Coral reefs bleaching out due to heat wave
Climate change dept secretary mum on extent of dead reefs in Gulf of Mannar due to bleaching
CHENNAI: A survey completed by the state Forest Department has revealed that a majority of coral reefs in ecologically sensitive Gulf of Mannar Biosphere Reserve have already bleached due to heat wave conditions in the coastal region as well as increasing sea temperature.
A source privy to the marine biosphere said that experts from the Forest Department and Thoothukudi-based Suganthi Devadason Marine Research Institute (SDMRI) have conducted a survey across the region to ascertain the extent of coral bleaching.
“During the survey, it was observed that coral bleaching has started. A survey report has been prepared and submitted to the department. It is expected to be released in twothree days. If high temperatures continue, more corals will be lost to bleaching,” the source added.
However, state Environment, Forest and Climate Change Department secretary Supriya Sahu refused to disclose the extent of coral reefs that died out due to the bleaching or measures taken to mitigate it.
In March, the National Oceanic and Atmospheric Administration (NOAA) of the USA issued a red alert for the Gulf of Mannar and warned that high temperatures would trigger mass bleaching and coral mortality.
It may be noted that Gulf of Mannar had 37 per cent of coral cover in 2005 and the cover increased to 42.9 per cent in 2009 due to complete halt of coral mining activities. However, due to severe coral bleaching in 2010, the average cover was reduced to 33.2 per cent. In 2015, corals grew to cover 38.9 per cent area before reducing to 22.7 per cent again due to another bleaching event in 2016. As of 2021, coral reef cover was 27.3 per cent.
A study led by the Indian Institute of Tropical Meteorology in Pune has predicted that the Indian Ocean is moving to a near-permanent marine heatwave state causing habitat destruction due to coral bleaching, seagrass destruction and loss of kelp forests, affecting the fisheries sector adversely and rapid intensification of cyclones.