Threats to coral reef diversity of Andaman Islands, India: A review

The mass coral bleaching event induced by sea surface temperature (SST) anomalies coupled with the El Niño Southern Oscillation (ENSO) phenomena in 2010 led to a loss of almost 70% of live coral in the South Button Island, Havelock Island, North Bay, Chidiyatapu and Redskin Island. Between 28th March and 30th April 2016, in-situ temperatures of 31.80 ° C to 32.30 ° C were reported at North Bay leading to bleaching of Acropora fungoid. The crustal upliftment and crustal subsidence associated with the mega earthquake during December 2004 Tsunami led to loss of 30% coral cover in north Andaman and 20% loss in south Andaman, respectively. Siltation and tourist activities in certain areas of south Andaman that were affecting the coral reefs were identified as important anthropogenic threats to the survival of the reefs. The study reviewed the recovery status of different coral species from existing literature and observed that massive species like the Porites sp. were comparatively stress tolerant, and showed good resilience to bleaching and with better recovery potential due to higher thermal thresholds. In contrast, species like the Fungiid sp. were reported to be susceptible to bleaching with capabilities to regenerate and recruit slowly.