3. The dolphins are dying

Posted: 10 July 2001

Dolphins, the most playful and beguiling mammals of water, are threatened everywhere by human activities, says the Centre for Science and Environment (CSE), in Delhi.

Dolphins are most often trapped in fishing nets, but everywhere they suffer from some degree of pollution and, conservation experts fear, tourism is also taking its toll on the animal.

To investigate this latter danger, scientists are to study how tourism is affecting the 100-strong population of dolphins in Port Phillip Bay, near Melbourne in Australia.

Australian environment and conservation minister Sherryl Garbutt says the Sustainable Dolphin Tourism in Port Phillip Bay programme will see whether tour operators' activities are having a detrimental effect on the bay's bottle-nosed and common dolphins.

Boys with Ganges dolphin. Credit: CSE.The highest number of dolphin deaths is reported from the South Pacific where they get snared in the purse seines used for tuna catching, but the most threatened species is found in the Yangtse River in China, where only a few survive.

In India, river dolphins, particularly the Ganga river dolphins (Platanista gangetica) have been dwindling at an alarming rate. While thousands of them were found in the depths of the Ganga-Brahmaputra river system in the last century, a recent survey puts their number at only 2,500.

Protected by law

Unfortunately, people in general, and forest officials in particular, know little about these marine animals. When public interest litigation was filed against the fishermen of Beypore beach in Calicut for killing three common dolphins it was difficult to convince the forest officials, including the district forest officer, that dolphins are wild animals protected by law. The World Conservation Union (IUCN) declared dolphins an endangered species in 1996.

According to a recent survey conducted along the Kerala coast, at least 1,000 dolphins are killed every year mainly in the gill nets. The number of humpback dolphins (Sousa chinensis) is dwindling alarmingly, mainly because these are near-shore species often entering the estuaries and backwaters where they become entangled in the nets.

Fishing for dolphins in the Indian Ocean is prohibited by the International Whaling Commission. But many fishermen are not aware of this. It is possible to bring down the mortality rate of dolphins by initiating awareness programmes

A wall of nets

Dolphins, despite their sophisticated echo- location capabilities, often get entangled in the gill nets. These nets have floats and sinkers and stand like a wall in the sea for three to four kilometre. India has about 2.2 million gill nets along the coast. These nets are transparent and the dolphins' flippers and beaks get caught in them. Moreover, the dolphins often get entangled while trying to take the fishes caught in the nets.

Dolphin oil is popularly used as an aphrodisiac, as a fish bait and also for medicinal purposes, according to WWF. It is also used for soap making and tanning, as well as for meat.

In the South Pacific huge numbers of dolphins are trapped in the nets of the nets of the tuna fishers. Around two to three million dolphins are killed in the purse seines every year.

Raising awareness

As the Indian Ocean has now been declared a sanctuary for whales by the International Whaling Commission, fishing for dolphins and whales there is prohibited. But many fishermen are not aware of this.

It is quite feasible to bring down the mortality rate of this remarkable animal if awareness programmes are initiated. The Dolphin Protection Committee has arranged such programmes and WWF, too, has started a six-month project to create awareness and education on dolphins.

Unfortunately, many fishermen consider dolphins to be their enemies and intentionally hunt them as they feed on their catch. What they fail to comprehend is that it is we, humans, who are encroaching on the dolphins' natural habitat.

For more information from CSE, go to Down to Earth.