The stark possibility of a Hawaiʻi—and a planet—without living coral reefs became alarmingly real. Reefs, which support over 25 percent of all marine life, are vital ecosystems that provide food, shelter, and breeding grounds for countless species. Beyond their ecological importance, coral reefs protect shorelines and sustain fisheries, anchoring the livelihoods of millions. The loss of these reefs threatens biodiversity, coastal communities, and economies worldwide.
Global coral bleaching events are becoming more frequent and severe. In 2023, NOAA confirmed the fourth such global event on record, the second in just a decade. As of 2024, an estimated 50 percent of the world’s coral reefs are dead, and experts warn that up to 90 percent could vanish within the next few decades if urgent action is not taken.
Since 2023, mass bleaching has been reported across tropical regions, including Florida, the Caribbean, Brazil, Mexico, and Central America, as well as in Australia’s Great Barrier Reef and vast stretches of the South Pacific—spanning Fiji, Vanuatu, Tuvalu, Kiribati, Samoa, and French Polynesia. The Red Sea, Persian Gulf, and Indian Ocean basin have also experienced widespread bleaching. Driven by warming seas, these events underscore the global scope of the crisis.
The death of coral reefs has profound implications for economies, livelihoods, food security, and more. Without reefs, entire marine ecosystems and fisheries are at risk. Coastal communities may be forced to abandon their homes as waves and rising sea levels batter shorelines unprotected by reefs. Despite the urgency of the crisis, reef restoration efforts remain slow, labor-intensive, and expensive, unable to keep pace with the rapid degradation of these vital ecosystems.
The End of Reefs as We Know Them
Scientists and engineers are rising to the challenge of climate-driven reef loss. In Hawaiʻi, researchers have developed an innovative and efficient method to restore and create coral reef habitats by designing in situ nurseries that grow corals and revitalize critical marine ecosystems referred to as “Meta-Reefs”. Unlike traditional approaches that rely on expensive, land-based labs to grow corals in tanks, Hawaiʻi’s novel strategy utilizes at-sea coral nurseries. These nurseries employ the latest advancements in AI-assisted 3D printing, submerged low-crested structure (LCS) design, and coastal engineering.
Oceanit’s Resilient and Sustainable Engineering (RiSE) team is pioneering these methods off the shores of Oahu’s iconic Waikīkī Beach, creating a playbook for global coastal restoration.
The RiSE team is perfecting in situ coral nursery engineering by designing structures from modular units akin to LEGO sets. These modules, 3D-printed from reclaimed concrete materials, individually as well as when combined, mimic the shapes and forms of natural reefs. Each module is printed with holes and overhangs to attract fish and other marine life, and they can be configured in various designs to suit specific sites. Once deployed at carefully selected nearshore locations, these modules form a foundation for young corals to grow and thrive. This biomimetic approach supports marine habitat restoration and establishes new reefs.
Visualization of modular coral nursery 3D-printed with concrete.
By utilizing at-sea nurseries, corals can grow faster and more affordably than in lab settings. These corals are then transplanted to dying reefs or left on the nursery modules to form permanent habitats for marine life. In doing so, Hawaiʻi aims to restore its reefs to their former vitality, ensuring they remain a precious resource for people and wildlife alike. Healthy reefs have long been the backbone of Hawaiʻi’s local economy, supporting tourism, fishing, and recreation while fostering a vibrant marine ecosystem.
Oceanit’s RiSE team mission is to be leaders in restoring the planet’s severely degraded coral reefs, starting in Hawaiʻi, by establishing many permanent in situ coral nurseries. In collaboration with local and national stakeholders, two nurseries are currently under development, each spanning 100 feet by 100 feet on bare rock seafloor approximately three-quarters of a mile off Waikīkī Beach. Deployment of these modular nurseries is slated for 2025.
Oceanit will oversee the implementation and deployment of the first in situ nurseries and is currently conducting engineering assessments in Waikīkī.
From Hawai’i to the World
This groundbreaking approach has the potential to scale beyond Hawaiʻi, serving as a model for coral habitat restoration in tropical regions worldwide. The U.S. National Oceanic and Atmospheric Administration (NOAA) is already exploring ways to adapt Hawaiʻi’s methods for use in Florida and Puerto Rico. The techniques refined in Hawaiʻi—including coral nursery design, 3D module printing, environmental assessments, engineering and construction practices, and installation strategies—could guide similar projects across the globe.
Since the 1980s, Oceanit has been at the forefront of coastal engineering and shoreline resilience, coral restoration, reef habitat construction, and coastal erosion mitigation. The organization has partnered with entities such as the Defense Advanced Research Projects Agency (DARPA) on project CORAL: Carbon-negative Ocean Reef for Aquatic Life.
