Sundarbans (; pronounced ) is a mangrove forest area in the Ganges Delta formed by the confluence of the Ganges River, Brahmaputra and in the Bay of Bengal. It spans the area from the Hooghly River in India's state of West Bengal to the Baleswar River in Bangladesh's Khulna Division. It comprises closed and open mangrove forests, land used for agricultural purpose, and barren land, and is intersected by multiple tide streams and channels. Spread across , it is the world's largest mangrove forest. The islands are also of great economic importance as a storm barrier, shore stabiliser, nutrient and sediment trap, a source of timber and natural resources, and support a wide variety of aquatic, benthic and terrestrial organisms. They are an excellent example of the ecological processes of monsoon rain flooding, delta formation, tidal influence and plant colonisation. Covering 133,010 ha, the area is estimated to comprise about 55% forest land and 45% wetlands in the form of tidal rivers, creeks, canals and vast estuarine mouths of the river. About 66% of the entire mangrove forest area is estimated to occur in Bangladesh, with the remaining 34% in India.[1]
Four protected areas in the Sundarbans are enlisted as UNESCO World Heritage Sites, viz. Sundarbans West, Sundarbans South, Sundarbans East in Bangladesh and Sundarbans National Park in India. The Indian Sundarbans were considered endangered in a 2020 assessment under the IUCN Red List of Ecosystems framework. The most abundant tree species are sundri ( Heritiera fomes) and gewa ( Excoecaria agallocha). The forests provide habitat to 453 fauna wildlife, including 290 bird, 120 fish, 42 mammal, 35 reptile and eight amphibian species. Despite a total ban on all killing or capture of wildlife other than fish and some invertebrates, there has been a consistent pattern of depleted biodiversity or loss of species in the 20th century, with the ecological quality of the forest declining.
The Sundarbans are under threat from both natural and human-made causes. In 2007, the landfall of Cyclone Sidr damaged around 40% of the Sundarbans. The forest is also suffering from increased salinity caused by sea level rise due to effects of climate change and reduced freshwater supply. In May 2009, Cyclone Aila devastated the Sundarbans with massive casualties. At least 100,000 people were affected by this cyclone. Climate change is expected to continue to negatively affect both natural systems and human populations in the region, resulting in further ecosystem degradation and climate migration. Experts examining the region recommend further focus on mangrove restoration and management and advocating for adaptation of human populations, through processes like managed retreat and investments in resilient infrastructure. The proposed coal-fired Rampal power station is anticipated to further damage this unique mangrove forest according to a 2016 report by UNESCO.
The Sundarbans is intersected by a complex network of tide waterways, and small islands of salt-tolerant mangrove forests. The interconnected network of waterways makes almost every corner of the forest accessible by boat. The area is known for the Bengal tiger ( Panthera tigris), as well as numerous fauna including species of birds, chital, and snakes. The fertile soils of the delta have been subject to intensive human use for centuries, and the ecoregion has been mostly converted to intensive agriculture, with few enclaves of forest remaining. The remaining forests, taken together with the Sundarbans mangroves, are important habitat for the endangered tiger. Additionally, the Mangroves species present in the Sundarban area serve a crucial function as a protective barrier for the millions of inhabitants in and around Kolkata, Khulna and Port of Mongla against the floods that result from the . It also protects from tsunami and soil erosion for the coastal population.
The Sundarbans along the Bay of Bengal has evolved over the millennia through natural deposition of upstream sediments accompanied by intertidal segregation. The physiography is dominated by deltaic formations that include innumerable drainage lines associated with surface and subaqueous levees, splays and tidal flats. There are also marginal marshes above mean tide level, tidal sandbars and islands with their networks of tidal channels, subaqueous distal bars and proto-delta clays and silt sediments. The Sundarbans' floor varies from above sea level.Katebi, M.N.A. and Habib, M.G. (1987). Sundarbans and Forestry in Coastal Area Resource Development and Management Part II, BRAC Printers, Dhaka, Bangladesh.
