Relative efficacy of three approaches to mitigate Crown‑of‑Thorns Starfish outbreaks on Australia’s Great Barrier Reef

Westcott, David A., Fletcher, Cameron S., Kroon, Frederieke J., Babcock, Russel C., Plagányi, Eva E., Pratchett, Morgan S., and Bonin, Mary C. (2020) Relative efficacy of three approaches to mitigate Crown‑of‑Thorns Starfish outbreaks on Australia’s Great Barrier Reef. Scientific Reports, 10. 12594.

PDF (Published version) - Published Version
Available under License Creative Commons Attribution.

Download (2MB) | Preview
View at Publisher Website:


Population outbreaks of Crown-of-Thorns Starfish (COTS; Acanthaster spp.) are a major contributor to loss of hard coral throughout the Indo-Pacific. On Australia’s Great Barrier Reef (GBR), management interventions have evolved over four COTS outbreaks to include: (1) manual COTS control, (2) Marine Protected Area (MPA) zoning, and, (3) water quality improvement. Here we evaluate the contribution of these three approaches to managing population outbreaks of COTS to minimize coral loss. Strategic manual control at sites reduced COTS numbers, including larger, more fecund and damaging individuals. Sustained reduction in COTS densities and improvements in hard coral cover at a site were achieved through repeated control visits. MPAs influenced initial COTS densities but only marginally influenced final hard coral cover following COTS control. Water quality improvement programs have achieved only marginal reductions in river nutrient loads delivered to the GBR and the study region. This, a subsequent COTS outbreak, and declining coral cover across the region suggest their contributions are negligible. These findings support manual control as the most direct, and only effective, means of reducing COTS densities and improving hard coral cover currently available at a site. We provide recommendations for improving control program effectiveness with application to supporting reef resilience across the Indo-Pacific.

Item ID: 63922
Item Type: Article (Research - C1)
ISSN: 2045-2322
Keywords: conservation biology, ecology, ocean sciences, tropical ecology
Copyright Information: © The Author(s) 2020. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.
Funders: National Environmental Science Programme (NESP)
Projects and Grants: NESP Tropical Water Quality Hub
Date Deposited: 04 Aug 2020 02:22
FoR Codes: 41 ENVIRONMENTAL SCIENCES > 4104 Environmental management > 410404 Environmental management @ 60%
31 BIOLOGICAL SCIENCES > 3103 Ecology > 310305 Marine and estuarine ecology (incl. marine ichthyology) @ 40%
SEO Codes: 97 EXPANDING KNOWLEDGE > 970106 Expanding Knowledge in the Biological Sciences @ 40%
96 ENVIRONMENT > 9604 Control of Pests, Diseases and Exotic Species > 960407 Control of Pests, Diseases and Exotic Species in Marine Environments @ 60%
Downloads: Total: 955
Last 12 Months: 32
More Statistics

Actions (Repository Staff Only)

Item Control Page Item Control Page