Littoral and swamp forests: wetlands and mangroves

Detail

What littoral and swamp forests are

• Littoral forests (littoral means "of the seashore") grow along coasts. Swamp forests grow in wet, waterlogged land such as marshes.
• This group has two main parts:
• Mangroves, which grow in river deltas (where a river splits into many channels before it meets the sea) and in estuaries (where a river mouth mixes fresh water with sea water).

• Swamp forests of inland marshes and wetlands.

• A wetland is land that is covered with water, or soaked with it, for all or part of the year. Marshes, lakes, floodplains, lagoons and mudflats are all wetlands.

India's wetlands: the NCERT frame

• Area: about 3.9 million hectares. About 70 per cent of this is under paddy (rice) cultivation.
• Ramsar waterfowl sites named by NCERT:
• Chilika Lake (Odisha): a large brackish-water lagoon (a lagoon is a shallow coastal water body cut off from the sea by a sand bar) on the east coast.

• Keoladeo National Park (Bharatpur, Rajasthan): a freshwater wetland that hosts migratory birds.

• A Ramsar site is a wetland of international importance listed under the Ramsar Convention (1971, signed at Ramsar, Iran).

• Ramsar count now:
• India had 98 Ramsar sites on 31 January 2026, up from 26 in 2014. This is the highest number in Asia and the third highest in the world [5].
• 11 sites were added in 2025 [5].
• Glaw Lake became Arunachal Pradesh's first Ramsar site in August 2026, which took India's total to 101 [6]. (Details are in biodiversity-conservation.)
• Udaipur and Indore became India's first Ramsar-accredited Wetland Cities [5].

The eight wetland categories (NCERT)

#	Category	Example region
1	Reservoirs of the Deccan Plateau, plus lagoons and other wetlands of the south-west coast	Kerala backwaters
2	Vast saline (salty) expanses	Rajasthan, Gujarat, Rann and Gulf of Kachchh
3	Freshwater lakes and reservoirs from Gujarat eastward	Rajasthan (Keoladeo), Madhya Pradesh
4	Delta wetlands and lagoons of the east coast	Chilika (Odisha)
5	Freshwater marshes	Gangetic plain
6	Floodplains, plus hill marshes and swamps	Brahmaputra valley, North-East, Himalayan foothills
7	Mountain lakes and rivers	Kashmir and Ladakh
8	Mangrove forests and other island wetlands	Andaman and Nicobar island arcs

• Exam trap: the Rann of Kachchh is a saline wetland. It is not a mangrove forest. Gujarat's mangroves grow along the Gulf of Kachchh coast.

Mangroves: what they are and how they survive

• Mangrove: salt-tolerant trees and shrubs that grow on salt marshes, tidal creeks, mudflats and estuaries in tropical and subtropical coasts. A tidal creek is a narrow channel that fills and empties with the tide.
• How they adapt:
• The problem: tidal mud is waterlogged, so it holds very little oxygen.
  • Pneumatophores (breathing roots) grow upward out of the mud and take in air.

• The problem: the mud is soft and shifts with every tide.

  • Stilt roots (prop roots) arch down from the trunk and hold the tree firmly in place.

• Ecological role: they shelter birds and act as fish nurseries. Young fish, prawns and crabs grow up safely among the roots.

Mangrove area and where it is found

• NCERT figure: 4,992 sq km, about 7 per cent of the world's mangroves.

• NCERT says they are best developed in the Sundarbans and the Andaman and Nicobar Islands, then in the Mahanadi, Godavari and Krishna deltas.

• ISFR 2023 (India State of Forest Report, prepared every two years by the Forest Survey of India):

• Mangrove cover: 4,991.68 sq km, which is 0.15 per cent of India's geographical area [2].
• Share by state or UT:

Rank	State or UT	Share of India's mangroves (ISFR 2023)	Area
1	West Bengal (Sundarbans)	42.45% [2]	2,119.16 sq km [2]
2	Gujarat (Gulf of Kachchh coast)	23.66% [2]	1,164.06 sq km [2]
3	Andaman and Nicobar Islands	12.39% [2]	—

• Gujarat's growth: mangrove cover rose by 253.06 sq km between 2001 and 2023. This came from large planting drives, Public-Private Partnership, community involvement and protection [2].

• Distribution pattern:

• Mangroves grow mostly on the east coast. Its rivers (Ganga, Mahanadi, Godavari, Krishna, Kaveri) build wide, gently sloping deltas with large tidal mudflats.
• The west coast is narrow and steep and has few deltas, so its mangroves grow in thin strips. Gujarat is the exception, because its gulfs are shallow and have large tidal mudflats.

Map points (from east to south along the coast)

Sundarbans (West Bengal, about 21–22°N)

• It lies in the delta of the Ganga, Brahmaputra and Meghna rivers on the Bay of Bengal [7].
• It is the world's largest mangrove forest, shared between India and Bangladesh [7].
• The wider Sundarbans area covers about 10,000 sq km of land and water, and more than half of it is in India [7].
• About 78 mangrove species have been recorded here. This makes it the richest mangrove forest in the world [7].
• It is named after the sundari tree (Heritiera fomes).
• It holds the world's single largest population of tigers living in mangroves. The Royal Bengal tiger here has adapted to an almost amphibious life (living partly on land and partly in water). It swims long distances and eats fish and crabs [7].
• Other threatened species include Ganges and Irrawaddy dolphins, estuarine crocodiles and the critically endangered river terrapin (Batagur baska) [7].
• Status:
• Sundarbans National Park (India) became a UNESCO World Heritage Site in 1987 [7].
• The Bangladesh part is a separate World Heritage property, "The Sundarbans" [8].
• Indian Sundarbans became a Ramsar site in 2019.

