Biological cohesion as the architect of bed movement under wave action

Xindi Chen, Changkuan Zhang, Ian Townend, David M. Paterson, Zheng Gong, Qin Jiang, Qian Feng, Xiping Yu

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)

Abstract

Cohesive extracellular polymeric substances (EPS) generated by microorganisms abundant on Earth are regarded as bed “stabilizers” increasing the erosion threshold in sedimentary systems. However, most observations of this phenomenon have been taken under steady flow conditions. In contrast, we present how EPS affect the bed movement under wave action, showing a destabilization of the system. We demonstrate a complex behavior of the bio‐sedimentary deposits, which encompasses liquefaction, mass motion, varying bed formations and erosion, depending on the amount of EPS present. Small quantities of EPS induce higher mobility of the sediments, liquefying an otherwise stable bed. Bed with larger quantities of EPS undergoes a synchronized mechanical oscillation. Our analysis clarifies how biological cohesion can potentially put coastal wetlands at risk by increasing their vulnerability to waves. These findings lead to a revised understanding of the different roles played by microbial life, and their importance as mediators of seabed mobility.
Original languageEnglish
Article numbere2020GL092137
JournalGeophysical Research Letters
Volume48
Issue number5
Early online date14 Jan 2021
DOIs
Publication statusPublished - 16 Mar 2021

Keywords

  • Bed stability
  • Biological cohesion
  • Biostabilization
  • Coastal safety
  • Sediment erosion
  • Wave action

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