CORDIS - EU research results

Iron speciation in the microenvironment surrounding phytoplankton cells and the consequences for Fe bioavailability

Project description

Atmospheric CO2 and its role in iron deficiency among photosynthetic plankton

Photosynthetic plankton (phytoplankton) require iron for the synthesis of chlorophyll and several photosynthetic electron transport proteins as well as for the reduction of CO2 and other ions during the photosynthetic production of organic compounds. The acidification of the ocean caused by increasing atmospheric levels of CO2 and subsequent higher levels of carbonic acid in the waters can lower the availability of iron to living organisms that need it. The transfer of CO2 into organic carbon by phytoplankton contributes to CO2 sequestration and the reduction of atmospheric CO2. The EU-funded Phycosphere Fe project is investigating iron in the phycosphere, a microscopic layer around the phytoplankton cell and analogous to the plant rhizosphere, to get a better handle on the interplay between CO2 levels, warming, iron bioavailability and phytoplankton growth in the face of anthropogenic increases in CO2 and ocean warming.


The interaction between metals and microscopic plant-like organisms called phytoplankton is a key link to global carbon balance. More than a half of atmospheric CO2 on earth is taken up by phytoplankton, but iron (Fe) limits their growth in large regions of the oceans. Ongoing ocean acidification and global warming will influence Fe-stress in marine phytoplankton and hence the biological carbon fixation. Key existing knowledge gaps are the pathways by which phytoplankton take up Fe, and influences of chemical conditions in the microenvironment surrounding algal cells (i.e. phycosphere) on Fe speciation and bioavailability. This knowledge represents an impediment to understanding the complex effects of climate change on Fe uptake and oceanic carbon fixation. The project ‘Phycosphere Fe’ will determine chemical conditions and Fe speciation in the phycosphere of model phytoplankton species, quantify the role of phycosphere Fe speciation in Fe bioavailability, and investigate influences of climate change (i.e. warming and increased CO2) on Fe-algae interfacial processes. The project is key to the assessment of Fe bioavailability, growth and CO2 fixation of phytoplankton in current and future oceans, which make key contributions to global carbon sequestration. The project will improve our ability to model phytoplankton dynamics and predict biological carbon fixation in a changing ocean.


Net EU contribution
€ 174 806,40
24148 Kiel

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Schleswig-Holstein Schleswig-Holstein Kiel, Kreisfreie Stadt
Activity type
Research Organisations
Total cost
€ 174 806,40