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Indus River Dolphin

Bleak outlook for this river dweller

Common Name: Indus River dolphin, bhulan, blind river dolphin, Indus dolphin, side swimming dolphin; Plataniste de l'Indus (Fr); Delfín del Indo (Sp)

Scientific Name: Platanista minor

Population: Approximately 1,100

Background

The Indus River dolphin (Platanista minor) is one of the world's rarest mammals and the second most endangered freshwater river dolphin. Approximately 1,100 specimens of this species exist today in a small fraction of their former range, the lower reaches of the Indus River in Pakistan.

However, the population of this species has gradually declined because of various factors, including water pollution, poaching, fragmentation of habitat due to barrages, and dolphin strandings in the irrigation canals.

Numbers have dramatically declined since the construction of the irrigation system in the Indus. Most individuals now remain in a 1,200 km stretch of the Indus River.

In addition to efforts to conserve their habitat, including addressing problems such as river pollution, WWF staff have also been involved in rescue missions when individual dolphins become trapped in canals. WWF also coordinated the largest survey of the species ever in 2001 in collaboration with partners.

WWF-Pakistan assists in a number of education initiatives and has arranged training courses for various institutions. An aerial survey of the species range was conducted in 2003.

WWF's objective for freshwater cetaceans is to ensure that habitat degradation, strandings and fisheries bycatch do not threaten freshwater cetaceans.

Physical Description

The species is characterized by a long beak, rounded belly, stocky body, very small dorsal fin and large flippers. Although its eye hasn't developed a lens (this species is also referred to as the "blind dolphin"), the dolphin still uses its eyes to differentiate between light and dark. It relies on echolocation (sound sensors) to find fish, shrimp, and other prey in the bottom mud.

The Indus River dolphin swims on its side, at times enabling it to move in water as shallow as 30 cm. As it swims on its side, it trails a flipper along the bottom of the river. After 30 to 60 seconds, when it needs to breath, it swims to the surface, rotates upright to take in the air, and then rotates 90 degrees again as it swims back to the bottom. This unique side swimming behaviour is not consistently seen in any other dolphin, except the Ganges River dolphin.

The Indus River dolphin migrates upstream into the smaller tributaries during the monsoon rains and migrates downstream to the main channels in the dry season.

Size
The Indus River dolphin weighs 70-110 kg (155-245 lbs). The maximum size is 2.5m (8.2 ft), with males smaller than females.