Heavy metal accumulation in the skeletons of scleractinian corals around the Gulf of Mannar Marine National Park, India

Abstract

The present work was carried out to assess the elemental accumulation (Fe, Mn, Cu, Cd, Ni, Pb and Zn) in the selected species of coral skeletons from the Mandapam group of Islands, Gulf of Mannar Marine National Park. The coral skeleton samples were analysed for their metal content using the Inductively Coupled Plasma Atomic Emission Spectrometry (ICPAES), X-ray Diffractometer (XRD) and Scanning Electron Microscopy with Energy Dispersive X-ray Spectroscopy (SEM-EDS) techniques. The analyses suggest that the accumulated elements in the coral skeletons are largely derived from natural and riverine processes. The maximum concentration of Zn and Cu was noticed in Goniopora minor (38.79 and 15 µg/g) and Acropora valida (8.3 and 11.5 µg/g). The measured metal contents in the reef skeleton were compared with values obtained from the earlier work carried out around the world and found with low metal accumulation. The overall assessment of metal accumulation indicates that metal constituents are derived from natural sources followed by feeble anthropogenic stress. The present study is helpful to document the metal concentration of individual species and serves as baseline data for metal-related environmental issues.