China’s coastline covers approximately 14,500 km (around 9,010 mi) from the Bohai gulf in the north to the Gulf of Tonkin in the south. Most of the northern half is low lying, although some of the mountains and hills of Northeast China and the Shandong Peninsula extend to the coast. The southern half is more irregular. In Zhejiang and Fujian provinces, for example, much of the coast is rocky and steep. South of this area the coast becomes less rugged: Low mountains and hills extend more gradually to the coast, and small river deltas are common. China’s coasts are on the Yellow Sea, East China Sea and South China Sea. China claims a 12-nautical-mile territorial sea, a 24-nautical-mile contiguous zone, a 200-nautical-mile exclusive economic zone, and a 200-nautical-mile continental shelf or the distance to the edge of the continental shelf. Seas Yellow Sea East China Sea South China Sea Straits Bohai Strait (渤海海峡) Taiwan Strait Qiongzhou Strait Islands Islands of China Bays Bohai Bay Bohai Sea Dalian Bay Daya Bay Haitang Bay Hangzhou Bay Hong Kong bays Jiaozhou Bay Korea Bay Laizhou Bay Liaodong Bay Sanya Bay Yalong Bay Yellow River Delta and Bohai Sea Peninsulas Dapeng Peninsula Leizhou Peninsula Liaodong Peninsula Macau Peninsula Shandong Peninsula Tashi Dor Places Liaoning Dalian Dandong Jinzhou Hebei Qinhuangdao Tianjin Tianjin Shandong Yantai Qingdao Shanghai Shanghai Zhejiang Hangzhou Ningbo Wenzhou Fujian Fuzhou Putian Xiamen Guangdong Chaozhou Hong Kong Hong Kong Macau Macau Guangxi Zhangjiang Beihai Qinzhou Hainan Haikou Wenchang Qionghai Wanning Donglang Ports Ports of China Pollution A total of 145,000 square kilometers of shallow waters along China's vast coast failed to meet national quality standards for clean oceanic water, of which 29,000 square kilometers of seawater were seriously polluted. These severely polluted water areas included East Liaoning, Bohai and Hangzhou bays, and the estuaries of Yellow, Yangtze and Zhujiang rivers, as well as inshore areas of major coastal cities. Content of major pollutants, such as inorganic nitrogen and phosphate, remains high in contaminated seawater. During the past 50 years, the inshore ecosystem had seen 50 percent of coastal wetlands disappear in excessive reclamation and 80 percent of coral reefs and mangroves destroyed. See also List of countries by length of coastline Geography of the People's Republic of China List of national parks of the People's Republic of China Protected areas of the People's Republic of China List of UNESCO Biosphere Reserves in China