Biotic factors here play a significant role in physical coastal evolution, and for wildlife a variety of have developed which include beaches, Estuary, permanent and semi-permanent swamps, tidal flats, , coastal dunes, back dunes and levees. The mangrove vegetation itself assists in the formation of new landmass and the intertidal vegetation plays a significant role in swamp morphology. The activities of mangrove fauna in the intertidal mudflats develop micromorphological features that trap and hold sediments to create a substratum for mangrove seeds. The morphology and evolution of the eolian dunes is controlled by an abundance of xerophytic and halophytic plants. Creepers, grasses and sedges stabilise sand dunes and uncompacted sediments. The Sunderbans mudflats (Banerjee, 1998) are found at the estuary and on the deltaic islands where low velocity of river and tidal current occurs. The flats are exposed in low tides and submerged in high tides, thus being changed morphologically even in one tidal cycle. The tides are so large that approximately one third of the land disappears and reappears every day. The interior parts of the mudflats serve as a perfect home for mangroves.
A victim of large-scale clearing and settlement to support one of the densest human populations in Asia, this ecoregion is under a great threat of extinction. Hundreds of years of habitation and exploitation have exacted a heavy toll on this ecoregion's habitat and biodiversity. There are two protected areas – Narendrapur (110 km2) and Ata Danga Baor (20 km2) that cover a mere 130 km2 of the ecoregion. Habitat loss in this ecoregion is so extensive, and the remaining habitat is so fragmented, that it is difficult to ascertain the composition of the original vegetation of this ecoregion. According to Champion and Seth (1968), the freshwater swamp forests are characterised by Heritiera minor, Xylocarpus molluccensis, Bruguiera, Sonneratia apetala, Avicennia officinalis, and Sonneratia caseolaris, with Pandanus tectorius, Hibiscus tiliaceus, and Nipa fruticans along the fringing banks.
The Sundarbans flora is characterised by the abundance of sundari ( Heritiera fomes), gewa ( Excoecaria agallocha), goran ( Ceriops decandra) and keora ( Sonneratia apetala) all of which occur prominently throughout the area. The characteristic tree of the forest is the sundari ( Heritiera littoralis), from which the name of the forest had probably been derived. It yields a hard wood, used for building houses and making boats, furniture and other things. New forest accretions is often conspicuously dominated by keora ( Sonneratia apetala) and tidal forests. It is an indicator species for newly accreted mudbanks and is an important species for wildlife, especially spotted deer ( Axis axis). There is abundance of or ( Xylocarpus granatum) and ( Bruguiera gymnorhiza) though distribution is discontinuous. Among palms, Poresia coaractata, Myriostachya wightiana and golpata ( Nypa fruticans), and among grasses spear grass ( Imperata cylindrica) and khagra ( Phragmites karka) are well distributed.
The varieties of the forests that exist in Sundarbans include mangrove scrub, Littoral zone, saline water mixed forest, brackish water mixed forest and swamp forest. Besides the forest, there are extensive areas of brackish water and freshwater marshes, intertidal , , with typical dune vegetation, open grassland on sandy soils and raised areas supporting a variety of terrestrial shrubs and trees. Since Prain's report there have been considerable changes in the status of various mangrove species and taxonomic revision of the man-grove flora. However, very little exploration of the botanical nature of the Sundarbans has been made to keep up with these changes. Differences in vegetation have been explained in terms of freshwater and low salinity influences in the Northeast and variations in Drainage basin and siltation. The Sundarbans has been classified as a moist tropical forest demonstrating a whole mosaic of Seral community, comprising primary colonisation on new accretions to more mature beach forests. Historically vegetation types have been recognised in broad correlation with varying degrees of water salinity, freshwater flushing and physiography.
