The Chinese paddlefish, one of the largest freshwater fish to inhabit our planet for over 150 million years, has gone extinct under humanity’s watch, according to new research.
The fish, which could grow up to seven metres (23 feet) long from tail to paddle-nosed snout, is thought to have gone extinct sometime between 2005 and 2010, according to new findings published in the journal Science of the Total Environment.
The Chinese paddlefish was widespread some 34-75 million years ago, but its population dwindled sometime after 1271 C.E. Only a few remained in China’s Yangtze River late in the last century, according to the paper. The fish was declared functionally extinct in 1993, which meant there were no longer enough of them to reproduce or play a meaningful role in their ecosystem.
It was last seen in the wild in 2003, and declared completely extinct based on the findings of an expert panel assembled by the International Union for Conservation of Nature (IUCN) in Shanghai last September.
“We respect the evaluation model and experts from the IUCN, although we accept this result with a heavy heart,” study co-author Wei Qiwei said, according to the South China Morning Post.
“There have been no successful cases of breeding the Chinese paddlefish in captivity,” Wei told state broadcaster CCTV in a separate interview.
Wei and his fellow researchers blamed the Chinese paddlefish’s demise on overfishing, dam-building, pollution and busy water traffic on the Yangtze River. Lack of reproduction was also listed as a major cause.
“As no individuals 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,” Wei and his fellow researchers wrote in their paper.
The IUCN previously listed the Chinese paddlefish, or Psephurus gladius, as critically endangered based on another study involving Wei in 2010. The IUCN website has yet to be updated with the new assessment.
China had faced criticism in 2007 for allowing a new dam to be built of the Yangtze River, despite concerns that it might threaten the Chinese paddlefish and the Yangtze River dolphin, another critically endangered species.
China announced last week that it will impose a 10-year fishing ban along several stretches of the river in an effort to protect its biodiversity.
The Chinese paddlefish’s only cousin, the American paddlefish, is listed as an endangered species in the United States.
The extinction paper says urgent steps must be taken to protect the remaining biodiversity on the Yangtze River, such as the narrow-ridged finless porpoise.
“Optimizing conservation efforts on endangered Yangtze fauna is urgently needed,” the paper said.