Thermal Bleaching Events, Species-Specific Recovery Trajectories, and Reef Biodiversity Loss in the Lakshadweep Archipelago and Andaman Reefs

India's tropical coral reef ecosystems — centred on the Lakshadweep Islands in the Arabian Sea, the Andaman and Nicobar Islands in the Bay of Bengal, and the Gulf of Mannar fringing reefs along the Tamil Nadu coast — support exceptional marine biodiversity and provide critical ecosystem services to coastal and island communities including fisheries, coastal protection, and tourism valued at over INR 18,000 crore annually. Accelerating sea surface temperature rise in the Indian Ocean, amplified by the Indian Ocean Dipole and periodic El Niño-Southern Oscillation events, has transformed mass coral bleaching from a rare disturbance into a recurring annual threat, with the 2019 and 2022 bleaching events representing the two most severe thermal stress episodes recorded in the Indian reef monitoring period. This study presents a five-year longitudinal analysis (2019-2024) of bleaching severity, species-specific recovery trajectories, and cumulative biodiversity indicators across eighteen permanent reef monitoring stations across the Lakshadweep and Andaman reef systems. Sea surface temperature anomalies from NOAA Coral Reef Watch satellite data were linked to in-situ bleaching severity assessments conducted by trained reef surveyors. Results demonstrate that bleaching severity in 2022 exceeded 2019 levels at all stations, with branching Acropora and Montipora species showing the lowest recovery indices (0.19-0.34). Overall coral cover declined from 38.4 percent in 2019 to 24.7 percent in 2024, a 35.7 percent reduction. Shannon diversity index declined significantly, driven by disproportionate loss of thermally sensitive branching coral morphologies