Gangetic Dolphins Near Extinction

Nepal's diverse ecosystems harbour a rich array of biodiversity, encompassing many mammals, birds, reptiles, fish, butterflies, and amphibians. The endangered Gangetic River dolphin, a freshwater apex predator and indicator species for river health, inhabits Nepali rivers. Its echolocation capabilities compensate for its functional blindness, enabling successful predation of fish and invertebrates.

The dolphin ('Platanista gangetica'), known as Shons or Su-su in Nepali, is critically endangered in Nepal, with fewer than 20 adults inhabiting the Karnali, Geruwa, Mohana, Patharaiya Kandra, Bhada, Kandha, and Narayani rivers. Outside Bardia National Park, it lacks protected status. First classified in 1801 by Lebeck and Roxburgh as 'Delphinus gangeticus', this species is also found in Bangladesh and India. It is listed as an endangered species on the IUCN Red List. However, the National Red List of Mammals also classifies it as critically endangered.

According to Bhojraj Dhungana, chairman and conservationist of Dolphin Aquatic and Biodiversity Conservation Nepal, although this aquatic wildlife was seen in the Koshi River, Gandaki River, and Mahakali River in Nepal about 30 years ago, it is currently seen only in the area from Chisapani in Karnali to Kothiyaghat River and in the Mohana, Kandra, Patharaiya, and Kadan rivers in Kailali district during the rainy season. Rising river levels in Bhajani Municipality bring dolphins closer to shore, attracting domestic and international tourists, said Dhungana. India also declared the dolphin the national aquatic animal on 18 

May 2009.

Features

Gangetic river dolphins (Platanista gangetica) reach 2.2-2.6 metres long and weigh 150-170 kg. Their colouration ranges from grey-brown to chocolate-brown in calves. The dolphins are equipped with two four-digit flippers and a caudal fin, which serve as their primary means of propulsion, but they lack fully developed hind limbs. Slower swimmers than oceanic dolphins possess a long snout (0.58 m) and a two-chambered stomach similar to terrestrial carnivores, comprising fundic and pyloric chambers. Respiration occurs via blowholes.

Habitat and breeding

The blind Gangetic river dolphin (often called the Gangetic tiger) uses echolocation to hunt fish and crustaceans. Shy and solitary, it rarely breaches and is challenging to observe. Its conical teeth are adapted for catching small fish. Sociable and intelligent, like humans, it reaches sexual maturity at 6-10 years, with a gestation period of roughly one year and typically one or two calves per birth. Calves are weaned after a year, and the dolphin's average lifespan is 28 years.

According to Rajesh Sada, freshwater programme head at WWF Nepal, there has been a significant decline in the range of these species. Formerly distributed throughout Nepal's Koshi, Narayani, Karnali, and Mahakali river systems, they are now found only in the Koshi, Narayani, and Karnali. A 2016 IUCN/DNPWC study counted 52 dolphins in Nepal (43 in the Mohana and its tributaries and nine in the Koshi).  

Nepal's 1961 Aquatic Animals Protection Act protects river dolphins, yet their conservation remains underfunded and under-prioritised compared to other large mammals. While a 2021-2025 Dolphin Conservation Action Plan exists, current efforts are minimal. Despite two decades of work on awareness campaigns, watchtower construction, community livelihood improvement, and research, WWF Nepal operates on a limited budget. Recently, we partnered with the Department of Forests and Soil Conservation to pilot a novel, non-invasive FPOD tracking system in the Karnali, Mohana, Kaada, and Pathraiya Rivers. Data analysis is underway, and results will be shared with the government.

The Gangetic River dolphin faces critical endangerment from multiple anthropogenic threats. These include hunting for their oil, habitat loss resulting from agricultural and industrial expansion, pollution, and infrastructural development, which fragments populations and severely restricts their range.

(The author is a wildlife photographer. The photos used in this article are by the author.)