Indian coral reef study reveals stark regional differences in bleaching during 2024 global event

Key facts

• A study published in the journal Coral Reefs by Springer Nature examined the effects of the fourth global coral bleaching event on India's coral reefs in 2024.
• Rapid bleaching assessments were conducted across five reef regions — the Lakshadweep archipelago, Goa, Palk Bay, Mahatma Gandhi Marine National Park (MGMNP) in the Andaman Islands, and Ritchie's Archipelago — with all surveys conducted between April 20 and June 7, 2024.
• Lakshadweep was the most affected region, with up to 37% of coral cover bleached or dead at intermediate heat stress levels, while MGMNP faced only 11.5% bleaching or mortality.
• The corals most affected across regions were Acropora, Pocillopora, Galaxea, and Montipora, while Pavona, Platygyra, Goniastrea, and Favites were among the least affected.
• In Palk Bay, Acropora corals showed only 13.6% bleaching or mortality, while generally resistant Porites colonies displayed 61.8% mortality, an unusual pattern.
• More than 80% of the world's coral reefs were affected by the fourth global coral bleaching event between 2023 and 2025, driven by long-term ocean warming, marine heatwaves, and a strong El Niño in 2023.
• The study highlights the shortage of data on coral reef bleaching impacts across South Asia compared with the rest of the world.
• With a very strong El Niño expected towards the end of 2026 and continuing into 2027, researchers plan another coordinated regional assessment to track bleaching progression and recovery.