Sundarban has gradually been deforested on the northern part although the dominance of green is recovering on its southern front hit by Sidr and Aila.
A recent study by the Soil Resource Development Institute unveils that an area of about 50,000 hectares of the country’s mangrove forest has been deforested in a decade after 2000.
The study also assessed that the aquaculture, excluding homestead ponds, in Khulna division has increased by about 50,000 hectares over the same period.
The study, titled ‘Trends in availability of agricultural land in Bangladesh’, was conducted using aerial photographs and land sat images to assess the changes in land use in various sectors, including crop agriculture, forestry, housing and aquaculture, between a 34-year time span from 1976 to 2010.
SRDI principal scientific officer Nazmul Hasan, also the principal investigator of the study, told the agency that the non-pond aquaculture, that is popularly known as Ghers (enclosures), particularly shrimp Ghers, that has marked the most significant rise in Khulna division between 2000 and 2010.
‘The area of non-pond aquaculture in that area was zero back in 1976, as it was recorded by previous studies, whereas in expanded over an area of 45,596 hectares in 2000, and 96,283 hectares in 2010, thanks to the expansion of shrimp Ghers,’ he pointed out.
Nazmul said the satellite images also indicate that the green cover of the Sundarbans was not much degraded due to cyclones like Sidr and Aila as it is claimed by different non-government organisations.
‘Contrary to the popular belief, the Sundarbans has been deforested along its northern front. It must be human interventions like felling of trees, salt pans, and Ghers,’ he said.
‘Factors responsible for the destruction of the mangrove forests are the removal of forest products for fuel, haphazard fishing activities, human settlement, salt production and shrimp farming,’ according to ‘National Programme of Action for Protection of the Coastal and Marine Environment from Land-Based Activities’ framed by the Department of Environment.
Nazmul said another important factor in this regard is that the mangroves of the country, including the planted mangroves along the shore land of the coastal districts, was in an increasing trend from 1976 to 2010.
‘We observed a 10 per cent increase in the mangroves between 1976 and 2000. This increase in mangrove forest may be due to mangrove plantation of 132000 hectares of land along the shore land of coastal districts up to 2000,’ he said.
Raihan Siddique, an assistant lab curator of Fisheries and Marine Resource Technology Department of Khulna University, who has frequented a major portion eastern part of the Sundarbans under a research project as a student of the same university from 2009-10, held that the shrimp firms are always expanding in Swarankhola and Satkhira ranges of the mangrove.
‘But the deforestation on the northern front is not as visible from the ground as it is observed inside the forests. Our research team has covered almost one-third of the Sundarbans. During the expeditions, we came across small pockets inside the forest where tree felling was going on,’ he said.
‘Aila and Sidr might not have left a severe impact on the green cover in the southern part of the forest. And we also came across mangroves at tender stages growing on newly accreted chars in that part. But the cyclones had an indirect impact by forcing out people towards the north,’ he noted.
After the cyclones, a good number of people from the southern ranges of the Sundarbans had to move towards the northern ranges that created immense pressure on the fisheries and even the vegetation in the northern Sundarbans, he said.
‘These days, the fishing is frequently done by mixing poisonous chemicals like Rotenone in the water of the canals and rivers inside Sundarbans. Besides polluting the water, the poison is also affecting the soil and the vegetation
at the tender stages,’ he added.
-With New Age input
