Bangladesh’s iconic river dolphins—the Ganges River Dolphin (Platanista gangetica) and the Irrawaddy Dolphin (Orcaella brevirostris)—are rapidly losing their habitats as pollution, water diversion, and unregulated river use continue to degrade the country’s aquatic ecosystems, according to a government-backed atlas published by the Bangladesh Forest Department.
The Atlas on Ganges River Dolphin and Irrawaddy Dolphin of Bangladesh, jointly prepared by the Forest Department and the United Nations Development Programme (UNDP), offers the most comprehensive mapping yet of the nation’s freshwater and coastal dolphin habitats.
It identifies at least 10 critical winter habitats across major river systems, including the Padma, Jamuna, Meghna, Halda, and Karnafuli rivers, while warning that many tributaries may no longer support dolphins during the dry season.
“Although all the major river systems still support Ganges River Dolphins, tributaries like the Dorla, Teesta, Sangu, and Kushiyara have become unsuitable during winter months,” the atlas states.
A vanishing symbol of river health
Once abundant across the Ganges-Brahmaputra-Meghna river network, the Ganges River Dolphin—locally known as Shushuk—is now classified as endangered by the International Union for Conservation of Nature (IUCN).
Fewer than 1,200 individuals remain worldwide, with Bangladesh hosting one of the last viable populations.
The Irrawaddy Dolphin, which thrives in brackish waters, is confined to moderate and high-salinity zones in the Sundarbans and the coastal belt.
But rising salinity, intensified boat traffic, and pollution are threatening its survival.
“The Irrawaddy dolphin’s range is shrinking as salinity levels rise and boat traffic increases in the Sundarbans estuaries. Pollutants from large commercial vessels and the use of fishing nets near the Sundarbans are endangering the species,” said Syed Mahmudur Rahman, a mammologist at the Forest Department.
Pollution, dams choking river life
The atlas highlights the combined threats of industrial waste, agricultural runoff, and reduced freshwater flow caused by upstream barrages such as Farakka and Teesta.
In many stretches of the Padma and Jamuna, dissolved oxygen levels have plummeted, while fish diversity—an essential food source for dolphins—continues to decline.
Dolphins frequently die after becoming entangled in fishing nets, particularly gillnets used by local fishers.
Carcasses have recently been found near Godagari and Boral in Rajshahi and close to the Bhairab Bridge in Meghna—areas once known as dolphin hotspots.
“The rivers are dying, and with them, the dolphins,” said a Forest Department official involved in the survey.
“Their disappearance is a warning that our river ecosystems are collapsing.”
Fragmented habitats, weak enforcement
Bangladesh has so far declared nine dolphin sanctuaries—three in the Sundarbans (Chandpai, Dhangmari, and Dudhmukhi), three in the Padma–Jamuna confluence (Silonda–Nagderma, Nazirgonj, and Nagarbari–Mohonganj), and three more near the Sundarbans established in 2022.
However, enforcement remains weak. Researchers have documented illegal fishing and sand extraction even within protected zones.
“Habitat fragmentation, unregulated vessel movement, and lack of seasonal water flow management are making sanctuaries less effective,” the atlas warns.
Climate change deepens the crisis
Climate change is compounding the threats, with erratic rainfall, prolonged dry seasons, and rising salinity transforming river ecosystems faster than dolphins can adapt.
“Dolphins are indicator species; their survival mirrors the health of our rivers,” said Dr Abdul Aziz, zoologist at Jahangirnagar University and lead author of the atlas. “If they disappear, it means the river itself is beyond recovery.”
Action plan stalled
In October 2023, the government launched a 10-year Conservation Action Plan (2021–2030) to address dolphin killings, habitat loss, and the growing dependency of river communities on shrinking aquatic ecosystems.
The plan, developed by the Forest Department with UNDP, NGOs, research institutions, and law enforcement agencies, proposed nationwide habitat monitoring, tracking dolphin movements, reducing accidental deaths, and expanding protected areas.
The estimated implementation cost was about Tk300 million over the decade.
Yet, Forest Department officials confirmed that no large-scale programs have begun since the plan’s publication.
“A few smaller projects like SUFOL exist, but no combined, nationwide efforts have been taken,” said Dr Aziz.
“We need a coordinated national plan to save dolphins before it’s too late. Without immediate protection, we risk losing them within our lifetime.”
Counting the last survivors
Md Amir Hosain Chowdhury, chief conservator of forests, said a nationwide survey last year estimated 1,352 Ganges River Dolphins in Bangladesh.
Awareness campaigns are ongoing in coastal areas to reduce fishing-related deaths, he added.
“International Freshwater Dolphin Day is observed annually on October 24. This year, celebrations will be held on October 26 to raise public awareness about dolphin conservation,” he said.
