Macquarie University
01whole.pdf (1.19 MB)

Sediment microbial communities associated with bioturbators around remnant oyster reefs

Download (1.19 MB)
posted on 2022-11-09, 04:30 authored by Julia Palmer

The effects of biodiversity on ecosystem function have gained significant interest as global species loss continues. In estuarine sediments, microbial communities and their capacity to cycle nitrogen is influenced by bioturbating benthic macrofauna (bioturbators) and the burrow structures they create. Oyster reefs also influence microbial communities and their function by enriching surrounding sediments, which can increase bioturbator activity and nitrogen cycling bacteria. However, the interactions between sediment microbes and bioturbators, and consequences for ecosystem functions have not been fully explored. This study sampled sediment microbial DNA and in situ flux measurements of oxygen and nitrogen to assess how bioturbator activity can modulate microbial biodiversity and function at six remnant oyster reefs along the east coast of Australia. While bioturbator burrows were found to have similar microbial community composition and functioning to that of the surrounding surface sediments, these communities were related to bioturbation activity measured as number of burrows. Moreover, bioturbation activity explained sediment oxygen consumption, while the composition of core microbial communities explained gas fluxes between sediments and water column. This study highlights the importance of microbial sediment diversity and the functional roles of bioturbators in influencing biogeochemical cycles in estuarine sediments. 


Table of Contents

1. Introduction -- 2. Methods -- 3. Results -- 4. Discussion -- 5. Conclusions -- 6. References -- 7. Supplementary tables and figures


A thesis submitted in partial fulfillment of the requirements for the degree of Master of Research

Awarding Institution

Macquarie University

Degree Type

Thesis MRes


Thesis (MRes), Macquarie University, Faculty of Science and Engineering, School of Natural Sciences, 2022

Department, Centre or School

School of Natural Sciences

Year of Award


Principal Supervisor

Katherine Dafforn

Additional Supervisor 1

Ana Bugnot

Additional Supervisor 2

Deepa Varkey


Copyright: The Author Copyright disclaimer:




75 pages