East China Sea
In South Korea, the sea is sometimes called South Sea, but this is more often used to denote only the area near South Korea's southern coast.
The East China Sea is bounded on the East by the Kyūshū and Ryukyu Islands, on the South by Taiwan, and on the West by mainland China. It is connected with the South China Sea by the Taiwan Strait and with the Sea of Japan by the Korea Strait; it opens in the North to the Yellow Sea.
According to the International Hydrographic Organization (IHO SP 23, Limits of Oceans and Seas, 3ed edition, 1953), the East China Sea is closed to the south by a line running from the Chinese coast of Fukien along parallel 25°24’ to the southern tip of Haitan Dao (a Fukien coastal island), then Kiushan Dao (a.k.a. Niu Shan Dao or Turnabout Island, a small island south-east of Haitan Dao), east to Fuki Kaku (a.k.a. Puki Kaku, cape Syauki, northern tip of Taiwan), the Taiwanese coast to Santyo Kaku (a.k.a. cape Samtiau, north-eastern tip of Taiwan island), to cape Irizaki (western tip of Yonakuni Jima or Yonaguni Jima, the westernmost of the Ryū-Kyū Islands), then to Haderuma Jima (Hateruma Jima, the southernmost of the Ryū-Kyū). On the east, the boundary runs through the eastern tip of Miyako Jima, then Okinan Kaku (southern tip of Okinawa Island), Ada-Ko Jima (a.k.a. Adaka Jima or Sidmouth Island, a tiny islet less than a kilometre east of the northern tip of Okinawa), the eastern tip of Kikai Jima, the northern tip of Tanega Jima, and finally Hi Saki on Kyūshū (cape Hi, at the southern end of Shibushi Bay). On the north, the boundary follows the coast of Kyūshū to Nomo Saki (Noma Misaki, cape Noma, westernmost point of the Satsuma Peninsula), the southern tip of Fukue Jima (Hukae Jima, the largest of the Gotō Islands), the coast of that island to Ose Saki (cape Ose, cape Goto, the western end of the island), Hunan Kan (cape Hunan, southern tip of Jeju-do (a.k.a. Saisyo Do or Quelpart Island)), the coast of Jeju to its western tip, and finally the 33°17’ parallel back to the Chinese coast.
The Yangtze River (Chang Jiang) is the largest river flowing into the East China Sea.
Islands and reefs
There is a cluster of submerged reefs in the northern East China Sea. These include:
Socotra Rock, also called Suyan Rock or Ieodo, subject of an EEZ dispute between the People's Republic of China and South Korea.
Hupijiao Rock (虎皮礁)
Yajiao Rock (鸭礁)
There are disputes between China, Japan, and South Korea over the extent of their respective exclusive economic zones.
The dispute between China and Japan concerns natural gas. The People's Republic of China (PRC) recently discovered that there exists an undersea natural gas field in the East China Sea, part of the field lies within the Chinese EEZ while the remaining lies on the disputed EEZ between Japan and the PRC. Under the United Nation's Law of the Sea, PRC claims the disputed ocean territory as its own Exclusive Economic Zone (EEZ) due to its being part of PRC's natural extension of its continental shelf, while Japan claims the disputed ocean territory as its own EEZ because it is within 200 nautical miles (370 km) from Japan's coast.
China has set up the Chunxiao gas field, which is located more than 4 km inside the Chinese side of the EEZ boundary claimed by Japan and is within China's own EEZ, to extract the natural gas. Japan maintains that although the Chunxiao gas field rigs are on China's side of a median line that Tokyo regards as the two sides' sea boundary, they may tap into a field that stretches into the disputed area. Japan therefore seeks a share in the natural gas resources.
The dispute between China and South Korea concerns Socotra Rock, a submerged reef on which South Korea has constructed a scientific research station. While neither country claims the rock as territory, China has objected to Korean activities there as a breach of its EEZ rights. (Wikipedia)