Plastic waste is quietly turning into a growing ecological threat to the Sundarbans, with bottles, discarded fishing gear, polythene bags, foam sheets, sandals and other plastic debris increasingly washing into the world’s largest mangrove forest through rivers, tidal channels and the sea.
For fishermen who spend days inside the forest, the problem is no longer difficult to spot.
“Even when we don’t find fish in our nets, we find plastic bottles, fishing-net buoys, plastic packets, foam sheets, sandals and gas lighters in different parts of the forest,” said Khobir Sheikh, 65, a fisherman from Mongla in Bagerhat.
He said the Forest Department repeatedly warns fishermen not to carry polythene or other plastic items when they collect permits to enter the forest.
The growing presence of plastic has alarmed forest-dependent communities, tourism operators and forest officials, who fear that pollution could gradually undermine the ecological health of the Sundarbans and the livelihoods that depend on it.
At a consultation meeting held at the Bagerhat deputy commissioner’s conference room on Tuesday, participants called for coordinated action involving government agencies, private organisations, elected representatives, the media and young people to curb plastic pollution and improve waste segregation and recycling.
Microplastics already in river sediments
The scale of the problem is also reflected in recent scientific findings.
A study by the Department of Environmental Science and Technology at Jashore University of Science and Technology, published in the international journal Emerging Contaminants in January this year, detected microplastics and heavy metals in sediment from the Bhairab and Rupsha rivers, two waterways connected to the wider coastal ecosystem.
Researchers found as many as 5,700 microplastic particles per kilogramme of sediment at depths of 10 to 30 centimetres.
Polyethylene accounted for around 23 percent of the identified plastics and polystyrene about 21 percent. The researchers also detected heavy metals including lead, copper, nickel, cadmium and chromium.
The findings raise concerns over the combined impact of plastic particles and toxic metals on aquatic ecosystems and organisms that depend on them.
A separate joint study by Bangladeshi and Indian researchers, published in the Journal of Hazardous Materials Advances in 2022, also warned of increasing plastic and microplastic pollution in the Sundarbans and the Bay of Bengal.
According to the study, around three billion microplastic particles enter the Bay of Bengal every day through the Ganges-Brahmaputra-Meghna river system. It estimated that millions of tonnes of plastic waste from rivers in Bangladesh and India enter the Bay of Bengal and the Sundarbans region each year.
Researchers warned that the problem goes beyond visible waste. Tidal movements can carry microplastics through the forest’s waterways and sediments, potentially allowing them to enter the food chain.
Waste management remains the weak link
Tourism operators say inadequate waste management is one of the major reasons behind the accumulation of plastic in and around the forest.
Shah Zaman Khan Popul, general secretary of the Tour Operators Association of Sundarbans (TOAS), said a clean-up campaign conducted in the first week of September, following the three-month closure of the forest, collected 15 sacks of plastic waste in just three days.
“Plastic bottles, sandals, lighters, fishing buoys, foam sheets and polythene were among the waste we collected,” he said.
Not all of the waste, however, comes from tourists, Popul said.
“Plastic waste is also reaching the Sundarbans through rivers and the sea. Tour operators are working strictly to prevent pollution, but the Sundarbans cannot be protected without an effective overall waste-management system,” he said.
Around 70 vessels are involved in tourism operations in the Sundarbans, according to people familiar with the sector. The tourism season began in September, but visitor numbers have so far remained below expectations. Operators expect the situation to improve in November and December.
Forest Department seeks collective action
The Forest Department says it has tightened measures to prevent pollution and is working to raise awareness among local communities, young people and forest-dependent people.
“The Forest Department is taking a strict position to prevent pollution in the Sundarbans,” said Mohammad Imran Ahmed, regional forest conservator in Khulna.
“We are working to raise awareness among local communities, young people and forest-dependent people. But ultimately, everything depends on collective awareness,” he said.
“The Sundarbans has been protecting and sustaining us. If we fail to protect the forest, a major disaster could follow,” he added.
Experts say tackling the problem will require measures far beyond the boundaries of the forest, including better waste collection and recycling systems in upstream towns and cities, tighter control over single-use plastics and stronger coordination among government agencies, businesses and local communities.
For the Sundarbans, where hundreds of rivers and tidal waterways connect the forest to the Bay of Bengal, preventing plastic from entering the water system may be far more effective than trying to remove it after it reaches the mangrove ecosystem.
