Sundarbans East

Sundarbans East Wildlife Sanctuary is one of three wildlife sanctuaries that together protect the core zone of the Sundarbans, the world's largest tidal mangrove forest, located in the Khulna Division of southwestern Bangladesh. The Sundarbans covers approximately 10,000 square kilometres across Bangladesh and India, and the Bangladeshi portion is divided into three wildlife sanctuaries — East, South, and West — alongside surrounding reserve forest. Sundarbans East Wildlife Sanctuary protects the eastern section of this UNESCO World Heritage Site, which was inscribed in 1997 alongside the other two sanctuaries. The sanctuary forms part of the largest remaining habitat for the Bengal tiger and is the only mangrove forest in the world to sustain a viable tiger population.

Sundarbans East Wildlife Sanctuary is renowned as critical Bengal tiger habitat. Tigers in the Sundarbans have uniquely adapted to swimming between islands and hunting in tidal waterways, behaviors not seen in inland tiger populations. Spotted deer, wild boar, and rhesus macaques are among the main prey species supporting the tiger population. Estuarine crocodiles inhabit the tidal rivers and creeks throughout the sanctuary. The Sundarbans is one of the most important habitats in Asia for Irrawaddy dolphins and Ganges river dolphins. Saltwater crocodiles, though historically present, are now very rare. The sanctuary provides critical habitat for numerous globally threatened fish species in its intricate network of tidal creeks and estuaries.

The vegetation of Sundarbans East is dominated by mangrove forest, one of the most structurally complex and ecologically diverse mangrove ecosystems on earth. The dominant tree is sundri, from which the Sundarbans takes its name, along with gewa, goran, and keora, each occupying different zones of the intertidal gradient. The mangrove forest is adapted to a unique combination of tidal flooding, high salinity, and anaerobic soils, with specialized root structures including pneumatophores and prop roots allowing trees to breathe in waterlogged conditions. Dense herbaceous undergrowth and climbing plants occupy the forest floor. Golpata, a palm-like plant, forms dense stands in freshwater-influenced areas and is harvested for roofing material by communities on the forest margins.

Sundarbans East sits on the active delta of the Ganges-Brahmaputra river system, one of the largest river deltas in the world. The substrate is entirely composed of river-borne alluvial sediment deposited over thousands of years as the major Himalayan rivers spread across the Bengal lowlands. The land surface is extremely flat and low-lying, rarely more than a few metres above sea level, making the entire Sundarbans acutely vulnerable to sea level rise. The tidal drainage network creates a complex pattern of islands and channels that constantly evolve as new sediment is deposited and channels shift course. The interaction between freshwater input from rivers and saltwater intrusion from the Bay of Bengal creates a dynamic salinity gradient that shapes the zonation of vegetation across the delta.

The Sundarbans experiences a tropical monsoon climate with extremely high annual rainfall, most of which falls between June and October during the Bay of Bengal monsoon. Cyclones are a recurring threat to the region, with powerful storms capable of generating devastating storm surges that penetrate deep into the delta. The dry season from November through March brings cooler conditions and more settled weather. Humidity is high year-round due to the maritime environment and the dense transpiring vegetation. The sanctuary's position on the Bay of Bengal coast means it regularly experiences the first landfall of tropical systems developing over the Bay. The warming of Bay of Bengal sea surface temperatures due to climate change is linked to increased cyclone intensity in the region.

The Sundarbans has been used by coastal communities for centuries. Honey collectors, woodcutters, and fishers have historically entered the forest to harvest its resources, often at great personal risk due to tiger attacks. A specialized group of traditional honey collectors known as mawalis conduct seasonal forays into the forest to collect wild honey and beeswax, protected by ritual ceremonies intended to appease the forest deity Bonbibi. Fishing in the tidal rivers and creeks has been a primary livelihood for communities along the forest margins. The extreme danger posed by tigers has shaped a complex cultural relationship between human communities and the forest, with the tiger occupying a powerful and ambivalent place in local religious and cultural life.

The Sundarbans has been under formal forest management since the British colonial period, when it was brought under the Bengal Forest Department in the mid-nineteenth century. Scientific management, including the delineation of reserve forest and restrictions on settlement, was established over subsequent decades. The three wildlife sanctuaries — East, South, and West — were designated in 1977 to provide the highest level of protection to the most ecologically important sections of the forest. UNESCO World Heritage inscription followed in 1997, recognizing the outstanding universal value of the Sundarbans' ecosystem. The site is managed jointly by the Bangladesh Forest Department and forms part of a transboundary ecosystem that extends into West Bengal, India.

Sundarbans East is accessible by boat through the network of tidal rivers and creeks that traverse the forest. Boat tours from the port city of Mongla and from tourist departure points such as Khulna allow visitors to navigate the waterways, observe wildlife from the river, and make supervised landings at designated points within the sanctuary. Tiger sightings are possible but unpredictable, while spotted deer, birds, and crocodiles are more commonly observed. The forest canopy viewed from the water and the extraordinary atmosphere of the tidal mangrove environment make a powerful impression. Watch towers at certain locations allow elevated viewing of wildlife in forest clearings.

Access to Sundarbans East Wildlife Sanctuary is by boat, with organized tours departing from Khulna or Mongla, which are connected to Dhaka by road and rail. All visits to the wildlife sanctuary require permits issued by the Forest Department, and visitors must be accompanied by a licensed guide. Overnight tours allow deeper exploration of the forest, with accommodation on hired launch boats. Tour operators in Khulna and Dhaka offer organized packages of varying lengths. The best wildlife viewing conditions are typically during the dry season from November through February. Visitors should be aware of the genuine safety risks associated with tigers and crocodiles and must follow guide instructions at all times.

The Sundarbans faces existential threats from climate change, with sea level rise, increased storm surge intensity, and rising salinity threatening the mangrove ecosystem's long-term viability. The gradual upstream diversion of freshwater from the Ganges and Brahmaputra river systems reduces the fresh water flow into the Sundarbans, increasing salinity and threatening sundri and other freshwater-dependent tree species. Tiger poaching, although reduced by intensive anti-poaching efforts, remains a concern. Illegal fishing and resource extraction from the sanctuary is difficult to prevent given the vast and complex terrain. International conservation attention and UNESCO World Heritage status have brought resources and global recognition to the conservation challenge facing this irreplaceable ecosystem.