Biostabilization: Parameterizing the interactions between microorganisms and siliciclastic marine sediments

Abstract

Microbial mats have existed for much of Earth's history. They represent some of the earliest evidence of life, are essential in biogeochemical cycles, and played a pivotal role in oxygenating the atmosphere. In addition, benthic microbiota impact sediment properties by enhancing the cohesion and stability of the substratum, a process known as ‘biostabilization’, which affects sediment dynamics and rheology. A substantial body of research has focused on experimentally quantifying biostabilization in siliciclastic sediments. This review compiles and synthesizes these studies in order to facilitate comparison of results. They, in turn, are compared with; (1) the Shields' diagram, (2) shear stress values in shallow marine environments, and (3) occurrences of microbially induced sedimentary structures in the marine stratigraphic record. The findings reveal significant variability in outcomes, with increases in the Shields' Parameter ranging from 0.1 to 4 orders of magnitude. They also demonstrate that high-energy hydrodynamic conditions, such as those above fairweather wave base, inhibit microbial colonization. Additionally, the review briefly discusses two applications of the data: (1) refining models of the Great Oxidation Event, and (2) evaluating microbial biostabilization as a response to increased coastal erosion driven by climate change.