Published online by Cambridge University Press: 24 April 2009
The endemic freshwater dolphins in the Indus River system of Pakistan, Platanista minor, have been considered endangered since the early 1970s. Measures taken to protect them from deliberate capture seem to have stopped a rapid decline, and combined counts in Sindh and Punjab provinces since the early 1980s suggest a total population of at least a few hundred animals. Severe problems remain, however. In addition to the risks inherent to any species with an effective population size in the low hundreds (at most), these dolphins are subject to long-term threats associated with living in an artificially controlled waterway used intensively by humans. Irrigation barrages partition the aggregate population into discrete subpopulations for much of the year. Dolphins that ‘escape’ during the flood season into irrigation canals or into reaches downstream of barrages where winter water levels are low have little chance of survival. A few dolphins probably die each year after being caught in fishing nets. Pollution by untreated urban sewage, agricultural runoff and industrial effluent threatens the health of the entire Indus system. The future of this dolphin species depends on Pakistan's commitment to protecting biological diversity in the face of escalating human demands on dwindling resources.