The Yangtze River sturgeon, the king of freshwater fish, declared extinction. In recent centuries, human activities have been intensified, and the natural population of sturgeon has declined sharply and is on the verge of extinction. It is called "the most threatened group in the world". The "king of freshwater fish" Yangtze paddlefish declared extinction.
"King of Freshwater Fish" The Yangtze River paddlefish declared extinct 1 The Yangtze River paddlefish, known as "King of Freshwater Fish in China", was officially declared extinct by the World Conservation Union (IUCN).
On the evening of July 2 1, the International Union for Conservation of Nature and Natural Resources (IUCN) released an update report on the global red list of endangered species, announcing the extinction of ACIPENSER sinensis and ACIPENSER Changjiang in the wild.
According to the latest report of IUCN official website, 26 species of sturgeon are threatened with extinction. The list shows that the endemic species of the Yangtze River, the white sturgeon (Psephurus gladius), the wild sturgeon (Acipenser dabryanus) and the naked-bellied sturgeon are extinct. The Red List also improved the protection level of the other seven sturgeons.
▲ Photo courtesy of Baiqi Qiwei
The re-evaluation results of IUCN global sturgeon show that about 2/3 sturgeon populations are in an extremely endangered state. The biodiversity of rivers and freshwater is very important to human beings and nature, but the global freshwater biodiversity is continuously lost and the river ecology is constantly degraded. Arne Ludwig, chairman of the IUCN sturgeon expert group, said, "The result is shocking and sad, but it is expected. The assessment shows that sturgeon still can't get rid of the title of' the most threatened group in the world'. "
The report also pointed out that the main threats faced by sturgeons around the world include: illegal fishing caused by illegal trade in wild caviar and fish, dams blocking their migration routes, unsustainable sand mining destroying their spawning grounds, and habitat loss.
The three Asian sturgeons upgraded this time include natural populations of ACIPENSER sinensis, ACIPENSER Changjiang and ACIPENSER Siberia, and the first two are representative aquatic species in the Yangtze River basin.
The paddlefish last appeared in the Yangtze River in 2003.
According to public information, the white sturgeon is one of the largest freshwater fish in the world. Sichuan fishermen say that it is a "10,000-kilo wax (Chinese sturgeon) and a 10,000-kilo elephant (white sturgeon)", which can reach 7 meters in length and originated about 200 million years ago. It is endemic to China and the flagship species of the Yangtze River.
19In 1989, the paddlefish was listed as a national first-class protected wild animal. In 1996, it was listed as "extremely endangered" by the World Conservation Union (IUCN), and it was determined as "extremely endangered (possibly extinct)" when it was re-evaluated in 2009. In addition, the paddlefish is a protected species in Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) and one of the main protected objects in the national nature reserve of rare and endemic fish in the upper reaches of the Yangtze River.
The last living record of the white sturgeon was in 2003 1 month, which was caught by mistake in Yibin section of Sichuan in the upper reaches of the Yangtze River and released after successful rescue.
"This is not an accident, but a profound lesson."
Wei Qiwei, the only member of the IUCN sturgeon expert group in China, a researcher at the Yangtze Institute of Chinese Academy of Fishery Sciences and the founder of the Yangtze River sturgeon protection center in Wuhan, compared the sturgeon with the baiji: "It is true that the sturgeon is the most threatened group in the world, but the extinction of the sturgeon should not happen.
The ecological habits of paddlefish and baiji are different. One breeds in the upper reaches of the Yangtze River, and the other habitat is mainly in the middle and lower reaches of the Yangtze River. However, their extinction fate is similar to the period. This is not an accident, but a profound lesson. Other aquatic organisms in the Yangtze River must not repeat the same mistakes. "
In the evaluation of this report, the Yangtze sturgeon was assessed as extinct in the wild because it failed to find the juvenile fish of the breeding and releasing population. Regarding the current situation of the Yangtze sturgeon, Wei Qiwei said, "The Yangtze sturgeon has not naturally propagated for 20 years, indicating that the ecological environment of the Yangtze River can not be said to have recovered well."
"The extinction of the white sturgeon and the wild extinction of the Yangtze sturgeon have sounded the alarm for us," said Zhou Fei, deputy director-general (project) of WWF Beijing Representative Office.
"The results of this red list update remind us that it is necessary to reverse the trend of freshwater biodiversity loss through rescue protection, and it is even more necessary to plan and implement systematic protection measures to solve long-term threats. It is far from enough to rely solely on manual measures and input from a single department. We need the participation and support of more institutions and social forces to help the Yangtze sturgeon' downgrade' as soon as possible, better protect the Chinese sturgeon migrating in the rivers and seas, and create a bright future for the rivers and seas ecosystem."
On the evening of July 2 1, the World Conservation Union (IUCN) released an update report on the global red list of endangered species, announcing the extinction of the white sturgeon. The news that the Yangtze sturgeon was extinct in the wild quickly topped the hot search list in Weibo.
According to the latest report of IUCN official website
All the 26 species of sturgeon in the world are threatened with extinction.
The re-evaluation results of IUCN global sturgeon show that
About two-thirds of the sturgeon population is in an extremely endangered state.
Image source: WWF World Wide Fund for Nature
They lived with dinosaurs at the same time.
Sturgeon population is a unique unit in the evolutionary tree. The geological age of the giant panda ancestors was only 8 million years, while the sturgeon fossils can be traced back to the Triassic in Mesozoic, which means that they lived with dinosaurs at the same time and were really "living fossils in water".
