Removal of river water for irrigation and habitat fragmentation by irrigation dams are contributing to the decline of the endangered Indus river dolphins, a new study has warned.
Many freshwater marine mammals are endangered due to rapidly degrading habitat and conservation of these mega-fauna species depends on maintaining intact habitat.
The study by Gill Braulik from the Wildlife Conservation Society and University of St Andrews and colleagues used historical range data and information on dolphin presence from fisher interviews to better understand the timing pattern of range decline of the Indus River Dolphin, an endangered freshwater dolphin that inhabits one of the most modified rivers in the world.
Additionally, the authors’ modelled seven potential explanations of declining range, including date of construction of the nearest dam, dry season river discharge, distance from the edge of the former range and length of river section to identify the factors responsible for the decline.Results indicate that the historical range of the Indus dolphin has been fragmented into 17 river sections by diversion dams. River dolphins disappeared from ten river sections, still live in six, and are of unknown status in one section.