In recent decades, the transplantation of corals has been a primary focus of restoration strategies in areas where coral populations have declined [
1]. Although studies of hard coral (Hexacorallia: Scleractinia) transplantations are far more common, soft coral (Octocorallia: Alcyonacea) transplantation attempts are also promising [
2]. Soft coral aggregations provide an important habitat for fish and invertebrates in both temperate and tropical marine environments [
3,
4], and restoration of these habitats is important for maintaining regional biodiversity.
Port Stephens, a tidal estuary in northern New South Wales (NSW), Australia, is home to a diverse assemblage of filter-feeders, including the threatened soft coral
Dendronephthya australis. This soft coral has rapidly declined in the last 10 years [
5,
6], and is now listed as Endangered in NSW [
7].
Dendronephthya australis aggregations support unique faunal assemblages that include juveniles of the fishery—important pink snapper (
Chrysophrys auratus) and the Endangered White’s seahorse (
Hippocampus whitei) [
3,
8].
To assist the recovery of
D. australis, we are trialling laboratory rearing of cuttings (nubbins) with subsequent transplantation into suitable habitats. In the first trial, we recorded rapid colonisation of almost half (22) of the 48 nubbins by invertebrates. Within 24 h, two sponge decorator crabs
Hyastenus elatus (
Figure 1B) had colonised fragments. After 13 d, a species of ovulid (Ovulidae: Gastropda) (
Globovula cavanaghi) was found feeding on a nubbin. Two other species of ovulid (shown in
Figure 1A,D), the trochid gastropod
Astele scitula (
Figure 1C), and the heterobranch sea slug
Dermatobranchus sp. (
Figure 1D) were also found on nubbins within six weeks of deployment. These species are known to display a preference for soft coral habitats [
9,
10]. These preliminary results suggest great potential for
D. australis transplantation programs to have positive impacts on biodiversity within the Port Stephens estuary.
Author Contributions
Conceptualization, M.F.L., D.H., S.D.A.S. and T.R.D.; methodology, M.F.L.; software, M.F.L.; validation, M.F.L., D.H., S.D.A.S. and T.R.D.; formal analysis, M.F.L.; investigation, M.F.L.; resources, M.F.L. and D.H.; data curation, M.F.L.; writing—original draft preparation, M.F.L.; writing—review and editing, M.F.L., D.H., S.D.A.S. and T.R.D.; visualization, M.F.L.; supervision, D.H., S.D.A.S. and T.R.D.; project administration, M.F.L., D.H., and S.D.A.S.; funding acquisition, D.H., and M.F.L. All authors have read and agreed to the published version of the manuscript.
Funding
This research was funded by the NSW Department of Primary Industries (DPI), the Marine Ecology Research Centre, Southern Cross University, and the Australian Government Research Training Program Scholarship. Data collection was undertaken in accordance with NSW DPI permit: P01/0059(A)-4.0 and Marine Parks permit: PSGLMP 2018/10 and 2018/15.
Institutional Review Board Statement
Ethical review and approval were waived for this research, due to the study of invertebrates only.
Acknowledgments
We thank Christopher Westley and Gwenael Cadiou for their valuable assistance in the field. Many thanks also to Bennan Chen and Madeleine Tresselt for their help in the laboratory component of this study.
Conflicts of Interest
The authors declare no conflict of interest.
References
- Clark, S.; Edwards, A. Coral transplantation as an aid to reef rehabilitation: evaluation of a case study in the Maldive Islands. Coral Reefs 1995, 14, 201–213. [Google Scholar]
- Sella, I.; Benayahu, Y. Rearing cuttings of the soft coral Sarcophyton glaucum (Octocorallia, Alcyonacea): Towards mass production in a closed seawater system. Aquac. Res. 2010, 41, 1748–1758. [Google Scholar] [CrossRef]
- Poulos, D.E.; Harasti, D.; Gallen, C.; Booth, D.J. Biodiversity value of a geographically restricted soft coral species within a temperate estuary. Aquat. Conserv. 2013, 23, 838–849. [Google Scholar] [CrossRef]
- Epstein, H.E.; Kingsford, M.J. Are soft coral habitats unfavourable? A closer look at the association between reef fishes and their habitat. Environ. Biol. Fish 2019, 102, 479–497. [Google Scholar] [CrossRef]
- Harasti, D. Declining seahorse populations linked to loss of essential marine habitats. Mar. Ecol. Prog. Ser. 2016, 546, 173–181. [Google Scholar] [CrossRef]
- Larkin, M.F.; Davis, T.R.; Harasti, D.; Cadiou, G.; Poulos, D.E.; Smith, S.D.A. The rapid decline of an endangered temperate soft coral species. Estuar. Coast. Shelf Sci. under review.
- NSW Fisheries Scientific Committee. Fisheries Scientific Committee Determination for Cauliflower Soft Coral (Dendronephthya australis). Department of Primary Industries; 2021. Available online: https://www.dpi.nsw.gov.au/fishing/species-protection/threatened-species-list/endangered-species2/cauliflower-soft-coral (accessed on 14 February 2021).
- Harasti, D.; Martin-Smith, K.; Gladstone, W. Ontogenetic and sex-based differences in habitat preferences and site fidelity of White's seahorse Hippocampus whitei. J. Fish Biol. 2014, 85, 1413–1428. [Google Scholar] [PubMed]
- Davis, T.R.; Harasti, D.; Kelaher, B.; Smith, S.D.A. Spatial and temporal variation in subtidal molluscan diversity amongst temperate estuarine habitats. Mar. Ecol. 2017, 38, e12428. [Google Scholar] [CrossRef]
- Davis, T.R.; Harasti, D.; Smith, S.D.A. Responses of Dendronephthya australis to predation by Dermatobranchus sp. nudibranchs. Mar. Freshw. Res. 2018, 69, 186–190. [Google Scholar] [CrossRef]
| Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. |
© 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
