According to the Updated Red List of Species by the International Union for Conservation of Nature (IUCN), the Yangtze River endemic species of white sturgeon has become extinct, although this result is not unexpected, but for people who care about the Yangtze River, there is always hope that miracles will happen, but there is still no!
For the Yangtze River white sturgeon, many friends may say that they are very unfamiliar, what is the origin of this fish, what are the fish that are facing extinction like it, and how should we protect it?
Announcing the extinction of the Yangtze River white sturgeon: there has long been a premonition!
On December 23, 2019, the international academic journal "Holistic Environmental Science" published the research papers of experts from the Yangtze River Fisheries Research Institute of the Chinese Academy of Fishery Sciences:
The Yangtze River white sturgeon is expected to become extinct between 2005 and 2010. However, the matter has not been publicly confirmed by the IUCN, and in January 2020, the International Union for Conservation of Nature (IUCN) responded that there is no official release and update on the extinction of the Yangtze River sturgeon, and "further discussion is needed in the future.".
Although everyone knows that the research conclusions of the Chinese Academy of Fisheries Sciences are not general, they also hope that the white sturgeon can continue to survive in the Yangtze River, and there will be such speculation after many years of no trace, but everyone still has a glimmer of hope for this, and suddenly one day will announce that the white sturgeon will appear again in the Yangtze River.
Unfortunately, the miracle did not happen, waited for more than 1 year, and finally waited for the news that the IUCN finally confirmed the extinction, which is undoubtedly bad news for the workers who are working hard to protect the ecology of the Zhangjiang River, and for the majority of friends who care about the Yangtze River, they are also in a bad mood, the Yangtze River white sturgeon, what kind of fish is it, why will it become extinct on the Yangtze River?
Yangtze River white sturgeon: what kind of fish is it; What exactly caused the extinction?
Yangtze River white sturgeon is also known as the Chinese spoon-kissed sturgeon, its appearance is very distinctive, its snout is long like a duck's beak, also known as the duck-billed sturgeon or Chinese swordfish, in ancient China the white sturgeon is called the sturgeon, the earliest can be traced back to the "Book of Poetry" record:
In the "Zhou Song Qian" in the Book of Poetry, there are "Yi and lacquer depression, diving with many fish." There are fish and tuna, carp and carp. To enjoy the blessings, to introduce the blessings. "It means that during the Spring and Autumn Period, the white sturgeon was used for sacrifice.
The more detailed description is in the Three Kingdoms of Wu · In Lu Ji's "Mao Shi Grass, Wood, Birds, Animals, Insects, And FishEs":
The tuna, blue and black, has a small and pointed head, like an iron hood, the mouth is under the chin, and its armor can grind ginger, and the large one is no more than seven or eight feet. The big one is the king tuna, and the small one is the uncle tuna.
One foot in the Three Kingdoms is about 0.242m, 7-8 feet is almost 2 meters or so, which means that the size of the white sturgeon is still relatively large, but according to modern records, the white sturgeon can grow up to about 3 meters, weighing up to 250 kg ~ 300 kg, is one of the world's largest freshwater fish, also known as "the king of Freshwater Fish in China".
Another unofficial record was recorded by ichthyologist Bingzhi in the 1950s, in the vicinity of Nanjing, a 7.5-meter-long, 908-kilogram oversized white sturgeon was caught, so this "king of China's freshwater fish" is really not blown.
Among the folk fishermen in Sichuan, there is a saying that "a thousand pounds of wax and ten thousand pounds of elephants, the yellow row is not very large", of which the ten thousand pound elephant refers to the white sturgeon, and the yellow row is the rouge fish, although it sounds exaggerated, but it also shows that this fish is still quite large.
The Yangtze River white sturgeon and the Mississippi River spoon-sturgeon belong to the same subspecies of the spoon-sturgeon family, and these two species are the only two living species in the Polyodontidae family. The white sturgeon is more recognizable, and in addition to the strange snout, its characteristics are very obvious:
The lower abdomen of the white sturgeon is white, the back and head are gray, and the limbs such as the beak and fins are pink. It has a distinct white ridge on either side of its body that extends from the middle of its body to its caudal fin, with the dorsal and fins located quite far behind the body.
White sturgeon is a cartilaginous fish, can live in the ocean, but most of their time in the estuary and lake to spend, the Yangtze River white sturgeon in the growth to 25 kg to reach sexual maturity, need to return to the middle and upper reaches of the Yangtze River to spawn, hatch and then return to the Yangtze River estuary to live, mainly to anchovies, carp and other small and medium-sized fish for food, and sometimes also prey on shrimp and crabs.
