The microbial community ecology of the Baltic Proper is studied within this project, funded by the Foundation for Baltic and East European Studies, and several microbial ecosystem functions are investigated in order to understand the microbial capacities to cope with environmental change. With low surface salinity, a steep halocline, an eutrophication process and infrequent water mixing, areas of anoxic deep waters and sediments are gradually increasing, resulting in a steep oxygen gradient. The stratification of microbial community structure and functional capacity along the oxygen gradient through the water into the sediment is investigated (applying direct metagenomic sequencing at Sci Life, bioinformatics, metadata analysis

and statistics).

The project includes three parts, one has a particular focus on the key processes important for balancing the nitrogen budget and in the removal of nitrogen, denitrification and anaerobic ammonia oxidation, anammox. The second part of the project focuses on investigating the extent of stratification of microbial community structure and functional capacity along the oxygen gradient. The third part of the project focuses on developing ribonucleotide reductases as novel biomarkers for oxic-anoxic habitability (the project is in collaboration with researchers at Stockholm University).