At 14:00 p.m. European time on July 21 (20:00 Beijing time), the International Union for Conservation of Nature (IUCN) released an updated report on the global red list of endangered species. Among them, the white sturgeon was declared extinct, and the Yangtze River sturgeon became extinct in the wild.
According to the latest report on the IUCN website, 26 species of sturgeon are threatened with extinction around the world. The list shows that the Yangtze River endemic species Psephurus gladius is extinct, the Yangtze River sturgeon (Acipenser dabryanus) is extinct in the wild, and the naked-bellied sturgeon is extinct. The Red List also raises the protection level of seven other species of sturgeon.
The IUCN Global Sturgeon Re-assessment shows that about two-thirds of sturgeon stocks are critically endangered. River and freshwater biodiversity is vital to humans and nature, but global freshwater biodiversity continues to be lost and river ecology continues to degrade. Arne Ludwig, chair of the IUCN Sturgeon Expert Group, said: "The results are shocking and sad, but expected."
When a species is considered extinct, in addition to mourning and commemoration, what is needed is reflection. Protecting other endangered animals should become something that all walks of life should strive to accomplish.
The Chinese sturgeon is a first-class key protected wild animal in mainland China, which has been listed as "critically endangered" by the International Union for Conservation of Nature (IUCN) and is one of the 92 endangered fish species in the Red Book of Endangered Animals and Fishes of China.
Specimen of white sturgeon in the Museum of Hydrobiology, Chinese Academy of Sciences.
"Yangtze River Fish King" Chinese sturgeon
Chinese sturgeon is a sturgeon of the family Teleostidae (spokefin fish). Common individuals are 0.4 to 1.3 meters long and weigh 50 to 300 kg; The largest individual is 5 meters long and weighs up to 600 kg, making it the largest and longest-lived fish among freshwater fish. Because it is mainly distributed in the main stream of the Yangtze River Jinsha River and below to the mouth of the yangtze river, it is the largest fish in the Yangtze River, so it is called "Yangtze River Fish King".
The Chinese sturgeon is a typical river-tracing migratory fish, it is born in the waves of the Yangtze River, but grows in the vast sea. In summer and autumn, the Chinese sturgeon, which lives in the shallow waters outside the mouth of the Yangtze River, migrates to the Yangtze River and travels more than 3,000 kilometers before returning to the Jinsha River to spawn and breed. After giving birth, the juveniles grow to about 15 cm and carry them to live in the open sea.
Chinese sturgeon are benthic fish with a very narrow feeding habit, carnivorous fish, feeding mainly on some small or slow-moving benthic animals, mainly fish in the ocean, followed by crustaceans, less predatory mollusks. Chinese juvenile fish mainly eat benthic fish snakefish genus, pupa genus, as well as scaly shrimp and clams, etc., and generally fast during the spawning period.
The survival crisis of the "Yangtze River Fish King"
In 1981, the Gezhouba was intercepted, and the passage of the Chinese sturgeon migrating to the traditional spawning grounds of the Jinsha River in the upper reaches of the Yangtze River was blocked, and although a new spawning field was formed under the Gezhouba, the breeding scale was reduced and the gonads degenerated. Since the past 90 years of last century, the Chinese sturgeon has faced an unprecedented existential crisis, the population has declined sharply, and since 2013, the spawning behavior has changed from continuous to occasional, and the wild Chinese sturgeon population is in danger.
The 3.45-meter giant Chinese sturgeon stumbled into a fishing net.
From May to October 2014, the Fish Resources Monitoring Vessel of the East China Sea Fisheries Research Institute continued to monitor nearly 10,000 square kilometers of water, and it was eclipsed that not a single juvenile Chinese sturgeon was found.
From 2013 to 2019, no natural spawning behavior of Chinese sturgeon was detected for 5 of the 7 years, and no juvenile Chinese sturgeon hatched during these years was detected.
