The average live coral cover in Gulf of Mannar, one of the major coral reef areas in India, dropped from 37% in 2005 to 27.3% in 2021, shows a study by the Suganthi Devadason Marine Research Institute (SDMRI) and the Departments of Environment, Climate Change and Forests.
The report titled ‘Coral Reefs of the Gulf of Mannar: Decadal Changes in Status and Management Paradigms’, released at the Tamil Nadu Climate Summit 2.0 in Chennai on Thursday, provides data on important changes in coral status from the baseline survey in 2005 and the subsequent surveys at permanent monitoring sites from 2007 to 2021.
The share of live corals hit an all time high of 42.9% in 2009, possibly due to the halting of coral mining activities following the 2004 tsunami, but it dropped after widespread coral mortalities due to the second (2010) and third (2016) global bleaching events with a more severe impact in the Mandapam region than in the Keelakarai and Tuticorin regions.
Further, the baseline survey in 2005 recorded 117 coral species and more were added by the subsequent surveys till 2021 with updated nomenclature increasing the number to 132. Notably, there are several deep water coral patches in the Gulf of Mannar that have not been fully explored till date. “The process of confirmation and authentication of the species in association with international experts is in progress. More coral species are expected to be added to the list,” the report noted.
Coral reefs in the GoM have been the source of sustainable livelihood for thousands of low-income fisher folk through associated fishery resources. However, the reefs have been subjected to various natural and human-induced threats during the past few decades.
Jagdish S. Bakan, Wildlife Warden, Gulf of Mannar Biosphere Reserve, said 2,575 sq. m of coral reef restoration had been carried out through transplantation techniques over the past year. Supriya Sahu, Additional Chief Secretary to Departments of Environment, Climate Change and Forests, said the State was focusing on the Gulf of Mannar islands through the newly-launched Tamil Nadu Coastal Restoration Mission, of which the Kariyachalli Island Restoration project is a part of. A Marine Elite Force had been set up to combat marine wildlife crimes in the Gulf of Mannar biosphere, she added.
