Health monitoring status of corals in Gulf of Mannar and Palk Bay (India) with special reference to coral bleaching event

Abstract

Abstract. Sadhukhan K, Chatragadda E, Shunmugaraj T, Murthy MVR. 2022. Health monitoring status of corals in Gulf of Mannar and Palk Bay (India) with special reference to coral bleaching event. Indo Pac J Ocean Life 6: 72-84. Coral reef ecosystems are highly important regarding ecological, cultural, and economic values. Unfortunately, these ecosystems are declining rapidly due to climate change and local anthropogenic threats. The present study assessed the coral reef health status in the Gulf of Mannar (GoM) and Palk Bay (PB), India, to understand the diversity and abundance of corals and the bleaching vulnerability of the reef areas. Extensive underwater surveys were conducted from August 2018 to August 2020. Line intercept transect methods were employed in triplicates and estimated the bleaching-mediated reef threats. As a result, the average live coral cover of the Gulf of Mannar was 39.55±15.45% (Mean±SD), and Palk Bay was 28.40±14.60%, of which Mandapam Group of Islands has maximum live coral coverage (51.80±15.10%). Severe coral bleaching was also observed in the Gulf of Mannar and Palk Bay during the summer of two the consecutive year, 2019 and 2020, triggered by increased sea surface temperature (SST) of 4°C-5°C than the average temperature (28°C-31°C). The current study highlights the detailed distribution of the coral community with comparative analysis since 2000 and the adaptive response of native coral species to bleaching events that will help to implement management interventions like coral restoration of those native species to strengthen the reef resilience in the Gulf of Mannar and Palk Bay.