Hope for Hawaiʻi’s Coral Reefs: December Action Reattaches Coral Fragments After Large Winter Surf at Kahuwai Bay on Hawaiʻi Island

In a hopeful action closing out 2025, scientific divers, community members, snorkelers and boat crews carefully recovered and reattached 313 ko‘a (coral) colonies that had been broken or overturned in Kahuwai Bay on Hawaiʻi Island. The work took place in early December and focused on stabilizing coral as close to its original location as possible, helping give it the best chance to recover and continue supporting the health of the reef.

A large north swell in November caused extensive damage, breaking off large pieces of coral. When this happens, the detached pieces often die and the remaining reef structure tends to erode faster. Coral fragments—sometimes called “corals of opportunity”—can be replanted onto the reef using epoxy, cement or other non-toxic underwater adhesives.

Reattaching and stabilizing the fragments dramatically increases their chances of survival and regrowth and prevents them from rolling around on the sea floor, where they can cause further reef damage.

“I think what made this event special is also what created Hui Kahuwai, a group of people who have long been tended by this place, and are tending this place, coming together,” said Kaikea Nakachi, Board Vice President for Hui Kahuwai, the community-based nonprofit organization that leads stewardship in the area. “This is just the latest iteration of the place calling us together to care for our home.”

This work is an extension of Kanu Ko‘a, a project launched in 2023 within the ahupuaʻa of Kaʻūpūlehu that integrates Hawaiian culture, local community and the science of coral restoration to accelerate coral reef growth and recovery. Kahuwai Bay sits within a broader landscape shaped by decades of community-led stewardship, including the Try Wait fishing rest period for the Kaʻūpūlehu Marine Reserve which is helping to restore abundance for food security and reef health.

The quick action to reattach the coral was taken by the Hawaiʻi Emergency Reef Restoration (HERR) Network, a coalition facilitated by The Nature Conservancy (TNC) that enables rapid response by local partners, including the Division of Aquatic Resources (DAR) and National Oceanic and Atmospheric Administration (NOAA), trained in damage assessment and coral reattachment techniques. Once coral fragments break off, they only survive a handful of weeks, so this preparedness is vital. The HERR Network, enabled by Hawaiʻi’s reef insurance policy, is prepared to respond to disasters as well as restoration opportunities like this one.

Already, HERR teams have reattached hundreds of large coral pieces—some the size of basketballs—at sites like Kewalo Basin on Oʻahu and on Hawaiʻi Island. These coral rescue and repair efforts reflect the values of kilo (observation), shared kuleana (responsibility), and the reciprocal relationship to mālama (care for) place embraced by Hui Kahuwai, TNC and all HERR partners.

“Reef restoration is not a one-and-done fix. It is mālama ʻāina, a commitment to stewardship,” said Julia Rose, Coral Restoration Program Manager at The Nature Conservancy, Hawaiʻi and Palmyra. “While our reefs face mounting pressures, reducing physical damage is something we can act on now to give them a fighting chance. We are deeply grateful to the Kaʻūpūlehu community and leaders, our incredible volunteers and crews on and off the water, and our partners at DAR and NOAA for making this work possible.”

Hawaiʻi’s coral reefs are under increasing pressure from sediments, land-based pollutants, overfishing and climate change impacts, including rising sea levels and water temperatures, which are expected to intensify in coming years. Scientists estimate that live coral cover in at least some areas of Hawai‘i has declined by 60% over the past several decades. Reducing the impacts of local and global threats is critical to the survival of coral reefs.

Kaʻūpūlehu was prioritized for restoration through a statewide planning process because it is a healthy, well-managed area where restoration is likely to succeed. Kahuwai Bay has few land-based pollution sources and is in a sheltered location that is less likely to experience severe storm damage.

All work with ko‘a is being conducted under a permit with the State Division of Aquatic Resources and required NOAA permits, as applicable. 

About Hui Kahuwai

Hui Kahuwai is a community-led non-profit (501c3) organization, formed by the Ka‘ūpūlehu Marine Life Advisory Committee (KMLAC) in 2023, to implement the stewardship strategies to care for the natural and cultural resources at Ka‘ūpūlehu and Kūki‘o. To learn more, visit huikahuwai.org or @huikahuwai on Instagram.