The Yangtze River is the third longest river in the world, and the largest one in China. The river winds for about 3,964 miles, originating from the Tanggula Range in the Qinghai Province of western China, and ultimately draining into the East China Sea at Shanghai. On its way from west to east, it traverses 11 provinces and cities within the country. The Yangtze River system has historically, culturally, and economically been of great significance to China. The River nearly divides the country into two halves, with northern and southern China each having their own distinct climates, landscapes, economics, and cultures. The Min, Han, Huangpu, Jialing, and Gan rivers are the main tributaries of the Yangtze. The largest hydroelectric power station in the world, the Three Gorges Dam Project, is also built on the Yangtze River.
The Yangtze River has played a central role in shaping Chinese civilization since the most ancient of recorded historical times. The great economic importance of this river, attributed to the possibility of setting up productive agricultural cultivation practices along its fertile banks, has attracted successive dynasties and foreign invaders to this land for a long time as well. The Yangtze was also the focus of the 19th Century imperial invasions into China. The riverine route has been used since these ancient ages as an important trade route into the heart of China from the South China Sea, and thusly the rest of the world's oceans, as well. The southernmost part of the Grand Canal is believed to have been built as far back as the 4th Century, dug out in order to allow for the transport of grain from the Yangtze basin to the major cities of northern China.
Currently, the Yangtze basin houses a significant portion of the Chinese population, with the Yangtze Delta and the plains adjoining the banks of the river and its tributaries having some of the highest population densities in all of China. The economy of the people settled along the Yangtze largely depends on agriculture, while a few cities, like the coastal city of Shanghai and the inland cities of Wuhan and Chongqing, are highly industrialized. Nearly half of the country’s crop production is contributed by crops grown in the Yangtze basin. The Yangtze River and its associated tributaries also thrive with aquatic life, and a fishing trade has been highly developed in this region. The Yangtze is also the principal navigable waterway in China, with intensive cargo and passenger traffic making its way along the length and breadth of the river. Water routes in the Yangtze basin cover a distance of around 56,300 kilometers. The Three Gorges Dam project, with a capacity of generating around 22,500 Megawatts (MW) of hydroelectricity, is one of the most ambitious power projects not only along the Yangtze River, but in the world as a whole.
The Yangtze River forms a networks species-rich ecosystems, harboring around 416 fish species, with 362 among them being exclusively freshwater species. 178 fish species are endemic to the Yangtze River Basin. The Cypriniformes, Perciformes, Tetraodontiformes, Siluriformes, and Osmeriformes form the largest orders of fish species found in the Yangtze. Over the years, may of these species have declined in numbers and two, the Anabarilius liui and Atrilinea macrolepis, are believed to have gone extinct. Besides these, two more of the Yangtze's native fish species are believed to be extinct in the wild, and five are listed as "critically endangered" by the IUCN. The Chinese sturgeon and the Yangtze sturgeon are both among the critically endangered, and attempts to revive their numbers by the release of captive-bred specimens are being made. Besides fish, the Yangtze River basin is also home to a large number of threatened or critically endangered animal species. These include the finless porpoise, the Yangtze River dolphin, the Chinese alligator, the Chinese giant salamander, and the Yangtze Giant soft-shell turtle. The Yangtze River dolphin is, however, believed to be functionally extinct in the region.
Threats and Disputes
The Yangtze Basin faces a large threat from the pollution generated by human activities along its riverbanks. Over the past 50 years, the Yangtze has suffered a 73% increase in pollution of its waters. Hundreds of cities situated along the banks of this river eliminate an annual discharge of sewage and industrial waste of 25 billion tons, accounting for 42% of China’s total sewage discharge and 45% of the country's total industrial discharge. Agricultural run-offs are also damaging the river significantly, with 92% of the nitrogen discharged into the Yangtze being contributed by agricultural fertilizer run-offs from the region's crop fields. Shipping discharges are also polluting the river heavily. Large scale hydroelectric power projects, like the aforementioned Three Gorges Project, have also taken their toll on the river. They have done so by exacerbating pollution by impounding the natural flow of the river, and in the process trapping sediments and encouraging eutrophification. Besides these, the damming actions also render the river system highly susceptible to riverbank collapses and landslides. The high levels of pollution of the river and exploitative fishing practices have also rendered the Yangtze devoid of many of its native species of fish, reptiles, amphibians, and aquatic mammals alike, which once thrived in the region. As mentioned previously, a number of species endemic to this region are either extinct or critically endangered, while others are on the verge of decline. This has led to a drastic decline in certain fisheries' operations, and therefore increased the possibilities of a loss of livelihoods for many people.