Earth’s largest mangrove forest spans ten thousand square kilometres
Where the Ganges, Brahmaputra, and Meghna meet the Bay of Bengal, the Sundarbans spread about 10,277 square kilometres of mangrove, mudflat, and tidal creek—the world’s largest mangrove forest. Roughly sixty percent lies in Bangladesh and forty percent in India’s West Bengal.
Four protected tracts—Sundarbans West, South, and East in Bangladesh plus India’s Sundarbans National Park—are UNESCO World Heritage Sites. Habitat shelters 453 fauna species: 290 birds, 120 fish, 42 mammals, 35 reptiles, and eight amphibians. Sundri (Heritiera fomes) and gewa (Excoecaria agallocha) dominate the canopy; Bengal tigers haunt the boat-threaded maze. The name likely nods to sundari trees, though folk etymologies offer “beautiful forest,” Samudraban (“sea forest”), or a Chandra-bandhe tribal root.
Cyclone Sidr in 2007 damaged around forty percent of the forest. Rising seas and reduced freshwater raise salinity across the delta fringe; later storms keep scoring hits. In 2020, IUCN’s ecosystem Red List methods rated the Indian Sundarbans as endangered. UNESCO warned in 2016 that the coal-fired Rampal Power Station could further harm the mangroves. Human settlement traces reach Mauryan times; Baghmara Forest Block ruins tie to the Chand Sadagar legend in Bengali folklore.
The forest grew over millennia as silt from upstream settled among tidal channels, and the mangroves themselves help build new land. Behind the salty coastal fringe lies a second ecoregion of freshwater swamp forest, only slightly brackish and almost fresh in the rainy season when Ganges and Brahmaputra floodwater pushes the sea back. That inland zone has been cleared to support one of Asia's densest populations and is gravely threatened; its two reserves, Narendrapur and Ata Danga Baor, cover just 130 km² between them. Sundri alone makes up about 70% of the trees and is prized for timber, but over-harvesting and upstream water diversions put it at risk. The waterways also shelter chital, crocodiles, snakes and a goby, Awaouichthys menoni, found nowhere else and the sole member of its genus.
Source: Sundarbans
