The University of Southampton
University of Southampton Institutional Repository

Algal turf sediments limit the spatial extent of function delivery on coral reefs

Algal turf sediments limit the spatial extent of function delivery on coral reefs
Algal turf sediments limit the spatial extent of function delivery on coral reefs
The presence of key organisms is frequently associated with the delivery of specific ecosystem functions. Areas with such organisms are therefore often considered to have greater levels of these functions. While this assumption has been the backbone of coral reef ecosystem-based management approaches for decades, we currently have only a limited understanding of how fish presence equates to function on coral reefs and whether this relationship is susceptible to stressors. To assess the capacity of a stressor to shape function delivery we used a multi-scale approach ranging from tens of kilometres across the continental shelf of Australia's Great Barrier Reef, down to centimetres within a reef habitat. At each scale, we quantified the spatial extent of a model function (detritivory) by a coral reef surgeonfish (Ctenochaetus striatus) and its potential to be shaped by sediments. At broad spatial scales, C. striatus presence was correlated strongly with algal turf sediment loads, while at smaller spatial scales, function delivery appears to be constrained by algal turf sediment distributions. In all cases, sediment loads above ~250–500 g m−2 were associated with a marked decrease in fish abundance or feeding activity, suggesting that a common ecological threshold lies within this range. Our results reveal a complex functional dynamic between proximate agents of function delivery (fish) and the ultimate drivers of function delivery (sediments), which emphasizes: a) weaknesses in the assumed links between fish presence and function, and b) the multi-scale capacity of algal turf sediments to shape reef processes. Unless direct extractive activities (e.g. fishing) are the main driver of function loss on coral reefs, managing to conserve fish abundance is unlikely to yield the desired outcomes. It only addresses one potential driver. Instead, management of both the agents that deliver functions (e.g. fishes), and the drivers that modify functions (e.g. sediments), is needed.
0048-9697
Tebbett, Sterling B
cdb96273-f8e9-4213-af08-1740215e4b37
Goatley, Christopher Harry Robert
b158dc1a-76f3-4ace-9d33-260d8c76ac93
Streit, Robert P
1e4681ab-19d4-4f13-8929-19617e26cd38
Bellwood, David R
829e5839-9ac7-4f63-961c-8d0bf8caab8a
Tebbett, Sterling B
cdb96273-f8e9-4213-af08-1740215e4b37
Goatley, Christopher Harry Robert
b158dc1a-76f3-4ace-9d33-260d8c76ac93
Streit, Robert P
1e4681ab-19d4-4f13-8929-19617e26cd38
Bellwood, David R
829e5839-9ac7-4f63-961c-8d0bf8caab8a

Tebbett, Sterling B, Goatley, Christopher Harry Robert, Streit, Robert P and Bellwood, David R (2020) Algal turf sediments limit the spatial extent of function delivery on coral reefs. Science of the Total Environment, 734, [139422]. (doi:10.1016/j.scitotenv.2020.139422).

Record type: Article

Abstract

The presence of key organisms is frequently associated with the delivery of specific ecosystem functions. Areas with such organisms are therefore often considered to have greater levels of these functions. While this assumption has been the backbone of coral reef ecosystem-based management approaches for decades, we currently have only a limited understanding of how fish presence equates to function on coral reefs and whether this relationship is susceptible to stressors. To assess the capacity of a stressor to shape function delivery we used a multi-scale approach ranging from tens of kilometres across the continental shelf of Australia's Great Barrier Reef, down to centimetres within a reef habitat. At each scale, we quantified the spatial extent of a model function (detritivory) by a coral reef surgeonfish (Ctenochaetus striatus) and its potential to be shaped by sediments. At broad spatial scales, C. striatus presence was correlated strongly with algal turf sediment loads, while at smaller spatial scales, function delivery appears to be constrained by algal turf sediment distributions. In all cases, sediment loads above ~250–500 g m−2 were associated with a marked decrease in fish abundance or feeding activity, suggesting that a common ecological threshold lies within this range. Our results reveal a complex functional dynamic between proximate agents of function delivery (fish) and the ultimate drivers of function delivery (sediments), which emphasizes: a) weaknesses in the assumed links between fish presence and function, and b) the multi-scale capacity of algal turf sediments to shape reef processes. Unless direct extractive activities (e.g. fishing) are the main driver of function loss on coral reefs, managing to conserve fish abundance is unlikely to yield the desired outcomes. It only addresses one potential driver. Instead, management of both the agents that deliver functions (e.g. fishes), and the drivers that modify functions (e.g. sediments), is needed.

This record has no associated files available for download.

More information

Published date: 10 September 2020

Identifiers

Local EPrints ID: 470317
URI: http://eprints.soton.ac.uk/id/eprint/470317
ISSN: 0048-9697
PURE UUID: 8c097330-c04f-41f9-a262-d1c475198da7
ORCID for Christopher Harry Robert Goatley: ORCID iD orcid.org/0000-0002-2930-5591

Catalogue record

Date deposited: 06 Oct 2022 16:40
Last modified: 17 Mar 2024 04:14

Export record

Altmetrics

Contributors

Author: Sterling B Tebbett
Author: Christopher Harry Robert Goatley ORCID iD
Author: Robert P Streit
Author: David R Bellwood

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×