A comprehensive 24-year study has revealed a sharp decline in coral health across the Lakshadweep Archipelago, with live coral cover dropping by nearly 50% since 1998 due to repeated marine heatwaves. The findings, published on July 17, 2025, in Diversity and Distributions, highlight how even the toughest corals are struggling to recover as climate shocks become more frequent.
Scientists from India and Spain studied 12 reef sites across Agatti, Kadmat, and Kavaratti islands, observing the impacts of three major marine heatwaves triggered by El Niño events in 1998, 2010, and 2016. The most severe of these occurred in 2010, with a Degree Heating Weeks (DHW) score of 6.7, a key indicator of sustained ocean heat stress that causes coral bleaching.
Coral cover in the region plunged from an average of 37.24% in 1998 to just 19.06% by 2022. However, while the 2016 heatwave caused less visible damage only a 1.8% drop in cover it wasn’t a sign of resilience. Instead, researchers believe many heat-sensitive corals had already vanished, leaving behind more stress-tolerant species like Porites, and mixed communities including Isopora, Favia, and Goniopora.
Crucially, the study found that reefs can only meaningfully recover if given at least a six-year window between heatwave events. The six-year gap between 1998 and 2004 showed signs of rebound, but the shorter period between 2010 and 2016 left fast-growing corals like Acropora with little chance to regenerate.
Lakshadweep India worst-hit coral region has no formal reef management in place. Researchers stressed that the study could serve as a predictive tool to identify which areas are most vulnerable and which could be prioritized for protection and restoration.
Yet, the warning is clear: even the hardiest coral ecosystems cannot survive the pace of accelerating climate change. The authors urge global-scale climate action, in addition to local conservation, to preserve the fragile future of coral reefs.