Researcher calls for release of other artificially bred species

A researcher has called for increased releases of artificially farmed fish of some endangered species into the Yangtze River, as well as more thorough restoration of shorelines, to further improve the aquatic ecosystem in Asia's longest waterway.

Liu Huanzhang, a professor at the Institute of Hydrobiology of the Chinese Academy of Sciences in Wuhan, the provincial capital of Hubei, also praised the ten-year fishing moratorium in the Yangtze Basin, which came into force on January 1, 2020, as a bold initiative that is unprecedented in the world in both its scale and duration.

The urgency of this action is underlined by the alarming decline in the Yangtze's aquatic resources and a severe decline in its biodiversity. Previous attempts to impose three-month annual fishing bans proved inadequate, and unsustainable fishing practices quickly undid any progress made.

Liu stressed that the ban offers the Yangtze ecosystem a crucial opportunity to recover. But he also said that for some endangered species, such as the Chinese sturgeon, whose males take nine years to reach sexual maturity and whose females take 14 years to do so, the release of artificially bred fish is necessary to restore their population.

However, the scale of the release so far has been inadequate and the work has also been hampered by overfishing, he said.

According to the Ministry of Agriculture and Rural Affairs, starting this year, the ministry will provide 50 million yuan ($7 million) in annual funding to expand the release of artificially bred endangered species in the Yangtze River.

The ministry will use the money to release one million young fish of endangered species into the Yangtze this year, it said. By further increasing the quantities released, it will try to gradually increase the number to five million per year in three to five years.

In addition to increasing populations, it is also important to release artificially bred older fish, Liu said. “These young fish are easily preyed upon by predators in the wild,” he noted.

He stressed that coastline restoration is another key measure that China must further pursue to rejuvenate the Yangtze River's aquatic ecosystem.

Many of the Yangtze River floodplains, once important spawning and breeding areas, have been severely damaged by the development of coastlines for flood control and shipping purposes, he said.

China could learn from Europe's experience and adopt strategies such as creating meandering river banks, he said. This could create small bays in which moss and aquatic plants grow. This would create a favorable habitat for small insects, which in turn serve as a source of food for small fish.