Limited to the special living habits and breeding methods of the Chinese sturgeon, various changes in the living environment may threaten its life, such as illegal fishing, pollution, shipping, global climate change, Yangtze River dams, etc. According to the study, among the above five influencing factors, the Yangtze River dam is the main cause of the decline of the Chinese sturgeon population.
The value and protection of the "Yangtze River Fish King"
Chinese sturgeon is the flagship species of the Yangtze River, the oldest vertebrate on the earth, is the common ancestor of fish - the descendants of the ancient spiny fish, has a history of 140 million years, is also a living fossil, known as the "giant panda in the water". Due to the series of primitive characteristics of the Chinese sturgeon itself, it shows that they are not only between cartilaginous fish (sharks, etc.) and teleost fish, but also the more primitive taxa of teleost fish, and have important scientific value and immeasurable ecological, social and economic value in the study of biological evolution, geology, geomorphology, transgression, sea retreat and other aspects of earth changes.
In order to save the Chinese sturgeon, the Yangtze River region launched ecological joint remediation to open up more "habitats" for the Chinese sturgeon. The mainland has established three provincial, municipal and national large-scale Chinese sturgeon nature reserves, including dongtai city in Jiangsu Province, the Chinese sturgeon nature reserve at the mouth of the Yangtze River in Shanghai, and the Chinese sturgeon nature reserve in Yichang, Hubei Province.
Juvenile Chinese sturgeon waiting to be released.
In September 2015, the Ministry of Agriculture issued the "Chinese Sturgeon Rescue Action Plan (2015-2030)"; On May 14, 2020, the first local regulation on the protection and management of Chinese sturgeon in China, the Shanghai Municipal Regulations on the Protection and Management of Chinese Sturgeon, was voted and approved; The revised Criminal Law of the People's Republic of China, which came into effect on 1 March 2021, revises the "crime of illegally hunting and killing rare and endangered wild animals and the crime of illegally acquiring, transporting and selling rare, endangered wild animals, precious and endangered wildlife products" to "crimes of endangering rare and endangered wild animals", and prohibits and severely cracks down on all illegal hunting, trading and consumption of wild animals with the strictest legal provisions.
Juvenile Chinese sturgeon waiting to be released.
In 30 years, a total of 7 million fish have been released, and no natural breeding has been found for 5 years
Protecting and saving the Rare and endangered "living fossil" of the Chinese sturgeon is of far-reaching significance to the development and rational development and utilization of wildlife resources and the maintenance of ecological balance. The protection of the Chinese sturgeon is not only to protect the earth's biodiversity, but also to preserve China's ancient history and far-reaching civilization.
According to the monitoring of the Yangtze River Fisheries Research Institute of the Chinese Academy of Fishery Sciences, since 2017, the only natural spawning ground for Chinese sturgeon, the core reserve of Chinese sturgeon in the lower reaches of Gezhouba, has not been found for 5 consecutive years.
"At the mouth of the Yangtze River in Shanghai, the only passage for juvenile fish to enter the sea, monitoring has also found nothing." Researchers at the Yangtze River Fisheries Research Institute told Jimu News.
According to China Net, before the Gezhouba interception, the spawning grounds of Chinese sturgeon were distributed in the lower reaches of the Jinsha River and the upper reaches of the scene about 600 kilometers, and more than 16 spawning grounds have been reported; After the interception in 1981, the original spawning grounds were completely lost; In 1982, a new spawning ground was discovered under the Gezhou Dam, which is still the only one.
In the 1990s, Wei Qiwei, chief scientist of the Yangtze River Fisheries Research Institute of the Chinese Academy of Fishery Sciences, photographed injured white sturgeon on the yichang river.
In 2013, the natural reproduction of Chinese sturgeon at this spawning ground was interrupted for the first time, a second interruption occurred in 2015, and then from 2017 to 2021, there was no natural reproduction for five consecutive years, and the self-renewal ability of the species's wild population has been completely lost. In the past 30 years, more than 7 million have been artificially released, but the natural reproduction of its wild populations has still not been restored.
