MicroPolar - Processes and Players in Arctic Marine Pelagic Food Webs

Biological production and consumption of CO2 in ocean surface waters is essential for understanding ocean-atmosphere inreaction. Small microorganisms can have a great impact on the biosphere and understanding their influence is of great importance with respect to increasing CO2-levels in the atmospehere.

MicroPolar image of coccolithophore, Arctic Ocean

Coccolithophore Papposhaera lepida (Haptophyta) from Arctic Ocean north of Svalbard at 475 m depth in March. Photo: Sesilie F. Tverberg, UiB. 

About the project

The interaction between the biosphere, the atmosphere and the hydrosphere is mediated by microorganisms being the main drivers of biogeochemical cycles in the ocean and the main producers and consumers of inorganic nutrients, organic carbon and CO2. Microbial communities, including phytoplankton, protozoa, bacteria, archaea and virus are by far the most abundant, and taxonomic and genetically diverse group of organisms in marine pelagic ecosystems.

Biological activity, biomass, production and remineralization in these systems are essentially microbial; and these microorganisms, at the base of the marine food web, also delimit the production at trophic levels of economic interest.

Microorganisms may in addition be important sentinels of environmental change, as alterations in the structure and biomass of microbial communities can herald changes not only in pathways of nutrient and energy transfer in food webs, but also in biogeochemical cycles. 

We seek to get a comprehensive picture of “Who they are”, “What they do”, “How they interact” and “How they respond to environmental change”.



  • Describe the structure, function and diversity of the microbial community in Arctic waters during a full annual cycle.

  • Quantify carbon flow in Arctic microbial food webs and the factors regulating production and consumption of dissolved organic carbon (DOC) and CO2.

  • Refine current microbial food web models experimentally in Arctic systems by exploring combined effects of altered microbial community structure and nutrient conditions as foreseen caused by progressing climate changes.

  • Provide data on organism, ecosystem and biogeochemical processes from natural systems and from perturbation experiments to be used for parameterization of marine biogeochemical models and for improved regional and global scale climate projections.


By focusing our research on marine microbial food webs and biogeochemical cycles in the Arctic Ocean we aim for a better description and understanding of the organisms, the processes, and the feedback mechanisms that shape the interaction between the biosphere, the atmosphere and the hydrosphere. MicroPolar will generate a unique dataset on microbial biodiversity and activity, and biogeochemical processes in polar water that will improve Earth system models and climate projections. It will thus contribute to the conception needed for a knowledge based management of natural resources and industrial activity in the polar regions.


RCN (Research Council of Norway)


Core Partners: University of Bergen, Uni Research, University of Oslo, NIVA and SALT

National collaboration: UiT, UNIS 

International collaboration: AWI, Bremerhaven, Germany; CNRS & UPMC Roscoff, France; CNRS & UPMC Banuyls sur-mer, France



Published Jan. 6, 2017 3:16 PM - Last modified July 31, 2019 6:10 PM


Gunnar Bratbak (UiB, project leader)

Aud Larsen (UniResearch, project leader)

Bente Edvardsen (UiO, PI)




  • Bente Edvardsen
  • Elianne Dunthorn Egge
  • Richard Bellerby
  • Kris Rokkan Iversen
  • Uwe John
  • Daniel Vaulot
  • Herv√© Moreau
Detailed list of participants