Sundarbans

The Sundarbans occupies the seaward part of the Ganges–Brahmaputra–Meghna delta, where the rivers meet the Bay of Bengal. The wider mangrove region extends across southern Bangladesh and the Indian state of West Bengal. Its landscape is a mosaic of tidal rivers and creeks, mudflats, low islands and salt-tolerant mangrove forests rather than a uniform stretch of woodland. River-borne sediment, monsoon rainfall and tidal action continually shape the delta and the habitats that develop on its islands. Reported area figures depend on whether a source is describing the ecological region, a national reserve or a designated protected site; UNESCO's Bangladesh World Heritage property, for example, covers 140,000 hectares and borders the Indian property.

Mangroves are trees and shrubs adapted to the brackish, tidally influenced conditions of tropical and subtropical coasts. In the Sundarbans, they form an important habitat within a wider network of terrestrial, freshwater and marine environments. UNESCO describes the Bangladesh property as supporting 260 bird species and identifies the Bengal tiger, estuarine crocodile and Indian python among its notable wildlife. The forest's waters and mangrove edges also provide spawning and nursery grounds for fish, linking the health of the landscape to fisheries in the Bay of Bengal.

The Sundarbans is one ecological system governed through separate reserves and protected sites in two countries. India's Sundarbans National Park was inscribed on the UNESCO World Heritage List in 1987; the Bangladesh property, also called The Sundarbans, was inscribed in 1997. The Bangladeshi wetland is also recognized under the Ramsar Convention. These designations cover particular areas, not every part of the wider delta ecosystem. Communities around the forest rely on activities such as fishing and honey collection, while the mangroves also help sustain regional fisheries. A peer-reviewed study of co-management in Bangladesh highlights the ongoing challenge of balancing conservation with local participation and access to resources.

The delta's low-lying coastal setting makes the Sundarbans sensitive to changes in tides, sediment and freshwater. IUCN's 2025 conservation assessment for the Bangladesh World Heritage property rates its outlook as being of significant concern. It discusses pressures that include sea-level rise, cyclones, coastal erosion and changes to freshwater inflow and salinity. The Nature Conservancy also describes climate hazards and land loss as concerns for mangroves in the Indian Sundarbans. Because rivers, sediment and tidal processes cross administrative boundaries, conservation decisions in one part of the delta are connected to conditions elsewhere in the wider system.