More about the project
It is widely recognized that the emergence and expansion of silica biomineralization in the oceans has affected evolutionary competition for dissolved Si (DSi). This resulted in changes in the global biogeochemical cycles of silica, carbon and other nutrients that regulate ocean productivity and ultimately climate.
However, a series of very recent discoveries in geology and biology suggest that the first biological impacts on the global Si cycle were likely by prokaryotes during the Archean with further decrease in oceanic DSi with the evolution of widespread, large-scale skeletal biosilicification significantly earlier that the current paradigm. Three critically important time periods when large-scale changes in Si-cycling occurred will be investigated; 1) the transition from bacterial to eukaryotic marine primary productivity in the Meso- and Neoproterozoic, 2) the role of stramenopiles, including diatoms, in changing oceanic DSi concentrations starting in the lower Mesozoic, and 3) the impact of changing DSi inputs on the Cenozoic oceans.
The major goal of this project is to understand the interactions between biosilicification in organisms and the oceans and how these interactions have evolved through Earth’s history until today. In the modern oceans the availability of DSi controls the amount of diatom primary productivity, which today account for 20% of the world’s primary production- Therefore, understanding the mechanisms of the past and present regulation of oceanic DSi and the interactions with other key biogeochemical cycles is critically important to understanding climate and food webs.
We will utilize state of the art stable isotope measurements of biosilicification in fossil material from deep time coupled with an exploration of the role of the three major groups of extant eukaryotic phytoplankton (cyanobacteria, diatoms and dinoflagellates) under a number of different ecologically relevant conditions present in the ancient oceans. It is through this unique combination of novel analyses of the geological record coupled with experimental biological investigation of key prokaryotes and silicifying eukaryotic phytoplankton groups that we will achieve a new understanding of the functioning of the Earth’s oceans through geological time.
The project is part of the research in the research group Marine microbiology and in Linnaeus University Centre for Ecology and Evolution in Microbial model Systems (EEMiS).
