Scientists say that a species of giant fish that managed to survive at least 150 million years has been completely eliminated by human activity.
Research published in Science of The Total Environment, which will appear in the journal’s March issue, says that the Chinese giant swordfish, also known as Chinese swordfish, is officially extinct.
The fish, one of the world’s largest freshwater species with lengths of up to 7 meters, was once common in China’s Yangtze River. Due to its speed, it is commonly known as the “water tiger” in China.
Study leader Qiwei Wei of the Chinese Academy of Fishery Sciences called it “a reprehensible and irreparable loss”.
Zeb Hogan, a fish expert at the University of Nevada, Reno, told National Geographic it was “very sad” to see the “ultimate loss of a unique and extraordinary animal, with no hope of recovery.”
According to the researchers, no giant swordfish have been sighted in the Yangtze since 2003, and there are none in captivity. They estimate that the last fish probably died between 2005 and 2010.
The species had been considered “functionally extinct”or unable to reproduce sufficiently to maintain their populations, since 1993.
The main causes of the disappearance of this ancient species are overfishing and the construction of a major dam in 1981 that cut the Yangtze and China’s population of paddlefish in two, effectively fragmenting the species.
According to Chinese media, the ecosystem of the Yangsé River, which measures 6,200 kilometers, has experienced the extinction of half of the 175 species unique to its waters.
Two other species native to the river have also been declared functionally extinct: Reeves’s shad and the Yangtze dolphin.
Last week, China announced a 10-year fishing ban in some areas of the Yangtze in a bid to protect its beleaguered biodiversity.
The researchers concluded that “the late extinction of the Chinese paddlefish is the result of multiple threats, suggesting that urgently needed to optimize conservation efforts in endangered Yangtze fauna“.
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Science Direct