Approx. 850 (2001). Endemic to the rivers of the lower Indus River basin in Pakistan. The main reason for their decline was the construction of dams and barrages, starting in the 1930's, that have fragmented the population and reduced the amount of available habitat. Another severe threat to their survival is probably the increasing withdrawal of water. Dolphins no longer occur in the lower reaches of the Indus because upstream water extraction leaves downstream channels virtually dry for several months each year.