Ten-year fishing ban revives the Yangtze: fish stocks double, rare porpoises increase

The Yangtze is Asia's longest river and the third longest in the world. Rising in the Tanggula mountains of the Tibetan Plateau, it travels about 6,300 kilometres through central and eastern China before meeting the East China Sea near Shanghai.

Besides giving water and livelihoods to hundreds of millions of people, the river was home to many strange and beautiful aquatic animals. Among them are the baiji dolphin, the huge Chinese paddlefish, the Chinese giant salamander, the Yangtze finless porpoise and the Chinese sucker.

But as the river's environment was damaged over decades, many of these animals are now extinct, nearly extinct or on the way to extinction. Overfishing, dam building one after another, pollution, dredging and encroachment on land around the river have put the Yangtze's biodiversity under severe threat since 1950. As fish declined, some dishonest fishers turned to destructive methods such as electric fishing and poison.

By the start of the 21st century, fish production in the river had fallen to only 25 percent of what it was in the first half of the 20th century. According to historical records, at least 135 fish species have disappeared from the river completely.

Realising the gravity of the situation, China's government took a major step in 2021. A 10-year ban on commercial fishing was imposed across the whole river area, to end around 2030. About 2.74 billion dollars was spent implementing it. Under the project, 111,000 boats were removed from the river and more than 231,000 people who had lived by fishing were rehabilitated into other occupations.

The benefit of this huge investment is now clearly visible. A study published early this year in the journal Science compared the state of fish at 57 locations on the river, observing data from before the ban (2018-20) and after it (2021-23).

The study found that the total amount of fish in the river has roughly doubled. The number of large fish in particular has risen by more than 232 percent. The presence of different fish species in the river has increased by 13 percent after the ban. Even for some rare species on the very edge of extinction there are signs of hope — the Yangtze sturgeon and the Chinese sucker are being seen again. Although the huge dams prevent these fish from properly reaching their spawning grounds, early signs show their numbers slowly increasing.

The most positive change has been seen in the Yangtze finless porpoise. It is the world's only freshwater porpoise, a dolphin-like animal distinct from dolphins, known for its smiling face and melon-like head. According to the research, their number in the river rose from 445 in 2017 to 595 in 2022 — an increase of about one-third in just a few years.

What happened to the lives of the fishers who had lived on the river's banks for generations did not come up directly in this study. But some information is available from government accounts. Of the nearly 231,000 affected people, about 160,000 had found new work by 2023; some of them now work guarding or protecting the Yangtze. About 220,000 people were also brought under government social allowances or assistance. However, without neutral data from any independent body other than the government, it is not clearly known whether the fishers' incomes are as before or whether they are satisfied with their new work.

The researchers cautioned that this observation covers a very short period. Longer monitoring will be needed to understand how well the ban is really working and whether this environmental improvement will last.

Yet the researchers have not lost hope. In their view, this initiative can be a new inspiration for environmental protection worldwide. In the paper, the scientists said they are optimistic seeing this change in biodiversity in a short time. But if fishing resumes, or if problems such as the impact of dams, river pollution and reduced water flow are not resolved, this success could easily be lost.

The researchers added that similar steps could be taken on big rivers such as South-East Asia's Mekong or South America's Amazon. If fish demand can be met through farming in that case, people's protein needs would be met on one side and the river's natural environment would survive on the other.