- Severe degradation of Nepal’s rivers due to overexploitation has negatively impacted otters and other aquatic species.
- Dumping of raw sewage and industrial waste, leaching of agricultural pesticides, and rapid urbanization and infrastructure developments are undermining otter habitats across the country.
- The widespread damming of rivers coupled with unsustainable fishing practices have also reduced food sources for Nepal’s otters.
- The country is home to two, possibly three, otter species, but conservationists say funding and attention for the welfare of these animals tend to be overshadowed by that for Nepal’s higher-profile wildlife, such as tigers and rhinos.
KATHMANDU — In September 2023, Nepali conservationists celebrated the rare sighting of a smooth-coated otter in Chitwan National Park, the first one had been spotted there in some two decades.
But while the incident sparked elation, it also highlighted concerns about the degraded state of Nepal’s overexploited rivers, which has impacted otters and other aquatic species. The sighting of that lone otter has since become emblematic of the problem, and was raised once again in the lead-up to this year’s World Otter Day, marked on the last Wednesday of May.
“Otters that are considered the tigers of the freshwater ecosystems are paying the price of overexploitation of rivers in the country,” Sanjan Thapa, deputy coordinator of the Otter Specialist Group’s Himalayan region at the IUCN, the global wildlife conservation authority, told Mongabay on the May 28, the eve of this year’s World Otter Day. “They need undisturbed and unpolluted rivers to survive and thrive, but they aren’t getting that in Nepal.”
The overexploitation takes various forms, from the dumping of raw sewage and industrial waste, to the leaching of agricultural pesticides, to rapid urbanization and infrastructure development that have eroded riverbanks, silted up waterways, and cleared riparian forests. Roads constructed along riverbanks and water-guzzling hydropower projects have exacerbated the problems.
Nepal hosts two, possibly three, freshwater otter species: the smooth-coated otter (Lutrogale perspicillata), like the one spotted in Chitwan; the Eurasian otter (Lutra lutra); and, historically at least, the Asian small-clawed otter (Aonyx cinerea).
The Eurasian otter, categorized as near-threatened on the IUCN Red List, inhabits mountain streams, rivers and lakes, while the smooth-coated otter (listed as vulnerable) lives in major rivers such as the Narayani, Koshi, Karnali and Mahakali. The small-clawed otter is also listed as vulnerable, but hasn’t been recorded in Nepal since 1839.
Lack of sewage treatment in many of Nepal’s towns and urban settlements means raw sewage and industrial waste continue to be piped near rivers by more than a quarter of municipalities, according to government data. During the monsoon, the rain-swollen rivers wash all the waste downstream.
“Similarly, roads constructed along riverbanks further disturb habitats and contribute to pollution,” Thapa said. Nepal’s mountainous terrain means the cheapest way to engineer roads is to follow the route of the rivers. But this often means tearing up riparian forests with heavy machinery and dumping construction waste into rivers.
In addition to this, major highways in the country such as the Prithvi and Mahendra highways built on the banks of rivers are being widened to facilitate traffic, threatening even greater pollution and damage to waterways.
“The rapid proliferation of hydropower adds to the problem,” Thapa said. During the dry season, hydropower plant operators often don’t release the 10% water flow they’re required to, leaving rivers that are typically fed by snowmelt dry, he said. Most rivers and their tributaries in Nepal’s hills, except for the Karnali, are home to multiple hydropower projects at various altitudes. Most of the projects also don’t have fish ladders that allow fish migrations for breeding, which in turn impacts the otters that feed of these fish.
“Otters are indicator species that need water and food to survive,” said Jyoti Bhandari, assistant professor at the Institute of Forestry in Pokhara. “That we don’t see otters in major river systems of the country indicates that the rivers’ health is not good.”
The IUCN has echoed these concerns, noting that infrastructure development, agricultural runoff and wetland reclamation are destroying otter habitats across their range in Asia.
Unsustainable fishing practices, especially during the dry season, further depletes otter food sources. “Communities employ destructive techniques like gill nets, poisoning and blasting, leading to declining fish populations and disappearing otters,” Thapa said. “There are communities that are using extremely fine nets to even capture small eggs laid by fish.”
Bhandari said otters are often misidentified as other species by local people, especially those who have migrated to the plains from the hills. There also have been cases where people have hunted them for their meat and fur. “Also getting funding for research on otters is difficult as people are attracted to megafauna such as tigers [Panthera tigris] and rhinos [Rhinoceros unicornis],” she added.
Addressing the extensive and pervasive challenges to the survival of these animals requires an equally ambitious plan, both Bhandari and Thapa suggested. Nepal’s Department of National Parks and Wildlife Conservation and the Forest Department are currently working on an action plan for otter conservation, similar to those for other, higher-profile species such as tigers and rhinos.
“After the action plan is prepared, we can work in a more focused manner by implementing its recommendations,” Thapa said.
Thapa’s own organization, Small Mammals Conservation and Research Foundation, is also working with WWF, with funding from the U.K. government-funded Darwin Initiative, to boost communities’ livelihoods and their ownership to conserve otters in the Karnali River, the last major river in the country still untouched by hydropower plants.
“Although the situation is grim,” Thapa said, “initiatives such as these provide a glimmer of hope to attract attention towards these species.”
Banner image: Smooth-coated otters in Borneo. Image by Andrea Schieber via Flickr (CC BY-NC-ND 2.0).
Abhaya Raj Joshi is a staff writer for Nepal at Mongabay. Find him on 𝕏 @arj272.
In Nepal, environmental advocates fend off ‘anti-development’ smear
