The Yangtze finless porpoise (Neophocaena asiaeorientalis asiaeorientalis), the world’s only freshwater porpoise, has been upgraded to Critically Endangered on the IUCN Red List of Threatened Species. This follows the recent probable extinction of the other cetacean once found in China’s Yangtze River system, the Yangtze River dolphin or baiji (Lipotes vexillifer). The change in threat status (it was previously classified as EN) is based on analysis of data for 279 stranded porpoises collected from the middle and lower reaches of the Yangtze River from 1978 onwards, which reveal that the porpoise population is experiencing an accelerating decline, and predict a further population decline of >80% within three generations.
Recent survey results from late 2012 suggest that the porpoise population in the main Yangtze channel has almost halved since the previous survey in 2006, with initial estimates suggesting that there are now only around 500 individuals left in the mainstem compared to over 1,100 six years earlier. The primary drivers of this decline are still not clear because of the range of harmful anthropogenic factors operating in the Yangtze ecosystem, although ship collisions, by-catch in legal and illegal fishing gears, reduction of fish prey base, habitat degradation, and the effects of pollutants are all likely to play a role.
To read the full assessment on the Redlist, click here