On April 9, the Yangtze River ushered in another good news, in the Hubei Yichang Rouge Garden held in the Chinese sturgeon stocking activity, there are 230,000 tails of the second generation of Chinese sturgeon fry released into the Yangtze River, which is also the largest ever released activity, and the size of the fry is not small, the largest has dozens of pounds, the scene is very spectacular.
In January 2022, the five Lakes in Hubei in the water system ushered in the "Fishing Order" due to the flooding of fish, planning to catch 18 million catties, and there are obviously many fish in the Yangtze River, so why spend a lot of money to cultivate Chinese sturgeon fry?
What is a child generation?
Maybe you are curious: Chinese sturgeon fry is Chinese sturgeon fry, why add a "sub-second generation" in front of it, what does this mean? What is more interesting is that in December 2021, the test base of the Institute of Water Engineering Ecology of the Chinese Academy of Sciences of the Ministry of Water Resources bred "sub-2.5 generations" of Chinese sturgeon fry.
Chinese sturgeon fry is not better than other fry, Chinese sturgeon life is relatively long, up to 40 years old, is more than half of the human, male fish generally to 9 years old adult, body length of about 1.7 meters, weight more than 50 kg, female fish a sailing direction to 14 years old adult, body length of more than 2 meters, weight of more than 100 kg.
As early as the 1980s, the mainland cultivated Chinese sturgeon through artificial breeding technology, but the long life cycle of Chinese sturgeon directly led to a long cycle of breeding fry, which took decades.
In 1992, the Chinese sturgeon was bred for many years to give birth to a male fish, it belongs to the sub-generation of Chinese sturgeon fry, in 1995, another female was born, it is also a sub-generation of Chinese sturgeon fry, in 2009, the sub-generation male fish and the sub-generation of female fish combined to give birth to a male fish, it belongs to the sub-generation of Chinese sturgeon fry.
The 230,000 tails of the second generation of Chinese sturgeon fry released now come from this way, if the male fish of the second generation of the child is combined with the female of the child generation, the Chinese sturgeon fry born is the "son 2.5 generation".
There are obviously a lot of fish in the Yangtze River, so why spend a lot of money to cultivate fish fry?
Since January 2020, the Yangtze River has ushered in a ten-year fishing ban period, and now that two years have passed, there are obviously many fish in many lakes in the Yangtze River system, so why spend a lot of money to cultivate fish fry?
There are many species of fish in the Yangtze River are very common fish, such as grass carp, bluefish, silver carp, silver carp, carp and crucian carp, etc., their reproductive ability is extremely strong, the growth rate is extremely fast, if they are allowed to grow freely, they can reach the flooding point in two or three years.
These fish eat all the aquatic weeds and nutrients in the rivers and lakes, so that it is not conducive to the protection of the ecological environment, the five Hubei lakes Baoan Lake, Huiting Reservoir, Wild Boar Lake, Lu Lake and Wu Lake are because the children have reached the flooding point, only to issue a "fishing order".
These common fish are many, but the Chinese sturgeon is very small, if there is no artificial breeding, now I am afraid it may have become extinct, before the 10-year fishing ban period, the number of wild Chinese sturgeon in the entire Yangtze River has dropped to only a few dozen, in a state of extreme extinction.
In 1998, the number of wild Chinese sturgeon fell to 680, in 2002, the number of wild Chinese sturgeon fell to more than 300, in 2008, the number of wild Chinese sturgeon fell to more than 200, in 2009 there were only 72, in 2012, due to artificial breeding and stocking, it increased to 200, and by 2014, the number dropped to 57.
Why the number of wild Chinese sturgeon continues to decline, in addition to artificial fishing, but also affected by water conservancy projects, every November, wild Chinese sturgeon into the concentrated spawning period, but since 2017, for 4 consecutive years, no spawning, which is related to the Gezhou Dam interception, but also related to the Three Gorges Dam interception.
Every autumn, there are a large number of Chinese sturgeon accompanying the upstream, tirelessly returning to the birth of the real estate eggs, Chinese sturgeon spawning places are many, some even far away in the upper reaches of the Yangtze River main stream, the lower part of the Jinsha River is the spawning ground, Gezhouba intercepted the flow, prevented them from returning to the spawning ground.
Just when the Chinese sturgeon began to adapt to finding a suitable spawning site in the downstream waters of Gezhouba, the Three Gorges Project came again, and the Three Gorges Reservoir stored water, which made the newly found spawning grounds have abnormal water temperature and the phenomenon of "stagnant temperature", which led to a large number of Chinese sturgeon natural breeding time delayed by one month, or simply did not spawn.
Wild Chinese sturgeon can lay a large number of eggs at a time, but the Chinese sturgeon that can reach adulthood is actually very small, relying on the natural reproduction of wild Chinese sturgeon to restore the population, it seems unlikely, and there is a risk of extinction.
Chinese sturgeon is a fish that has existed on the earth for tens of millions of years, known as a "living fossil", if it is really extinct, it would be a pity, so the mainland spent a lot of money to artificially breed Chinese sturgeon, and constantly released Chinese sturgeon seedlings into the Yangtze River to restore the population.
At last
Chinese sturgeon is a very important fish in the Yangtze River Basin, an important link in the food chain, the protection of the Chinese sturgeon is equivalent to protecting the Yangtze River ecosystem, the Yangtze River ecosystem is an important part of the entire ecosystem, the Yangtze River ecosystem imbalance, will have an impact on the entire ecosystem, so the cultivation of Chinese sturgeon fry is a good thing that is beneficial and harmless. Interesting and informative scientific content, please pay attention to the only WeChat public account: Interesting Exploration