Disease and stress-induced mortality of corals in Indian reefs and observations on bleaching of corals in the Andamans

• Main Authors: Ravindran, J., Raghukumar, C., Raghukumar, S.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Current Science Association, Bangalore, India 1999
• Subjects: coral reefs; coral; mortality; necroses; predation; biological stress; silting; Ross Island; Indian; Paga
• Online Access: http://drs.nio.org/drs/handle/2264/1865

A study was carried out in the Lakshadweep and Andaman islands and the Gulf of Kutch to assess the health of corals in Indian reefs. Disease, predation and stress were the major factors of coral mortality. Death caused by diseases - the black band disease (BBD), the white band disease (WBD) - necrotic lesions, and bleaching was observed in Kavaratti and Kdamat islands of Lakshadweep. The predatory starfish, Acanthaster planci, grazing on coral polyps was also noticed in these reefs. Large-scale silt deposition in the intertidal zone of Paga, Boria, Vadinar and Mangunda reefs in the Gulf of Kutch buried the coral colonies and appeared to be the main cause of coral mortality. A severe incidence of coral bleaching was observed during July 1998 in some reefs in the Andamans. While more than 85% of corals near Ross island and Marine Park exhibited partial bleaching, up to 10% were totally bleached.