The team of researchers, including Dr David Roberts of Kent’s award-winning Durrell Institute of Conservation and Ecology (DICE), confirmed that the extinction had likely been caused by overfishing in the 1970’s, and habitat fragmentation in the Chinese paddlefish’s native habitat, the River Yangtze e.g. through the construction of the Gezhouba Dam. Furthermore, the Chinese paddlefish had been functionally extinct (unable to reproduce) since 1993.
The paddlefish, scientifically known as ‘Psephurus gladius’, could attain a length of 23 feet and was easily recognised by its snout-like structure. It was one of the largest freshwater fish species on record.
A basin-wide survey between 2017 and 2018 was carried out by Dr Roberts’ Chinese collaborators to confirm the news, with 332 fish species found and identified, but not a single specimen of Chinese paddlefish. It is thought that the timing of extinction was 2005, but no later than 2010.
Dr Roberts said: ‘There are many factors that could have contributed to the Chinese paddlefish becoming extinct, but we know that disruption by dams to their natural habitat alongside wider environmental impact such as pollution will have had damaging effects. As we know, many other fish species are continuing to suffer from these circumstances too. It is a real shame that loss of biodiversity is often only recognised once it is too late for some species and we hope that cases like this can raise the awareness to protect endangered species in the future.’
The research paper ‘Extinction of one of the world’s largest freshwater fishes: Lessons for conserving the endangered Yangtze fauna’ has been published in Science of the Total Environment.