Sundarbans

Topic: Biodiversity and its Conservation · NCERT: Class 7, Ch 1 "Geographical Diversity of India"; Class 7, Ch 2 "India and Her Neighbours"

Meaning

The Sundarbans is the world's largest mangrove forest. It lies in the Ganga-Brahmaputra delta at the head of the Bay of Bengal. India holds about 40% of it, in West Bengal, and Bangladesh holds the rest. Mangroves are salt-tolerant trees and shrubs that grow in tidal mud along warm coasts.

It matters for two reasons. It is a natural wall that protects the coast from cyclones. It is also the only mangrove home of the Royal Bengal tiger, and it carries several global labels: tiger reserve, World Heritage Site and Ramsar site.

Explanation

How the Sundarbans forms (cause → process → result)

• Rivers bring silt:
• The Ganga and the Brahmaputra carry huge loads of silt (fine, fertile soil) down to the sea. On the Bangladesh side, the Meghna also joins in [4].
• Near the sea the rivers slow down and drop this silt. Over time the silt builds a delta (a low, fan-shaped area of land at a river's mouth).

• The result is hundreds of islands cut by a maze of rivers, rivulets and creeks [3].

• Tides make the land salty:

• Twice a day, sea water flows in and out along the creeks.
• The mud becomes salty and is often under water.
• Only mangroves, which can live in salty, tidal mud, grow well here. The forest gets its name from the sundari tree, a common mangrove of the area.

Conditions mangroves need

• Warm tropical coasts.
• Tidal mud flats that fill with sea water and drain again.
• Mixed fresh and salt water, which a delta gives, since river water meets sea water there.
• Shelter from very strong waves, which a maze of islands and creeks gives.

Why it matters

• Coastal shield:
• Cyclones form over the Bay of Bengal and drive storm surges (walls of sea water pushed onto land by strong winds).
• Dense mangrove roots slow the waves and hold the mud in place.

• The result is less flooding and less erosion inland.

• India's mangrove store: the Indian Sundarban has over 60% of India's total mangrove area and 90% of Indian mangrove species [3].

• Royal Bengal tiger: the tigers here swim in saline (salty) water and live on tidal islands.

Protection status (Indian side, Sundarbans National Park)

Label	Year	Note
Tiger reserve	1973	One of the first nine Project Tiger reserves
World Heritage Site	1987	Natural site, West Bengal [2]
Ramsar site	2019	"Sundarban Wetland", Site no. 2370. It is India's largest Ramsar site, at about 0.42 million ha [3]

• Project Tiger (1973) is India's central programme to save tigers through tiger reserves, which are protected areas managed mainly for tigers.
• A Ramsar site is a wetland of international importance under the Ramsar Convention (1971), a global treaty to protect wetlands.
• A World Heritage Site is a place listed by UNESCO under the World Heritage Convention (1972) for its "outstanding universal value".

Problems it faces

• Human-tiger conflict:
• People enter the forest to collect honey, catch fish or gather crabs.

• Tigers sometimes attack them.

• Sea-level rise:

• The sea rises, so low islands go under water and the soil becomes saltier.
• As a result, people and wildlife lose their habitat.

Where it occurs

• Location: the Ganga-Brahmaputra delta, at the head of the Bay of Bengal. The Meghna joins on the Bangladesh side [4].
• India: about 40% of the forest, in West Bengal. It is protected as Sundarbans National Park, which is a tiger reserve (1973), a World Heritage Site (1987) [2] and a Ramsar site ("Sundarban Wetland", 2019) [3].
• Bangladesh: the rest of the forest. The Sundarbans Reserved Forest has been a Ramsar site since 21 May 1992. It covers 6,01,700 ha [4].
• Its place among India's natural World Heritage Sites: it came after the 1985 group (Kaziranga, Manas and Keoladeo) and before Nanda Devi and Valley of Flowers (1988) [2].

Don't confuse with

• Kaziranga National Park (Assam): a Brahmaputra floodplain and grassland ecosystem, famous for the one-horned rhino and listed as a World Heritage Site in 1985 [2]. The Sundarbans is a delta mangrove ecosystem, famous for the tiger and listed in 1987 [2].
• Keoladeo (Bharatpur, Rajasthan): one of India's first two Ramsar sites (1981) [5]. The Sundarban Wetland (2019) is India's largest Ramsar site [3], not one of the first.
• "Reserved forest" as an Indian forest category: in India this is a legal type of forest land, the one with the strongest protection. The Sundarbans Reserved Forest is the name of the Bangladesh Ramsar site (1992) [4], not the Indian part.
• Protected area vs protected forest: Sundarbans National Park is a protected area under the Wild Life (Protection) Act, 1972. A "protected forest" is only a forest-land category.

Prelims Hooks

• World's largest mangrove forest → Sundarbans → Ganga-Brahmaputra delta (with the Meghna on the Bangladesh side) [4]. India has about 40% (West Bengal) and Bangladesh has the rest.
• India's largest Ramsar site → Sundarban Wetland, added in 2019, Site no. 2370, about 0.42 million ha [3].
• Sundarbans National Park → tiger reserve 1973 (one of the first nine) → World Heritage Site 1987 [2] → Ramsar site 2019 [3].
• The Indian Sundarban has over 60% of India's mangrove area and 90% of Indian mangrove species [3].
• Bangladesh's Sundarbans Reserved Forest became a Ramsar site on 21 May 1992, earlier than the Indian side (2019) [4].
• Trap: Sundarbans (1987) is not part of the 1985 natural World Heritage group (Kaziranga, Manas, Keoladeo).

Mains Points

• Climate frontline (GS-III, disasters and environment):
• Mangroves weaken cyclones and storm surges from the Bay of Bengal. They protect the coast and hold over 60% of India's mangrove area [3].
• Sea-level rise drowns low islands and makes the soil saltier, which threatens both wildlife and the people who live there.

• Response: protect and replant mangroves as a nature-based coastal defence.

• People and wildlife (GS-III):

• People who collect honey, catch fish or gather crabs face tiger attacks. This is human-tiger conflict.

• Response: provide other ways to earn a living, and involve local people in conservation instead of only keeping them out.

• Shared across a border (GS-II/III):

• India's Sundarban Wetland [3] and Bangladesh's Sundarbans Reserved Forest [4] are both Ramsar sites.
• The tigers, rivers and silt move across the border, so the two countries need to manage the forest together and share data.

Related concepts

• National park
• Wildlife sanctuary
• Corbett National Park
• Kaziranga National Park
• Keoladeo National Park
• Great Himalayan National Park
• Sundarbans National Park
• Natural World Heritage Sites of India

Read more

• Protected forests and protected areas: national parks, sanctuaries and World Heritage sites