The critically endangered Yangtze flightless porpoise is one of the last species of freshwater porpoises on Earth and the only mammal currently inhabiting the Yangtze River in China.
Once the home of the Baiji dolphin, a close cousin of the flightless Yangtze porpoise that was declared functionally extinct due to human activity in 2006, the Yangtze River is the longest river in Asia at nearly 4,000 miles in length. . This shy porpoise species is an important indicator species for the health of the river ecosystem, which also supports the livelihoods of some 500 million people and contributes more than 40% of China’s gross domestic product.
Today, the number of mature individuals remaining is believed to be between 500 and 1,800, making the Yangtze flightless porpoise even rarer than the Chinese giant panda in the wild.
In 2017, scientists used prediction models to project population trends and estimate an updated time to extinction for wild wingless porpoises in the Yangtze across its current range. They found that the median predicted time to extinction was 25 to 33 years in the Yangtze River and 37 to 49 years overall. If something doesn’t change, the entire species could disappear from the face of the planet by 2054.
The Yangtze River Basin protects incredible levels of biodiversity, including habitats for other endangered species like snow leopards and giant pandas. It also supports a large number of local communities who depend on the river for drinking water, agriculture, fishing and transportation.
Unfortunately, factors such as pollution, poorly planned infrastructure, and economic development overwhelm the ecosystem where the Yangtze wingless porpoises once thrived.
Pollution and climate change
It’s no secret that China’s industrial sector has played an important role in its economy, and much of it culminates in the Yangtze River. The Vital River has experienced major challenges from climate change for decades, including flooding, degradation of aquatic ecosystems and water quality, and drought.
Pollution from agriculture, chemical production and other industrial processes such as textile dyeing continue to threaten the ecosystem. Studies show that the Yangtze deposits a whopping 55% (or 1.5 million metric tons) of all marine plastic pollution in rivers.
The Three Gorges Dam power station, the largest hydroelectric power station in the world, is located a few kilometers from the river. Despite promises to bring clean energy to China, the construction of the dam also brought massive freighters to increase commercial shipping and a host of controversial issues.
Noise pollution from the powerful propellers and motors of passing boats and barges affects the species just as much, if not more, than traditional pollution.
Like many other cetaceans, Yangtze porpoises use echolocation, or natural sonar, to navigate their environment. Research on the morphology of the Yangtze flightless porpoise shows that it has the ability to hear from all directions, which means it may have more difficulty discerning signals among the almost constant clutter of noise. This artificial noise pollution can cause mothers to be separated from their young, disrupt foraging habits and make it difficult for them to navigate, communicate or reproduce (Yangtze porpoises only breed once a year, their population recovery is therefore relatively slow).
Increased economic development
As China has reached new economic heights, rapid development and population growth are placing immense pressure on riverine habitats. According to the World Wide Fund for Nature, the number of human populations in the Yangtze River Basin has more than doubled over the past 50 years, mainly in areas along the river itself.
Construction projects like hydrologic engineering, when poorly planned, can interrupt the natural flow of porpoise ecosystems and degrade or completely destroy entire habitats or hunt species.
Massive dredging vessels harvesting sand from the river bottom (in a process sometimes referred to as sand mining) to replace it with concrete for the latest development can also destroy crustacean populations and riverbed vegetation. on which the porpoise depends for its survival. Sand mining, which can occur both legally and illegally, is also known to block passages between different water bodies and to lower water levels in the area during the dry season.
Likewise, the more developed the river, the more boats and ships ply its waters. Yangtze Flightless porpoises do not only occur in the Yangtze River, but also in the water bodies that connect to it, including Dongting and Poyang Lakes and Tian’e-Zhou Oxbow Nature Reserve. Their habitats almost exclusively overlap with the main gillnet areas of the river, so even if the animals themselves are not targeted by fishermen, porpoises can easily accidentally become entangled in fishing gear or be struck by boats. fishing.
What we can do
We can learn from the tragic plight of the Baiji dolphin with whom the wingless Yangtze porpoise once shared a habitat and whose fate was primarily determined by the destruction of its food supply due to overfishing.
As the Baiji dolphin is also considered the first toothed whale species to be threatened with extinction by humans, the race to save the species’ flightless porpoise cousin seems too urgent, which has resulted in even more d ‘studies to better understand the problem.
Research on porpoise populations may highlight the need to establish a network of reintroduction refuges to preserve as many individuals as possible. In the 1990s, a group of about five porpoises were transferred to a “semi-natural” lake habitat in the Tian’e-Zhou Oxbow Nature Reserve in Hubei Province (central China). By 2014, the population had grown to around 40 individuals.
Researchers continue to monitor and study the species to find out how best to protect it, while conservationists work alongside local communities to protect and restore porpoise habitat and support legislation that makes them safer by under the law. For example, while determining the distribution of the flightless porpoise of the Yangtze historically relied on simple visual and counting methods, researchers are discovering newer and more sophisticated strategies, such as measuring environmental DNA in river water. .
Whether it’s working with local fishermen to find other sources of income to stop overfishing and help develop sustainable economies, or rallying lawmakers to prioritize its protection, the Yangtze Flightless Porpoise has many organizations by its side.
In 2021, the species received a well-deserved victory when the Chinese Ministry of Agriculture provided the Yangtze Wingless porpoise with a new classification as a premium national protected species. The designation, which is the strictest classification for wild animals available by law, has enabled conservationists and the Ministry of Agriculture to exercise control over illegal fishing, regular inspections of construction works. protection and occupation of porpoise habitat, migration channels or foraging areas.
What you can do to help the Yangtze flightless porpoise