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.
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.
