The Chinese paddlefish has been declared extinct in a study published in Science of the Total Environment.
The Chinese paddlefish (Psephurus gladius) lived in the Yangtze River in China and could grow up to 23 feet long. The last known sighting of the species, named for its long, paddle-like snout, was in 2003, Mongabay reports. There is one other living species of paddlefish, native to North America.
“Given that the Chinese paddlefish was one of the two extant species of paddlefishes, loss of such unique and charismatic megafauna representative of freshwater ecosystems is a reprehensible and an irreparable loss,” Qiwei Wei, co-author of the study, told Mongabay.
The large fish was once plentiful in the rivers of China, but by the 1950s it was mainly found in the Yangtze. In the 1970s, the annual catch totaled an estimated 25 tons, but continued overfishing saw the catch decline until China listed the paddlefish as a protected species in 1989. On top of pressure from fishing, the construction of the Gezhouba Dam hurt the species by dividing the fish’s population into two groups and disrupting their life cycle. Historically, the paddlefish swam upstream to spawn and their offspring swam downstream to feeding grounds after hatching, but the dam blocked access to these areas.
The study estimates that the Chinese paddlefish was functionally extinct, meaning it no longer served a meaningful function in the Yangtze ecosystem, as early as 1993. The declaration of the species as fully extinct comes after an extensive survey of the entire Yangtze River basin.
Researchers say the species’ complete extinction in the wild likely occurred between 2005 and 2010.
Another iconic species of the Yangtze may have already suffered the same fate. The baiji, or Yangtze River dolphin, hasn’t been seen since 2002. Many other species are also likely close to the brink, and researchers urge that efforts to assess and conserve their populations must continue.
“The present search and rescue work on other possibly extinct species, such as baiji and Reeves shad [Tenualosa reevesii], should not be stopped but intensified,” Wei told Mongabay. “The dead are dead, take care of the species that are about to go extinct.”