Welcome to OCB

OCB was established in 2006 as one of the major activities of the U.S. Carbon Cycle Science Program, an interagency body that coordinates and facilitates activities relevant to carbon cycle science, climate, and global change issues. The scientific mission of OCB is to study the evolving role of the ocean in the global carbon cycle, in the face of environmental variability and change through studies of marine biogeochemical cycles and associated ecosystems.

Overarching Themes

Improve understanding and prediction of:

  1. oceanic uptake and release of atmospheric CO2 and other greenhouse gases;
  2. environmental sensitivities of biogeochemical cycles, marine ecosystems, and interactions between the two   

Currently Identified Research Priorities

  • Climate- and human-driven changes in ocean chemistry (e.g., acidification, expanding low-oxygen conditions, nutrient loading, etc.) and associated impacts on biogeochemical cycles and marine ecosystems 
  • Ocean carbon uptake and storage
  • Estuarine and coastal carbon fluxes and processes, including exchanges with open ocean, terrestrial, and atmospheric reservoirs
  • Water column and seafloor ecological and biogeochemical processes and associated effects on carbon export and the biological pump
  • Molecular-level responses of marine organisms (primarily lower trophic levels, including plankton, mollusks, etc.) to their changing environment  
  • Impacts of evolutionary changes on plankton community structure, function and biogeochemical cycling in the face of global change

Science Highlights

Submit your science features to the OCB Project Office.

From source to sink: The changing face of the coastal carbon cycle


Multiple processes along the land-ocean continuum affect the cycling of carbon in continental margin systems. Jim Bauer and colleagues have published a review paper in Nature that synthesizes our current understanding of how inorganic and organic carbon enter and move through estuarine and shelf systems and how human activities are impacting the coastal carbon cycle. From riverine delivery of terrestrial carbon to processing within estuarine and coastal systems (air-sea exchange, photosynthesis, respiration, burial, resuspension, etc.) to export to the open ocean, the authors summarize the current state of knowledge on observation- and model-based estimates of key carbon fluxes.

A widely held view is that in response to anthropogenic nutrient inputs, coastal systems have shifted from net heterotrophy to net autotrophy, resulting in increased drawdown of atmospheric CO2 in coastal waters. Using literature-based estimates and a mass balance approach, the authors propose a mechanism involving no net change in the metabolic state of the coastal ocean, but rather an increased physical uptake of atmospheric CO2 by the surface ocean, consistent with much greater measured increases in atmospheric CO2 levels relative to coastal surface water CO2 levels. This mechanism yields a large increase in DIC export to the open ocean relative to preindustrial time, and, if verified by additional field studies, will have important ramifications for ocean CO2 uptake and ocean acidification research.


Vesicle production in photoautotrophs and implications for marine ecosystems


Steven Biller and colleagues have published a paper in Science documenting the production of extracellular vesicles in Prochlorococcus. These lipid vesicles contain proteins, DNA, and RNA, and are thought to support the growth of marine heterotrophic bacteria, which has implications for processes involving the marine carbon cycle and exchange of genetic material. Read more here.


We gratefully acknowledge the support of the National Science Foundation and the National Aeronautics and Space Administration.

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