Scientists declare Chinese paddlefish is extinct

The Chinese paddlefish, one of the world's largest freshwater fishes and native to the Yangtze River, was recently declared extinct by scientists.

Reaching up to 7 meters in length, the Chinese paddlefish might have become extinct between 2005 and 2010, according to a research paper published online by the Science of The Total Environment journal on Dec 23.

"The Chinese paddlefish was once common in the Yangtze River. However, its population has declined drastically since the late 1970s as a result of overfishing and habitat fragmentation," the paper said.

Surveys from 2017 to 2018 found 332 fish species in the Yangtze River, but did not find a single live Chinese paddlefish, according to the paper jointly released by Chinese experts from the Yangtze River Fisheries Research Institute and two experts from the UK and Czech Republic.

Furthermore, it also showed that 140 historically reported fish species have not been found, and most of them are considered highly endangered.

"Based on 210 sightings of the Chinese paddlefish during the period from 1981 to 2003, we estimated the timing of extinction to be by 2005, and no later than by 2010," the paper said. In addition, the paddlefish probably became functionally extinct, unable to reproduce, in 1993, the report said.

"It is likely that the lack of reproduction was among the major causes of extinction. As no live specimens exist in captivity, and no living tissues are conserved for potential resurrection, the fish should be considered extinct according to the IUCN Red List criteria," it said.

In September 2019, Wei Qiwei, one of the authors of the paper, said experts from the International Union for Conservation of Nature estimated that this unique and firstclass protected fish was already extinct.

On Friday, the IUCN China office said on its Sina Weibo account that it has not officially announced the species' extinct. It said an expert team was making further evaluations and the result will be released in June.

"Under the current research, the situation of Chinese paddlefish is not optimistic," it said.

If its extinction is officially confirmed, the Chinese paddlefish will be another species to have disappeared from the Yangtze River in recent years, following the Yangtze River dolphin and reeves shad.

The Chinese paddlefish, or Psephurus gladius, normally grows to about 2 to 3 meters long, and sometimes longer than 7 meters. The fish is estimated to have existed for 15 million years.

The last sighting of the Chinese paddlefish was in 2003. Scientists tried to track it, but a boat accident ruined the efforts. Since then, no sighting has been reported.

"The Chinese paddlefish was so big that it was hard to raise in captivity," Wei said. He said between 1984 and 1993, he tried to save four trapped fish, but only one survived and returned to the river.

The extinction of the fish has aroused public attention as people expressed sadness over the paddlefish's disappearance, hoping that more animals can be better protected for future generations to enjoy.

From Jan 1, China began a 10-year fishing ban on key areas of the Yangtze River to protect biodiversity in the country's longest river, according to the Ministry of Agriculture and Rural Affairs.