Climate & Environment
Migratory dolphins return to Nepali waters earlier than usual
An early sighting of the Ganges river dolphin leaves locals happy, but conservationists worry about their future.Chandan Kumar Mandal
An early sighting of dolphins in the Mohana and other rivers in Kailali district has elated locals and conservationists.
According to conservationists, endangered Gangetic river dolphins enter smaller tributaries of the Karnali and the Ganges such as
the Mohana to remain safe from floodwaters in the big rivers during the monsoon.
The first sighting of the dolphin (Plantanista gangetica), was recorded by locals last Saturday. Bijay Raj Shrestha, a resident of Bhajani Municipality-2 and a local dolphin conservationist, said two dolphins, one adult and one calf, were spotted on Saturday afternoon.
“The early arrival of the dolphins in the river can be attributed to rainfall that improved the water level in the Mohana and tributaries,” said Shrestha, who has been working for the conservation of dolphins for several years. “The rainfall was not, however, due to the monsoon, but due to cyclone Nisarga that caused rainfall over the Chure range..”
Every year, dolphins are seen in the Mohana river and its tributaries such as Pathraiya, Kandra and Kanda when water level reaches five to seven ft. According to locals, these dolphins migrate to the Nepali side from India’s Ghaghra river, called Karnali in Nepal just as the monsoon rains arrive.
Last year dolphins were first sighted on July 3 and they were found to have returned to the Ganges and the Karnali in the second week of October. According to Shrestha, who is also secretary for Dolphin Conservation Centre, a local group working for dolphin conservation, this is the second time dolphins appeared so early in nearly two decades. In 2001, the dolphins were seen on June 3.
These rivers and creeks of western Nepal provide a perfect habitat and foraging ground for dolphins due to their slower currents and adequacy of food.
“We estimate that their number ranges between 100-130. However, there is no regular monitoring of the population,” he said.
The first Integrated Dolphin Census of Nepal, conducted in 2016, had recorded a total 52 dolphins throughout the country. Of the 52 dolphins, 43 were sighted in the Mohana and its tributaries.
The Ganges River Dolphin has been classified as “endangered” by IUCN. In Nepal, the species has been recognised as “critically endangered” and is the only aquatic mammal protected by the National Park and Wildlife Conservation Act.
Haphazard fishing, overfishing, fishing by poisoning, water pollution, construction of dams and canals, are among the major threats the mammals face. As a result, their number is declining.
“Local authorities from both India and Nepal give permission to fish in the Mohana through tenders. During fishing, their calves and even adults are killed due to poisoning. Not only that small fish that they eat are also killed,” said Shrestha.
South Asian River Dolphins are found in four countries of the region –Nepal, India, Bangladesh and Pakistan. River dolphins are the national aquatic animals of India for the mammal is said to represent the purity of the holy Ganga as it can only survive in pure and freshwater.
“Since this species is found in four countries, there should be a common agenda among SAARC countries for preserving the river dolphins through the formation of a multinational network,” said Shrestha.
“Nepal government should invest more resources in the conservation of dolphins like it has done for other wildlife. Otherwise, community-level conservation efforts can’t be enough.”