Posted on November, 20 2012

Yichang, China -- Scientists from a research expedition that is looking to find out how many finless porpoises now live in the Yangtze have spotted 10 individuals in a 630km section of the river, fewer than detected in the area during a similar study six years ago.

A combination of visual and sonar identification are being used to guarantee the independence and accuracy of the findings, according to the expedition team, which docked near the city of Yichang Monday afternoon.

Initial results suggest a drop in the population of the world’s only freshwater finless porpoise but the results are pending until late next month when the evaluation is finalized.

"We have spotted 10 finless porpoises from Wuhan to Yichang, the first leg of the survey, mainly in the lower reaches of the Honghu section, upper reaches of the Dongting estuary, upper and lower reaches of the river near Jianli county and the section adjacent to Gong'an county, with few discoveries elsewhere," said Wang Kexiong, deputy head of the research expedition and an associate researcher at the Chinese Academy of Sciences’ Institute of Hydrobiology (IHB).

Shipping traffic, infrastructure to blame for population decline

The Yangtze finless porpoise (Neophocaena phocaenoides asiaeorientalis), which numbers between 1,200 to 1,500 in the wild, lives mainly in the central and lower reaches of the 6300km Yangtze River and two large adjoining lakes, Dongting and Poyang.

Estimates from the 2006 survey say that the finless porpoise is expected to decline to around 200 by 2035 - Critically Endangered on the IUCN Red List – but more recent studies say that the species could become extinct in 15 years if nothing is done to protect them.

Scientists on the expedition point to the growth of commercial shipping traffic and the construction of dams and other large-scale infrastructure projects as some of the major reasons behind the decline of the rare species.

“In order to study human impacts on finless porpoises in a scientific and comprehensive manner, we will count the number of cargo and fishing ships in the Yangtze from Yichang to Shanghai to evaluate the pressure posed by shipping and fishery activities on the endangered species," said Zhang Xinqiao, expedition team member and WWF finless porpoise programme officer. 

The expedition team, which first set sail on 11 November, is scheduled to depart Yichang for Wuhan on 20 November, travelling along the Yangtze through the provinces of Anhui, Jiangxi, and Jiangsu to Shanghai, wrapping up the voyage in late-December when the first research report is to be published.

Led by China's Ministry of Agriculture and organized by the IHB, WWF and Wuhan Baiji Dolphin Conservation Fund, the expedition comes only six years after the Baiji dolphin - another rare cetacean and close relative of the finless porpoise - was declared functionally extinct.

"Statistics will be finalized after we take into consideration the validity of calculation, density of distribution, width of the river, sailing length and areas covered," said Wang Kexiong from the IHB.