Sundarbans

Sundarbans, the world’s largest mangrove forest ecosystem, is a biodiversity hotspot located in the delta formed by the Ganges, Brahmaputra, and Meghna Rivers in the Bay of Bengal.  This unique ecosystem, spanning from the Hooghly River in West Bengal to the Baleswar River in Bangladesh, is home to a rich variety of flora and fauna, including the Royal Bengal Tiger. The Sundarbans, recognized as a UNESCO World Heritage Site, plays a significant role in the livelihood of over 4 million people.

In this article, you will learn about unique flora and fauna, climate, soil, and ecoregions of Sundarbans, its global recognition, and the challenges it faces. It is a must-read for aspirants preparing for UPSC CSE Exam as it is most important topic for GS Paper-3 Environment & Ecology.

Table of Contents

• What is Sundarbans?
• Flora and Fauna in Sundarbans
• Soils of Sundarbans
• Climate of Sundarbans
• Ecoregion of Sundarbans
• Recognition Given to Sundarbans
• Significance of Sudnarbans
• Threats faced by Sundarbans
• Conclusion
• Frequently Asked Questions on Sundarbans

What is Sundarban?

• Sundarbans are world’s largest mangrove forest ecosystem and accounts to 60% of all mangrove forests in India.
• Sundarbans is located in the delta formed by the confluence of Ganges, Brahmaputra and Meghna Rivers in the Bay of Bengal.
• Sundarban delta or mangrove-dominated Ganges Delta or Ganges Brahmaputra delta is the world’s largest and fastest growing delta.
• Sundarbans spans from the Hooghly River in West Bengal to the Baleswar River in Bangladesh.
• Sundarban Reserve Forest (SRF), a natural biodiversity hotspot, of Bangladesh is the largest mangrove forest in the world.
  • SRF is located in Bangladesh between the river Baleswar in the East and the Harinbanga in the West, adjoining to the Bay of Bengal.
• The entire Sundarbans landscape covers around 10,000 km², with only 4200 sq.km of mangrove habitat being within Indian territory.
• While the Sundarbans Tiger Reserve was created in 1973, the Sundarbans National Park, was established in 1984 and constitutes a core region within the tiger reserve.
• Sundarbans derive its name from the Sundari trees (Heritiera fomes) that are found abundantly in the Sundarbans.
  • Four protected areas in the Sundarbans are enlisted as UNESCO World Heritage Sites:
• Sundarbans National Park
• Sundarbans West Wildlife Sanctuary
• Sundarbans South Wildlife Sanctuary
• Sundarbans East Wildlife Sanctuary

Flora and Fauna in Sundarbans

• Sundarbans, including Sundarbans national park, is famous for Royal Bengal tigers.
  • Out of world’s 2,500 Royal Bengal tigers, it is home to about more than 100 Royal Bengal Tigers.
• The Sundarbans wildlife is rich and diverse, with the Sundarbans forests (locally known as Badabon) being home to a variety of species including Ganges and Irawadi dolphins, Estuarine Crocodile, Water Monitor Lizard, the critically endangered endemic river terrapin (Batagur baska), and Olive Ridley Turtles.
• It is the only mangrove habitat in the world for Panthera tigris tigris species.
• The tigers of Sundarbans are morphologically different from Peninsular India.
  • Due to the uniqueness of the landscape, geographical extent of the sundarbans tiger population is limited to the available mangrove habitat.
• It is home to nine out of 12 species of kingfishers found in India as well rare species such as the Goliath heron and Spoon-billed Sandpiper.
• The mudflats and wetlands of Sundarbans act as a stopover site for migratory flight south (south wards) and back.
  • The mudflats exposed in the low tides, rich in microorganisms deposited during tidal activity are ideal feeding for migratory birds.  
• Other flora found here includeGewa, Kankra, Khalsi, Dhundal, Passur, Garjan, Goran, Kankara etc.

