Local name: Bhulan (Urdu, Sindhi)
Discription and Biology:
Description: The specific name, minor, refers to the dolphins’ supposedly smaller size. Until the 1970s, this species was thought to be the same as the Ganges River Dolphin.The Indus River Dolphin has a long beak which thickens toward the tip, revealing the large teeth; the mouthline curves upward. The body is stocky with a rounded belly, the flippers are large and paddle-shaped, and there is a low triangular hump in place of a ‘true’ dorsal. The forehead is steep and the blowhole is on the left of the head, above the tiny, poorly-seeing eye. The tail flukes are broad in relation to the body size. Indus River Dolphins are grey-brown in colour, sometimes with a pinkish belly, and measure between 1.5 and 2.5m in length, weighing a maximum of 90kg.Social Behavior:Indus River Dolphins travel either as couples or individuals. Since these dolphins do not have a crystalline eye lens they are effectively blind; all they can do is detect the direction and intensity of light. Navigation, therefore, is entirely by a sophisticated echolocation system. This blindness is one of the reasons why these dolphins swim on one side underwater, with one flipper trailing in the muddy riverbed. The physical touch gives the dolphins important information about their surroundings and helps them find food.
Diet:These dolphins take fish and crustaceans. (all above information from Cetacea Online and Animal Info).
Habitat and Distribution:
The Indus River Dolphin is the only cetacean to inhabit the Indus river. These dolphins favour the silt-laden, turbid waters of the Indus river system, at temperatures between 8°C and 33°C.
The Indus River Dolphin is one of the world’s most endangered mammals and has been listen in IUCN’s list of threatened species. This dolphin is endemic to Pakistan. The species inhabits the Indus river in Pakistan from Kotri, Sind, to Jinnah, northwestern Punjab. The Indus River dolphin was apparently formerly common and distributed throughout the Indus River system in Pakistan, from the Himalayan foothills to the mouth of the Indus, and in the main tributaries – Jhelum, Chenab, Ravi and Sutlej – from the hills to their junction with the Indus . Beginning in the 1930’s, numerous dams and barrages were constructed in the Indus. This split the dolphin’s population into small groups, degraded its habitat and impeded migration. As a result, by the 1970’s the abundance and distribution of the Indus River dolphin had significantly declined, and most of the remaining population was concentrated between two of the barrages, the Sukkur and Guddu barrages in Sind Province. The government of Sind established this region as the Indus River Dolphin Reserve in 1974. The Reserve continues to harbor the majority of the remaining population. Its population has apparently increased there, while few of the dolphin remain elsewhere. Besides Sind Province, the Indus River dolphin also exists in Punjab Province, but it continues to decline. The Indus River Dolphins have suffered as a result of incidental and direct exploitation. They have been accidentally caught in fishing nets, but have also been hunted for meat, oil and traditional medicines. The most recent population servey was done in 2001, by WWF-Pakistan, the Wildlife Departments of Sindh, the Punjab and the NWFP, the Adventure Foundation of Pakistan, the Whale and Dolphin Conservation Society of UK and Karavan Leaders. During the survey 965 dolphins were counted in the river system. The survey which started from Kalabagh in the Punjab on March 12, ended at Hyderabad, 1,400 kilometres downstream, after seven weeks. A section, about 40 kilometres long, between Sukkur and Kotri barrages was missed for security reasons. Considering that the mammal is also found in these stretches, the total number could be 1,000 or slightly higher. The team counted two dolphins between the Jinnah and Chashma Barrages, 84 between Chashma and Taunsa Barrages, 259 between Taunsa and Guddu Barrages, 602 between Guddu and Sukkur Barrages and 18 between the 500 kilometres stretch between Sukkur and Kotri Barrages. The number of mammals counted is greater than earlier estimates of 500-700. It could, however, not be considered enough to take the species off the endangered list. .(all above information from Cetacea Online, Survey of Pakistan Indus river dolphins 2001, and Animal Info).
Population estimated by years:
1974: 450 – 600 (Nowak & Paradiso 1983)
Late 1970’s: 400 (Burton & Pearson 1987)
1984: 600 (Macdonald 1984)
1986: 400 – 600 (Bonner 1989)
1989: 500 (Klinowska 1991)
1998: Probably fewer than 1000 (Reeves & Chaudhry 1998)
2001: 965 total (See MAP below), Breakup = Two dolphins between the Jinnah and Chashma Barrages, 84 between Chashma and Taunsa Barrages, 259 between Taunsa and Guddu Barrages, 602 between Guddu and Sukkur Barrages and 18 between the 500 kilometres stretch between Sukkur and Kotri Barrages (Survey done by WWF-Pakistan, the Wildlife Departments of Sindh, the Punjab and the NWFP, the Adventure Foundation of Pakistan, the Whale and Dolphin Conservation Society of UK and Karavan Leaders)
MAP Source = WWF-Pakistan
