Nepal's Karnali, Kosi, Mahakali and Narayani rivers were once home to a thriving susu population in the section of the Tarai plains before they enter Indian territory. In recent decades however, there has been a dramatic drop in Nepal's river dolphin population, primarily attributable to barrages, which block rivers' flow and impede fish and dolphin migration. But while all Nepali dolphin watchers agree that a drop has occurred, opinions on precise numbers are anything but unanimous.
While conservation officials in Kathmandu are declaring the virtual extinction of the susu in Nepali waters, the dolphin protection centre in Nepal's western Tarai district of Kailali, a unique private effort involving local enthusiasts, has reported an increase in dolphin sightings. The centre says the rise has been evident for the past three years, a claim that government experts treat with unveiled scepticism. The dispute extends to even whether the susu is extinct in certain rivers. According to Dr Shanta Ram Gyawali of the King Mahendra Trust for Nature Conservation, dolphins have completely disappeared from the Mahakali and Narayani rivers in western and central Nepal. Additionally, he says that while 15 to 20 dolphins appear in the Karnali and Kosi rivers during the annual monsoon, only four to six inhabit them in the dry winter period.
The Kailali centre claims there are around 100 dolphins in the Karnali's various tributaries, including in the Pathriya, Kadha, Kandra and Mohana. While the government has not been able to confirm or disprove the centre's claims, officials look askance at these reports. Narayan Prasad Poudel, deputy director of the Department of National Parks and Wildlife Conservation, says that while "the centre has done exemplary work in dolphin conservation at the local level, their claims of increases in the number of dolphins appear unscientific".
Gyawali, who served on a government census team during the 2001 monsoon, says the group was only able to confirm the existence of eight dolphins, despite its visit being timed to coincide with the annual peak presence of dolphins in Nepal. But Bijay Raj Shrestha, secretary of the Kailali centre, takes issue with the government researchers' methodology. "It was a short and incomplete research", he says. "If the government's officials come with adequate time, we will show them dozens of dolphins". Gyawali says his team plans to make a follow-up visit in a few months.