A recent possible sighting of a white dolphin native to the Yangtze River - that scientists declared extinct last year - may offer a shred of hope for the animal's survival.

But a top researcher yesterday said he still considered the baiji, or white-flag dolphin, to be "functionally extinct".

Wang Ding, chief scientist at the Institute of Hydrobiology of the Chinese Academy of Sciences in Wuhan of Hubei Province, said that it is still quite difficult to protect the animal as few of the species may be living and their chances of mating are slim.

A resident of Tongling of Anhui Province took several minutes of footage with a digital video camera featuring a large white animal moving upstream in the Yangtze River on August 19.

Wang and his colleagues checked the footage and agreed that it is likely to be a baiji, a fresh water dolphin which lives exclusively in the Yangtze.

It is quite possible that the animal is a baiji, based on the white and gray color and its movement pattern," Wang told China Daily yesterday.

"Moreover, the animal in the footage was seen 40 km downstream from Tongling - a section of the river that used to be known as a habitat for the dolphins," Wang said.

"This finding brings us some slight hope."

Wang said he and his colleagues are planning a trip to Tongling in the next few days to do a detailed survey of the area.

The baiji has survived for millions of years but was declared effectively extinct in December last year after a fruitless six-week search of its Yangtze River habitat.

Environment degradation, ship traffic and overfishing are blamed.

But even if one or more baiji are left, Wang said they are unlikely to be able to find each other for breeding.

"We don't have high hopes for the future of the baiji," Wang said.

If any baiji are found, scientists will try to capture them and move them to a reserve for possible breeding, Wang said.

"This is no easy task. But if we don't do that, white-flag dolphins are doomed to become extinct," Wang said.

The last captive dolphin, Qi Qi, died in 2002 at the age of 23.

Listed as one of the 12 most endangered species in the world, the baiji population dropped to below 150 in the early 1990s from around 400 a decade earlier.

If the baiji is extinct, it will be the first cetacean to vanish as a result of human activity as it is on the top of food chain in the Yangtze River and has no natural enemy, experts said.

The baiji's cousin, the Yangtze finless porpoise - a dark gray freshwater porpoise - is also endangered as its population is less than 1,400, Wang said.

(China Daily August 31, 2007)