The Research Division Marine Biogeochemistry has four Research Units: Biogeochemical Modelling, Biological Oceanography, Chemical Oceanography and Marine Geosystems.

Work in the Marine Biogeochemistry Research Division focuses on interactions between sediment, oceanic, and atmospheric material reservoirs and the organisms (including humans) which mediate marine biogeochemical processes.

Major emphasis is on the highly dynamic interfaces between atmosphere and ocean and sediment and ocean. Particular attention is paid to elements and compounds that are highly mobile and radiatively active.

 The research activities of the Division extend from the oceanic crust and sediments, through the water column to the surface layer and marine atmosphere. Investigative approaches include field work, laboratory and mesocosm studies as well as modeling.

A closely related theme is the development of chemical, biological and isotopic diagnostic tools (proxies) that are suited to investigation of current and past oceanic conditions. An emerging research area concerns the future biogeochemical state of the oceans in a high-CO₂ environment.

The Division comprises a community of geochemists, biologists, geologists, physicists and modellers with complementary skills, diverse perspectives and inter-related scientific interests.