The long goodbye: Study declares ancient Chinese paddlefish extinct
In 2003, researchers from the Chinese Academy of Fishery Sciences captured, tagged and released a female Chinese paddlefish (Psephurus gladius) that had accidentally been caught in the Yangtze River. In just 12 hours, all communication with the fish tag was lost. That was the last time scientists saw a living Chinese paddlefish.
The same team of researchers, led by Qiwei Wei, assessed the species as critically endangered (possibly extinct) for the IUCN Red List in 2009. But the Chinese paddlefish, listed among the worldβs largest freshwater fish species with lengths reaching up to 7 meters (23 feet), likely went extinct before that assessment, a new study concludes. In fact, by 1993, the species was most probably functionally extinct; that is, it was unable to reproduce successfully and its population was too small to be significant in any manner, researchers have now determined.
The Chinese paddlefish is, or rather was, a unique species. It was one of only two living species of paddlefish, the other being the American paddlefish (Polyodon spathula), part of an ancient group of fish known to have existed since the Lower Jurassic, 200 million years ago. It was also the only species in the genus Psephurus.
βGiven 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,β Wei, a professor at the Chinese Academy of Fishery Sciences and co-author of the study, told Mongabay.
The Chinese paddlefish wasnβt always rare. Historically it occurred across many large rivers that flow into the West Pacific, but since the 1950s it was seen mostly in the Yangtze River, researchers say. There, too, its numbers declined dramatically due to overfishing β estimates put harvests at around 25 tonnes of paddlefish per year during the 1970s β and fragmentation of its riverine habitat. A major death knell came with the construction of the first dam on the Yangtze River, the Gezhouba Dam, which blocked the routes of most migratory fish in the river, including the Chinese paddlefish. The dam split the fishβs population into two isolated groups, and prevented adult fish from moving upstream to spawn and young fish from swimming to downstream feeding areas.
