Blind Dolphin of the Indus

Once found in all the five major rivers of the country, the Indus river dolphin is now restricted to just a portion of the Indus. However, the hard work put in for the conservation of this endangered species is paying off and an increase in population has been recorded

The Indus River flows across Pakistan, meandering through its entire length and is considered the country's bloodline. And it is so, undoubtedly.

The middle section of the river's course tends to be highly braided, creating a variety of habitats for numerous species. The Indus is among the 200 global eco-regions that have been identified by the World Wildlife Fund (WWF) as priorities for conservation.

Research shows that conserving these eco-regions, also referred to as G200, would mean conserving 95 per cent of all species and most habitats on Earth. The most high profile species in the Indus eco-region is the Indus river dolphin

The Indus river dolphin is a very special species for Pakistan because of many reasons; it is endemic to Pakistan and it is one of the only four obligate freshwater dolphin species found in the world. The others are Ganges Dolphin in India, Bangladesh and Nepal, Pink Dolphin or Boto in Amazon River, and Yangtze River Dolphin in China, although the Yangtze Dolphin is considered to have become functionally extinct recently. All the freshwater dolphin species are endangered, which means that their populations need to be protected for their long-term survival.

Historically, the Indus river dolphin was found in all the five major rivers of Pakistan, however, with the infrastructure development of the water of these rivers, the habitat became fragmented as water was diverted into canals. This restricted the movement of the species and decreased the water available in the rivers and also led to the decline in their numbers. Today this species is only found in the 1,375km stretch of the Indus between Jinnah and Kotri barrages.

The dolphin population is divided into five smaller populations due to six barrages on the river. World Wide Fund for Nature -- Pakistan, conducted the first comprehensive survey of the current home range of the species in 2001 and the population was found to be 1100. The survey was repeated in 2006 and there were found to be 1,341 Indus dolphins in Pakistan. This proves that the hard work put in for the conservation of the species paid off and there is at least 20 per cent increase in the population. The largest population is found between Guddu and Sukkur barrages. This section is also a protected area for the species, as declared by the Sindh Wildlife Department in 1974.

Technology is important in conservation. In the last dolphin survey, a device known as 'depth sounder' was used to study the habitat features of the places where the presenceb of dolphins were recorded. A depth sounder has an integrated global positioning system (GPS) and has another part called the 'transducer', which can be attached to the bottom of a boat. This transducer emits sound waves that touch the bottom of the river, bounce off and are received into the portion with GPS, giving precise data on the depth of the river. Scientists are able to develop a map of the river with its depth and locations of the dolphins.

WWF — Pakistan, as part of the Pakistan Wetlands Programme, conducted similar research and found that the Indus dolphins were never found in river sections less than two metres deep. This demonstrates that maintaining a minimum level of water in the river is critical to the survival of this endangered species. Moreover, the minimum flow in any river is important to maintain the ecosystem and dilute the pollutants from industry and human settlements.

Geographic Information System (GIS) is also an integral part of conservation. For example, to study the Indus dolphin, satellite images are used to identify the extensive network of side channels. The distance along the main channel is also measured to help plan the survey and other factors such as survey route and time. Dolphin sighting data are collected with the GPS points that help in developing the distribution maps. Analysis was conducted to determine species linear density at different cross-sections of the river.

Although we hypothesise that the Indus dolphins are capable of moving through the barrages gates, maybe just downstream, this needed to be studied scientifically. Two radio transmitters were used for this which work in a simple manner -- a small transmitter is attached to the dorsal fin of a dolphin and the signals emitted from it are received by the receiver, thus the movement of the animal can be tracked. There is a plan to put these on the dolphins to track their movement and this tracking will help in identifying future conservation needs. If the dolphins can move through the barrages then there is enough flow of genetic material, and genetic deterioration or inbreeding is not an immediate threat to the species. Becoming stranded in irrigation canals is another threat to these dolphins. Water is diverted into irrigation canals and some of these canals in Pakistan can be compared with rivers in other countries! Dolphins accidentally swim into these canals when the gates are open, however, when the gates of the canals close in January, the water level begins to drop and dolphins become trapped in small pools with depleting fish supply. Furthermore, there are contracts given out for fishing in the canals, risking the lives of those dolphins still stuck there.

Thus, such dolphins need to be translocated back into the mainstream. Rescue efforts for this have been carried out by the Sindh Wildlife Department, with the technical support from WWF -- Pakistan. The dolphins are carefully captured, placed on a stretcher, kept moist with a wet towel and dripping of water and are released in the mainstream of the Indus. Recently, with the support of Engro Chemicals Pakistan, a fully equipped dolphin rescue ambulance was acquired. This was a much-needed support because the translocation of a rescued Indus dolphin from a canal to the main river channel in an open vehicle causes undue stress that can even be fatal.

These dolphins were once hunted for meat, oil and to decrease the competition for fish resources. Its oil had different uses such as in the treatment of joint pain, as a protective emulsion on wooden boat, and a bait for fishing, to mention a few. However, with strict legislations and its better implementation because of the high profile of the species, and possibly as a result of changes in religious beliefs, the dolphin is no more hunted for meat. Now there are no reports of advertent killing of the mammal, however, entanglements in fishing nets remain a problem.

