SHANGHAI, Aug 8: China's rapid industrialisation has likely made extinct a species of fresh water dolphin that had been on Earth for over 20 million years, a marine biologist said on Wednesday.

A team of scientists from China, Japan and the United States failed to find the white dolphin, known as the baiji, during a six-week search of its natural habitat in the Yangtze river late last year.

“This result means the baiji is likely extinct,” Wang Ding, who led the survey and is one of the world's leading experts on the species said.

The dolphin was a victim of devastating pollution, illegal fishing and heavy cargo traffic on the Yangtze, Wang said.

The findings mean the baiji is likely the first mammal to become extinct in more than 50 years. It is the cousin of the bottlenose dolphin, which is also on the critically endangered list.

Wang, from the Chinese Academy of Sciences, emphasised that not all hope was lost for the dolphin, which had made its home along the lower reaches of China's now heavily polluted Yangtze River for more than 20 million years.

“We are not saying the baiji is already gone,” he said.

But he lamented that further searches this year had failed to find any sign of the dolphin.

Wang said that a letter written by the survey team had been published in the latest issue of the Royal Society Biology Letters journal in Britain to confirm the dolphin was believed to be extinct.

The baiji, identifiable by its long, teeth-filled snout and low dorsal fin, was last officially sighted more than two years ago.

The last confirmed count by a research team was conducted in 1997, when just 13 were recorded. Up to 5,000 baiji were believed to have lived in the Yangtze less than a century ago, according to the baiji.org website, which was established by a range of international conservation groups.—AFP