A snapshot of sediment dynamics on an inshore coral reef

Jodie A Schlaefer; Sterling B Tebbett; Casey L Bowden; William P Collins; Stephanie Duce; Christopher R Hemingson; Victor Huertas; Michalis Mihalitsis; Juliano Morais; Renato A Morais; Alexandre C Siqueira; Robert P Streit; Sam Swan; Jessica Valenzuela; David R Bellwood

doi:10.1016/j.marenvres.2022.105763

A snapshot of sediment dynamics on an inshore coral reef

Mar Environ Res. 2022 Nov:181:105763. doi: 10.1016/j.marenvres.2022.105763. Epub 2022 Sep 30.

Authors

Affiliations

¹ Research Hub for Coral Reef Ecosystem Functions, James Cook University, Townsville, QLD, 4811, Australia; ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD, 4811, Australia; College of Science and Engineering, James Cook University, Townsville, QLD, 4811, Australia; Commonwealth Scientific and Industrial Research Organisation (CSIRO), Oceans and Atmosphere, Hobart, Tasmania, 7000, Australia.
² Research Hub for Coral Reef Ecosystem Functions, James Cook University, Townsville, QLD, 4811, Australia; ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD, 4811, Australia; College of Science and Engineering, James Cook University, Townsville, QLD, 4811, Australia.
³ College of Science and Engineering, James Cook University, Townsville, QLD, 4811, Australia.
⁴ Research Hub for Coral Reef Ecosystem Functions, James Cook University, Townsville, QLD, 4811, Australia; ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD, 4811, Australia; College of Science and Engineering, James Cook University, Townsville, QLD, 4811, Australia. Electronic address: david.bellwood@jcu.edu.au.

PMID: 36206642
DOI: 10.1016/j.marenvres.2022.105763

Abstract

Sediments are ubiquitous on coral reefs. However, studies of reef sediments have largely focused on isolated reservoirs, or processes, and rarely consider hydrodynamic drivers. We therefore provide a quantitative snapshot of sediment dynamics on a coral reef. Across a depth profile, we simultaneously examined: suspended sediments, sediment deposition and accumulation, and hydrodynamic and biological movement processes. We reveal the marked potential for the water column to deliver sediments. Currents carried 12.6 t of sediment over the 2,314 m² study area in 6 days. Sediment traps suggested that a surprisingly high percentage of this sediment was potentially deposited (5.2%). Furthermore, wave-driven resuspension and reworking by parrotfishes separated a highly dynamic sediment regime on the shallow reef flat (3 m), from a more stagnant reef slope (4.5 m-12 m). This study provides a comprehensive model of how hydrodynamic forces and on-reef processes may shape sediment dynamics on a coral reef.

Keywords: Algal turf; Hydrodynamics; Parrotfish; Sediment resuspension; Sediment trap; Turbidity.

MeSH terms

Animals
Anthozoa*
Coral Reefs
Geologic Sediments
Perciformes*