Hope is fading for China's rare Yangtze River 'white-flag' dolphin after an international expedition failed to find one of the mammals after almost two weeks of searching.
Scientists from six countries including China, the United States and Britain are saddened after their search in a national ‘white-flag’ dolphin reserve in Honghu Lake, in the central province of Hubei, has failed to find the mammal.
They’ve now got their fingers and toes crossed that they’ll discover the mammal when they arrive Wednesday night at the Tongling National Freshwater Dolphin Reserve in the eastern province of Anhui. Zheng Bangyou, director of the Tongling Reserve Administration, said they’d a better chance of finding the dolphin there as the reserve boasts a good ecosystem.
The team started the six-week search on November 8 in Wuhan. The city is on the middle reaches of the nation's longest river. The expedition will cover about 1,750 kilometers of the waterway up to Shanghai.
The scientists on two ships use high-powered binoculars and advanced acoustic equipment to detect the dolphin which has been dubbed "goddess of Yangtze River". It’s one of the world's 12 most endangered species.
Wang Ding, deputy director of the institute of hydrobiology under the Chinese Academy of Sciences, said he’d seen with his own eyes 17 ‘white-flag’ dolphins during a 1980s research expedition without any need for high-tech optical and acoustic equipment.
"Ten years ago or a little longer I could see white-flag dolphins quite often but now it’s headlines if I spot just one. The dolphin is vanishing too fast," said Zhang Zhongxiang, an elderly staffer at the ‘white-flag’ dolphin natural reserve in Honghu Lake.
According to estimates less than 50 of the dolphins, believed to be among the world's oldest freshwater mammals, remain. This is a sharp decline from about 400 in the early 1980s. Some pessimistic experts put the number as low as 10.
Earlier media reports cited experts as saying that the ‘white-flag’ dolphin, a unique Chinese species with a habitat in the middle and lower reaches of Yangtze, could become the first whale type species to become extinct if efforts were not made to protect it.
Wang said it would be very hard for the species to survive if there were less than 20 of them left. The dolphin gives birth to only one young a year. "If we find one we’ll do our utmost to trace it, hold it and then transfer it to a natural reserve for better protection," he added.
Experts blame worsening water pollution, increasing river traffic, illegal fishing using dynamite and ‘electro fishing’ for the sharp decline and even extinction of the highly endangered species. They say ships' engine noise can disturb the dolphin's sonar system. The dolphin relies on its highly developed sonar system for movement.
Experts believe water conservation projects and toxic pesticide washed into the river from farmland have also taken their toll on the mammal.
China has devised plans to transfer the ‘white-flag’ dolphin to special reserves near the Yangtze to better protect the 25-million-year-old species but as yet not a single specimen has been delivered, said Wang.
For the research team the only good news is that they have found over 70 black finless porpoises which is the ‘white-flag’ dolphin's Yangtze cousin. Porpoise numbers have also declined sharply over the past 20 years.
"We’re doing more than just protecting the freshwater dolphins," said Wang. Water and silt samples were being taken every 50 to 100 kilometers of the river to monitor and later protect its deteriorating ecosystem, Wang explained.
(Xinhua News Agency November 23, 2006)