Assessment of Reef Restoration Techniques in West Hawai‘i
This study evaluated four coral restoration techniques at two environmentally distinct sites along the west coast of Hawai‘i Island. The findings provide practical guidance for optimizing reef restoration success while maximizing the benefit of restoration investment and underscore the importance of tailoring restoration strategies to the local context in Hawai‘i and beyond.
Subject Tags
- Climate resilience
- Reefs
- Climate adaptation
Introduction
This technical report evaluates coral restoration techniques in West Hawai‘i through a pilot study conducted at Kahuwai Bay and Kealakekua Bay. The study compares four restoration approaches: direct reattachment of whole Porites lobata colonies, fragment arrays, nursery-grown fragments, and direct outplanting of Pocillopora meandrina. Monitoring over approximately one year assessed coral survival and growth using photogrammetry and in-water surveys. Results showed higher survival and better reef condition at Kahuwai Bay, with fragment arrays achieving up to 100% survival and colony reattachment reaching 94%. Kealakekua Bay exhibited lower survival rates, influenced by environmental stressors such as sedimentation and predation. Cost-benefit analysis identified direct reattachment as the most cost-effective method, significantly outperforming other techniques. The study highlights the importance of site-specific conditions, demonstrating that restoration outcomes depend on local environmental factors, species traits, and technique selection, providing practical guidance for optimizing coral restoration in Hawai‘i.
Suggested Citation
Grady, B., Barnwell, M., Rose, J., Humphreys, E., Conklin, E., & Pollock, F.J. 2025. Assessment of Reef Restoration Techniques in West Hawai‘i. The Nature Conservancy. Honolulu, HI. 22 pp.
TNC Authors
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Bryant Grady
Marine Data and Restoration Project Manager
The Nature Conservancy
Email: bryant.grady@tnc.org -
Mikayla Barnwell
Coral Restoration Specialist
The Nature Conservancy
Email: mikayla.barnwell@tnc.org -
Julia Rose
Coral Restoration Program Manager
The Nature Conservancy
Email: julia.rose@tnc.org -
Eric Conklin
Marine Science Director, Hawai‘i and Palmyra
The Nature Conservancy
Email: econklin@tnc.org
TNC Authors
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F. Joseph Pollock
Senior Reef Strategy Lead
The Nature Conservancy
Email: joseph.pollack@tnc.org