Bhitarkanika mangroves (Odisha)

• They are India's second largest mangrove ecosystem, in the Brahmani–Baitarani delta (Kendrapara district, Odisha).
• They are known for saltwater (estuarine) crocodiles.
• Nearby Gahirmatha beach is a mass-nesting site for olive ridley turtles. Mass nesting, called arribada, is when thousands of female turtles come ashore together to lay eggs.

Other deltas and sites

• Mahanadi delta (Odisha).
• Coringa (Godavari delta, near Kakinada, Andhra Pradesh).
• Krishna delta (Andhra Pradesh).
• Pichavaram (Tamil Nadu, near the Vellar–Coleroon estuary).

Why mangroves matter

• Protection from storm surge and tsunami:
• A storm surge is a rise of sea water pushed onshore by a cyclone.
• How mangroves help: dense roots and trunks slow incoming waves → wave energy and water speed fall → less flooding and damage inland.

• 2004 Indian Ocean tsunami: villages behind thick mangroves (for example around Pichavaram in Tamil Nadu) suffered less damage than open coasts. (Link: natural-hazards-disasters.)

• Blue carbon: carbon stored in coastal ecosystems such as mangroves, seagrass and salt marshes.

• How mangroves store it: they take in CO₂ → roots and leaf litter are trapped in waterlogged mud → little oxygen means slow decay → carbon stays locked in the soil for long periods.

• Fisheries and livelihoods: fish nurseries, honey, crabs and prawns support coastal communities.

• Shoreline stability: roots trap silt, which helps hold the coast in place against erosion.

Threats

• Aquaculture ponds: prawn and shrimp farms are dug into mangrove land, for example in the Godavari and Krishna deltas.
• Land reclamation for farms, salt pans and towns.
• Port building and coastal industry.
• Pollution, and changes in fresh-water flow when upstream dams hold back river water. Mangroves need a balance of salt and fresh water.

MISHTI: the policy response

• MISHTI stands for Mangrove Initiative for Shoreline Habitats and Tangible Incomes.
• It was announced in the 2023-24 Union Budget and launched on 5 June 2023 (World Environment Day) [3].
• Target: restore and plant mangroves over about 540 sq km in 9 coastal states and 4 Union Territories [3].
• Period: five years, 2023-24 to 2027-28 [4].
• Funding by convergence (joining money from schemes that already exist):
• MGNREGS (rural job scheme).
• CAMPA (Compensatory Afforestation Fund Management and Planning Authority: money that projects pay when they use forest land, kept for replanting forests).

• Other sources [4].

• Where it plants: along the coastline and on salt-pan land.

• Progress:
• In FY 2024-25, ₹17.96 crore was given to Andhra Pradesh, Gujarat, Kerala, Odisha, West Bengal and Puducherry.
• This money is to treat and restore 3,836 hectares of degraded mangroves [3].
• Operational guidelines have been sent to the states [4].

Prelims Hooks

• ISFR 2023 mangrove cover: 4,991.68 sq km, which is 0.15% of India's area. (NCERT: 4,992 sq km, 7% of the world's mangroves.)
• Ranking of mangrove cover (ISFR 2023): West Bengal (42.45%) > Gujarat (23.66%) > Andaman and Nicobar (12.39%).
• Sundarbans: Ganga–Brahmaputra–Meghna delta; sundari tree; Royal Bengal tiger; UNESCO World Heritage Site 1987; Ramsar site 2019; shared with Bangladesh.
• Bhitarkanika: Brahmani–Baitarani delta, Odisha; saltwater crocodiles; nearby Gahirmatha has olive ridley mass nesting.
• Site–state pairs: Coringa → Andhra Pradesh (Godavari delta); Pichavaram → Tamil Nadu; Chilika → Odisha; Keoladeo → Rajasthan (Bharatpur).
• Root–function pairs: pneumatophores → breathing in oxygen-poor mud; stilt roots → holding the tree up in soft mud.
• Wetlands (NCERT): 3.9 million ha, about 70% under paddy, grouped into eight categories. Trap: the Rann of Kachchh is a saline wetland, not a mangrove.
• Ramsar sites: 98 on 31 January 2026; 101 after Glaw Lake (Arunachal Pradesh's first), August 2026. Udaipur and Indore are India's first Ramsar Wetland Cities.
• MISHTI: launched 5 June 2023; 540 sq km; 9 states and 4 UTs; 2023-24 to 2027-28; MGNREGS + CAMPA convergence.

Mains Points

• Distribution (GS-I):
• Mangroves are concentrated on the east coast and in the islands. Large deltas with tidal mudflats and a sheltered Bay of Bengal coast favour them.
• The west coast is steep and narrow, so its mangroves are thin strips. The exception is Gujarat's shallow gulfs.

• Gujarat's gain of 253 sq km between 2001 and 2023 shows that people-led planting can reverse the loss.

• Disaster risk reduction (GS-III):

• Mangroves are a bio-shield. The 2004 tsunami and repeated Bay of Bengal cyclones show that they reduce surge damage.

• This argues for "green-grey" coastal defence: mangroves used together with sea walls.

• Climate and economy (GS-III):

• Blue-carbon storage helps India's carbon-sink goals.
• Fish nurseries support coastal food security.

• Losses to aquaculture, reclamation and ports are a cost to development that environmental impact assessment should count.

• Policy response:

• MISHTI (540 sq km, MGNREGS + CAMPA convergence) and India's rapid growth in Ramsar sites (26 in 2014 → 101 in 2026) show a shift towards wetland and coastal conservation.
• The open questions are how many planted seedlings survive, how well salt-pan land is chosen, and how local communities take part.