The sea is steadily eating into the Sundarbans, the world's largest delta and mangrove forest, threatening an ecological disaster for the Bengal basin region.
Saving the Sundarbans may be a lost cause, experts say
The 20,000 square kilometre forest delta stretches across the lower reaches of the Bengal basin - 60% falling in Bangladesh and the rest in the Indian state
of West Bengal.
Satellite imagery shows that the sea level in the Sundarbans has risen at an average rate of 3.14 centimetres a year over the past two decades - much higher than the global average of two millimetres a year.
Scientists believe that in the next 50 years, a rise of even one metre in sea level would inundate 1,000 sq.km of the Sundarbans.
"The Sundarbans appears to be a lost cause," says Professor Sugato Hazra, director of the School of Oceanographic Studies at Calcutta's Jadavpur
University, which runs a project in the Indian Sundarbans.
In the past two decades, four islands - Bedford, Lohachara, Kabasgadi and Suparibhanga - have sunk into the sea and 6,000 families have been made homeless.
Two other islands - Ghoramara and Mousuni - are fast going under.
Sagar, the biggest island in the Sundarbans, has already lost 30 sq.km.
By 2020, it will have lost another 15% of its habitable area, displacing more than 30,000 people, says Professor Hazra.
His study of satellite pictures reveals a worrying rate of coastal erosion in
the Indian Sundarbans.
"The entire island system is faced with a rapid loss of land area and
embankments, flooding and salinisation of drinking water," says Professor Hazra.
"Many residents are moving out; these islands are becoming uninhabitable," says Utpal Mukherjee, additional district magistrate of South 24-Parganas district, under which the Indian Sundarbans falls.
"It is a matter of time before the two islands of Ghoramara and Mousuni are swallowed up by the sea. We can only provide relief to the people. We cannot fight nature."
However, on Sagar, the district administration has tried to do just that.
It has constructed huge embankments to ring the coastal inlands.
But during high tides, the embankments are damaged. Some develop cracks and collapse.
Every winter, Sagar hosts the great Hindu festival, the Gangasagar Mela.
Tens of thousands of devotees pray at the temple of the great sage, Kapil Muni.
The new temple on Sagar is also under threat from the sea
The original temple was devoured by the sea during British rule. A new one had to be built several kilometres inland, but now the sea is closing in on that as well.
At Lot-8, the nearest land port to Ghoramara or Sagar, scores of families are
taking shelter from the islands.
"We will go looking for land elsewhere but many of us will become landless labourers," says Jagabandhu Das, a fisherman from Ghoramara.
A total of 54 of the 102 islands in the Indian Sundarbans are still habitable.
But they also face other pressures.
About 2,500 sq.km have been set aside as a tiger reserve since 1973 but poaching of the royal Bengal tiger continues, aided by corrupt forest officials.
Tree-felling during the past century has more than halved the mangrove cover in the Indian section as successive administrations allowed rampant land reclamation for human settlement.
Since the first settlements in 1770, the population of the Indian Sundarbans has risen 200% to nearly 4.3 million.
The population has put pressure on the ecosystem, which acts as a nursery for the aquatic resources of the Bay of Bengal.
Professor Hazra says mangrove depletion will increase the threat of flooding upstream in Calcutta. "It is an ecological disaster in the making," he says.
West Bengal's minister for Sundarbans development, Kanti Ganguly, admits that the situation is serious.
Under a directive from federal authorities, his government formed the Coastal Regulatory Zone Authority in 1999, specifically for the Sundarbans.
But the body did not meet for two years - and did little after that.
The authorities need to address a range of vital matters.
- The move towards a prawn monoculture - the cultivation of a single species that can lead to its extinction
- Erosion caused by the barraging of rivers and diversion or blocking of upstream water
- The use of mangrove wood to feed a gas plant in the Gosaba and
Choto Mollakhali islands. (The West Bengal Renewable Energy Development Agency has vowed to investigate the allegations and, if proven, halt the practice)
- The silting of West Bengal's largest port, Haldia, because only three of seven walls to divert the Hooghly river have been built by the Port Trust of India.
In the Sundarbans, the rising sea level and soil erosion threaten to submerge large swathes of land, making thousands more homeless.
The diverse marine life - river sharks, red crabs, shrimps, snakes - all uniquely adapted to the saline water - will be harmed, drastically affecting the food
chain and fishing industry.
Scientists say that the Sundarbans, South Asia's largest "carbon sink" - which mops up carbon dioxide - must survive to help prevent global warming. But will it?