Annual linear extension, skeletal density, and calcification rate data from coral cores collected across Bermuda in 2016 (NCEI Accession 0278114)

Acquisition Description:
Coral cores were collected in August 2016 using a 2-inch diameter wet concrete diamond drill bit powered by an underwater pneumatic drill. The colonies were sealed with a cement plug and underwater epoxy to promote recovery of the coral following core extraction. Each core was scanned via a GE Lightspeed VCT at San Diego Imagery alongside density reference materials provided by Dr. Karl Castillo (University of North Carolina at Chapel Hill) in three separate scans. Three scans were necessary to fit all of the cored material in the center region of the scanning table to avoid any potential heel effects near the boundaries of the scanned region. The density standards were scanned in each of the three scans to correct for any intra-scan variability in CT imagery. Approximately 3 mm thick slabs were extracted from the center of each of the cores and standards using standardized window widths and window levels and exported as images via the software Horos for subsequent growth rate analysis in CoralXDS. Annual growth rates and luminance values along the major growth axis were quantified using the half-range mode of the software CoralXDS. The density of the reference materials were strongly correlated with the scanned luminance intensity for each scan and these relationships were used to calculate annual skeletal densities from the annual coral skeletal luminance intensities using the statistical software R. Annual calcification rates were determined as the product of annual linear extension rate and skeletal density using the statistical software R.

All cores were collected under the Government of Bermuda Department of Environment and Natural Resources license number 2015–05–26–46.

Please see Courtney et al. (in review) for further details.