Most of the existing sturgeon-like fish are huge. The longest sturgeon, once the world's largest freshwater fish, can reach 7.5 meters, and the Chinese sturgeon can reach 4 meters. Most sturgeons are "migrating upstream to spawn", which are distributed in the large rivers in the northern hemisphere and the relatively wide water surface in the coastal shallow waters. As an important link of information and material exchange between oceans and rivers, they become indicative species of ecological conditions and reliable indicators to measure aquatic biodiversity in the northern hemisphere.
"The most threatened group in the world"
In recent centuries, human activities have intensified, and the natural population of sturgeon has declined sharply and is on the verge of extinction. It is called "the most threatened group in the world".
Globally, the main threats faced by sturgeon include: fishing caused by illegal trade in wild caviar and fish, dam blocking migration routes, unsustainable sand mining destroying spawning grounds, and habitat loss.
Wei Qiwei, a member of the IUCN sturgeon expert group, a researcher at the Yangtze Institute of the Chinese Academy of Fishery Sciences and the founder of the Yangtze River Chinese Sturgeon Protection Center in Wuhan, made a comparison between the sturgeon and the baiji: "The ecological habits of the sturgeon and the baiji are different, one breeds in the upper reaches of the Yangtze River, and the other habitat is mainly in the middle and lower reaches of the Yangtze River, but their extinction fate is similar to that of the period. This is not an accident, but a profound lesson. Other aquatic organisms in the Yangtze River must not repeat it.
What about the Chinese sturgeon?
The flagship species of the Yangtze River, ACIPENSER sinensis, has been declining in recent years. In 1988, it was listed as a national first-class wild protected animal, and in 20 10, it was listed as an extremely endangered species by the World Conservation Union (IUCN).
Juvenile Chinese sturgeon. Image source: Zhuang Ping
Artificial propagation and release have always been one of the important measures for species protection of Chinese sturgeon. As of last year, many institutions, including the Chinese sturgeon research institute, have released more than 7 million Chinese sturgeons for more than 30 years.
However, the researchers said that the recovery of rare and endemic species is very difficult, and they are still racing against time to minimize the adverse effects of the decline of wild resources on the population reproduction of Chinese sturgeon.
"At present, the Yangtze River Rare Fish Conservation Center, together with the supporting construction of the Chinese sturgeon sperm and tissue cell bank, is running better and better. It can basically ensure that the Chinese sturgeon will not take the old road of extinction of the baiji, and the species will continue forever. " Li Zhiyuan, Party branch secretary and deputy director of the Chinese sturgeon research institute, said.
"King of Freshwater Fish" The Yangtze River paddlefish declared extinction. As the saying goes, "A thousand pounds of wax is like a ten thousand pounds of elephant." "Lazi" refers to the Chinese sturgeon, and "Xiang" refers to the Yangtze River paddlefish. The sturgeon is huge, up to seven or eight meters long.
The last appearance of the Yangtze River sturgeon was on the first day of New Year's Day in 2003. Wei Qiwei and his colleagues rescued an sturgeon in Nanxi River section of Yibin, Sichuan, and released it and followed it. But then the ship hit the rocks and the radio signal of the released white sturgeon disappeared.
"We searched along the river for 8 times in 6 years, but it was fruitless and sad!" Wei Qiwei deplored it.
No one can imagine that losing this fish will also lose the whole species. Since 2003, researchers have never found the paddlefish again, and there are no artificially bred individuals left.
Wei Qiwei first saw the Yangtze River paddlefish in 1984, a dead paddlefish under Gezhouba. "The white sturgeon is large and very difficult to feed." He said. From 1984 to 1993, he and his colleagues rescued four trapped paddlefish, only one of which was successfully saved and released back to the Yangtze River. The longest deposit period they have supported is 29 days, which is a white sturgeon rescued in Nanjing section in 2002.
20 19 In mid-September, the expert group of IUCN held a three-day meeting in Shanghai, focusing on the endangered assessment of more than a dozen sturgeon species in Europe and Asia, such as the Yangtze River paddlefish. Foreign experts believe that the paddlefish should be declared extinct. Previously, Wei Qiwei always disagreed. But this time, Wei Qiwei accepted the evaluation result of the extinction of the paddlefish.
After years of fruitless monitoring, in recent years, he and his team began to study the current situation of ACIPENSER sinensis according to the IUCN evaluation model, and came to the conclusion that ACIPENSER sinensis may have been extinct from 2005 to 20 10, and may have been functionally extinct as early as 1993, that is, the natural population could not carry out breeding activities.
How does IUCN define extinction of a species? "In layman's terms, if a species has not naturally propagated, and the time limit for the life of this species has passed, and no individuals have been found during this period, the species can be considered extinct." Wei Qiwei said that the spawning ground of ACIPENSER sinensis was in the Jinsha River in the upper reaches of the Yangtze River, but no natural breeding of ACIPENSER sinensis was found after 199 1 year. Before 1993, there was a record of the accidental catch of ACIPENSER sinensis every one or two years, but it was not found for a long time after that.
Why can't ACIPENSER sinensis be artificially propagated? Wei Qiwei explained: First, the traffic conditions were inconvenient at that time. After receiving the information of fishermen's accidental arrest, they rushed to the scene, and many white sturgeons were dying; Second, the scientific research conditions were limited at that time, and the cultivation of white sturgeon needed a pool with a diameter of nearly 20 meters, and the requirements for water bodies were very high, and sufficient oxygen supply was needed.
"When we were able to understand and help it, it never appeared again." Wei Qiwei said with regret.
In 2020 1 month, Chutian Metropolis Daily first reported that the white sturgeon was facing extinction (see this newspaper's report on 2020 1 month 4 for details), and netizens lamented that they had never met before, but heard that it was farewell forever.