In an advancement that will ring alarm bells for both environmentalists and policy producers, the mangrove forest cover in the Indian Sunderbans has been depleting alarmingly finished the past couple of decades.
Mangrove Forest Cover Changes in Indian Sundarban (1986-2012) Using Remote Sensing and GIS, a publication by the School of Oceanographic Studies, Jadavpur University, uncovers that from 1986 to 2012, 124.418 sq. km. mangrove forest cover has been lost.
The aggregate forest cover of the Indian Sunderbans as evaluated by remote sensing studies for the year 1986 was around 2,246.839 sq. km., which bit by bit declined by 2,201.41 sq. km. in 1996, at that point down to 2168.914 sq km in 2001 and to 2122.421 sq km in 2012. The loss in the mangrove forest in the Indian Sunderbans is around 5.5 %.
“The continuation of this process in light of climate change and sea level rise represents a genuine threat to the carbon sequestration potential and other ecosystem services of this mangrove forest in future,” creators SugataHazra and KaberiSamata noted.
The paper additionally takes note of that the mean sea level rise at the Sagar Island Station, measured from 1985 ahead till 2010, demonstrates a rise by 2.6-4 mm a year, which can be viewed as a driving factor for coastal erosion, coastal flooding, and an expansion in the quantity of tidal creeks.
The publication highlights a period arrangement of the erosion of no less than 18 mangrove forested islands of the Indian Sunderbans from 1986 to 2012. For example, the loss in mangrove cover at Gosaba has been around 20%, down from 517.47 sq km in 1986 to 506.691 sq km in 2012.
In Dulibhasani West, the loss of mangrove cover has been around 9.7% — from 180.03 sq. km. in 1986 to 163.475 sq. km. in 2012. The mangrove forest cover of Dalhousie, another island, has exhausted by 16%, from 76.606 sq. km. in 1986 to 64.241 of every 2012. Bhangaduni has one of the highest erosion levels of mangrove forest land, from 40.4 sq. km. in 1986 to 24.9 sq km in 2012, assuming the loss to more than 37%.
Jambudwip, one of the smallest uninhabited islands at the mouth of the sea, additionally has reduced forest cover from 6.095 sq. km. in 1986 to 5.003 sq. km. in 2012, or around 10%.
Different islands like Sajnekhali North, Matla and Bulchery have additionally endured critical mangrove loss.
Professor Hazra, who heads the School of Oceanographic Studies, Jadavpur University, clarified how climate change and sea level rise has added to the marvel of losing land, incorporating mangrove forests in the Sundarbans, in the last part of the 21st century.
“This is on the grounds that there is less fresh water stream and sediment supply in the western (Indian) part of the delta, so we have starvation of sediment and the rate of sea level rise is higher than sediment supply. Subsequently we are losing land, including mangrove forest,” he revealed to The Hindu.
As indicated by Professor Hazra, the eastern (Bangladesh) side of the delta is gaining land in light of the colossal measure of sediment and water spill out of the Brahmaputra and Meghna rivers. The loss of forest cover happens in spite of noteworthy expansion of forest land as plantations.
Ajanta Dey, joint secretary and project director of the Nature Environment and Wildlife Society (NEWS), a NGO that has been working in the Sunderban ecosystem, said that a critical minimal inflow of freshwater is necessary for the luxuriant growth of mangroves.
“At the point when freshwater inflow is missing, there is a change in mangrove progression, and freshwater cherishing species of mangroves are supplanted by salt-water adoring ones,” she called attention to.
She said the immediate impact of salinity will be on the fishing community, where commercially sought after fish species will be supplanted by fish that does not have as much market esteem.
Ms. Dey likewise alluded to a report by the Indian Space Research Organization (ISRO), which was presented before the Eastern Circuit Bench of the National Green Tribunal in 2015.
The report brought up that the Sunderbans has lost 3.71% of its mangrove and other forest cover, while losing 9,990 hectares of its landmass to erosion in one decade.
While prior studies likewise communicated concerns over the delicate ecosystem of the Indian Sunderbans that, other than being home to the Royal Bengal Tiger, additionally harbors a populace of 4.5 million individuals, this examination presents clear proof of the loss of land and mangrove cover.
