Marine heatwaves since October 2023 have led to widespread coral bleaching in the pristine waters of the Lakshadweep Sea, as reported by the ICAR-Central Marine Fisheries Research Institute (CMFRI).
The extent of damage has been estimated at approximately 75% of the corals across the archipelago, marking a significant ecological crisis in the region. The severity of the situation is underscored by recent observations from the Indian National Centre for Ocean Information Services, which recorded marine heatwave events of moderate to extreme categories over the Lakshadweep and South Tamil Nadu coasts. These events, coupled with bleaching incidents in the Gulf of Mannar, highlight the alarming escalation of ocean temperatures and their adverse effects on marine ecosystems. Marine heatwaves, characterised by prolonged periods of abnormally high ocean temperatures, have led to a surge in the Degree Heating Week (DHW) indicator in Lakshadweep, exceeding 4°C-weeks. According to the National Oceanic and Atmospheric Administration (NOAA), such levels of DHW pose a substantial risk of coral bleaching, jeopardising the region’s rich biodiversity.
The Degree Heating Week (DHW) metric, which measures accumulated heat stress over the past 12 weeks, serves as a crucial indicator of coral health. When DHW exceeds 4°C-weeks, significant bleaching is likely, posing a severe threat to sensitive coral species. If DHW levels continue to rise beyond 12°C-weeks, it could precipitate an unprecedented biodiversity crisis, leading to widespread mortality across marine habitats. Experts at CMFRI have been closely monitoring the escalating bleaching events since mid-April, highlighting the urgent need for conservation efforts and mitigation strategies to safeguard coral reef ecosystems in Lakshadweep. The ongoing crisis underscores the critical importance of addressing climate change and mitigating its adverse impacts on marine biodiversity.