Most importantly, mangroves are a transition from the marine to freshwater and terrestrial systems, and provide critical habitat for numerous species of small fish, crabs, shrimps and other crustaceans that adapt to feed and shelter, and reproduce among the tangled mass of roots, known as , which grow upward from the anaerobic mud to get the supply of oxygen. A 1991 study has revealed that the Indian part of the Sundarbans supports diverse biological resources including at least 150 species of commercially important fish, 270 species of birds, 42 species of mammals, 35 reptiles and 8 amphibian species, although new ones are being discovered. This represents a significant proportion of the species present in Bangladesh (i.e. about 30% of the reptiles, 37% the birds and 34% of the mammals) and includes many species which are now extinct elsewhere in the country. Two amphibians, 14 reptiles, 25 aves and five mammals are endangered. The Sundarbans is an important wintering area for migrant water birds and is an area suitable for watching and studying avifauna.Habib, M.G. (1999). Message In: Nuruzzaman, M., I.U. Ahmed and H. Banik (eds.). The Sundarbans world heritage site: an introduction, Forest Department, Ministry of Environment and Forest, Government of the People's Republic of Bangladesh.
The management of wildlife is restricted to, firstly, the protection of fauna from poaching, and, secondly, designation of some areas as wildlife sanctuaries where no extraction of forest produce is allowed and where the wildlife face few disturbances. Although the fauna of Bangladesh have diminished in recent times and the Sundarbans has not been spared from this decline, the mangrove forest retains several good wildlife habitats and their associated fauna. Of these, the tiger and dolphin are target species for planning wildlife management and tourism development. There are high profile and vulnerable mammals living in two contrasting environments, and their statuses and management are strong indicators of the general condition and management of wildlife. Some species are protected by legislation, notably by the Bangladesh Wildlife (Preservation) Order, 1973 (P.O. 23 of 1973). THE ORIGINAL BANGLADESH WILDLIFE PRESERVATION ORDER 1973 THE DRAFT. nishorgo.org
Several predators dwell in the labyrinth of channels, branches, and roots that poke up into the air. This is the only mangrove ecoregion that harbors the Indo-Pacific region's largest terrestrial predator, the Bengal tiger. Unlike in other habitats, tigers live here and swim among the mangrove islands, where they hunt scarce prey such as the chital deer ( Axis axis), ( Muntiacus muntjak), wild boar ( Sus scrofa), and Rhesus macaque ( Macaca mulatta). It is estimated that there are now 180 Bengal tigers and about 30,000 spotted deer in the area. The tigers are known to attack and kill humans who venture into the forest, with around 40 deaths recorded in 2000–2010.
The endangered species that live within the Sundarbans and extinct species that used to be include the Bengal tiger, estuarine crocodile, northern river terrapin ( Batagur baska), olive ridley sea turtle, Gangetic dolphin, ground turtles, hawksbill sea turtles and king crabs (horse shoe). The Sundarbans hold globally important numbers of the critically endangered masked finfoot and are important wintering sites for the spoon-billed sandpiper and the Indian skimmer. Some species such as hog deer ( Axis porcinus), ( Bubalus bubalis), barasingha or swamp deer ( Cervus duvauceli), Javan rhinoceros ( Rhinoceros sondaicus), Indian rhinoceros ( Rhinoceros unicornis) and the mugger crocodile ( Crocodylus palustris) started to become extinct in the Sundarbans towards the middle of the 20th century, because of extensive poaching and hunting by the British and locals.Sarker, S.U. 1993. Ecology of Wildlife UNDP/FAO/BGD/85/011. Field Document N. 50 Institute of Forestry and Environmental Sciences. Chittagong, Bangladesh. There are other threatened mammal species, such as the capped langur ( Semnopithecus pileatus), smooth-coated otter ( Lutrogale perspicillata), Asian small-clawed otter ( Aonyx cinerea) and large Indian civet ( Viverra zibetha).
