East China Sea ecosystem.

The East China Sea is the major sea off the eastern coast of China; it is a marginal sea of the North Pacific Ocean. The East China Sea is bound on the west by mainland China, where the large estuary of the Yangtze River flows in at Shanghai, via Hangzhou Bay. To the south, it is bound by the Taiwan Strait (the channel to the South China Sea) and by Taiwan. To the east, the East China Sea is separated from the Philippine Sea and greater North Pacific Ocean by the arc of the Ryukyu Islands chain, and to the northeast by Kyushu, southernmost of Japan's “big four” main islands. Directly north lies the Korea Strait (channel to the Sea of Japan), the South Korean island of Jeju, and the Yellow Sea.