- The Indus river dolphin is found only in the lower Indus river system in Pakistan and India. Since the 1870s, its habitat has shrunk by 80%, with an estimated 2,000 individuals remaining today.
- In 2007, an isolated population was discovered in the Beas river in India, 600 kilometres from their known habitat. As per surveys between 2011 and 2022, they were found only in the lower third of the river, with counts ranging from one to eight individuals.
- This small population of dolphins face numerous threats, from accidental entanglement in fishing gear, water pollution to changing river flows. Researchers emphasise the need for strict conservation measures for the dolphins’ survival and recovery.
The waters of the Beas river in northern India are home to a small, endangered population of Indus river dolphins. With their numbers dwindling and their habitat under threat, a new paper highlights the urgent conservation efforts needed to ensure their long-term survival.
The Indus river dolphin (Platanista minor) is a species of freshwater dolphin. Listed as endangered by the IUCN Red List, it is found only in the lower Indus river system in Pakistan and in India. Since the 1870s, its habitat reportedly shrunk by 80% due to the construction of irrigation barrages, with only around 2,000 recorded individuals today. In 2007, the discovery of an isolated population in the Beas river in India, about 600 kilometres from their previously known habitat, renewed conservation efforts in the area. This population is important for its genetic diversity.
“The estimated numbers of Indus river dolphins in the Beas river is very small, with fewer than 10 individuals,” says Sandeep Behera, a consultant for the National Mission for Clean Ganga, Ministry of Jal Shakti, Government of India, and one of the researchers of the study. He adds that as apex predators, the Indus river dolphins shape the population dynamics of fish and other aquatic species. “They crucial for sustaining the overall health of the river system,” he says.
Indus river dolphins are endemic to the Indus river basin, where their murky, silt-laden habitat limits their vision. They rely on echolocation to navigate and find food. They are also considered living fossils, being among the most ancient dolphin species still alive. Until 2021, they were classified as subspecies of the South Asian river dolphin, but are now recognised as two separate species.
Numbers matter
In 2010 and 2011, conservation organisation WWF-India and the Department of Forests and Wildlife Preservation, Punjab (DFWP), conducted a survey of sightings of the Indus river dolphin. They interviewed 104 members in the riparian communities located along 470 kilometres on the banks of the three rivers, Beas, Ravi and Sutlej, using open-ended questionnaires and colour photographs of dolphins for reference. The survey revealed that the dolphins were only present in Harike Wildlife Sanctuary and downstream of Beas Dera on the Beas river and were absent in the Ravi and Sutlej rivers.
To further understand the habitat and distribution of this small, fragmented river dolphin population, an additional 40 direct count surveys were conducted in the Beas river between 2011 and 2022. These surveys, using a boat with three observers, found dolphins only in the lower third of the river, with counts ranging from one to eight individuals. Annual sightings of calves indicate ongoing reproduction, a fact corroborated by locals in the area.
“We spot calves every year with their mothers, but juveniles are rarely sighted. Also, the numbers sighted remain nearly constant,” says Amarjeet Singh, a ferryman on the Beas river. Data supports this too. During several surveys in 2011 and 2012, five individual dolphins were recorded. From 2013 to 2018, the highest count was four individuals, and since 2018, the count has never exceeded three dolphins.
Also, since 2015, dolphins have been found mainly downstream of Beas town, with rare sightings upstream. Two hotspots of dolphin occurrence have also been identified (separated by approximately 15 kilometres): one near Verowal and Gagrewal and another further downstream near Karmowala and Mundapind. Of them, Karmowala and Mundapind have witnessed more frequent sightings, with a decline in Verowal and Gagrewal since 2018, suggesting that this habitat is no longer used as frequently, and a possible decline or shift in range has occurred.
“Further research is needed to understand this population better,” says Behera. “But in all recent surveys, small calves have been recorded, and no deaths have been reported, making it a mystery as to where this population is going (geographically).”
Multiple challenges
The possibility of the small dolphin population in the Beas river reconnecting with populations in the Indus river is remote. Numerous barrages and dry rivers separate them, ensuring their complete isolation. They also face several challenges in their current range, including getting caught in fishing gear, water pollution from industrial waste and escaping downstream through the Harike Barrage.
Additionally, it is not yet known which habitat features are important for the dolphins in the Beas river and why they persist only in certain stretches of the river. It is assumed that the dolphins, similar to elsewhere in their range, select pools with high volume, especially during the low water season. However, hydrological alterations affecting the upper reaches may be reducing available habitat and limiting their range. Understanding river hydrology and morphology would help identify why certain habitats are not used and what features are crucial for dolphin survival.
“Today the greatest threats to the Indus river dolphins in the Beas river are water availability and pollution. Upstream hydropower projects cause frequent water fluctuations, creating an unstable habitat for these dolphins. The confluence of the Sutlej river with the Beas river at Harike marks the area where I first sighted Indus dolphins. This suggests their preference for this location due to stable water depth provided by the barrage. However, high levels of pollution are now causing them to avoid this stretch,” says Behera.
Time to act
The Indus river dolphin is recognised as a priority species by both the Indian and the Punjab state government, which underscores a strong commitment to its conservation. However, the Beas river population is so small that the loss of even a single individual could jeopardise the entire population. Researchers imply that achieving zero mortality from human-related causes is crucial for the dolphins’ survival and recovery.
They recommend several management actions such as completely removing fishing nets from dolphin habitats to prevent accidental entanglement, implementing measures to reduce river pollution, ensuring adequate river discharge to maintain a healthy aquatic ecosystem, and monitoring dolphin movements through the Harike barrage and into adjacent canals. They also suggest involving riverside communities in conservation efforts to protect the dolphins.
“It might also be a good idea to explore the possibility of conservation translocations to supplement the Beas river population with individuals from healthier, larger populations elsewhere in the Indus river system. This could significantly enhance their genetic diversity and numbers,” says Karunesh Singh, an independent biologist, who has been studying the Indus and Gangetic river dolphins for over a decade.
The survival of the Indus river dolphins in the Beas river hinges on immediate and coordinated efforts from conservationists, local communities, and governments. By addressing the threats they face and implementing targeted conservation actions, there is hope that this endangered species may make a comeback in its natural habitat.
Read more: The Indus dolphin is struggling in India, thriving in Pakistan
Banner image: Surveys have found Indus river dolphins only in the lower third of the Beas, with counts ranging from one to eight individuals. Image by Dr. Sandeep Behera.
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