Project Completed by Gabrielle Rochon
Research Questions / Objectives
This project tested short-term survivorship and growth of two coral genera, Porites (“lobe corals”) and Pocillopora (“cauliflower corals”), following fragmentation and transfer to nursery tables in Maunalua Bay. The study addressed a major gap in Hawaiian restoration research, as most prior work has focused on Acropora species rather than the dominant reef-building corals of O’ahu. The primary research questions were:
- How does survivorship differ between Porites and Pocillopora fragments during the first three weeks post-fragmentation?
- What differences in growth trajectories occur between the two genera under identical nursery conditions?
- How can these results inform mixed-species restoration approaches for Maunalua Bay and other Hawaiian reefs?
Methods
Restoration efforts were conducted with community collaboration under the Hana Pūkoʻa initiative (“working together for coral”). The process included:
- Collecting corals of opportunity (naturally broken fragments) from Maunalua Bay, in partnership with the Department of Aquatic Resources.
- Stress testing and fragmenting colonies, then securing fragments to plugs with epoxy, in partnership with Hawaii Institute of Marine Biology.
- Fragmentation and attachment, where colonies were cut into smaller pieces, glued onto ceramic plugs, and stabilized with the participation of community members.
- Transfer to nursery tables, with two fabricated structures deployed in Maunalua Bay.
- Monitoring for three weeks, using routine counts of each fragment classified as Healthy, Partially Healthy, or Dead to track survivorship and early growth trends.
Results
Monitoring supported the initial hypothesis that Porites fragments would survive at higher rates than Pocillopora over the first three weeks post-fragmentation.
- Porites: Mean fragment area increased from 3.63cm² (Week 1) to 4.36 cm² (Week 3), showing consistent, moderate growth with low variability.
- Pocillopora: Mean area increased from 1.71cm² (Week 1) to 2.80cm² (Week 3), with faster but more variable growth and several extreme outliers.
- Both genera exhibited high survivorship during the initial three-week period, indicating strong early adaptation to nursery setting.
Significance
These results suggest Porites offers stability for restoration, while Pocillopora provides rapid reef-building potential despite higher variability. A mixed-species approach may therefore optimize resilience and growth. By generating the first short-term survivorship data for non-Acropora corals in O’ahu, this work helps fill a critical knowledge gap and offers practical guidance for scaling community-based nursery projects.