Soils of Sundarbans

• The vegetation in the Sundarbans mangrove forest is naturally affected by the effects of salinity and waterlogging, which are not present in other inland soils.
• The soils in some places are semi-solid and poorly consolidated.
• The grain size distribution of the Sundarbans soil is highly variable, despite being generally medium textured, sandy loam, silt loam, or clay loam.
• While soil salinity increases from east to west, it is not uniform from north to south throughout the forest.

Climate of Sundarbans

• Since the forest is located on the south of the Tropic of Cancer and bounded by the northern limits of the Bay of Bengal, it is classified as tropical moist forest.
• The temperatures in the Sundarbans are fairly equable than those of the adjacent land areas.

Ecoregion of Sundarbans

Sundarbans has two ecoregions: Sundarbans freshwater swamp forests and Sundarbans mangroves.

Sundarbans freshwater swamp forests

• These tropical moist broadleaf forests are found in Bangladesh’s Sundarban region.
• Situated between the inland Lower Gangetic plains moist deciduous forests and the Sundarbans mangroves along the Bay of Bengal, they form a unique ecosystem.

Sundarbans Mangroves

• This ecoregion forms the coastal edge of the delta.
• It is characterized by a dense canopy and an undergrowth largely comprising mangrove tree seedlings.

Recognition Given to Sundarbans

• UNESCO World Heritage site- 1987
• Biosphere Reserve by UNESCO- 2001
• Wetland of International Importance under the Ramsar Convention- 2019
• Important Bird Area (IBA)

Significance of Sundarbans

• Over 4 million people live in the Sundarbans.
• Agricultural communities inhabit numerous villages along the north-western border of the Sundarban tiger reserve, relying heavily on the area’s natural resources for their livelihood.
• It is the single largest source of forest products in Bangladesh.
• Non-timber forest products, such as thatching materials, honey, and beeswax, are also found in the region.
• The vegetated tidal lands of the Sundarbans serve as critical habitat, nutrient producers, and water purifiers.
• The region acts as a storm barrier, coastal stabilizer, and energy storage system.
• The Sundarban attract both local and international tourists for their natural beauty.
• Various industries, including newsprint mills and match factories, rely on raw materials sourced from the Sundarbans ecosystem.
• Folk songs and dances celebrating the Sundarbans, its unique culture and local deities (such as Bonbibi, Dakshin Rai, Manasa, and Chand Sadagar), are popular in the region.
• Sundarbans is not only famous for its tigers, but also for its medicinal plants, other wild animals, rivers, food, and habitat.

Threats faced by Sundarbans

• The Sundarbans’ geographic position makes it susceptible to climate change and rising sea levels.
  • However, diversion of water by India through the Farakka Barrage since the 1970s has resulted in reduced water flow to Bangladesh’s mangrove wetlands.
• Annual accretion and erosion significantly impact the region.
• Livelihood activities, such as forestry, fishing, and extraction of palm and timber, as well as increased national and international waterways, lead to interference in the ecosystem.
• The Sundari trees, highly sensitive to salinity, face the threat of extinction.
• Many argue that the Rampal Power Station, under construction just 14 km from the Sundarbans in Bangladesh, violates the provisions of the Ramsar Convention and will badly impact the Sundarbans ecosystem.        

Sundarbans Oil Spill (2014)

• The 2014 Sundarbans oil spill, a significant environmental incident, occurred when an oil-tanker collided with a cargo vessel in Bangladesh’s Shela River, spilling 350,000 litres of furnace oil across 350 km² of this UNESCO World Heritage Site.

Conclusion

Given the various challenges faced by the region, it is crucial for the Indian government to take proactive measures to ensure the long-term sustainability of Sundarbans. A balanced approach should involve collaboration with the Bangladeshi government to address transboundary issues and develop joint conservation strategies. It can also invest in R&D of sustainable livelihood alternatives for local communities that depend on the Sundarbans’ resources.

Ref: Source-1

FAQs (frequently asked question)