n = 3 fragments per genotype per tank). For ~1.5 months (47 d), Ambient tanks were maintained under nutrient levels consistent with the values in Virginia Key, FL, while elevated NH4 tanks were dosed with NH4Cl [3 mM] every 15 minutes using peristaltic pumps. The initial NH4 dose volume was 10 mL of the stock solution, targeting a ~10 μM increase in NH4 concentration. These values were calculated to account for the dilution of the nutrients resulting from adding new ambient seawater to the tanks (200 mL/min in a total tank volume of 180 L). After detecting higher than normal NH4 concentrations in the incoming seawater from Biscayne Bay, the NH4 dose volume was lowered to 5 mL of the stock solution, targeting ~5 μM NH4 increase above ambient values. The fragments were also assigned to disease vs. placebo treatments, the disease treatments involving exposure to homogenates of corals showing signs of white band disease following the protocol found in Rosales & Palacio-Castro (2024). Water samples (~40 mL) were collected to monitor NH4 levels in the treatments and immediately refrigerated at 4C. The elevated NH4 tanks were sampled daily, but the Ambient tanks were sampled less frequently (~2-3 days and no samples were collected during weeks 1 and 3 of the experiment). Nutrient concentrations were measured at NOAA-AOML using an AA3 nutrient analyzer (Seal Analytical, Southampton, UK). The instrument was calibrated before each run using standard solutions and procedures. Initially, only NH4 was monitored, but after high NH4 concentrations in the source seawater were detected, additional measurements of PO4 were included.