Salinity turns coastal land unfarming
The intrusion of saline seawater into Bangladesh’s coastal belt is increasingly threatening freshwater sources, agriculture, and biodiversity, raising serious concerns over the long-term sustainability of life in the Sundarbans region.
Experts say rising sea levels in the Bay of Bengal, driven by climate change, are accelerating saltwater intrusion into farmland and freshwater bodies, resulting in declining crop yields, unsafe drinking water, and growing climate-induced migration toward urban areas.
At the same time, environmental degradation caused by the unchecked use of plastic and polythene is worsening the crisis. During the monsoon season, even moderate rainfall leads to widespread waterlogging as drainage systems become clogged with plastic waste.
These non-biodegradable materials also accumulate underground, disrupting natural water flow and contributing to the gradual depletion of groundwater reserves, further intensifying the environmental stress on coastal communities.
According to the Department of Public Health Engineering (DPHE), water containing 0 to 1,000 milligrams of dissolved salts per litre is considered safe for drinking. However, salinity levels in many coastal districts now range between 1,000 and as high as 10,000 milligrams per litre, leaving large populations with extremely limited access to safe drinking water.
This growing crisis is forcing communities to rely on unsafe sources or travel long distances to collect potable water.
Local residents describe the situation as increasingly unlivable. Alam Sana, a resident of Amadi village in Koyra, said that droughts, cyclones, heavy rainfall, and river erosion have become part of everyday life. He added that since Cyclone Aila, vegetation in the area has drastically declined, with most trees dying due to salinity, while the shortage of safe drinking water continues to worsen living conditions.
Nazrul Islam, deputy director of the Khulna Department of Agricultural Extension, told The New Nation that rice production is becoming increasingly vulnerable to rising temperatures. He said rice grows best at temperatures between 18 and 35 degrees Celsius, but yields decline once the temperature exceeds this range. He added that in recent years, average temperatures in Bangladesh have frequently crossed 40 degrees Celsius, disrupting pollination and adversely affecting overall crop production.
Officials from the Department of Public Health Engineering (DPHE), also speaking to The New Nation, said that water containing 0 to 1,000 milligrams of dissolved salts per litre is considered safe for drinking.
However, they warned that salinity levels in many coastal areas have now risen sharply, ranging from 1,000 to as high as 10,000 milligrams per litre, leaving communities with severely limited access to safe drinking water.
Alam Sana, a resident of Amadi village in Koyra, told The New Nation that extreme weather events have become a regular part of life in the coastal belt.
He said droughts, cyclones, heavy rainfall, and river erosion now occur frequently, adding that since Cyclone Aila, the area has lost much of its vegetation. He noted that most trees have died due to salinity, making the region increasingly difficult to live in, while the shortage of safe drinking water continues to worsen.
Dr Abdul Harun Chowdhury, professor at the Department of Environmental Science at Khulna University, told The New Nation that rising salinity is severely affecting biodiversity in the Sundarbans. He said salt-sensitive species such as the Sundari tree are gradually disappearing and being replaced by less valuable salt-tolerant species. He further added that habitats for wildlife and freshwater fish are shrinking, posing a serious threat to the overall ecosystem.
Md Shariful Islam, deputy director of the Department of Environment, told The New Nation that excessive groundwater extraction for agriculture and other uses in the Khulna region must be reduced.
He said falling groundwater levels, declining tree cover, and the filling of ponds are contributing to rising temperatures, although comprehensive research is still lacking to determine the exact causes. He added that the proposed Padma Barrage, if implemented and properly managed, could help reduce salinity intrusion in the region.
