Document Type
Journal Article
Publication Title
Limnology and Oceanography
Volume
69
Issue
6
First Page
1439
Last Page
1449
Publisher
Wiley
School
Centre for Marine Ecosystems Research / School of Science
RAS ID
71175
Funders
Ningaloo Outlook / CSIRO / Woodside Energy
Abstract
Erosion is a key process in shaping the physical structure of coral reefs, yet due to erosion being semi-cryptic and difficult to quantify, information remains limited. Here, we investigate erosional processes along Ningaloo Reef, an extensive fringing coral reef in Western Australia. We employed both direct and indirect methods to measure erosion in wave-exposed reef slopes and protected lagoonal habitats. Direct measurements of erosion on coral blocks were among the highest found globally, with total erosion of 3.07 kg m−2 yr−1 (4% from micro, 0.6% from macro, and 94% from external), whilst indirect rates were estimated at 2.4 ± 0.20 kg m−2 yr−1 (78% from parrotfish, 22% from urchins). Indirect erosion rates were influenced by the species and size of parrotfish, with Chlorurus microrhinos removing 0.44 ± 0.19 kg m−2 yr−1 (22% of parrotfish erosion). Scanning electron microscopy and computed tomography show that micro and macroborer erosion contributions to direct erosion were low, most likely due to heavy grazing by parrotfish and the short deployment period of experimental substrates. A substantial portion of external erosion on blocks (0.53 ± 0.23 kg m−2 yr−1) could not be attributed to bioeroders and was poorly correlated with wave exposure, suggesting processes not quantified contribute to this unaccounted aspect of erosion. Our results confirm that bioerosion by parrotfish is especially significant at Ningaloo Reef, and large-bodied individuals of C. microrhinos are key in conserving this key ecological process.
DOI
10.1002/lno.12586
Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.
Comments
Thomson, D. P., Dee, S., Doropoulos, C., Orr, M., Wilson, S. K., & Hoey, A. S. (2024). High rates of erosion on a wave‐exposed fringing coral reef. Limnology and Oceanography, 69(6), 1439-1449. https://doi.org/10.1002/lno.12586