The Yangtze River, known in China as the Cháng Jiāng, is the longest river in Asia and the third longest river system globally, stretching approximately 3,900 miles from the Tibetan Plateau to the East China Sea. This immense waterway and its basin cover about one-fifth of China’s land area, supporting a vast human population and an exceptional diversity of wildlife. The river’s varied ecosystems, which include extensive lakes, marshes, and tributaries, have made it a global hotspot for biodiversity. Many species that inhabit this basin are endemic, meaning they are found nowhere else on Earth, but the Yangtze ecosystem faces immense pressures that endanger its unique aquatic inhabitants.
Iconic Aquatic Mammals
The Yangtze River was historically one of the few rivers globally to host two different species of cetacean, both of which have become potent symbols of the river’s environmental decline. The Baiji, or Yangtze River Dolphin (Lipotes vexillifer), was a unique freshwater dolphin that represented an entire evolutionary family, but has been declared functionally extinct. Its decline was rapid, plummeting from an estimated population of 5,000 animals in the 1950s. This loss is largely attributed to human activities, including unsustainable bycatch from fishing gear, heavy boat traffic, and widespread habitat degradation.
The Baiji’s disappearance serves as a stark lesson for the survival of the river’s only remaining cetacean, the Yangtze Finless Porpoise (Neophocaena asiaeorientalis). This critically endangered porpoise is the world’s only freshwater porpoise, distinguished by its lack of a dorsal fin. The porpoise is also known for its bulbous head and a high level of intelligence. The current population is perilously low, with estimates suggesting only around 1,000 to 1,249 individuals remain, distributed primarily in the main river channel and connecting lakes.
The threats facing the porpoise mirror those that caused the Baiji’s demise, primarily illegal fishing, acoustic disturbance from boat traffic, and pollution. The Chinese government has granted the species the highest level of national protection. A 10-year fishing ban across the Yangtze River system was implemented starting in 2021. Conservation efforts focus on in-situ protection and relocation to semi-natural reserves to stabilize the remaining wild population.
Unique Reptiles and Amphibians
The Yangtze River basin is home to specialized cold-blooded vertebrates, including the Chinese Alligator (Alligator sinensis), one of only two living alligator species globally. This relatively small reptile, with males averaging about five feet in length, is restricted almost entirely to a small area within the lower Yangtze region, specifically in Anhui province. The species is classified as Critically Endangered, with the wild population estimated at fewer than 150 individuals.
The primary cause of the Chinese Alligator’s decline is the dramatic loss of its wetland habitat, which has been extensively converted to agricultural land. Although they historically inhabited rivers, lakes, and swamps, wild alligators are now often confined to farm ponds and drainage ditches. Extensive captive breeding programs have been successful, holding thousands of animals, and efforts are underway to reintroduce captive-bred individuals.
Another remarkable resident is the Chinese Giant Salamander (Andrias davidianus), the world’s largest amphibian, capable of reaching lengths of up to 1.8 meters. This fully aquatic creature is considered a “living fossil” due to its ancient lineage. The giant salamander is Critically Endangered in the wild, having suffered an estimated population decline of more than 80% since the 1950s. Overexploitation as a luxury food item and for use in traditional medicine, combined with habitat loss and pollution, have severely depleted its numbers.
Diverse Endemic Fish Species
The Yangtze River is characterized by a vast and unique fish fauna, historically hosting over 370 species, with 177 to 183 species being endemic to the river system. The ecosystem’s size and complexity allowed for the evolution of many specialized species, though this diversity is now severely threatened. The tragic extinction of the Chinese Paddlefish (Psephurus gladius) underscores the vulnerability of the river’s long-lived, ancient fish species. This fish was one of the largest freshwater species, with records of specimens over seven meters long.
The species was declared extinct in 2020, with its fate sealed by the construction of the Gezhouba Dam in 1981, which blocked its migration route to upstream spawning grounds. Compounding this habitat fragmentation were overfishing and pollution, leading to the species being considered functionally extinct by 1993. The sturgeon family faces similar existential threats, including the Chinese Sturgeon (Acipenser sinensis), an anadromous species that migrates from the sea up the Yangtze to spawn. Damming has drastically reduced its available spawning area, leading to a precipitous decline in the wild population.
Another unique species, the Yangtze Sturgeon (Acipenser dabryanus), is now considered extinct in the wild, with only captive-bred individuals remaining. These migratory fish, along with other endemic species like the Chinese sucker fish and Chinese rock carp, are all on the brink of extinction. The dominant fish groups belong to the order Cypriniformes, including common species such as carp, but even these face ecological challenges due to the declining health of the river.