Heron Island and One Tree Island, The Great Barrier Reef

Name of case study

Heron Island and One Tree Island, The Great Barrier Reef

Location

  • Queensland
  • Australia

Year

2016

Scale

Urban/landscape scale

Area / size

4 (2 X 2) sqm plots

NbS employed

Coral reseeding

Type of NbS

  • Engineered intervention
  • Ecosystem restoration

Initiator

  • Professor Peter Harrison
  • Southern Cross University 

Funder

Great Barrier Reef Marine Park Authority (GBRMPA) and Queensland Parks and Wildlife Service (QPWS)

Budget

unknown

Design group

Southern Cross University, James Cook University, University of Technology Sydney, the Great Barrier Reef Marine Park Authority, Queensland Parks & Wildlife Service, as well as other key industry partners.

Fig. 1: P. Harrison – Harrison and dela Cruz (2022). 2 × 2 m underwater mesh enclosures on coral patches in the Heron Island reef lagoon. CC BY-NC V4.0.
Climate change benefits
  • Biomass cover loss
  • Increased temperatures
  • Loss of ecosystem services. 
Societal/socio-cultural benefits
  • Biodiversity health and conservation
  • Climate change adaptation
  • Disaster risk reduction
  • Economic and social development
Ecological benefits
  • Aesthetic value / artistic inspiration
  • Genetic resources (diversity)
  • Species maintenance
  • Education and knowledge
  • Habitat provision
  • Recreation and Tourism.

Summary of case study

The Great Barrier Reef (GBR), located off the coast of Queensland, Australia, is one of the most iconic and diverse coral reef systems in the world. It supports over 1,500 species of fish, 400 types of coral, and six species of sea turtles. The reef also provides a habitat for sharks, dolphins, whales, and other marine mammals. It has faced significant threats in recent years, including coral bleaching events caused by rising sea temperatures and overfishing. As estimated by Deloitte, the social, economic, and icon benefits of the Great Barrier Reef, Australia is US$56 billion and contributed US$6.4 billion to the Australian economy in 2015-2016 (nearly 90%, US$5.7 billion, of this economic contribution was from tourism) (O’Mahoney et al., 2017).  

Coral larval restoration, also known as larval reseeding, was conceived by Professor Peter Harrison of Southern Cross University when mass coral spawning was discovered on the Great Barrier Reef in the early 1980s. After the success of the initial reef-based coral larval rearing and deployments in the Philippines in 2013, an initial coral larval restoration experiment on Heron Island Reef in the Southern GBR was instigated. In this project, coral spawn from A. spathulata colonies was collected, and around 1 million larvae were grown in tanks at the Heron Island Research Station. The experiment tested different larval densities (Low, Medium, High, and Controls with no added larvae) on 2 × 2 m plots. Each of the 12 larval restoration plots was covered by mesh tents to transfer larvae (Harrison and dela Cruz, 2022). Further, in 2017, this method for supplying larvae on a larger scale to damaged reef patches was tested at sites with low coral cover on Heron Island Reef and One Tree Island Reef in the southern Great Barrier Reef. Over five years of monitoring, the number of new corals and their density in each treatment was directly related to the initial larval density and the larger corals were able to reproduce, completing the reef life cycle (Harrison and dela Cruz, 2022). Subsequently, the “Reef Restoration and Adaptation Program” (RRAP) was launched in 2019 aiming to enhance the resilience of the Great Barrier Reef by using various restoration techniques, including coral reseeding (Great Barrier Reef Foundation, 2018; Harrison et al., 2019). The RRAP involves collecting coral larvae and breeding heat-tolerant coral varieties in a laboratory setting. Further, they are settled onto reef areas that have been affected by bleaching (Great Barrier Reef Foundation, 2018). 


This project has contributed to the economic well-being of local communities, especially those dependent on activities like tourism and fisheries. Restored coral reefs provide essential habitats for fish and other marine species, contributing to sustainable fisheries. This, in turn, supports local food security and livelihoods that depend on fishing (McLeod et al., 2022). Coral reefs are biodiversity hotspots, and the reseeding project at Heron Island promotes the recovery and diversity of marine life. Healthy reefs support a variety of fish, invertebrates, and other organisms, contributing to the overall health of the local ecosystem (McLeod et al., 2022). This coral reseeding project serves as a valuable platform for scientific research. Monitoring the success of reseeding, studying coral growth, and assessing the health of restored reefs contribute to a better understanding of coral ecology and conservation strategies.

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References
  • Great Barrier Reef Foundation (2018). Biggest coral reseeding project deployed as Great Barrier Reef spawns. https://barrierreef.org/news/news/biggest-coral-reseeding-project-deployed-as-great-barrier-reef-spawns. Accessed on 15/12/2023.
  • Harrison, P. L., dela Cruz, D. W., Cabaitan, P., Cameron, K., Ligson, C., Horan, K., Gomez, E., Gomez, R., Abrina, T., Boulotte, N. and Bennett, J (2019). Restoring damaged coral reefs using mass coral larval reseeding. Report to Australian Centre for International Agricultural Research, 55 pages.
  • Harrison, P. L., & dela Cruz, D. (2022). Methods for restoring damaged reefs using coral larval restoration. Southern Cross University Technical Report 2022. DOI: https://doi.org/10.25918/report.233
  • McLeod IM, Hein MY, Babcock R, Bay L, Bourne DG, Cook N, et al. (2022) Coral restoration and adaptation in Australia: The first five years. PLoS ONE 17(11): e0273325. https://doi.org/10.1371/journal.pone.0273325.
  • O’Mahoney, J., Simes, R., Redhill, D., Heaton, K., Atkinson, C., Hayward, E., & Nguyen, M. (2017). At what price? The economic, social and icon value of the Great Barrier Reef.

Further resources

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