The Indus dolphin is virtually blind, although it can differentiate between light and dark. The eyes are not useful in the silt-laden water of the Indus, so the dolphin has a very sophisticated sonar system. Just like a bat, it produces sound waves that bounce off the surrounding objects and are received by the dolphin in its lower jaw. These waves provide a perfect picture of the surrounding objects, their sizes, dimension, texture, etc. This sonar makes a dolphin an efficient predator. Although a dolphin is very intelligent, and with its sonar it can avoid fishing nets, sometimes the very thin nylon strings used to make nets are not detected properly and prove to be deadly for dolphins and turtles.

The sustainability of the riverine ecosystem and survival of the fishermen depend on sustainable fishing practices. Currently, there is no restriction on the amount of fish catches. Fishing is completely commercial. All types of fishing gears are harmful to aquatic mammals. The fisheries department legislation can be improved to minimise the threat to the dolphin population and also make fishing more sustainable. The existing legislation does not disallow fishing at night, and nets can be left overnight and unattended. This makes dolphins very vulnerable because a trapped dolphin can go undetected, therefore, there is no chance of rescuing the drowning animal. Once a dolphin dies in a fishing net, its blubber (fat) is extracted to make oil which is used to treat aching muscles.

Fish habitats are not protected anywhere in Pakistan. It has never been realised that the spawning habitat of fish needs to be protected. There is a reserve for the Indus dolphin in Sindh, the 190km stretch of the river between Guddu and Sukkur. But the Indus dolphin is not protected in the real sense if fishing is allowed in that area. Dolphins feed on fish and they can die if entangled in fishing nets.

There are also some unconfirmed reports that chloroform is used in this area for fishing, an illegal practice. Agriculture runoff and pollutants from industries deteriorate the habitat of fish and harmful chemicals accumulate in the organs and muscles, and when people or dolphins eat these fishes, the chemical are passed on with a magnified impact because they are not digested and are assimilated in the tissue.

WWF – Pakistan, as part of its dolphin conservation initiative, is helping the farmers to improve their agriculture practices by reducing the use of fertilisers, pesticides and water. By introducing better management practices in agriculture not only is the meagre resources of the poor farmers saved but it also helps to protect the dolphins' habitat from agriculture runoff which can be dangerous. Such practices benefit farmers in other ways too. For example environmentally conscious international cotton buyers prefer cotton which has been produced through environmentally sustainable practices. A consumer enlightened of environmental issues would make choices of products that have been produced without any negative impact on the environment. Today, international companies are conscious of becoming carbon and water neutral and prefer green business, reducing their ecological footprint.

The Indus has diversity in both culture and wildlife and provides an extraordinary experience. Many areas on the Indus are popular among visitors, with boats available for hire, to sail in the river and get a chance to look at the dolphins and birds of the river. Among the popular sites are Chashma Wildlife Sanctuary, Taunsa Wildlife Sanctuary and upstream Sukkur Barrage.

Current fishing practices are damaging the indigenous fishermen community and are stripping the ecosystem of its resources. In addition, industrial pollution is now damaging the habitat. This has serious implications on people and endangered species like the Indus dolphin. There is a dire need to revisit existing legislation, implement the laws and develop a strategy that ensures the survival of the indigenous fish communities and sustainable use of natural resources. Moreover, there is a need to maintain minimum environmental flows in rivers.

By: Uzma Khan

FACT FILE

• The Indus river dolphin is only found in Pakistan. It is one of the four types of dolphins that can only survive in freshwater.

• It was once found in the large five rivers of Pakistan, however, is now restricted to the Indus. There has been an 80 per cent reduction in the range of this species.

• There are only about 1,341 Indus dolphins left.

• The Indus dolphin is also referred to as the 'blind dolphin' because its eyes are only able to differentiate between light and dark.

• These dolphins use sonar waves to find their way in the muddy water of the river. They produce sound waves that bounce off on touching an object and are received in the lower jaw and forehead. They are able to judge the size and shape of the objects and distance from them. This system is called echolocation and also helps in maintaining contacts with the fellow dolphins.

• It is cannot breathe underwater like fishes. A large adult dolphin, on average, comes to the water surface after every two – three minutes.

• Like other dolphins, the Indus dolphin has a layer of fat under its skin, this layer helps in keeping the body warm and also stores energy.

• The Indus dolphin swims with a speed of about 6km per hour.

• It eats fishes and prawns. It has sharp teeth that may look scary to some people but are only for holding the prey. The Indus dolphin does not bite and is harmless to humans.

• Inside the flippers, dolphins have five fingers, just like us.

• Dolphins also sleep. But they sleep with half their brain active, maintaining their breathing and keeping them aware of their surroundings at all times. — UK

Other sites about the Blind Dolphin of the Indus

http://www.travel-culture.com/pakistan/indus_dolphin.shtml
http://www.wildlifeofpakistan.com/RiverDolphin.html