EPStromNet - Extant Peritidal Stromatolite Network

Stromatolites are the earliest macroscale lifeforms which are found in the fossil record during the Precambrian and Phanerozoic eras (3.5 billion years ago) and still form today. The characteristic feature of stromatolites is their laminated calcium carbonate structure produced through a close coupling between microbial (Bacteria particularly cyanobacteria, Archaea, and Eukarya, particularly diatoms) activity and geochemical processes, to create a persistent geological structure. Within the last two decades a new type of stromatolite, peritidal (upper shore) stromatolites, was discovered in beach locations in South Africa, Australia and the U.K.

EPStromNet will develop a new collaboration of leading international researchers from three continents, that will address key scientific questions underpinning the fundamental nature of these newly identified microbial-geological systems. The assembled team combines senior and early career scientists, complementary expertise, and an excellent track record in delivering leading international science. EPStromNet will pool expertise in microbial and macro-ecology, geochemistry, isotope chemistry and coastal geomorphology, into a new partnership. Cutting-edge next-generation sequencing and eco-informatics tools will be used to identify similarities and differences in the diversity and composition of stromatolite communities within and between continents. These similarities and differences will be aligned with field-based geological mapping and modelling approaches, to determine the associated geological conditions of present and past (during different sea-level states) stromatolites. Stromatolites can be perceived as mini islands, and so allow us to address questions of island biogeography such as the extent to which environmental selection and dispersal limitation influence the diversity and composition of communities living in or on them. This network provides a unique opportunity to explore such macroecological questions at the scale of metres to thousands of kilometres. Furthermore, the depth and taxonomic breadth of our analysis will allow us to ask to what extent these drivers differ between taxa. We will also measure the characteristics of the microbial polysaccharide "glue" that binds the biogeostructures and traps particles, and its association with carbonate structures, key elements in the formation of stromatolites. Metagenomics (analysis on genes in the community)and activity experiments will give a first insight into metabolic processes and how they may lead to CO2 capture and the formation of calcium carbonate structures. This will establish hypotheses that will form the basis of future collaborations. This research therefore comprises a novel world-first investigation into the geobiological dynamics and drivers (genes-to-geosphere) of a range of stromatolite systems, only now feasible because of the discovery of these ecosystems in each of the three locations. No previous direct global-level assessment has been conducted on these stromatolites, nor of any comparable stromatolites in general.

Outcomes will include new insights into the processes that create these geobiological systems, address questions of population-level similarity across diverse taxa across global spatial scales, and generate new ideas for interpreting the conditions required for early life and life on other worlds. Peritidal stromatolites are not directly protected anywhere globally, yet as a rare habitat, it is essential to document communities (including novel taxa), learn how they form, and determine their susceptibility to environmental change, so that they can be properly conserved. EPStromNet will create this new research partnership, which will continue into the future through plans to support early career researchers, develop post-graduate student opportunities and identify new research programmes and funding opportunities.