This aerial photo taken on May 29, 2020 shows the view of Qutang Gorge, one of the Three Gorges on the Yangtze River, in Southwest China's Chongqing. (PHOTO / XINHUA)

China has essentially eliminated large-scale illegal sand mining in the main stream of the Yangtze River and seen its aquatic environment improve significantly thanks to government efforts to conserve the country's longest watercourse, officials said.

The officials spoke on Monday during a forum themed on Yangtze conservation in Wuhan, capital of Hubei province, which marked the third anniversary of a symposium presided over by President Xi Jinping on promoting the development of the Yangtze River Economic Belt in the city.

During the symposium, Xi called for all-out efforts to protect the Yangtze, saying there should be no large-scale development of the watercourse.

The president also hosted two other symposiums under the same theme. One was in Chongqing in 2016, and the other one was in Nanjing, capital of Jiangsu province, last year.

Xi stressed the need for conservation of the river during those events. During the 2016 gathering, for example, he said restoring the Yangtze's ecology and environment would be an overwhelming task and that large-scale development along the river would be prohibited.

According to the Changjiang Water Resources Commission, the Yangtze saw water quality at all monitored sections in its mainstream rated at or above Grade II－the second highest in the country's five-tier assessment system for surface water－for the first time last year

Ma Jianhua, head of the Changjiang Water Resources Commission, said large-scale illegal sand mining has been basically terminated in the Yangtze's trunk thanks to the river management authority's intensified efforts to crack down on ships involved in the practice.

To date, his colleagues have conducted 300 surprise inspections targeting illegal mining during which they helped local government find 7,200 illegal mining ships, he said.

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Zhong Zhiyu, chief engineer of the commission, said illegal sand mining is only one of the various environmental problems in the Yangtze River Basin that have been effectively curbed.

"The aquatic environment in the basin has experienced continuous improvement," he said.

According to the commission, the Yangtze saw water quality at all monitored sections in its mainstream rated at or above Grade II－the second highest in the country's five-tier assessment system for surface water－for the first time last year.

Zhong said the commission will ramp up efforts to manage sewage drains to improve the river's environment. In preparation, over 24,000 such drains have been located and registered.

The Yangtze has also experienced marked restoration of fish resources.

The monitoring section in Shashi district in Hubei's Jingzhou city, for example, reported over 2 billion fish eggs laid last year by the four major Chinese carp species, including the grass carp－the most since 2011, he continued.

Wu Zhiguang, Party chief of Changjiang River Scientific Research Institute, said he expects to see further restoration of fish resources in the Yangtze as the country continues a 10-year fishing moratorium launched this year in all the Yangtze's natural waterways.

"In recent months, we have already seen good results from the moratorium," he said.

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"As long as we continue it, it will bring extraordinary benefits to the conservation of the Yangtze's ecosystem."

Contact the writers at houliqiang@chinadaily.com.cn