A diver checks coral growing on an artificial reef at Wuzhizhou Island. [Photo provided to chinadaily.com.cn]

Underwater robots will be used to monitor and safeguard marine ranching around Wuzhizhou Island, a 5A tourist resort in Sanya, said Yang Xiaohai, general manager of the tourism company on Tuesday at an international meeting on local government partnerships in environmental management for the seas of East Asia held in Sanya.

An extra three million yuan ($453,610) investment will be made to buy underwater robots and other monitoring equipment this year to support marine ranching construction around Wuzhizhou Island, one of the popular tourist attractions in the coastal resort city of Sanya, in South China's Hainan province, according to Yang.

Construction of marine ranches around Wuzhizhou Island started in 2011, and the total area was expanded to about 666 hectares in 2016 after two other parties, the Sanya Marine and Fishery Bureau and Hainan University, joined the project.

With projected investment of 300 million yuan ($45.3 million), marine ranching will evolve into a national marine ecological park - with undersea gardens, a museum, a sculpture zone, a fishing zone, a demonstration zone of traditional Hainan residential houses and a corridor of figures dipicting Chinese fairy tales - for both conservation purposes and as an undersea tourist attraction, by 2021.

"It will be the first of its kind in China, that a marine ecological park will be built on artificial reefs. We are building houses for fish and other sea species," Yang said.

About 38.3 million yuan has been spent to build 1,418 artificial cement reef bases. Twenty-one steel ships, which function as reef bases, had been installed in the waters by June, according to Yang.

"Years of efforts have already begun to pay off," he added.

"The coral reef in the area has increased and the fishery resources have been enriched."

Sanya, a well known tropical tourist city at the southern tip of Hainan island, has since 2015 launched a series of actions to restore its ecological environment in both land and water areas. The efforts will offer a better living environment for residents and a better resort for visitors.

So far, about 237,000 square meters of hills and mountains had been regreened, a total of 2.6 km of coastline has been restored, 1.5 km of sand vegetation has been protected and ecological restoration has been completed. Also, a mangrove ecological park that occupied about 8 hectares has been built downtown, according to Sanya government official.

"We will further enhance our efforts in marine ecological environmental protection to build Sanya into a world-class coastal tourist resort," said Wu Yanjun, mayor of Sanya, at the meeting on Tuesday.