Friday, January 8, 2010

Indus River Dolphin (Platanista Minor) Also Called Blind Dolphin - - Second Most Endangered Freshwater River Dolphin Found Near Sukkur, Sindh

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 Sukkur (third largest city of Sindh province) Pakistan. The river Indus is getting dirtier and the water is being distributed into canals and dams which are giving this species of the Dolphin a hard time for survival. It may be possible that in few more years we will only be able to just read about the Indus dolphin and not see it at all.

The Indus River Dolphin has a long beak and a stocky body. It has a low triangular hump on its back in place of a 'true' dorsal fin. It is gray-brown in color, sometimes with a pinkish belly. The eyes are extremely small, resembling pinhole openings slightly above the mouth. The Indus River dolphin measures between 1.5 - 2.5 m (5 - 8') in length and weighs 80 - 90 kg (180 - 200 lb). It is found exclusively in freshwater, living not only in the main channels, but also, during the flood season, in seasonal tributaries and the flooded lowlands. These dolphins favor silt-laden, turbid waters, at temperatures between 8 - 33°C (46 - 91°F).

The Indus River dolphin feeds mostly on several species of fish and invertebrates. It does much of its feeding at or near the bottom, using echolocation, swimming on one side, and probing the river bottom with its snout and its flipper. Although it is not usually considered to be gregarious, relatively high densities are found at sites where rivers join, in areas where the current is relatively weak, off the mouths of irrigation canals, and near villages and ferry routes.

The Indus River dolphin was apparently formerly common and distributed throughout 3,500 km (2200 mi) of the Indus River system in Pakistan. It was found from the Himalayan foothills to the mouth of the Indus, and in the main tributaries from the hills to their junction with the Indus. By the early 1970's its range had declined drastically to less than 700 km (430 mi) of river length. The majority of the remaining population lived between the Sukkur and Guddu barrages in Sind Province. This region continues to harbor the majority of the remaining population. Besides Sind Province, the Indus River dolphin also exists in Punjab Province, but it continues to decline.

The main reason for the decline of the Indus River dolphin from the historical distribution of approximately 3,500 km (2200 mi) of river length to a range of less than 700 km (430 mi) of river length was the construction of numerous dams and barrages, starting in the 1930's, which split the population into small groups, degraded habitat and impeded migration. In addition, 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. Accidental capture in fishing nets; and hunting for meat, oil and traditional medicine have also had an impact.

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