Active eukaryotes in microbialites from Highborne Cay, Bahamas, and Hamelin Pool (Shark Bay), Australia

A study of microbialites at Highborne Cay, Bahamas, and Hamelin Pool (Shark Bay), Australia, reveals significant novel eukaryotic diversity within these organosedimentary structures. Using RNA-based sequencing to focus on active organisms, researchers identified diverse communities dominated by stramenopiles, alveolates, metazoans, amoebozoans, and rhizarians, with many sequences showing less than 80% similarity to known GenBank entries. Notably, Hamelin Pool exhibited particularly high levels of novel eukaryotic diversity, possibly linked to its hypersaline conditions. The study also found vertical structuring in protist populations and highlighted greater foraminiferal diversity in bioturbated thrombolite mats at Highborne Cay, suggesting complex interactions between eukaryotes and sedimentary fabrics that may influence microbialite formation.

Edgcomb, V. P., Bernhard, J. M., Summons, R. E., Orsi, W., Beaudoin, D., & Visscher, P. T. (2013). Active eukaryotes in microbialites from Highborne Cay, Bahamas, and Hamelin Pool (Shark Bay), Australia. The ISME Journal, 8(2), 418–429. https://doi.org/10.1038/ismej.2013.130