J. Ravindran et al., Disease and stress-induced mortality of corals in Indian reefs and observations on bleaching of corals in the Andamans, CURRENT SCI, 76(2), 1999, pp. 233-237
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, predatio
n and stress were the major factors of coral mortality. Death caused by dis
eases - the black band disease (BBD), the white:band disease (WBD) - necrot
ic lesions, and bleaching was observed in Kavaratti and Kadamat islands of
Lakshadweep. The predatory starfish, Acanthaster planci, grazing on coral p
olyps was also noticed in these reefs. Large-scale silt deposition in the i
ntertidal zone of Paga, Boria, Vadinar and Mangunda reefs in the gulf of Ku
tch buried the coral colonies and appeared to be the main cause of coral mo
rtality. A severe incidence of coral bleaching was observed during July 199
8 in some reefs in the Andamans. While more than 85% of corals near Ross is
land and Marina Park exhibited partial bleaching, up to 10% were totally bl
eached.