On the delta of Brahmaputra, Ganges and Meghna lies 10,000 sq. km of mangrove forest cover (40% with India, rest with Bangladesh) that not only is known for its exceptional biodiversity but is also an ecologically fragile and economically important zone.
About Sunderbans
- It was declared as UNESCO’s world heritage site in 1987
- It’s an Amalgamate of 102 small islands.
- It’s also the world’s largest contiguous Mangrove cover.
- It’s an Abode for the National animal of India, the Royal Bengal Tiger
- Apart of being a Bioreserve, it’s also a part of Man and biosphere (MAB) program of UNESCO.
Importance
From preventing soil erosion by trapping sediments to Carbon sequestration and providing abode to numerous endangered species, mangroves are pivotal for the sustainable growth of various aquatic and terrestrial species. As for human settlements, mangroves act as excellent source for timber, animal fodder, medicinal plants and fuel wood. It also acts as a natural shield against calamities like sea storms, cyclones etc.
But Lately, this region has been under threat from human intervention and global warming. Unplanned constructions, increasing population, poverty, lack of awareness and illegal trading of timber and fuel wood has eventually lead to depletion of this vulnerable ecosystem. WWF, in 2010 published a report Sunderbans: Future imperfect (climate adaptation report)As per the report, Climate change has led to Unpredictable rainfall patterns, migration or extinction of some types of fish and rising sea level around mangroves.
Recently, the school of Oceanographic studies, Jadhavpur University published a report titled – Mangrove forest cover changes in Indian Sundarban (1986-2012) using remote sensing and GIS (Author : Kaberi Samanta, Sugata Hazra) which gives an insight as to how climate change is depleting Mangrove forests in Sunderbans.
Highlights Of Report (As per data published in The Hindu)
- Sunderbans has lost 5.5% of its Mangrove cover
- Total forest cover has declined by 2122.42 sq. km (2012) from 2,246.83 sq. km (1986)
- Bhangaduni, Gosaba, Dalhousie, Jambudwip and Dhulibasani west were the worst affected islands and witnessed a loss of 37%, 20%, 16%, 10% and 9.7% respectively.
- Sagar island (present at confluence of Ganga and Bay of Bengal) has been witnessing a mean sea level rise by 2.6-4mm per year (1986-2010)
Causes
- Increasing sea level due to climate change: This leads to intrusion of saline water in coastal regions which in turn leads to migration of various types of aquatic species.
- Less Inflow of fresh water and sediments
- Other causes: Deforestation, industrial pollution, indiscriminate encroachments since British era.
In India, Even though Mangroves have been included in the ecologically sensitive zone as per the Environment protection act of 1986, law enforcement remains weak. Both India and Bangladesh need to work closely to protect and preserve these dwindling forests. Creating awareness amongst the local communities regarding climate change, providing other employment opportunities, Promoting eco-tourism to reduce anthropogenic burden on the forests are some of the many suitable measures.
As per UNESCO, The mangrove ecosystem is depleting 4-5 times faster than the other forest systems. Thus, it’s required that the Countries where this ecosystem is prevalent work jointly and provide a time-bound action plan for its conservation before it’s too late.