Rivers of Bangladesh: Padma, Jamuna and Meghna — the Rivers That Built a Delta
Rivers of Bangladesh: the Padma, Jamuna and Meghna that built the world's largest delta — and the erosion, pollution and water disputes reshaping it today.
At the south-western edge of Bangladesh, where the great rivers finally give up their names to the sea, stands a forest that is half water. The Sundarbans — some 10,000 square kilometres of mangrove spread across the delta of the Ganges, Brahmaputra and Meghna — is the largest mangrove forest on Earth. Around 60 percent of it lies in Bangladesh, a 6,017-square-kilometre reserve of islands, creeks and tidal channels in Khulna Division; the rest continues into India. There are no roads here. Every journey is by boat, every path is a river, and the land itself is rearranged twice a day by the tide. It is home to the world's most famous swimming tigers, to two species of river dolphin found together nowhere else, and to millions of people who live by — and are sheltered by — its trees.
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A Forest Built by Rivers
The Sundarbans is a young landscape, still under construction. For thousands of years the Ganges, Brahmaputra and Meghna have carried Himalayan sediment south and dropped it at the head of the Bay of Bengal, building the largest river delta on the planet. At its seaward edge, that sediment settles into mudflats and low islands, and mangroves colonise the new ground. UNESCO, which inscribed the Bangladeshi forest as a World Heritage Site in 1997, describes it as an outstanding example of delta formation still in progress: monsoon flooding, tidal scouring and plant succession constantly remaking the map.
Within the Bangladesh reserve, about 70 percent is land and 30 percent open water — a maze of rivers, among them the Pashur, Sibsa, Shela and Baleswar, splitting into hundreds of creeks. The word Sundarbans literally means "beautiful forest" in Bengali, and the name is widely believed to come from the sundari tree (Heritiera fomes), once the forest's most abundant large tree. Sundari still dominates the fresher, eastern reaches, while the saltier west belongs to smaller, tougher species such as goran and gewa — a gradient written by the balance between river water and sea water across the forest. UNESCO counts 334 plant species here, from the stilt-rooted keora that fringes new mudflats to the golpata palm whose leaves roof the villages outside.
That international recognition is layered. The whole Bangladesh reserve — all 601,700 hectares of it — was designated a Ramsar wetland of international importance in 1992. The World Heritage inscription of 1997 covers its three southern wildlife sanctuaries, Sundarbans East, South and West, some 139,500 hectares of core habitat. India's share of the same forest had been listed a decade earlier, in 1987, as Sundarbans National Park: one ecosystem, two inscriptions, divided by a border the tides ignore.
The Tiger's Kingdom
The Sundarbans is the only mangrove forest in the world inhabited by tigers, and its Bengal tigers have adapted to a life no other population knows. They swim the wide rivers between islands, hunt in waterlogged forest where scent and sound carry strangely, and take prey — mainly spotted deer and wild boar — on mudflats and in the shallows. For decades their numbers were guessed from paw prints, and old estimates of 400 or more were repeated for years. Modern camera-trap censuses tell a smaller, more honest story: 106 tigers in 2015, 114 in 2018, and 125 in the Forest Department's most recent census, completed in October 2024. The trend, officials argue, is slowly upward, helped by intensified anti-poaching patrols — though 61 tigers were recorded dead between 2001 and 2025, and in 2026 the Forest Department was weighing whether some tigers should be translocated to the Chittagong Hill Tracts to give the population a second home beyond the climate-threatened delta.
The tiger shares its kingdom widely. Spotted deer graze the grassy clearings at Katka and Kochikhali in herds that can number in the hundreds; wild boar root in the mud; rhesus macaques raid the forest edge; fishing cats hunt the creek banks, and estuarine crocodiles — among the largest reptiles alive — bask on the mud at low tide. The critically endangered river terrapin Batagur baska survives here, and UNESCO lists 693 wildlife species in all, including 315 kinds of bird, from nine species of kingfisher to the white-bellied sea eagle.
The rivers hold their own rarities. The Sundarbans is the only place on Earth where the Ganges river dolphin and the Irrawaddy dolphin swim the same waters. In January 2012, acting on a Wildlife Conservation Society survey, the government declared three stretches of channel — Dhangmari, Chandpai and Dudhmukhi, about 31 kilometres in all — as dolphin sanctuaries, the first protected areas in the country created for freshwater dolphins. Against this wealth stands a plain fact UNESCO itself records: illegal hunting and trapping remain serious threats, and deer poaching for meat is a constant pressure on the tiger's prey base.
Life Among the Trees: Sundari, Golpata and the Honey Collectors
For the people of the forest edge, the Sundarbans is a workplace entered by permission and at real risk. Nothing may be taken from the reserve without a Forest Department permit, and each trade has its season. Fishermen work the rivers; crab collectors walk the mud at low tide; collectors cut golpata palm leaves for roofing; and every April, when the khalisha and goran trees flower and giant honey bees build their combs in the branches, the honey collectors — the mouals — go in.
