Presumably, the YS/ECS ecosystem is the one ecosystem in the Pacific, which is under the strong influence of various human activities such as fishing, mariculture, waste discharge, dumping, and habitat destruction,. There has also been strong evidence showing a gradual increase in the water temperature and northward movement in the isothermals. Given the variety of forcing factors, complicated changes in the ecosystem are anticipated. Rapid change and large fluctuations in the species composition and abundance in the major fishery have occurred.