Status and review of health of Indian coral reefs

Abstract

Status of reef health incorporating species-wise cover of scleractinians has been reported covering 61 stations in 29 reef locations of the four major reef regions in India as of March 2011, alongside a review of available reef health data since 1998 until 2011 Coral bleaching has been identified as a major factor determining the live coral cover (in the order high to low impact) in Lakshadweep, Gulf of Mannar (GOM) and Andaman reefs Reductions in live cover (from 2010) were observed in Lakshadweep and GOM reefs Recovery from the bleaching event in 2010 was reported from Andaman, though long-term impacts of bleaching, reef area loss due to seismic up-lift and the 2004-tsunami were observed by the declining trend in reef health Local scale stressors are more intense in Gulf of Kachchh (GOK) and GOM reefs, however are more chronic in the former, which is reflected in the species composition as stress tolerators (Edinger and Risk 2000) forming the major cover in these reefs In GOM, recovery from bleaching events are impeded by the local stressors, thus showing low scleractinian species richness in the transects (n = 19) Live cover versus diversity indices showed positive correlation (R2 = 0.96) with the dominance indices, of reefs influenced both by local and bleaching stresses (e g GOM) Conversely, good species diversity and richness were observed for majority of the reefs in Lakshadweep and Andaman, where the local stressors are minimal; which also indicated, most significantly, the resilience in these reefs in terms of maintaining diversity despite the large-scale mortality events.