Browse by author
Lookup NU author(s): Dr Eveline van der Steeg, Dr Adriana Humanes SchumannORCiD, Professor John BythellORCiD, Emeritus Professor Alasdair Edwards, Dr Liam LachsORCiD, Dr James GuestORCiD
This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).
© The Author(s) 2025.High mortality of juvenile corals hinder both the natural recovery of populations and the successful implementation of restoration efforts. Grazing is a significant cause of juvenile coral mortality, and grazer exclusion devices have been shown to increase juvenile coral survivorship. However, most experiments have used cages that typically alter water flow and light conditions, making it difficult to separate abiotic effects from those of grazing. Here, we test whether grazing deterrents can increase the survival and growth of six-month-old Acropora digitifera juveniles outplanted to a shallow reef crest, using arrangements of two or four long or short masonry nails designed to physically exclude larger grazers (e.g., parrotfish) while minimising abiotic changes. By the end of our study, colonies with deterrents had significantly larger planar area (almost tenfold for the most effective treatment), more branches, greater height, and higher survival than those without deterrents. A critical period in this study was the first week after outplanting when colonies with deterrents had significantly less tissue area loss from grazing than those without. Lower area loss in the first week was associated with significantly higher survival over the following 14 months, with an almost threefold improvement for the most effective treatment. For heavily grazed systems, our study highlights the importance of incorporating grazing deterrents into outplant devices to counteract the negative impact of large grazers on newly outplanted juvenile corals and boost restoration success.
Author(s): van der Steeg E, Humanes A, Bythell JC, Craggs JR, Edwards AJ, Golbuu Y, Lachs L, Miller MW, Randle JL, Guest JR
Publication type: Article
Publication status: Published
Journal: Coral Reefs
Year: 2025
Volume: 44
Pages: 1389–1401
Print publication date: 01/08/2025
Online publication date: 05/07/2025
Acceptance date: 16/06/2025
Date deposited: 21/07/2025
ISSN (print): 0722-4028
ISSN (electronic): 1432-0975
Publisher: Springer Nature
URL: https://doi.org/10.1007/s00338-025-02703-z
DOI: 10.1007/s00338-025-02703-z
Data Access Statement: The data will be made available upon request
Altmetrics provided by Altmetric