On May 21, 2022, under the initiative of Experts such as Wei Qiwei, Chief Scientist of the Yangtze River Fisheries Research Institute of the Chinese Academy of Fishery Sciences, Wuhan Yangtze River Chinese Sturgeon Conservation Center was inaugurated. This is the speed of ecological restoration of the Yangtze River in Wuhan, and it is also the Hubei act of protecting the Chinese sturgeon.
"To save the Chinese sturgeon in the Yangtze River, the top priority is to rebuild the natural habitat suitable for the Chinese sturgeon in the tributaries connecting Dongting Lake to the Yangtze River." Wei Qiwei said.
What other lessons have we learned from the extinction of the white sturgeon?
According to a 2020 report by Science and Technology Daily, the main reason for the extinction of the white sturgeon is the inability to reproduce, and the water conservancy project has cut off its migration channel. Overfishing, high-density shipping, habitat loss and fragmentation... Together, these factors push the white sturgeon into a desperate situation.
Yangtze River white sturgeon.
All of the substantial conservation of the white sturgeon was initiated after 2006, but according to the research of Wei Qiwei's team, the Yangtze River white sturgeon may have become extinct as early as 2005.
Missing a critical time node is missing forever.
In fact, the artificial breeding technology of white sturgeon has been in reserve. Previously, there were no successful cases of Yangtze River white sturgeon being artificially farmed, and in recent years, after the technical conditions were available, the research team has never caught live Yangtze River white sturgeon.
At present, there are two mainstream artificial breeding methods, one is female nuclear development, and the other is "borrowing the abdomen to give birth", that is, fish germ cell transplantation. Female nuclear development refers to the fish breeding method of stimulating fish eggs with nuclearly inactivated fish sperm and inducing the development of this egg nucleus into an individual. The white sturgeon's close relative is spoon-kissed sturgeon, which has been artificially bred. If there is an adult female white sturgeon, the eggs can be stimulated with inactivated spoon-kissed sturgeon sperm for artificial induction. The second method is to transplant the germ cells of one fish into another fish, so that the male and female of another fish produce the sperm and eggs of the former, so that it can produce "offspring" with all the genetic information of the white sturgeon.
However, there are no live white sturgeon, and all technical reserves are empty. The lessons are profound.
At the end of 2019, the team of Wei Qiwei, chief scientist of the Yangtze River Fisheries Research Institute of the Chinese Academy of Fishery Sciences, published an English paper online in the international academic journal "Holistic Environmental Science" - "The Extinction of One of the World's Largest Freshwater Fish: Lessons and Enlightenment of Biological Conservation in the Yangtze River". The paper notes that the white sturgeon was extinct between 2005 and 2010.
The paper also points out that a regular periodic comprehensive survey of the Yangtze River Basin should be conducted. In the 2017-2018 survey, 140 species of fish were not collected. But due to the lack of data, the research team was unable to judge the fate of these fish. It can also be seen from the tragedy of the white sturgeon that the response of changes in fish populations to human threats is lagging behind, and protective action must be taken as soon as possible. In fact, many fish species in the Yangtze River are already on the brink of extinction, and assessing their risk of extinction is critical and should be done as soon as possible. For some species, the window of time to protect it may have closed. After all, when a species reproduces in the wild and does not sustain the minimum number of populations it can survive, extinction is only a matter of time. Priority must be given to the protection of fish stocks that have not been detected for many years, have not reproduced naturally for many years, or whose populations have declined sharply and significantly, such as anchovies and Chinese sturgeon.
According to the biological and ecological characteristics of different populations, corresponding conservation measures are taken, which is a race against the rate of extinction of species.
From 2020 onwards, the key waters of the Yangtze River will be classified into a 10-year fishing ban period in stages.
The elegy of the white sturgeon has sounded, but the fate of other equally rare wild aquatic creatures in the Yangtze River is still in the hands of humans.