In 2012, there were only 1,040 finless porpoises in the Yangtze River, one of the very few porpoise species that live in freshwater, raising the alarm about the protection of the rare species.

As one of the rivers with the most biodiversity in the world, the Yangtze has over 4,300 aquatic species, of which 424 are fish.

However, the number of fish in the river has been declining sharply for reasons such as overfishing.

The number of black, grass, silver and bighead carp, which are common freshwater fish in China, is less than 10 percent the number from the 1960s.

Today over 90 percent of China's freshwater products are cultivated. However, Cao Wenxuan, a fish biologist with the Chinese Academy of Sciences, said fish cultivated through artificial means need to be constantly supplemented with wild fish eggs for reproduction to ensure a sustainable population, and Yangtze fish are a precious gene pool for aquacultured fish. If Yangtze fish are not protected, there may be no fish to eat in the future.

Cao has been advocating a 10-year fishing ban in the Yangtze since 2006 to let the river replenish its aquatic resources. This year, three ministries jointly issued a plan for a 10-year fishing ban in the Yangtze starting in 2020.

However, it's not easy to implement the ban as the Yangtze, the third longest river in the world, stretches over 6,300 km and passes through 11 provinces, municipalities and autonomous regions.

In addition, there are many other causes for the decline of aquatic life in the river. Construction of hydropower stations obstruct fish from going back to areas where they laid their eggs and change the water conditions of the river. Pollution is another factor.

To protect the Yangtze, the fishing ban is just the beginning. More needs to be done.

(This is an edited excerpt of an article originally published in China Newsweek on December 9)