Marine heatwaves cause intense coral bleaching in Lakshadweep: Researchers

NEW DELHI: A recent study conducted by researchers from the ICAR-Central Marine Fisheries Research Institute (CMFRI) has revealed that marine heatwaves are causing widespread bleaching of coral reefs in the Lakshadweep Sea. The survey results from various Lakshadweep Islands showed that a significant percentage of hard coral species have undergone severe bleaching due to prolonged exposure to abnormally high ocean temperatures since late October 2023.
According to the National Oceanic and Atmospheric Administration (NOAA), this level of DHW poses a substantial risk of coral bleaching, threatening the region's diverse marine ecosystems.
"Such heat stress levels signify a severe threat to coral health, leading to extensive bleaching where corals lose the symbiotic algae (zooxanthellae), compromising their survival by depriving them of essential nutrients." said Dr K R Sreenath, Senior Scientist of CMFRI.
He warned that if the Degree Heating Weeks (DHW) continue to increase, it could lead to an unprecedented biodiversity crisis due to the mortality of multiple species.
Dr. Shelton Padua, another senior scientist at CMFRI, identified excessive atmospheric heat transfer and changes in ocean currents as the main causes of these marine heatwaves. The Lakshadweep Sea, located between 80.0 to 12.0 N latitude and 71.0 to 75.0 E longitude, has been experiencing temperatures consistently rising more than one degree Celsius above the norm since October 27, 2023.
The ongoing marine heatwaves are expected to cause significant economic losses by disrupting the vital ecosystem services that are crucial to the livelihoods of coastal communities, particularly in the tourism and fisheries sectors. Moreover, the death and disintegration of coral reefs can leave coastal communities vulnerable to the impacts of sea level rise. The heatwaves also pose a threat to other critical marine habitats, such as seagrass meadows, which are experiencing impaired photosynthesis, reduced growth, and hindered reproductive functions.