Primary productivity Iron limitation in the Marginal Ice Zone of the Southern Ocean – unraveling the role of bacteria as mediators in the iron cycle (IMICROBE)

Iron is the most important micronutrient for oceanic phytoplankton production. In Southern Ocean, wide areas are low-productive due to the scarcity of iron despite high concentrations macronutrients. Iron availability decreases by distance from continent and increases again in seasonal sea-ice zone as ice releases iron.

Bacteria are better in low concentration nutrient uptake due to their small size. In offshore waters bacteria contain most of the biogenic iron in water. Many small unicellular algae are mixotrophic, i.e. they can prey on iron rich bacteria and photosynthesise. This route for iron is not well known.

The IMICROBE project studies the role of bacterial iron in regulation of primary productivity of the Southern Ocean across major habitats from subtropical to seasonal sea-ice zone. The project will look at bacterial capacity for iron uptake at molecular level, presence and grazing activity of mixotrophic protists and combine it with development of advanced biogeochemical ocean modelling. The research work is partly done during international research cruises.

Published 2022-10-07 at 19:12, updated 2022-11-02 at 15:43

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