In addition to the Yangtze River, the Yellow River also had a habitat for white sturgeon, but it disappeared as early as the 1960s, while the Yangtze River Basin was much later, for example, the annual catch of the Yangtze River white sturgeon reached 25 tons in the 1970s, but the number of this species has declined rapidly since then, and by 1983 it has been listed as a first-class protected animal of the People's Republic of China.
Yangtze River white sturgeon caught by mistake
In the 22 years from 1981 to 2003, only 210 Yangtze River white sturgeon were by mistake, which is far less than one-third of the annual catch in the 1970s. According to 1999 data, the entire Yangtze River may already have less than 400 white sturgeon! But the real situation could be even worse!
The Yangtze River white sturgeon has only been recorded twice since 2000:
One was a 3.3 m, 117 kg female white sturgeon caught in Nanjing in 2002, and the other was captured by fisherman Liu Longhua in Yibin, Sichuan Province, on January 24, 2003, and was later released with a radio beacon, but the vessel tracking the radio beacon lost its signal when it hit the reef and was never found two days later after the vessel was repaired.
White sturgeon caught by mistake in Sichuan
The Chinese Academy of Fisheries sciences in Jingzhou also failed to capture any white sturgeon in a 2006-2008 search of the Yangtze River basin, although the underwater acoustic detection equipment it carried found multiple suspected signals but were not confirmed, and no records were found in the 2017-2018 Yangtze River Basin survey.
White sturgeon caught by mistake in Nanjing
At that time, some experts said that the Yangtze River white sturgeon may have become extinct, the literature said that its extinction time may be between 2005 and 2010, and its functional extinction (the species lost its ability to reproduce in its natural state, which led to the eventual disappearance of all individuals of the entire species) was as early as 1993.
Overfishing and the construction of water conservancy in the Yangtze River: it is hard to blame
The extinction of the Yangtze River white sturgeon is related to two reasons, one is overfishing, because the individual of the white sturgeon is huge, the body surface is scaleless, the meat is tender and there is no intermuscular bone, etc., which has directly become the river fresh that the gourmets are most concerned about, so the reduction of the number of white sturgeon is not unrelated to overfishing.
The other is the construction of Gezhou Dam and the Three Gorges, after the completion of the Gezhou Dam, which was started in 1970 and completed in 1980, prevented the Yangtze River white sturgeon from migrating upstream to spawn, generally the white sturgeon will migrate to the Jiang'an County river section and the Yibin River section of Sichuan Province to spawn, after the destruction of the spawning area, the white sturgeon can not migrate to spawn, resulting in a sharp decline in numbers, and then the scale of the Three Gorges of the Yangtze River is larger than the scale of GezhouBa, of course, even if only Gezhouba is a huge obstacle that cannot be crossed.
For the construction of such water conservancy projects that benefit the country and the people, in the future, we can consider the construction that is conducive to ecological protection, such as the design of fish ladders, so that fish can go back to the upstream to spawn through fish ladders when migrating, this cost is not particularly high, but it is very helpful for the restoration of the ecological environment.
What other fish have also been encountered?
The Yangtze River is one of the busiest inland waterways in the world, its existence is not only a habitat for a large number of fish, but also a major artery for Inland River transportation in China, a large number of ships pass by every day, propellers, domestic garbage and leaking fuel, etc., resulting in the ecology of the Yangtze River is very fragile, there have been a variety of fish have suffered extinction crisis.
For example, the Chinese sturgeon in the water, the giant panda - whitefin dolphin, the Yangtze River porpoise and the Yangtze River knifefish are facing extinction crisis, so the protection of the Yangtze River ecology has reached the point of urgency, but the mainland's protection of the Yangtze River has long begun, in order to protect the fishery resources of the Yangtze River, from 2003, the Yangtze River Basin implemented an annual 3 to 4 months of fishing ban period.
However, this is not enough to support the rapid recovery of fishery resources, in January 2021, the Ministry of Agriculture and Rural Affairs issued a notice on the official website on the scope and time of the ban on fishing in key waters of the Yangtze River Basin, announcing that the implementation of the ten-year fishing ban plan for the Yangtze River will begin from 0:00 on January 1, 2020.
In addition to the ban on fishing, we are also actively restoring the population, the Three Gorges Group Chinese Sturgeon Research Institute since the first implementation of the Chinese sturgeon artificial breeding and stocking in 1984, has implemented 65 consecutive Chinese sturgeon stocking activities, a total of nearly 5.3 million Chinese sturgeon released to the Yangtze River, the release of more than 258,000 sub-generation Chinese sturgeon.
I hope that the rare fish on the Yangtze River will not repeat the mistakes of the Yangtze River white sturgeon, and I hope that I will never hear the news of the extinction of some fish! (End)