Tourists visit a street in Gulangyu island in Xiamen City, southeast China's Fujian Province, Aug. 29, 2017. The 9th BRICS summit will be held in Xiamen from Sept. 3 to 5. (Xinhua/Zhang Guojun)

The island gained popularity in the 1980s, and the past three decades witnessed an increasing number of visitors, with a record high of as many as 128,000 people in one day.

In Oct 2014, the city government of Xiamen decided to set a limit of 65,000 people on the island per day.

Before that, the island was extremely crowded in peak seasons, March to October. Streets were jammed with visitors walking from one scenic site to another. Meanwhile, trash disposal became another problem because the island had no recycling facilities and all trash had to be carried to other places.

From June 30, the number was further reduced to 50,000 each day. The island was voted a world heritage site in July.

Local authorities said the new ceiling has contributed to enriched tourism resources and improved experiences.

To achieve the goal, a monitoring system has been put in place to keep an eye on nine areas, including visitors, heritage sites and the local environment. For example, a list of old trees has been created.

On Sept 15 last year, Typhoon Meranti landed in Xiamen and damaged a large number of trees on the island. The management committee organized experts and rescuers to save them while restoring damaged buildings.

Residents also joined in the reconstruction to save scenic spots and communities, which astonished UNESCO experts during their field trips to the island.

Gulangyu Island being listed as a world cultural heritage site should be the most profound cultural event in Xiamen this year, said Huang Qiang, the city's executive vice-mayor.

Huang said limits on the number of visitors had reduced tourism revenues. However, protection of cultural heritage and the quality of services have become top priorities for the city, instead of simply the income, he said.

"We are striving to make a balance between protection and development to achieve sustainable development," he said.

Meanwhile, the vice-mayor said business operations on the island will be controlled as well.

"There used to be a lot of businesses running on the island to provide services such as accommodation and food. We cannot let the number of businesses increase anymore. New businesses will replace old ones. By doing so, a cleaner and more friendly environment can be made for locals and visitors," Huang said.

Lyu Zhou, a professor at the School of architecture at Tsinghua University, said the value of Gulangyu Island lies in its communities with local and foreign cultures intertwined with each other.

There is a long way ahead to forge sustainable development by promoting the island's cultural diversity based on socioeconomic traditions, Lyu said.

That process will surprise local residents and the rest of the world, he added.