Coral growth, survivorship and return-on-effort within nurseries at high-value sites on the Great Barrier Reef

Lorna Howlett; Emma F Camp; John Edmondson; Nicola Henderson; David J Suggett

doi:10.1371/journal.pone.0244961

Coral growth, survivorship and return-on-effort within nurseries at high-value sites on the Great Barrier Reef

PLoS One. 2021 Jan 11;16(1):e0244961. doi: 10.1371/journal.pone.0244961. eCollection 2021.

Authors

Lorna Howlett^{1

2}, Emma F Camp¹, John Edmondson², Nicola Henderson¹, David J Suggett¹

Affiliations

¹ Climate Change Cluster, Faculty of Science, University of Technology Sydney, Ultimo, NSW, Australia.
² Wavelength Reef Cruises, Port Douglas, QLD, Australia.

Abstract

Coral reefs are deteriorating worldwide prompting reef managers and stakeholders to increasingly explore new management tools. Following back-to-back bleaching in 2016/2017, multi-taxa coral nurseries were established in 2018 for the first time on the Great Barrier Reef (GBR) to aid reef maintenance and restoration at a "high-value" location-Opal Reef-frequented by the tourism industry. Various coral species (n = 11) were propagated within shallow water (ca. 4-7m) platforms installed across two sites characterised by differing environmental exposure-one adjacent to a deep-water channel (Blue Lagoon) and one that was relatively sheltered (RayBan). Growth rates of coral fragments placed onto nurseries were highly variable across taxa but generally higher at Blue Lagoon (2.1-10.8 cm2 month-1 over 12 months) compared to RayBan (0.6-6.6 cm2 month-1 over 9 months). Growth at Blue Lagoon was largely independent of season, except for Acropora tenuis and Acropora hyacinthus, where growth rates were 15-20% higher for December 2018-July 2019 ("warm season") compared to August-December 2018 ("cool season"). Survivorship across all 2,536 nursery fragments was ca. 80-100%, with some species exhibiting higher survivorship at Blue Lagoon (Acropora loripes, Porites cylindrica) and others at RayBan (A. hyacinthus, Montipora hispida). Parallel measurements of growth and survivorship were used to determine relative return-on-effort (RRE) scores as an integrated metric of "success" accounting for life history trade-offs, complementing the mutually exclusive assessment of growth or survivorship. RRE scores within sites (across species) were largely driven by growth, whereas RRE scores between sites were largely driven by survivorship. The initial nursery phase of coral propagation therefore appears useful to supplement coral material naturally available for stewardship of frequently visited Great Barrier Reef tourism (high-value) sites, but further assessment is needed to evaluate how well the growth rates and survival for nursery grown corals translate once material is outplanted.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Anthozoa / growth & development*
Australia
Coral Reefs*
Costs and Cost Analysis
Environmental Restoration and Remediation* / economics
Environmental Restoration and Remediation* / methods
Tourism

Grants and funding

Essential funding for the work was provided from the AMP Foundation (Tomorrow Maker Award to DJS), “Future-proofing the Great Barrier Reef through climate change-resilient super corals”, and the Australian & Queensland Governments (“Solving the bottleneck of reef rehabilitation through boosting coral abundance: Miniaturising and mechanising coral out-planting” to DJS, EFC, JE). Additional contribution of EFC to manuscript writing and final preparation was through the University of Technology Sydney Chancellor’s Postdoctoral Research Fellowship and ARC Discovery Early Career Research Award (DE190100142). Wavelength Reef Cruises provided support in the form of salaries for authors JE and LH but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of these authors are articulated in the ‘author contributions’ section.