Long-term survival of large relocated Porites colonies at the Cocos (Keeling) Islands
Joanna Buckee
A * and Craig Blount B
A Environmental and Conservation Sciences, Murdoch University, 90 South Street, Murdoch, WA 6150, Australia.
B Cardno (NSW/ACT) Pty Ltd., PO Box 19, St Leonards, NSW, Australia.
Pacific Conservation Biology 28(5) 455-456 https://doi.org/10.1071/PC21024
Submitted: 12 April 2021 Accepted: 9 August 2021 Published: 23 September 2021
© 2022 The Author(s) (or their employer(s)). Published by CSIRO Publishing. This is an open access article distributed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND)
Abstract
In August 2009, eight large Porites corals were relocated prior to dredging works at Cocos (Keeling) Islands. In March 2020, relocated colonies were found to have survived and grown, demonstrating that large Porites colonies growing on unconsolidated substrates can be relocated successfully if moved swiftly to a similar habitat to their source.
Keywords: bommies, coral conservation, coral transplantation, dredge management, Porites lobata.
Massive corals are considered more suited to relocation than other growth forms because they are less likely to be damaged in transit (Ammar et al. 2013); however, relocation of large massive coral colonies has only rarely been documented (Seguin et al. 2008). Here we report on the long-term survival (2009–2020) of large Porites corals which were relocated prior to dredging works at Cocos (Keeling) Islands in the Indian Ocean (12°12′S, 96°54′E).
The relocation of a number of coral ‘bommies’ was stipulated in the environmental management plan for a coastal development in the Cocos lagoon (GHD 2008). In August 2009, two Porites lobata and six Porites australiensis colonies, with diameters of 2–3 m, were relocated away from the dredge footprint to nearby similar habitat and depth (2–3 m below lowest astronomical tide). Colonies were naturally unattached to the sandy/coral rubble substratum, so no tools were required to detach colonies. Divers gently placed broad flat straps beneath the margins of each colony, which were then lifted by crane onto a barge (Fig. 1a) and transported around 50 m away from the edge of the area to be dredged. Colonies were moved one or two at a time to ensure they were emersed for less than 1 h, during which time they were shaded from the sun and kept wet using buckets of seawater.
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The relocated colonies were revisited in January 2016 and again in March 2020, more than 10 years after relocation. On both occasions, survival was found to be high, as indicated by the amount of live coral on each colony being qualitatively similar to that observed prior to relocation. Colony growth was evident in many of the corals (Fig. 1b, c). This report demonstrates that large Porites colonies growing on unconsolidated substrates can be relocated successfully with no long-term effects on survival if moved swiftly to similar habitats to their source.
Data availability
Data available on request to corresponding author.
Conflicts of interest
The authors declare that they have no conflicts of interest.
Declaration of funding
Coral translocation was funded by the Australian Government.
Acknowledgements
Permission for publication of this paper was obtained from the Department responsible for External Territories of Australia. All photographs taken by J. Buckee.
References
Ammar, MSA, El-Gammal, F, Nassar, M, Belal, A, Farag, W, El-Mesiry, G, El-Haddad, K, Orabi, A, Abdelreheem, A, and Shaaban, A (2013). Review: Current trends in coral transplantation – an approach to preserve biodiversity. Biodiversitas 14, 43–53.| Review: Current trends in coral transplantation – an approach to preserve biodiversity.Crossref | GoogleScholarGoogle Scholar |
GHD (2008) Rumah Baru-freight and passenger facilities, Cocos (Keeling) Islands. Environmental management plan. Report to the Attorney-General’s Department, November 2008. (GHD House: Perth, WA, Australia) Available at https://www.environment.gov.au/system/files/pages/f94cc97a-1dab-48f3-9d25-bd83b888cdc5/files/e2011-0048-environmental-management-plan.pdf
Seguin F, Le Brun O, Hirst R, Al-Thary I, Dutrieux E (2008) Large coral transplantation in Bal Haf (Yemen): an opportunity to save corals during the construction of a liquefied natural gas plant using innovative techniques. In ‘Proceedings of the 11th international coral reef symposium, Ft. Lauderdale, FL, USA, 7–11 July 2008.’ Available at https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.1045.2530&rep=rep1&type=pdf