In many of the Bangladesh's mangrove wetlands, freshwater reaching the mangroves was considerably reduced from the 1970s because of diversion of freshwater in the upstream area by neighbouring India through the use of the Farakka Barrage bordering Rajshahi, Bangladesh. Also, the Bengal Drainage basin is slowly tilting towards the east because of neo-tectonic movement, forcing greater freshwater input to the Bangladesh Sundarbans. As a result, the salinity of the Bangladesh Sundarbans is much lower than that of the Indian side. A 1990 study noted that there "is no evidence that environmental degradation in the Himalayas or a 'greenhouse' induced rise in sea level have aggravated floods in Bangladesh"; however, a 2007 report by UNESCO, "Case Studies on Climate Change and World Heritage" has stated that an anthropogenic rise in sea level (likely by the end of the 21st century, according to the Intergovernmental Panel on Climate Change), combined with other forms of anthropogenic stress on the Sundarbans, could lead to the destruction of 75 percent of the Sundarbans mangroves. Case Studies of Climate Change , UNESCO, 2007 Already, Lohachara Island and New Moore Island/South Talpatti Island have disappeared under the sea, and Ghoramara Island is half submerged.
In a study conducted in 2012, the Zoological Society of London (ZSL) found out that the Sunderban coast was retreating up to in a year. Agricultural activities had destroyed around of mangroves within three decades (1975–2010). Shrimp cultivation had destroyed another .
Researches from the School of Oceanographic Studies, Jadavpur University, estimated the annual rise in sea level to be in 2010. It had doubled from recorded in 2000. The rising sea levels had also submerged around of forest areas. This, coupled with an around rise in surface water temperatures and increased levels of salinity have posed a problem for the survival of the indigenous flora and fauna. The Sundari trees are exceptionally sensitive to salinity and are being threatened with extinction.
Mangroves mitigate the effects of cyclones and tsunamis on coastal areas. Protecting mangrove health is therefore an urgent concern. Climate change-linked worsening of tidal and storm surges is causing flight to the mainland; about 13% of residents relocated in the decade of 2000–2010.
A 2015 ethnographic study, conducted by a team of researchers from Heidelberg university in Germany, found a crisis brewing in the Sunderbans. The study contended that poor planning on the part of the India and Bangladesh governments coupled with natural ecological changes were forcing the flight of human capital from the region
On 9 December 2014 an oil-tanker named Southern Star VII, carrying of furnace oil, was sunk in the Sela river of Sundarbans after it had been hit by a cargo vessel. The oil spread over area after the clash, as of 17 December. The slick spread to a second river and a network of canals in the Sundarbans and blackened the shoreline. The event was very threatening to trees, plankton, and vast populations of small fishes and dolphins. The event occurred at a protected Sundarbans mangrove area, home to the rare Irrawaddy and . Until 15 December 2014 only of oil from the area had been cleaned up by local residents, the Bangladesh Navy, and the government of Bangladesh. Some reports indicated that the event killed some wildlife. On 13 December 2014, a dead Irrawaddy dolphin was seen floating on the Harintana-Tembulbunia channel of the Sela River.
The forest has immense protective and productive functions. Constituting 51% of the total Reserve forest of Bangladesh, it contributes about 41% of total forest revenue and accounts for about 45% of all timber and fuel wood output of the country. A number of industries (e.g., newsprint mill, match factory, hardboard, boat building, furniture making) are based on raw materials obtained from the Sundarbans ecosystem. Non-timber forest products and help generate considerable employment and income opportunities for at least half a million poor coastal people. It provides natural protection to life and properties of the coastal population in cyclone-prone Bangladesh.
The Directorate of Forest is responsible for the administration and management of Sundarban National Park in West Bengal. The Principal Chief Conservator of Forests (PCCF), Wildlife & Bio-Diversity & ex-officio Chief Wildlife Warden, West Bengal is the senior most executive officer looking over the administration of the park. The Chief Conservator of Forests (South) & Director, Sundarban Biosphere Reserve is the administrative head of the park at the local level and is assisted by a Deputy Field Director and an Assistant Field Director. The park area is divided into two ranges, overseen by range forest officers. Each range is further sub-divided into beats. The park also has floating watch stations and camps to protect the property from poachers.
