This book presents study findings involving the Changjiang River estuary and Jiaozhou Bay, China, etc. It takes a large catchment as a combined ecosystem to study nutrients biogeochemistry and environmental aspects of the Changjiang River. Some of the findings have sparked new research directions, including systematic studies of nutrients in the Changjiang River; sources and control mechanisms of nitrogen and phosphorus in the Changjiang River and its estuary; removal and transport of nutrients in the turbidity maximum zone and upwelling area of the Changjiang estuary; long-term changes in nutrients and ecological responses in the Changjiang River estuary and Jiaozhou Bay; and a study on nutrient structure and nutrient composition of phytoplankton, which are topics at the forefront ofinternational marine The studies address different fields, such as biogeochemistry, marine chemistry, ecology, environmental science, oceanography and biology.