CARDIFF U. (UK)—Finless porpoises living in the freshwaters of China’s Yangtze River are more endangered than previously thought, according to the results of a new genetic survey.

The survey of groups of finless porpoises from different regions has revealed that the Yangtze finless porpoise is genetically different from its marine counterparts. The researchers are now warning that these results will have major implications for conservation and survival.

A type of toothed whale, finless porpoises inhabits a wide range of waters in the Indo-Pacific region. For the purposes of the study, researchers analyzed the genetic structure of groups from the Yangtze River, the Yellow Sea, and the South China Sea.

The data revealed significant genetic differences between regions, suggesting that finless porpoises in Chinese waters can actually be classified as three distinct genetic groups.

Of these groupings, the Yangtze finless porpoise is the only one adapted for living in freshwater. Previous studies have shown that numbers are in sharp decline and only 1,000 are estimated to remain in the river.

The research was conducted by a team from Nanjing Normal University, China, along with Mike Bruford, a professor at Cardiff University.

“The unique genetic diversity of the Yangtze finless porpoise has major implications for how we tackle conservation,” says Bruford. “The survey also found that the Yellow Sea porpoises are distinct from those in the South China Sea. Each population group therefore requires separate conservation efforts.

“The population figures in the Yangtze river are decreasing annually and studies suggest that this population may become extinct this century. Special efforts need to be made to protect this rare species from suffering the same fate as the baiji, the Yangtze river dolphin declared extinct in 2007.”

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