Dolphin species declared extinct

Updated on 08 August 2007
Source PA News

A Chinese freshwater dolphin has been declared extinct after desperate efforts to rescue it came too late.

One British zoologist described the loss of the Yangtze River dolphin as a "shocking tragedy".

It is the first official extinction of a large vertebrate for more than 50 years.

Experts say human activity killed off the white long-beaked dolphin, which grew to 8ft weighed up to 500lb.

The animal is the first cetacean, the group of mammals that includes dolphins, whales and porpoises, to vanish from Earth as a direct result of human influence.

In the 1950s the dolphin, a species unique to the Yangtze river also known as the Baiji, had a population of thousands. Over the next five decades its numbers declined rapidly as China modernised and made heavy use of the river for fishing, transport, and electricity generation.

During Mao's "Great Leap Forward", traditional veneration of the Baiji - nicknamed "Goddess of the Yangtze" - was denounced and the dolphin hunted for its flesh and skin.

Industrial pollution, depleted food supplies due to overfishing, loss of habitat, and the construction of the Three Gorges Dam all put further pressure on the dolphin. Stocks of some of its prey species collapsed to one thousandth of their pre-industrial levels.

In the crowded Yangtze, many dolphins died after becoming entangled in fishermen's nets and being prevented from surfacing for air. Noise pollution also caused the animals, which navigate by sonar echo-location, to collide with shipping and get caught in propellers.

Surveys of the Yangtze River dolphin, Lipotes vexillifer, showed that by 2006 its population had dwindled to just 17 individuals.

http://www.channel4.com/news/articles/science_technology/dolphin+species+declared+extinct/659872