Saving the Ganges river dolphin, and healing the holy river

The Ganges River dolphin (GRD) (Platanista gangetica) is one of the world’s most endangered freshwater mammals. It is found in the Ganga river and its tributaries in India, such as the Yamuna, Chambal, Ghagra, Gandak, Rapti, Narayani and Kosi. The fish primarily inhabits freshwater and estuarine zones, is shy and blind and never ventures out into the ocean. 

Guardians of the river’s balance

Dolphins are crucial for maintaining the health of rivers. They are top predators in river habitats and maintain the food chain and the equilibrium of the river. The survival of other fish and crustaceans in the water and the survival of other animals in the food web depend on their healthy population.

However, their counts in the Ganges are dwindling. Once numbering around 6,000 in the 1980s, their population has dropped sharply due to pollution, dams, and habitat loss. A recent study on the presence of GRD in the Bhagirathi–Hooghly River systems of West Bengal has recorded 303 dolphins, with higher numbers found in the dry season than in the wet season. 

In 2009, India named the dolphin its National Aquatic Animal. Yet, only one sanctuary—the Vikramshila Dolphin Sanctuary near Bhagalpur—offers dedicated protection. The species is listed as Endangered by the IUCN and receives top-tier protection under Indian and international wildlife laws. Prime Minister Narendra Modi launched Project Dolphin in 2020 that aims to protect both river and marine dolphins by involving local communities, improving habitats, and raising awareness. 

But challenges remain. Most dolphin habitats are still unprotected, and threats like fishing nets and untreated sewage persist. 

Fragmented by barrages, confined by change

Since the Farakka Barrage began operating in 1975, the once-continuous Ganges River dolphin population has fractured into isolated groups. Today, dolphins are found in five distinct subpopulations across India:

• Farakka to Brahmaputra

• Ganga Sagar

• Bijnor to Narora

• Narora to Kanpur Barrage

• Kanpur Barrage to Farakka

These divisions caused by dams and barrages have disrupted dolphin movement, breeding, and access to prey and made the fish more vulnerable to local threats, highlighting the urgent need for habitat connectivity and coordinated conservation.

Little is known about the state of the lower Ganga GRD population at present. The study titled ‘Status of Ganges River dolphin Platanista gangetica (Lebeck, 1801) in the lower stretch of the Ganga River, India, with emphasis on threats, conservation, and recommendations’ published in Frontiers in Ecology and Evolution conducted a seasonal survey of the GRD at the Bhagirathi–Hooghly River systems of West Bengal to investigate the abundance, habitat use, and potential threats in the lower stretches of the river.

River dolphins in the lower Ganga: what the study reveals

• Three hundred three dolphins were counted in the lower Ganga stretch. More were seen in the dry season than the wet.

• Most dolphins swam in small groups of 3–5, but larger groups (up to 17) gathered at river confluences like Katwa, Nabadwip, Sabuj Dweep, Balagarh, and Kulpi—places with deeper water and more fish.

• The highest number of dolphin sightings were at the confluence of rivers and channels, as well as in the ferry ghats. River confluences, which are generally regarded as high fish assemblage areas due to favourable hydrobiological conditions and adequate depth were found to be favourable dolphin microhabitats. Ferry ghats, where human activities are more common and food supplies were accessible for the fish in the surrounding areas, were frequent sites of dolphin sightings.

• Even the Farakka Feeder Canal had 37 dolphins where dolphins assembled for breeding and/or migration from nearby areas, showing that man-made channels can support wildlife if conditions are right.

• The study found 0.29–0.47 dolphins per kilometre, depending on the season. Numbers may be rising, possibly due to less competition from large predatory fish.

• The substantial decrease in large predatory fish that compete with dolphins for fish prey was one of the reasons for river dolphin persistence in overexploited systems like the lower reaches of the Ganga

• But threats remain: pollution, dams, boat collisions, mining, noise, deforestation, and water diversion all put dolphins—and the river—at risk.

When humans and dolphins share the same waters

• Fishing nets are a big risk for dolphins

Many people in the lower Ganga region depend on fishing to earn a living. But this creates competition for fish and freshwater—and puts dolphins in danger. The fisherfolk use many types of nets and lines, like gill nets, seine nets, trawl nets, cast nets, and hooks. These often have small mesh sizes, which catch all kinds of fish including dolphins. Thus accidental entangling of dolphins in these nets and their deaths are common in busy fishing areas like Godakhali and Falta on the Hooghly River, where monofilament gill nets are often used.

• Dolphins need flowing, healthy rivers

• Sandmining, deforestation, pollution are making survival a challenge for dolphins

Sand mining disrupts river flow and destroys the counter-currents dolphins need to swim and hunt. Deforestation causes siltation, making riverbeds shallower and damages dolphin habitats. Water pollution lowers oxygen levels, reduces fish populations, and harms the entire aquatic ecosystem. Stone mining, noise from boats, and chemical pollution—from factories, farms, and cities—add to the damage. Too much water taken for irrigation also reduces flow, making rivers less livable for dolphins. All these pressures make it harder for dolphins to survive, find food, and move freely through the river.

• Fishing pressure in the Hooghly estuary is leading to a decline in dolphin numbers

The Hooghly estuary, part of the lower Ganga, is one of the most diverse and productive river systems in the world. Its rich waters attract intense fishing activity, especially for wild prawns and fish seeds used in aquaculture. Many local fishers—often women—collect prawn larvae and fish seeds, which reduces future fish stocks and overall productivity. Dolphins feed mainly on fish and prawns, and heavy fishing near dolphin habitats means less food for dolphins. This competition for food is leading to decline in their numbers.

• Boats and noise are putting dolphins at risk

Motorboats, trawlers, barges, and manual boats are widely used in the Bhagirathi-Hooghly River for fishing, transport, and sand mining. Dolphins are sometimes killed by boat collisions and underwater noise from engines can harm dolphins who are nearly blind and depend on echolocation to find food and navigate. In the middle stretch of the river, shallow water and constant boat movement make it hard for dolphins to swim freely.

Saving dolphins, supporting communities: What can be done?

Reduce harmful fishing practices

• Ban harmful nets and promote safer, dolphin-friendly fishing methods

• Train fishers to rescue and release dolphins caught in nets

• Use electronic pingers on nets and canal gates to keep dolphins away from danger

Protect and restore river habitats

• Ensure enough water flow and good water quality

• Enforce laws to stop illegal fishing and habitat destruction

• Restore riverbanks and reduce pollution from chemicals, sewage, and farming

Monitor and study dolphins

• Tag dolphins with satellite transmitters to track their movement and behaviour

• Conduct regular surveys to monitor dolphin populations and plan better

• Study dolphin biology to improve conservation strategies

Involve local communities

• Create community fisheries in connected water bodies

• Include fishers in planning and decision-making

• Raise awareness about how pollution and harmful practices affect fish and dolphins

• Train locals in dolphin rescue and river protection

Create livelihood opportunities

• Promote dolphin tourism and set up dolphin sanctuaries

• Support river patrols and citizen science to create jobs and build skills

• Encourage river ranching—breeding and releasing native fish to boost stocks and dolphin food

Sustainable fishing practices can thus go a long way to protect both fishers’ incomes and dolphin survival while healthier rivers can lead to better water availability for farming and homes. Involving communities is crucial in this endeavour to encourage citizen science initiatives and build local pride, knowledge, and resilience among communities.