Hope Spot Champion Grantee Highlight: Kahaluʻu Bay

September 19, 2025

Header Image: Identifying Coral Species. Credit: The Kohala Center. 

Hānau ka ʻUkukoʻakoʻa, hānau kāna, he ʻĀkoʻakoʻa, puka 

Born was the coral polyp, born was the coral, came forth  

Article written by: Cindi Punihaole & Kathleen Clark – The Kohala Center.

The Kumulipo, a Hawaiian genesis chant, reveals to us that the coral polyp was the first  being born from the darkness. Koʻa (coral) is the ancestor from which all other life  followed. Koʻa spawning, an ancient process, connects us to the past. This year, as our  team diligently prepared for another opportunity to learn from this sacred process, we  opened ourselves to the limitless wisdom found in the winds, currents, tides, fish, coral,  and limu. Kahaluʻu holds all the answers we seek; it is our kuleana (responsibility) to  listen. 

For generations, the coral reef found at Kahaluʻu Bay has teemed with life. Hundreds of  cauliflower, mound, and lobe coral colonies blanket the reef, shaping vibrant  underwater ecosystems. These corals provided critical habitat and shelter for marine  life—like the endemic ʻāloʻiloʻi (domino damselfish)—while also offering natural  protection to the shoreline.

In 2015 and again in 2019, extreme marine heatwaves swept across the globe. In  Hawaiʻi, these unprecedented events caused widespread coral bleaching and mortality  throughout the pae ʻāina (archipelago). At Kahaluʻu, the loss was devastating: 90% of  the cauliflower coral colonies vanished. And with them, many species, including the  ʻāloʻiloʻi, disappeared too, losing one of their primary habitats. In addition to thermal stress, a suite of other chronic, synergistic stressors, meaning that their combined  effects are greater than the sum of their individual effects, include:  

• Overcrowding and coral trampling: Because of the high volume of visitors  compared to its size (over 400,000 visitors/year) and its ready accessibility, the  coral reef is subject to trampling by those who are unaware of the sensitive  nature of the ecosystem. During low tides, snorkelers and swimmers often stand,  kick, and walk on coral as they are unable to differentiate live coral from rock.  During high tides, snorkelers routinely kick up sediment with their flippers, which  suffocates the delicate corals in the bay.  
• Coastal inundation: Coastal development mauka (upland) from the bay has  increased bacteria, nitrogen, phosphorus, ammonia, and other chemical levels in  the bay’s waters. All of these stressors reduce the bay’s resilience to climate  change effects, including storm surges and sea-level rise, which erode the beach  area and compromise habitat preservation areas for sea turtles, monk seals,  birds, fish, and native marine plants.  
• Impaired water quality, sewage, and runoff: Human and animal waste,  fertilizer, pesticides, and other land-based sources of pollution enter the bay daily  through submarine groundwater discharge and shoreline springs, evidence of  which is reflected in the water quality testing for nutrient levels. Oxybenzone  concentrations were once measured over 262 times higher than the EPA  threshold. Many corals have seen documented decline in the absence of  bleaching events.  
• Climate change: Climate change is leading to increased frequency and  intensity of thermal stress events and ongoing sea-level rise. It is important for island communities to develop policies and implement strategies that reduce  vulnerability to natural hazards. Poor water quality makes corals less resilient to  thermal stress. 

After water temperatures cooled, we continued to spend countless hours in the bay,  observing and listening to the reef. Our kilo (intentional observation) revealed that,  amazingly, six colonies had survived. Their resilience inspired the idea of a rest period— a time for the bay to breathe, recover, and restore itself during one of the most sacred  and sensitive times: spawning. By minimizing stress and disturbance, we could give  these surviving corals the best chance to reproduce and pass on their resilience to  future generations. 

Working closely with the County of Hawaiʻi, the State Division of Land and Natural  Resources, community members, and local businesses, The Kohala Center successfully  advocated for a period of rest focused around the peak spawning period of cauliflower  coral. The first year, 2018, Kahaluʻu was gifted two half days of rest; since then we  have increased the rest period to nine full days. Part of the success of this rest period is  that our amazing ReefTeach volunteers help share information about the rest period  and the importance of this time with beachgoers and community members. 

The cauliflower coral spawning season begins in the spring and early summer when the  water temperature begins to warm. Our kilo has revealed a tight correlation with the pō  mahina (lunar phase). As the full moon begins to wane and set in the early morning  hours, the tide shifts from low to rising, we can predict that these corals will spawn  bringing forth the next generation of corals. Each year, our team of dedicated  ReefTeacher volunteers are trained in the cultural significance of koʻa spawning and  how to respectfully engage while monitoring this sacred event. In addition to the in-water observation team, we have volunteers at the entrances to the park sharing about the importance of spawning and how the rest period is such an important part of caring for Kahaluʻu.  

Since the first rest period in 2018, our team has spent countless hours in the water,  monitoring coral recruitment and growth. In that time, and especially in the last three  years, we have witnessed a remarkable transformation: thousands of new cauliflower  coral colonies have begun to settle and grow, healing and regenerating the reef.

In 2024 Kahaluʻu Bay, the 141st Mission Blue Hope Spot, received a generous Mission  Blue Grant of $20,000 to expand our stewardship work. From June 2024 to May 2025 we honed our ability to predict the spawning times for P. Meandrina corals during April May and worked with County and State agencies to allow for a nine-day coral spawning rest period at Kahalu’u Beach Park. This involved educating over 30,000 community members and island visitors about the significance of coral spawning, emphasizing the importance of a park closure to foster coral growth and the bay’s overall ecosystem health. Despite thermal stress and bleaching in the fall of 2024, during this spring closure we observed significant P. Meandrina coral spawning, in some colonies for the first time. During a subsequent survey we identified over 500 newly recruited P. Meandrina corals. 

These corals are once again providing critical habitats and protection to our coastal  shorelines. Allowing Kahaluʻu to rest during sensitive times such as spawning is a  powerful act of reciprocity: a way to give back to the bay that has nurtured us for eons. 

The Mission Blue grant also provided the opportunity to host a community talk story sharing the  significance of coral spawning, the current status of P.meandrina in Kahaluʻu Bay, the  importance of the rest period, and the positive changes observed over the past eight years. This rest period and resulting increase in coral growth and resilience would not be possible without grant opportunities like Mission Blue and ongoing support for the community, local businesses  and managing agencies trust in The Kohala Center’s long term commitment to caring for this cherished place. With the success of the cauliflower coral spawning rest period, our team is working to identify additional times of stress and sensitivity when the bay would benefit from additional rest and space to enhance its natural resilience.

Learn more about how you can support our work or become a ReefTeach volunteer www.kohalacenter.org