Abundance and Distribution Modelling for Indus River Dolphin, Platanista gangetica minor in River Beas, India

The present study was conducted between April 2011 and May 2013 in an approximately 70 km long stretch of River Beas to estimate the abundance and distribution pattern of Indus river dolphin along the Beas, as an initial step towards its better conservation. Based on the line transect method for wide channel, seven vessel-based collinear line transects of 10 km each were surveyed once every month. A total of 33 sighting frequencies were possible during the study. The studied isolated sub-population was found to be extant in very low abundance of 0.047 dolphins/km. The distribution of the dolphins was found significantly different in all flow seasons. The dolphins were found migrating towards upstream during high flows as the increased water levels create new suitable habitat patches, whereas low flows restrict them to the only remaining habitats downstream. Persistence of dolphins, even in low density in this isolated small stretch of River Beas is indeed a good sign, but intensive fishing and increasing pollution remain a matter of concern. Hence it is suggested that the government withdraws fishing contracts throughout its range of distribution.