Structure and function of Shark Bay microbial communities following tropical cyclone Olwyn: A metatranscriptomic and organic geochemical perspective

Tropical cyclones significantly alter microbial communities and geochemical processes in Shark Bay, Western Australia. Following Cyclone Olwyn (2015), black sludge deposits formed between microbialite columns, dominated by heterotrophic and anaerobic microbes like methanogens and sulfate-reducing bacteria. These microbes drove calcium carbonate precipitation, aiding mat preservation. Organic geochemical analysis revealed elevated C25 highly branched isoprenoid (HBI) alkenes, linked to cyclone-induced relocation of subtidal sediments containing HBI-producing diatoms. Additionally, sulfur-bound hopanoids and benzohopanes in mucilaginous cobbles suggested microbial matter influenced by cyclone-driven anoxia, promoting organic sulfurization. The study used metatranscriptomic and GC-MS analyses to uncover these post-cyclone changes.

Campbell, M. A., Coolen, M. J. L., Visscher, P. T., Morris, T., & Grice, K. (2021). Structure and function of Shark Bay microbial communities following tropical cyclone Olwyn: A metatranscriptomic and organic geochemical perspective. Geobiology, 19(6), 642–664. Portico. https://doi.org/10.1111/gbi.12461