Research in this division is concerned primarily with the dynamics of those biophilic elements in marine environments and their coupling with various metabolisms of marine organisms. Emphasis is placed of the identification of the various types of biochemical processes operating in the water column and upper marine sediments, and their regulations and interactions. The metabolisms of those types of organism are related to each other because organic compounds once produced by primary producers are metabolized by bacteria as well as transferred to zooplankton. Investigations along this line have been conducted on the water column and sediments in the central Pacific, western North Pacific and Antarctic Oceans, and the littoral areas and embayments on the coast of Japan. Seagrass ecosystem studies focused on the coupling between food webs and nutrient cycling has also been carried out in selected sites located in coastal waters in the tropical Pacific.
Special emphasis is placed at present on the interactions between carbon and nitrogen metabolisms.
Also detail information on their vertical distribution, and diurnal, seasonal and geographical variations is necessary to evaluate the cycles in global scale.