Marine biodiversity

Story hook

When divers descended on the Lakshadweep reefs in May 2024, they returned with a number that froze coral scientists: 84 % of surveyed colonies had bleached white. Two months earlier, sea surface temperatures (SST) around the atolls had crossed 31°C — a 3-degree anomaly that lasted seven weeks. The same pattern played out around the Gulf of Mannar, the Andaman & Nicobar Islands, and the Gulf of Kachchh. By the time NOAA called it, the world was in the Fourth Global Coral Bleaching Event — the most extensive on record, more severe than 1998, 2010, or 2016.

But corals are only one strand of marine biodiversity. Mangroves cover 152,000 sq km globally and absorb 5× more carbon per hectare than terrestrial forests. Seagrasses carpet 300,000 sq km of shallow shelves and feed dugongs, turtles, and an estimated 20 % of the world's most landed fisheries. Marine Protected Areas (MPAs) — the ocean equivalent of national parks — cover 8 % of the global ocean, but less than half are well-managed.

This file is about that interconnected blue ecosystem — its three foundation habitats, the Global Biodiversity Framework's 30×30 target, and India's Wildlife Institute of India's CMPA (Coastal Marine Protected Area) initiative.

Why this matters for UPSC

Marine biodiversity is a recurring UPSC theme — coral bleaching has featured in 5+ Prelims years (2014-2024), and Mains has asked explicit questions on coral reefs, mangroves, MPAs, and the High Seas Treaty. With COP28's Ocean Day and the BBNJ Treaty (2023), this is a near-certain 2026 topic. Interview boards in coastal states probe candidates routinely.