Coral extension rate analysis using computed axial tomography

Biology, geology, and paleoclimatology studies of coral reefs often rely on annual rates corallite extension determined from cores skeletal material recovered scleractinian corals. To examine how orientation within such may affect measured rates, we used high-resolution X-ray computed axial tomography (CT) to image a suite short Orbicella faveolata corals living in the northwest Gulf Mexico. This nondestructive method enabled be several ways: (1) along transects that cross individual slice/slab images, (2) both 0.6-mm-thick CT slice corresponding conventional 8.4-mm-thick slab material, (3) slices/slab images oriented at varied angles relative core’s longitudinal axis. Additionally, true three-dimensional (3D) corallites were compared apparent two-dimensional (2D) slice/slab. Results suggest differences between all methods are not statistically significant, confirming rate methodology is suitable for if axis appropriately aligned with growth corallites. Effects core misalignment measurement appearance structures 2D described, applicability 3D imagery investigations polyp patterns colony development demonstrated.