It holds about seven potential factors that are feared to have contributed to the species population fall with among them are a low discharge of the river during the dry season and habitat destruction by the irrigation barrages. It said that the reduced flow impacts directly the dolphins limiting its physical habitat, besides changing depth of river, stream velocity and temperature of water.
The study is a joint effort of the WWF-Pakistan with the Provincial Wildlife Departments, Zoological Survey of Pakistan (ZSP), besides experts from its partner organisations to ascertain factors for dolphins' decline in upper Indus River. The Indus River dolphin is an endangered freshwater cetacean that is endemic to the Indus River system.
Dr. Gill Braullik, Cetaceans Expert and member of the IUCN Cetacean Specialists Group, said that the dolphin population is now confined to just 20 per cent of their natural habitat range due to the construction of numerous dams and barrages along the Indus River. "Dolphins are also threatened by stranding in irrigation canals and accidentally becoming caught in fishing nets," he said. Additionally, he said, the rapid industrialization has significantly contributed to increased surface water pollution in the country, as over 90 per cent of industrial and domestic effluents that are discharged into to the river are untreated. "The situation is severe in the Indus tributaries, which pass through major industrial areas as they carry even higher loads of pollutants than the main river itself," he said.
Lack of periodic and proper mechanisms of water quality assessment of the river further intensifies the problem to identify those sections of the river which carry higher loads of waste, he said, adding that "on Indus River, a satellite telemetry study and translocation of stranded dolphins to the stretch of Indus River between Jinnah and Chashma Barrages. This will help in the conservation of endangered fauna of the area, particularly the Indus River dolphin," he said.
Dr. Babar Khan, Director Wildlife, WWF-Pakistan said that the latest survey was carried out along an area of more than 70 kilometres in the Indus River, which is close to foothills of the Himalayas and has not been surveyed since 2006. "The previous surveys estimated less than five dolphins within this river section and this was the smallest known sub-population of the species," he added. "The survey was part of the continuous research efforts critical to facilitate conservation policymaking for endangered species, like the Indus River dolphin, based on scientific evidences," Director General Punjab Wildlife and Parks Department, Khalid Ayaz Khan said that the department initiated a development project along the Indus River to set up three dolphin rescue and monitoring stations.
A comprehensive dolphin population assessment was carried out by WWF-Pakistan last year (March to April 2017) covering the 800 km stretch that includes the three largest dolphin sub-populations between Chashma and Sukkur Barrages. The survey recorded a marked increase in the population of the species. There has been much focus on the largest sub-populations of Indus dolphins that are present downstream in Sindh and lower Punjab, and these populations appear to be increasing in abundance. However, the present distribution of the Indus River dolphin is about 80 percent less than what was determined in the 1870s.
WWF-Pakistan has been working towards the conservation of the species following a collaborative approach, integrating research, effective law enforcement and community engagement. Since 1992, WWF-Pakistan and the Sindh Wildlife Department have led a dolphin rescue programme, which has successfully saved over 140 dolphins from being stranded in irrigation canals and safely released them back into the river. A dolphin-monitoring network in collaboration with local communities and a 24-hour phone helpline have also been established for rescue and safe release of stranded dolphins in Sindh. It is a second such study that the WWF-Pakistan has carried out this year to investigate the existence of endangered species in different parts within its historical population radius. "The ultimate objective of these assessments is to help make informed decisions for conservation planning," the WWF said that traditionally, the species are found in five sub-populations separated by barrages on the Indus River.