China survey reports fewer sightings of engangered porpoise

A finless porpoise in Wuhan on November 11, 2012
An undated picture released by World Wildlife Fund shows a finless porpoise at the Research Centre for Aquatic Biodiversity and Resource Conservation of the Chinese Academy of Sciences in Wuhan on November 11, 2012. A survey of endangered porpoises in China's longest river has yielded fewer sightings as intense ship traffic threatens their existence, scientists said.

A survey of endangered porpoises in China's longest river has yielded fewer sightings as intense ship traffic threatens their existence, scientists said Monday.

Chinese researchers spent 44 days tracking the finless porpoise—or "river pig" in Chinese—along a little over half of the 6,000-kilometre (3,700-mile) Yangtze River.

The finless porpoise, which has only a small dorsal ridge rather than a fin, has been hurt by human intrusion and , group WWF, which supported the survey, said last month as it began.

The WWF has said the porpoise could become extinct in 15 years if no action is taken.

The survey, which began on November 11, marked the most comprehensive study of the species, found only in China, since 2006. A similar expedition then discovered just 1,800 of the porpoises.

Based on sonar tracking results, they said a total of 91 finless porpoises were detected while travelling the 3,400 kilometres from the cities of Yichang to Shanghai, down sharply from 177 in 2006.

The scientists said that was an initial estimate and warned it was too early to announce an actual number. Further data and analysis was needed and they expected to have a result within two months.

"There are fewer and fewer finless porpoises in the mainstream of the Yangtze River, while the animals were concentrating in the harbour areas in groups of three to five," said a release issued by the scientists from the Yangtze River city of Wuhan.

"Our concluded that this may be because there are comparatively more in the harbour areas," said Dr Wang Kexiong of the .

"However, in the mainstream of the , especially in the harbour areas, traffic is very intense, which is a huge threat to the survival of finless porpoises," added Wang, who is deputy director general of the survey.

"Such intense is a potentially deadly threat to finless porpoises, who totally depend on their sonar system to survive," said Dr Zhang Xinqiao, a survey team member and WWF official.

The 2006 expedition declared another species, a freshwater dolphin called the "Baiji", to be extinct.

Finless porpoise deaths have been caused by boat strikes and fishing gear accidents as well as degradation of rivers—and dolphin food sources—due to pollution and severe droughts blamed on climate change.

China's waterways have become heavily contaminated with toxic waste from factories and farms—pollution blamed on more than three decades of rapid economic growth and lax enforcement of environmental protection laws.


Explore further

China surveys Yangtze dolphin as extinction looms

(c) 2012 AFP

Citation: China survey reports fewer sightings of engangered porpoise (2012, December 24) retrieved 17 August 2019 from https://phys.org/news/2012-12-china-survey-sightings-engangered-porpoise.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
0 shares

Feedback to editors

User comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more