There are two species of blind river dolphins in south Asia - the Indus (Platanista minor), and Ganges (Platanista gangetica) River dolphins. [They were once thought to be the same species.] They do not have a crystalline eye lens, which makes them effectively blind. But the lack of vision is compensated by highly developed sound imaging skills, also termed ‘echolocation’ – a sophisticated sonar system that is a navigation aid in the muddy and silted rivers. Their 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." Although they prefer to live in deeper waters , the Indus and the Ganges dolphins can also survive in waters only three feet deep.

The Indus river dolphin is found in the Indus and Chenab rivers of Pakistan, while the Ganges river dolphin is found in the Ganges, Meghna, Brahmaputra, and Karnaphuli rivers that flow through India, Nepal, Bhutan and Bangladesh. Both varieties are endangered.

There are fewer than 600 blind river dolphins left in Pakistan, and the number is fast decreasing. The blind Indus dolphin is the only river dolphin found in Pakistan and is now seriously threatened in its only habitat. Their numbers and movement have been affected by the irrigation systems and also by the construction of dams along the river Indus. Earlier the dolphins migrated long distances to mate but the dams have rendered that impossible. The construction of multiple dams has split their population into several groups. The consequent in-breeding has not helped to increase their numbers. Localised presence in water also makes them prey to irresponsible hunting – for their meat as well as oil, which is considered to have medicinal value, and at times they are an inadvertent catch in the fishing nets. They are found in a localised 100 mile stretch between two dams. The Indus river dolphin, also known as Indus susu, is one of the five species of cetaceans that are threatened with extinction.

The Indus Dolpin has a long beak, a small, low hump, wide flippers and an adult can weigh 70- 90 kg. They are slow swimmers, "..but can move in rapid spurts when they need to. They breathe through their slit - like blowholes with a loud sound that is similar to a sneeze, and can be heard from quite a distance." It sometimes carries its young on its back, above the surface of the water.

The Pakistan Adventure Foundation is trying to create awareness about the endangered blind dolphin through rafting expeditions and visiting riverside fishing communities – a project funded by the UN Development programme. The Indus dolphin has been a victim of both deliberate and accidental exploitation.

Ganges river dolphins are almost identical to Indus river dolphins but for some minor differences of anatomy. They are more visible than other river dolphins. Of a similar size as the Indus dolphin, the Ganges dolphin, also known as Ganges susu, has also suffered as a result of dams being built on its habitat. Their numbers are not as devastatingly low as that of the Indus dolphin, yet they are an endangered species – there are only 4000 – 6000 Ganges dolphins today. Unlike the Indus dolphin, the Ganges dolphin shares its habitat with another dolphin – the Irrawaddy dolphin, which lacks a beak.

The Indus and the Ganges dolphins have been victims of both deliberate and accidental exploitation.Dam building, chemical pollution, accidental entanglement in fishing nets, and hunting have depleted the numbers of this fish to an alarmingly low level.

Drastic measures are required, involving communities, to help save this dying species. ‘Adopt a dolphin’ could be a start.