Other than the Chinese paddlefish, the survival of many rare aquatic animals, in particular the sturgeon species in the Yangtze River, also hangs in the balance.
From 2017 to 2019, the Ministry of Agriculture and Rural Affairs launched the Yangtze River Fishery Resources and Environment Survey Project. According to the report, over 130 of the 448 species of fish recorded in the Yangtze River were not spotted during the survey, accounting for nearly one-third of the total number of fish distributed in the Yangtze River. “It might be that some of the fish that were not found are already rare, but other species like the Chinese paddlefish may be already extinct,” Wei said.
According to the IUCN announcement in July, 100 percent of the world’s remaining 26 sturgeon species are at risk of extinction, up from 85 percent in 2009.
Among them, the Chinese sturgeon (Acipenser sinensis), another important species in the Yangtze River, is listed as “critically endangered” by the IUCN Red List of Threatened Species and the Yangtze sturgeon was moved from Critically Endangered to Extinct in the Wild.
The Chinese sturgeon conservation reserve, covering an area of 6,736 hectares, was established in 1996 in Yichang, Hubei Province in the middle reaches of the Yangtze.
The reserve is designated to protect the natural breeding area of the Chinese sturgeon, their habitats and spawning ground. It also provides a natural habitat for other rare aquatic species such as the Yangtze sturgeon and Yangtze finless porpoise, as well as for four commercially important fish species including herring, grass carp, silver carp and bighead carp. The conservation area plays a key role in preserving the Chinese sturgeon, since it includes the fish’s only spawning ground in the country.
Artificial breeding and release are important ways to protect the Chinese sturgeon. Juvenile, subadult and adult Chinese sturgeon are released into the Yangtze River to restore or revive the natural population of the species.
A widely cited figure is that China has released over 7 million captive-bred Chinese sturgeon in the past 40 years, and over 3 million Chinese sturgeon have been released in Yichang during this time. However, despite the continuous artificial proliferation and release, the natural population of Chinese sturgeon has declined. Wei believes this is because the number of released fish is too low.
“It’s completely different when you release aquatic animals compared with returning terrestrial animals to the wild. It would be a significant number if scientists released 10 tigers to the wild, but the natural fatality of fish is high, so releasing 100,000 fish in tributary rivers may only result in 5 percent surviving by the time they arrive at the Yangtze Estuary,” Wei said.
Artificial breeding of the Chinese sturgeon has been difficult. Private enterprises that breed sturgeon for repopulation and conservation cannot attract enough government support. In 2018, more than 6,000 artificially bred Chinese sturgeon died after local government-led construction projects disturbed breeding ponds owned by Hubei Hengsheng Industrial Company, the country’s first private Chinese sturgeon breeder.
The company was forced to relocate its breeding center. According to Wei, many other private enterprises retreated from this field over the years as they could not afford the high costs involved in breeding the Chinese sturgeon.
Addressing the rapid decline of the wild Chinese sturgeon, and in order to protect it, the Ministry of Agriculture and Rural Affairs compiled the Chinese Sturgeon Rescue Action Plan (2015-2030), its first single-species protection plan. However, Wei said that although it has been implemented for several years, the action plan has not been well promoted, and the main actions such as large-scale breeding base construction, spawning ground restoration and genetic diversity preservation have not been effectively implemented, and there is still no special funding for artificial breeding and release programs.
Wei called for immediate action to protect rare aquatic animals in the Yangtze River. He said the 10-year Yangtze fishing ban will give fish species time to recover.
“Before implementing the policy, fish could be caught as soon as they were released. We started releasing Yangtze sturgeon around 2007, and statistics revealed fishers caught almost all of them within three months.”
In He Shunping’s view, besides the ban, small hydropower stations should be dismantled to restore the natural flow of the river. Some small hydro projects along the Chishui River, an upstream tributary of the Yangtze, have been dismantled in recent years.
“If more places take action, it will have a relatively big impact,” He said. “As the extinction of rare aquatic animals in the Yangtze River is accelerating, humans should speed up the race against these extinctions.”
Although scientists have not seen the paddlefish for years, their rescue efforts never cease. In 2014, Wei Qiwei’s team introduced the most advanced endangered fish preservation technology from abroad and started surrogate pregnancy research among fish species to arm themselves with technical preparation for the rescue of the Chinese paddlefish.
“Extinction is a scientific conclusion, but we always hope that there might be an exception. If so, and someday we spot a Chinese paddlefish, could we use the technology to revive the species? At least we could adopt these technologies to help other endangered species,” Wei said.
He Shunping told NewsChina that he will attempt to genome sequence the Chinese paddlefish by taking tissue from dead specimens. But this is challenging since they were usually preserved using chemicals like arsenic, destroying its DNA. But scholars are still trying.
Wei told the reporter that if the State had ordered breeding efforts earlier, perhaps the giant fish would not be extinct.
“Just look at the Chinese sturgeon and the Yangtze sturgeon. Now we have artificially bred individuals, so at least this species can survive,” he said.