DOREMI
Dissolved Organic matter REmineralization in the ocean: MIcrobial and biogeochemical constraints
The new concept for the Microbial Carbon Pump (MCP) postulates mechanisms by which refractory organic matter is produced in the oceans through microbial activities, and the role that this refractory pool plays in carbon sequestration in marine systems. This postulate evokes the need to increase our understanding of organic matter transformation, particularly for the processes of organic carbon degradation. In this context, key questions about the drivers that govern these processes have been posed and require scientific answers. DO-RE-MI will examine the biological and biogeochemical mechanisms that hinder total DOC remineralisation in marine systems.
We will apply a multidisciplinary approach to the design of experiments, the field program and the analysis of the results. Our approach builds upon the strengths of the team members and collaborators who have varied expertise and can bring diverse methodological techniques and tools, and ideas originating in their different disciplines – microbial ecology, biogeochemistry, and physical oceanography. With these varied methodological strategies we will work to achieve the following objectives:
1) To quantify DOM remineralization in contrasting marine systems
2) To test the effects of nutrient availability and microbial metabolic capability on the efficiency of DOM degradation
3) To experimentally test whether DOC concentration and DOM chemical diversity can explain the limits of DOM degradation in the deep ocean
4) To evaluate the role of different bacterial community structures in the degradation processes.