By Zhan Yan, China Features

    BEIJING, Jan. 21 (Xinhua) -- An international expedition that recently declared the Yangtze River dolphin, or 'baiji' (literally translated as 'white fin') "functionally extinct" has aroused public attention to the environmental degradation of China's longest waterway.

    Over a six-week period between November and December 2006, and equipped with high performance optical instruments and underwater microphones, the team of scientists cruised on two research vessels over 3,500 kilometers from Yichang near the Three Gorges Dam to Shanghai in the Yangtze Delta, and back.

    "The moment that experts disembarked from the ships, was the moment that humankind bid farewell to the 20-million-year-old baiji," said Wang Kexiong, an expert working with the Institute of Hydrobiology (IHB), based in Wuhan, "the baiji can easily be spotted as they breathe on the surface and splash water almost every 30 seconds. It's a traditional and effective way to locate a baiji."

    Dubbed 'Goddess of the Yangtze', the baiji was held in high regard by the ancient peoples of the Yangtze, who believed that the white 'fish', the same size of a human being, could help safeguard sailing.

    In the early 1980s, the Yangtze reportedly had around 400 baiji swimming its waters. A 1997 survey yielded 13 confirmed sightings. The last confirmed sighting of a baiji was in September 2004.

    As the expedition returned to land having failed to sight a single baiji, August Pfluger, head of the Baiji.org Foundation and co-organizer of the expedition, pronounced the species "functionally extinct" as there are likely to be fewer alive than are needed to stop the species dying out.

    Nevertheless, Chinese experts say they will continue to search for the mammal in the Yangtze's waterways. International standards state that, in order for a species to be declared extinct, no sighting of it has to be reported for between 20 to 50 years.

    Most of the scientific world's knowledge of the species comes from 'QiQi', a male baiji that was rescued by the IHB in 1980 and died in 2002. Wang Kexiong who, along with his colleagues, had been taking care of QiQi, conceded that with his death in 2002, many people probably lost their last chance to cast eyes on the quickly vanishing species.

    "The Baiji is very friendly to humankind -- even though he had sharp teeth, QiQi would never attack people standing nearby. If he was unhappy with us, he would simply tap us with his tail -- at 2.5 meters long and weighing in at 200kg, QiQi could have given us a much more powerful whack if he had wanted to," said Wang.

    Wang added that, "The baiji has feelings and thoughts, just like other mammals -- we could sense QiQi was lonely at times but he was relatively happy when people were in his company. It's just a pity we failed to find him a mate -- the baiji usually lives in a nuclear family."

    Wang Kexiong expressed his concerns for the future of the Yangtze's entire ecological system stating that, "Cetaceans (whales, dolphins and porpoise) live at the top of the food chain -- if they are threatened by extinction, it means that their food sources are also dwindling and biodiversity in the Yangtze River is degenerating."