Kathmandu, September 17
Motorised boats roaming the downstream tributaries of the Karnali in western Nepal are the new threats to the already-endangered fresh water dolphins, researchers say.
Heavy siltation of the river bed and rampant poaching are also having severe impacts on the dolphin population in the Karnali, says team that conducted a study on the mammals recently.
Wildlife expert Dr Mukesh Chalise, biologist Dhirendra Bahadur Chand, engineer Salil Devkota, secretary at the local dolphin conservation centre Bijaya Raj Shrestha and local team leader Bhoj Raj Dhungana counted Dolphins on the Karnali (Mohana, Kada and Kadha rivers) from September 8-10.
“During the course of our count, we found that motorised boats roaming the downstream areas are not only polluting the river, but also disturbing silence-loving animals like dolphins,” Dr Chalise told Onlinekhabar. Similarly, silting on the river bed has decreased the depth of the river and this has forced dolphins further downstream, he said.
As areas where dolphins are found are not located inside any protected area, poachers can easily catch dolphins and take them away without any hassle, Dr Chalise said adding that poaching goes up in the post-monsoon period as farmers have spare time. Haphazard fishing has also caused food scarcity for dolphins.
A total of 22 dolphins were found at the confluence of Karnali and downstream areas, and not a single dolphin was found in the tributaries. Last year, 63 dolphins were counted on Karnali’s tributaries. Chalise said the 41 ‘unaccounted’ dolphins may have gone downstream.
The IUCN red-list includes Platanista gangetica as an endangered species. According to IUCN, water development projects have dramatically affected the habitat, abundance, and population structure of this species. “In addition to fragmenting populations, dams and barrages have degraded downstream habitat and created impoundments with high sedimentation and altered assemblages of fish and invertebrate species,” it says. Similarly, it also identifies pollutant loads and deliberate killing as the other threats it faces.
