Could the Yangtze River dolphin specie not be extinct after all?

A creature believed to be the rare Chinese white dolphin has been sighted in the Yangtze river, an expert said Wednesday, renewing hope for a mammal recently declared as probably extinct.
Video footage by a resident of eastern Anhui province purportedly taken this month appears to show the critically endangered white dolphin, known in China as the "baiji", frolicking in its native Yangtze habitat, said Wang Ding, one of the world's leading authorities on the species.

"We cannot confirm it 100 percent but it looks pretty much like a baiji," Wang, a researcher with the Chinese Academy of Sciences, told Agence France-Presse.

Wang led a survey by scientists from around the world last year in search of the dolphin which came up empty, and he told AFP earlier this month the 20-million-year-old species was "likely extinct."

But he said the new sighting means there is hope.

"If there is one, then we have more there," he said.

The Anhui resident, Zeng Yujiang, was quoted by Xinhua news agency as saying he filmed the dolphin, easily identifiable by its long, tooth-filled snout and low dorsal, along the banks of China's longest river on August 19.

Devastating pollution, illegal fishing and heavy cargo traffic on the Yangtze have been cited as key factors in the demise of the species.

Up to 5,000 baiji were believed to have lived in the Yangtze less than a century ago, according to the baiji.org website, a conservation group.

Wang said he planned to search for the dolphin along the stretch of river where the footage was purportedly shot.

Although the sighting will likely renew hopes for the long-term survival of the baiji, experts say at least 50 of the animals will be needed to prevent the gene pool from irrevocable degeneration and eventual extinction.

"The problem is if we don't do something, the animal will be gone for sure, and quite soon," Wang said.

"If we have 50 of them, that would be very good. But we can't expect too much."

Wang also said another creature, believed to be the finless porpoise, appeared to be swimming along with the white dolphin.

The finless porpoise is also endangered but not as critically as the baiji.

The last confirmed count of the white dolphin by a research team was conducted in 1997, when just 13 were recorded.

The baiji.org website blames illegal fishing and massive discharges of industrial and agricultural waste into the river.

Other rare species that live in the Yangtze, such as the Chinese sturgeon and the finless porpoise, also face possible extinction.