Gouqi Island in Zhoushan. [Photo/WeChat account: zjzsrbs]

Zhoushan in East China's Zhejiang province is an island city and the number of its islands has been revised several times as the definition of island has varied.

In the 1970s, the definition of island was changed so that an island referred to a place with more than a 500-square-meter exposed area at high tide. In the 1990s, the official statistics showed that Zhoushan has 1,390 islands.

According to the latest definition made in 2017 that states that an island is a place with an exposed area at high tide, the number of Zhoushan's islands increased to 2,085.

Among the inhabited islands, 50 are mainly used for costal tourism, 39 for port logistics, 20 for harbor industries, 16 for coastal and marine ecosystem conservation, four for marine science and education, two for clean energy, as well as two for modern fishery industries.