The park receives financial aid from the State Government as well as the Ministry of Environment and Forests under various Plan and Non-Plan Budgets. Additional funding is received under the Project Tiger from the Central Government. In 2001, a grant of US$20,000 was received as a preparatory assistance for promotion between India and Bangladesh from the World Heritage Fund.
A new Khulna Forest Circle was created in Bangladesh back in 1993 to preserve the forest, and Chief Conservators of Forests have been posted since. The direct administrative head of the Division is the Divisional Forest Officer, based at Khulna, who has a number of professional, subprofessional and support staff and logistic supports for the implementation of necessary management and administrative activities. The basic unit of management is the compartment. There are 55 compartments in four Forest Ranges and these are clearly demarcated mainly by natural features such as rivers, canals and creeks.
Recently West Bengal Cabinet has approved a new district in South 24 Parganas and proposed district was named Sundarban.
Protected areas cover 15% of the Sundarbans mangroves including Sundarbans National Park and Sajnakhali Wildlife Sanctuary, in West Bengal, Sundarbans East, Sundarbans South and Sundarbans West Wildlife Sanctuaries in Bangladesh.
In May 2019, the local authorities in Bangladesh killed 4 tiger poachers in a shootout in the Sunderbans mangrove area where currently 114 tigers dwell.
The area provides the setting for several novels by Emilio Salgari, (e.g. The Mystery of the Black Jungle). Sundarbaney Arjan Sardar, a novel by Shibshankar Mitra, and Padma Nadir Majhi, a novel by Manik Bandopadhyay, are based on the rigors of lives of villagers and fishermen living in the Sunderbans region, and are woven into the Bengali psyche to a great extent. Part of the plot of Salman Rushdie's Booker Prize winning novel Midnight's Children is set in the Sundarbans. This forest is adopted as the setting of Kunal Basu's short story "The Japanese Wife" and the subsequent film adaptation. Most of the plot of an internationally acclaimed novelist, Amitav Ghosh's 2004 novel, The Hungry Tide, is set in the Sundarbans. The plot centres on a headstrong American cetologist who arrives to study a rare species of river dolphin, enlisting a local fisherman and translator to aid her. The book also mentions two accounts of the Bonbibi story of "Dukhey's Redemption".Ghosh, A. (2005). The Hungry Tide: A Novel., Boston: Houghton Mifflin, pp. 84–88, 292–97 . Manik Bandopadhyay's Padma Nadir Majhi was made into a movie by Goutam Ghose.
The Sunderbans has been the subject of a detailed and well-researched scholarly work on Bonbibi (a 'forest goddess' venerated by Hindus), on the relation between the islanders and tigers and on conservation and how it is perceived by the inhabitants of the Sundarbans,Jalais, Annu. (2010). Forest of Tigers: People, Politics and Environment in the Sundarbans, Routledge: New Delhi, London, New York, . as well as numerous non-fiction books, including The Man-Eating Tigers of Sundarbans by Sy Montegomery for a young audience, which was shortlisted for the Dorothy Canfield Fisher Children's Book Award. In Up The Country, Emily Eden discusses her travels through the Sunderbans. Numerous documentary movies have been made about the Sunderbans, including the 2003 IMAX production Shining Bright about the Bengal tiger. The acclaimed BBC TV series Ganges documents the lives of villagers, especially , in the Sundarbans.
Sundarbans Mangroves
Ecological succession
Flora
Fauna
Mammals
Endangered and extinct species
Climate change impact
Hazards
Natural hazards
Human made hazards
Economy
Agriculture
Habitation
Administration
Protected areas
Sundarban National Park
Sundarbans West Wildlife Sanctuary
Sundarbans East Wildlife Sanctuary
Sundarbans South Wildlife Sanctuary
Sajnakhali Wildlife Sanctuary
In popular culture
See also
Notes
Sources
External links
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