A recent global assessment of coral reefs highlights a mixed outlook for South Asia, with overall regional recovery contrasting sharply with declines observed around Sri Lanka. The findings are detailed in the 2025 Status of Coral Reefs of the World report published by the Global Coral Reef Monitoring Network (GCRMN), which draws on over 21 million observations collected from nearly 37,000 reef sites between 1980 and 2024.

According to the report, South Asia’s average hard coral cover increased from 30.1% during 1997–2009 to 35% between 2020 and 2024, signifying a relative rise of 16.2%. South Asia, alongside the Western Indian Ocean, stands out as one of the few regions globally demonstrating signs of coral recovery. However, this regional improvement masks significant disparities within the area.

The majority of South Asia’s coral reefs are concentrated along the Lakshadweep-Maldives-Chagos Ridge, with the Maldives accounting for roughly 58% of the region’s reef area. The reefs surrounding Sri Lanka, however, predominantly fall within the West and South Indian Shelf subregion, which includes parts of southern India. Unlike the oceanic atolls of the Maldives and the relatively isolated Chagos Archipelago—both showing strong recovery—Sri Lanka’s reefs have experienced a decline in hard coral cover over the assessment period.

Experts attribute this pattern to differing environmental conditions and human pressures. Sri Lanka’s reefs are situated on a populated continental shelf and face multifaceted threats, including coastal development, pollution, sedimentation, destructive fishing practices, and other disturbances from both land and sea. In contrast, the Maldives and Chagos reefs benefit from relative isolation and oceanic conditions that enhance their resilience after widespread bleaching events.

Climate change is identified as a critical factor affecting reef health globally. The report notes a 9.5% decline in global hard coral cover when comparing the 1980–2009 period with 2020–2024. The trend accelerated in 2024, with an additional 8.9% loss recorded in a single year—the largest annual decline observed in the assessment. These decreases are closely linked to four major global bleaching events since 1998, driven by rising sea-surface temperatures and marine heatwaves.

Thermal stress events have become more frequent, with intervals between global bleaching episodes shrinking from about a decade to as little as four to six years. This shorter recovery window poses a significant threat to coral resilience worldwide, including in South Asia. During the 2024 bleaching event, some reefs in the Chagos Archipelago experienced bleaching in up to 85% of corals and recorded nearly a quarter loss in live coral cover.

Sri Lanka’s reefs remain highly vulnerable to these thermal stresses but have shown some capacity for recovery under improved conditions. For example, surveys on the Pareiwella Reef in Tangalle documented hard coral cover increasing from approximately 36% during the 2023 El Niño to over 56% by early 2025. This finding supports the report’s broader conclusion that coral reefs have not yet reached a point of no return, provided they receive sufficient recovery time.

Nonetheless, the report emphasizes that local conservation efforts alone cannot offset the overarching effects of climate change. Reducing pollution, sedimentation, and fishing pressures can help enhance reef resilience, but coordinated action to reduce greenhouse gas emissions remains essential to curbing further global coral decline.

Within Sri Lanka, coral cover varies widely with location and environmental conditions. Recent surveys near Colombo recorded some offshore reef sites with hard coral cover exceeding 50%, while nearshore areas suffering from pollution saw cover drop to as low as 2.3%. These disparate results highlight the importance of site-specific management and monitoring.

As South Asia’s reported 35% average coral cover offers a rare positive note amid global coral losses, experts caution that recovery in Sri Lanka is fragile and uneven. With climate change shortening recovery intervals and local pressures mounting, the future of the country’s coral reefs depends on combined efforts addressing both environmental protection and climate mitigation.