The honey season opens on 1 April and runs into June. In 2024–25 some 2,858 mouals entered the forest under 437 permits, working in groups, sleeping on boats, and following the bees deep into tiger country. The work is among the most dangerous in Bangladesh: mouals are killed by tigers in most years, and collectors in recent seasons have complained of a newer threat, armed bandits demanding ransom in the creeks. Recorded honey collection has fallen from 4,463 quintals in 2021 to 2,076 quintals in 2025. Before entering, moual parties traditionally seek the protection of Bonbibi, the guardian deity of the forest, honoured for centuries by Hindu and Muslim collectors alike — a measure of how completely the forest's dangers shape its culture.
The forest's signature tree is under quieter stress. Sundari has suffered since the 1960s and 1970s from "top-dying", a dieback of the crown that researchers associate with rising salinity, and its finest stands have thinned as salt water pushes further inland. The tree that probably gave the Sundarbans its name has become an indicator of the forest's largest slow-moving problem.
People of the Forest Edge
Beyond the reserve boundary, an estimated 3.5 million people in Bangladesh depend on the Sundarbans directly or indirectly, according to a 2024 synthesis of livelihood studies — fishing its waters, collecting its honey and palm leaves, crewing its tour boats, or farming the polders behind its shelter. A ten-kilometre belt around the forest has been declared an Ecologically Critical Area in recognition of how tightly lives there are bound to the forest's health.
The dependence cuts both ways. The same creeks that yield fish and honey produce the man-eating attacks that leave "tiger widows" in the fringe villages, and the same permits that regulate collection keep the poorest collectors in debt to the traders who finance their trips. Yet ask in Gabura, Burigoalini or Shyamnagar whether the forest should stand, and the answer is rarely in doubt: it is the wall between these villages and the sea.
Storms, Salt and a Warming Sea
That wall has been tested repeatedly. When Cyclone Sidr struck on 15 November 2007, the forest took the storm's first and worst force. A UNESCO mission found about 40 percent of the forest affected, foliage stripped across nearly a third of it; Bangladeshi assessments put the damage at roughly a quarter of the forest, with perhaps a tenth destroyed outright. The Sundarbans was badly hurt — and coastal Bangladesh was hurt far less than it would have been without it. The pattern has repeated: Aila in 2009, Bulbul in 2019, and Amphan in May 2020, when the Forest Department counted 12,358 trees uprooted, its own infrastructure damaged, and 40 of the forest's roughly 100 freshwater ponds — the wildlife's drinking water — turned saline. After Cyclone Remal in 2024, rangers recovered 138 dead animals, 134 of them deer. The forest heals between storms, but the intervals are shortening.
Salt is the slower assault. Dry-season flow down the Gorai River, the main distributary feeding the forest, has fallen sharply since the 1980s as more water is diverted upstream — a change researchers connect partly to the Farakka Barrage, operating since 1975 — while the sea itself rises. The result is a measurable creep of salinity from west to east, shifting whole zones from sundari towards hardier, smaller species and shrinking the freshwater refuges of fish and dolphins. A 2025 study in Communications Earth & Environment estimated that 10 to 15 percent of the forest showed a reduced ability to recover from stress between 2000 and 2024.
Industry presses at the edges. In December 2014 a tanker carrying some 358,000 litres of furnace oil sank in the Shela River after a collision, spreading oil through the forest's channels; a UN team found the immediate damage limited but warned that commercial shipping through the forest was an accident waiting to recur. Larger still is the Rampal power plant, a 1,320-megawatt coal station built about 14 kilometres from the forest boundary by a Bangladesh–India joint venture, which began generating in December 2022. A joint UNESCO–IUCN mission in 2016 recommended relocating the plant; the World Heritage Committee instead required a strategic environmental assessment of the region, and UNESCO has continued to press for its recommendations to be fully carried out. The government maintains that the plant's supercritical technology, tall chimney and emissions controls keep the forest safe; environmental groups continue to argue the risk is unacceptable. The argument, like the plant, is now a fixed feature of the landscape.
Protecting the Sundarbans
Protection here is older than the nation. The colonial government created a forest management division for the Sundarbans in 1869, declared most of it reserved forest in 1875–76, and set up the Khulna Forest Division in 1879 — making this one of the longest-managed mangrove forests in the world. Today the Forest Department runs the reserve through its Sundarbans East and West divisions and four ranges, policing a boundary that exists mostly on water. The three great southern sanctuaries, declared in 1977, anchor the World Heritage Site; the dolphin sanctuaries of 2012 extended protection into the rivers themselves.
Visitors see a fraction of it, on the forest's terms. There are no roads and no hotels in the reserve: travellers come by boat from Khulna or Mongla, under Forest Department permit, usually with licensed operators. Day trips reach Karamjal, with its boardwalks and wildlife breeding centre; cruises of two or three nights push on to the deer meadows of Katka and Kochikhali and the creeks of Hiron Point. The best months are November to February, and from June to August the forest closes to visitors entirely for the wildlife breeding season.
Conclusion
The Sundarbans is not wilderness set apart from Bangladesh; it is one of the country's working systems — a fish nursery, a honey reserve, a carbon store and, above all, a green wall that has absorbed the first shock of the Bay of Bengal's worst storms for as long as records exist. Its tigers are slowly increasing, its dolphins have sanctuaries of their own, and its protection regime is among the oldest in Asia. What it cannot do for itself is hold back the salt, the rising sea or the next cyclone. The forest that protects millions now depends, in turn, on how well it is protected.
