COMPUTERIZED-TOMOGRAPHY AND SKELETAL DENSITY OF CORAL SKELETONS

In this paper I describe and discuss the use of medical X-ray computerized tomography (CT) in the study of coral skeletons. CT generates X-ray images along freely chosen sections through the skeleton and offers, as well, the possibility of density measurements based on X-ray attenuation. This method has been applied to measure the skeletal density of the Caribbean reef-building coral Montastrea annularis, from Curacao, Netherlands Antilles. The observed, non-linear increase of skeletal density with depth can be attributed to decreasing photosynthetic rates with increasing water depth. A comparison with extension rate measurements shows the inverse relationship between extension rate and skeletal density. CT proves to be a quick and non-destructive method to reveal growth structures (density banding) since it measures skeletal density.