Remarkable recovery

Though it has been only over 3 years since the fishing moratorium was imposed, there have been positive signs that show the recovery of some fish species in the Yangtze.

The location where the Jinsha and Minjiang rivers converge into the Yangtze in Yibin city in Sichuan province is a popular destination for tourists. It has become even more popular because a large school of wild fish are usually visible there, with some weighing more than 20 kilograms.

"They don't shy away from crowds," said Quan Hong, a law-enforcement officer for fisheries management with the agriculture and rural affairs bureau of Xuzhou district, where the river convergence is located.

A recent assessment conducted by the China Institute of Water Resources and Hydropower Research shows that the aquatic biological integrity indexes in the Yangtze's mainstream, as well as Poyang and Dongting, the only two large lakes that remain naturally connected to the Yangtze, stood at the worst level of having "no fish at all" before the moratorium. Now, their indexes have all improved by two levels.

There are six levels under the index system with "excellent" being the best level, followed by "good", "average", "poor" and "very poor".

As a professor dedicated to researching fish with the Chinese Academy of Sciences' Institute of Hydrobiology, Liu Huanzhang has endorsed the improvement of Yangtze's aquatic biological integrity, noting the Ochetobius elongatus — a type of carp — as an example.

The fish used to be a common species in the Yangtze, but it became rare after the year 2000 and "could hardly be seen", especially over the decade before the moratorium. But Liu now finds the species multiple times a year in his fish monitoring and resources surveys of the Yangtze.

Ochetobius elongatus, a demanding fish with carnivorous tendencies, relies heavily on the presence of other fish for its survival, he said. The dramatic decline in its population this century happened mainly due to overfishing, which has not only directly impacted its numbers but also disrupted its food chain.

"The recovery of the Ochetobius elongatus certainly indicates a recovery of the overall fish stock," Liu said.

Wei, the scientist, believes that, with the gradual implementation of comprehensive protection measures for the Yangtze, the aquatic ecological environment of the river will significantly improve in the future.

"I can't wait to see the Yangtze in 2030," he said, indicating his high expectations to see a significantly positive transformation in Asia's longest river.

Xinhua contributed to the story.