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Preface
Since the dam was first impounded in 2003, the Three Gorges Dam has been impounded for 20 years, and the depth of the normal impoundment reaches 175 meters, even exceeding the depth of the Bohai Sea and the Yellow Sea.
With such a large amount of water storage, the Three Gorges Reservoir has become an inland sea, and now it has become a paradise for fish.
So, in the past 20 years, what can the fish in it look like?
The Three Gorges Dam of the World Project
As everyone knows, there are two mother rivers on the mainland, one Yangtze River and one Yellow River, and these two rivers run through the east and west of the mainland.
Among them, the Yangtze River is a rainwater river, and every time it reaches the rainstorm season, the Yangtze River is very likely to flood, and in order to avoid a situation like the 1998 catastrophic flood in the future, the mainland decided to build the Three Gorges Dam.
The Three Gorges Dam was officially started in December 1994 and completed in 2006, although it was only completed in 2006, but in 2003 the Three Gorges Reservoir has carried out the first water storage work, and it has been a full 20 years.
As one of the successful representatives of the mainland's infrastructure madness, the Three Gorges Dam has many proud achievements, and has won 112 awards in the world alone.
In terms of function, the Three Gorges Dam contains seven successful benefits, including integrated aquaculture, tourism, ecological protection, south-to-north water diversion, developmental resettlement, and water supply and irrigation, not to mention the achievements in the three major functions of flood control, power generation, and shipping.
In 2018, the Three Gorges Hydropower Station was able to generate a total of 101.6 billion kilowatt hours of electricity annually, making it the world's largest hydropower station in one fell swoop.
Just two years later, the Three Gorges Hydropower Station broke through again to 111.8 billion kilowatt hours, setting a record for the world's highest power generation by a single hydropower station.
The five-level locks of the Three Gorges Double Line were put into use in 2003, and in 2011, the cargo volume exceeded 100 million tons, and as of August last year, the total volume of cargo traffic in the Three Gorges has reached 1.797 billion tons.
It can be said that the Three Gorges Dam has achieved excellent results in every aspect, but the problems it faces are also very urgent, such as the problem of sediment accumulation.
In addition, in terms of dealing with sediment accumulation, the Three Gorges Dam cannot be directly treated with sand pumping boats like the Sanmenxia Dam, because it is necessary to protect the ecosystem that has been formed.
A paradise for fish
In the 20 years since the Three Gorges Dam was impounded, it can be said that it has formed a stable inland sea ecosystem, and together with the original river ecosystem, it can be said that it is very rich in life.
Coupled with the abundance of nutrients in the river water, it can almost be called a paradise for fish, according to incomplete statistics, there are as many as 424 species of fish in the waters of the Yangtze River, including many key protected species in the mainland.
According to the literature, there are more than 140 species of fish in the Three Gorges Reservoir area, including 47 species of fish endemic to the Yangtze River basin, and more than 30 species of fish with important economic value alone.
It can be said that the Three Gorges Reservoir itself is a natural fish reservoir, and before the fishing ban, the output of the four major fish in the reservoir was able to reach 200 tons at the beginning of the 21st century.
In addition to the four common fish species of herring, grass carp, bighead carp and silver carp, the output of economic fish such as catfish and yellow catfish can also reach 1,000 tons.
The fishery in the Three Gorges Reservoir is eye-catching, not only in terms of production, but also in terms of the size and weight of the fish, and even surprised the local residents for a time.
There have been reports that a 300-pound bighead carp was caught in a tributary of the Yangtze River in the Chongqing area, and the local residents have long been surprised, but the largest fish in the Yangtze River is the Chinese sturgeon.
The average Chinese sturgeon is about 0.4-1.3 meters in length and weighs 50-300 kilograms, so it can be said that it is generally a relatively large fish, but the Yangtze white sturgeon is larger, with a length of 2-3 meters and a weight of 200-300 kilograms.
Even the largest Yangtze sturgeon found so far has a maximum volume of 7.5 meters, which is why the Yangtze white sturgeon is also known as the "King of Yangtze River Fish".
It can be said that the Three Gorges Reservoir has not only brought huge economic benefits in recent years, but also protected countless people from the threat of flooding, and at the same time has also achieved some results in the fishing industry, and its achievements cannot be ignored.
The merit is in the present and the benefit is in the future
The construction of the Three Gorges Dam will cost about 250 billion yuan alone, including the construction phase of engineering facilities and later upgrades, as well as the related social costs such as ecological protection and relocation compensation.
It can be said that the Three Gorges Dam is a very large investment, but it has also brought huge benefits to the mainland's economic and energy development, and its name as the world's largest hydropower station alone is enough to prove its economic benefits.
But the construction of the Three Gorges Dam was also bumpy, not only because of the problems faced at the time, such as the accumulation of rivers and the livelihood problems involved in the surrounding areas, but also because the construction of the dam was bound to affect the local ecosystem.
Therefore, in the early days, the construction of the Three Gorges Dam was questioned by some experts, after all, the completion of the dam will definitely affect the survival of fish in the Yangtze River.
For example, the migratory fish of the river and sea, represented by the Chinese sturgeon, will migrate from the shallow waters outside the mouth of the Yangtze River to the Jinsha River to spawn in summer and autumn, and the establishment of the dam will undoubtedly block the migration of fish.
According to a 2020 report released by the World Fish Migration Foundation, from 1970 to 2016 alone, as many as 76% of the world's freshwater populations were reduced by the establishment of river barriers such as dams.
In particular, large fish such as the Chinese sturgeon, which is more than 1 meter in size, have difficulty passing through the dam, which has also led to the threat to the living environment of the Chinese sturgeon.
Not only the Chinese sturgeon, but also the smiling angel finless porpoise, known as the "giant panda in the water", was once in danger of extinction only in the fishing industry of the Three Gorges of the Yangtze River.
However, with the implementation of the mainland's fishing ban policy and the active protection measures, the situation has improved in recent years, and the shadow of the finless porpoise on the river has also increased.
epilogue
Although the Three Gorges Dam had a great impact on the ecological environment when it was established, the new and unique ecosystem formed now has brought a lot of benefits to the Yangtze River Basin.
The earth not only belongs to our human beings, in the pursuit of our own development, we should also pay attention to the protection of the environment, gold and silver mountains are not as good as green waters and green mountains, protecting the environment is the best investment.
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