Stromatolites on the rise in peat-bound karstic wetlands

Researchers have discovered living freshwater stromatolites in the peat-bound karstic wetlands of the Giblin River catchment, part of Australia's UNESCO-listed Tasmanian Wilderness World Heritage Area. These stromatolites, which are rare and typically found in extreme marine or saline environments, thrive in mildly alkaline conditions (pH 7.0-7.9) created by karstic spring mounds within an otherwise acidic terrain. The study used 16S rRNA gene clone library analysis to reveal a unique bacterial community dominated by Cyanobacteria, Alphaproteobacteria, and Chloroflexi, among others. Additionally, the findings suggest that stromatolites may flourish where metazoan predation is suppressed, as evidenced by the sparse macroinvertebrate population and shell damage in snails due to carbonate accumulations. This discovery challenges the conventional understanding of stromatolite habitats, indicating they may be more widespread than previously believed.

Proemse, B. C., Eberhard, R. S., Sharples, C., Bowman, J. P., Richards, K., Comfort, M., & Barmuta, L. A. (2017). Stromatolites on the rise in peat-bound karstic wetlands. Scientific Reports, 7(1). https://doi.org/10.1038/s41598-017-15507-1