Endangered porpoises die, raising extinction concern

Xinhua, April 19, 2012

More than 10 finless porpoises have recently died in two lakes linked to China's Yangtze River, raising public concerns over the endangered species.

Since March 3, 10 finless porpoises have been confirmed dead in central China's Dongting Lake, according to the Fishery Affairs Management Station (FAMS) of the Animal Husbandry and Aquatic Products Bureau of Hunan's Yueyang City.

Another six have been reported dead since the beginning of this year in east China's Poyang Lake in Jiangxi Province, according to the provincial fishery bureau.

The Yangtze finless porpoise is an endangered species that lives exclusively on the Yangtze River and Poyang and Dongting lakes.

Figures from 2006 show there were 1,200 finless porpoises left in the river at the time, making the species even more rare than giant panda. In January, experts carried out observational and sonar research that showed there were just 65 finless porpoises left in Dongting Lake, and 300 to 400in Poyang Lake.

The recent deaths brought the mortality rate of the finless porpoise between 5 to 10 percent, which means the species will be "functionally extinct" in 15 years, according to experts.

A local conservation association performed autopsies on three dead porpoises retrieved from Dongting Lake and found they may have died of starvation.

"They had no fatal injuries and there wasn't any food remaining in their digest systems," said Xie Yongjun, an associate professor with the Yueyang City Finless Porpoise Protection Association.

The findings were similar in Poyang Lake. Of six porpoises, two died of injuries caused by human impact, while the other four died of starvation.

Chen Fu, deputy chief of the Jiangxi provincial fishery department, said the weather has caused water levels on Poyang Lake to destabilize this year, adding that a sudden decline in the water levels may have made it difficult for the dolphins to find food.

"Most of the dead porpoises were found at the dry lake branches. They may have starved to death as there was not enough water for them to return to the main lake for food," said Chen.

Lu Weiyi, a FAMS official in Yueyang, said the Wuhan-based Institute of Hydrobiology under the Chinese Academy of Sciences (CASIH) will conduct a further investigation into the cause of the porpoises' deaths.

Lu said the city will organize an investigative team, check water quality and keep an eye out for illegal fishing activity in order to protect the endangered species.

Wang Kexiong, a CASIH researcher, said shipping, sand gathering, illegal fishing, sudden climate change and water pollution are all possible causes for the porpoises' deaths.

"The exact cause will be determined based on the autopsy results and environmental data from Yueyang," he said.

Internet users expressed sorrow over the deaths of the porpoise, saying human activity such as overfishing and water pollution had drastically reduced their food supply.

"If the Yangtze River is no longer suitable for the existence of the finless porpoise, it will barely support human beings in the near future," said a netizen called "Lailaiwei" on China's largest microblogging website Weibo.com.