Global Coral Restoration Frontlines: Lessons and Practices from Singapore, the United States, and Bali, Indonesia

Coral reefs are often called the tropical rainforests of the ocean — critical habitats for global biodiversity that support the livelihoods and economic activities of hundreds of millions of people. Yet climate change, urbanization, overdevelopment, and pollution are accelerating their decline. According to United Nations reports, coral reefs worldwide face severe threats and could lose most of their functional value within the coming decades if decisive action is not taken.

The pre-symposium workshop of the 2025 Delta International Symposium on Coral Restoration (DISCR) brought together coral restoration case studies from five countries — Singapore, Florida in the United States, Bali in Indonesia, and Okinawa in Japan — to examine the current state and challenges of local reefs, restoration strategies, results achieved, and the critical role of community engagement. These cases demonstrate not only the power of science and innovation, but also that the involvement of local communities is the cornerstone of lasting success. The Editor has summarized three coral restoration cases to share with our readers, in the hope of rallying more people to care about marine biodiversity.

Singapore: Coral Restoration Under Urban Pressure

Over the past five to six decades, Singapore has undergone rapid urbanization, with its land area expanding by more than 20% since the 1950s. Busy port operations have taken over much of the coastline with wharves and dockyards. These developments have left Singapore's waters murky and sediment-laden, dealing severe blows to coral ecosystems. Sediment smothers coral and impedes its growth, while deteriorating water quality makes survival increasingly difficult. As a result, Singapore's coral reef area has shrunk by more than 60% since the 1950s, leaving only about 10 tidal zones — roughly the size of a single island.

To overcome these challenges, Singaporean scientists have adopted several innovative strategies. First, artificial reef structures have been deployed — including flower-shaped fiberglass modules designed with a tilt to prevent sediment accumulation and encourage coral attachment. Second, a vertical cultivation system has been established at the St. John's Island National Marine Laboratory, using fishing line and toy building blocks to grow coral fragments; a single tank can nurture 1,300 fragments, far surpassing the 300 possible with traditional methods. Once mature, corals are transplanted to shallow areas or low-coverage zones at depths of 6 to 7 m, secured with metal mesh frames. The "100,000 Corals Project" launched last year aims to transplant 100,000 coral fragments within ten years to enhance reef resilience.

The results have been impressive: within one year of deployment, coral begins growing on artificial reefs; after ten years, sexually mature colonies form, attracting fish and other marine life; after twenty years, the structures integrate fully into the natural ecosystem. Transplanted coral survival rates are high, and coverage is progressively improving.

Community engagement is a hallmark of Singapore's approach. Public surveys found that most people support restoration efforts and prefer stress-tolerant coral species. The project frames coral as a "public asset for all," inviting citizens to participate in cultivation and transplantation through education programs and corporate sponsorships, and fostering a sense of long-term commitment.

Florida, USA: Large-Scale Restoration in the Face of Severe Degradation

The Florida Reef Tract is the world's third-largest reef system, stretching 563 km. Historically, live coral coverage reached 40% to 60%, supporting 70,000 jobs in South Florida and generating billions of dollars in economic value. Over the past half-century, however, the effects of climate change, disease, and erosion have reduced coverage to under 2%. In the past 17 years, nearly one-third of a metre of reef surface has been lost to erosion, threatening both the ecosystem and coastal protection.

Restoration teams are responding with a diverse set of approaches, including establishing three land-based and four offshore nurseries, with plans to add more. Over the past 15 years, more than 250,000 coral fragments have been transplanted. Heat-tolerant and disease-resistant genotypes are selected, and assisted reproduction and inter-site hybridization are carried out to boost genetic diversity. Herbivorous marine life — including the Caribbean King Crab (Maguimithrax spinosissimus) and the Long-spined Sea Urchin (Diadema setosum) — has been introduced to reduce algal competition. Trials showed that within 10 months, algal coverage dropped by 85%, fish abundance increased three to five times, and juvenile coral density doubled.

Our restoration work relies on large-scale monitoring and data analysis. Through wide-area imaging technology, we collect vast ecological datasets. Combined with genetic tracking and coral cultivation pipelines, we have developed digital tools to manage coral inventories and transplantation workflows. The application of artificial intelligence, machine learning, and machine vision not only optimizes restoration strategies, but also helps us predict the best transplantation sites and timing to ensure long-term outcomes.

Bali, Indonesia: Community-Led Restoration in a Biodiversity Hotspot

Bali lies within the Coral Triangle — a region spanning six countries that is home to more than 600 coral species and 3,000 fish species, supporting the livelihoods of 150 million people. Overfishing, destructive fishing practices, and tourism pressure have led to degradation, with low coral diversity and intense algal competition inside marine protected areas.

Our coral restoration program centers on Bali's marine protected areas — in particular, Nusa Penida, a mecca for divers. We employ a zone management strategy: brown zones allow fishers to use non-destructive fishing methods, while blue zones are restricted to tourism activities. This approach combines protected area management with coral restoration to accelerate ecological recovery.

Since 2015, we have partnered with local communities, using concrete modules and mesh structures for coral restoration. After three years, coral growth was healthy but species diversity remained low, with most being branching corals. These structures were heavy and time-consuming to deploy, prompting us to seek simpler methods. In 2021, we collaborated with two organizations to develop the "Reef Star" module — a lightweight hexagonal steel frame structure that is easy to deploy and can stabilize rubble on the seabed, promoting coral attachment and growth.

To ensure the sustainability of the program, we have developed an innovative financing model. Tourists pay US$25 to plant coral, with US$20 going toward community maintenance, generating US$100,000 in economic benefits. Outcomes include: 600 structures deployed, 7,000 fragments planted, and a one-year monitoring report showing a 35% growth rate for branching corals. A network linking 21 organizations shares experiences. Online courses and exhibitions have been developed; school children, fishers, and dive operators are invited to participate, integrating the program into tourism business operations to form a sustainable model.

Community Engagement: The Key Driver of Coral Restoration

Community engagement is indispensable to successful coral restoration. It provides not only human resources and local knowledge, but also ensures the long-term continuity of any program. Singapore leverages public surveys and education to frame coral care as a civic responsibility, inviting people to participate in cultivation and transplantation. Florida uses therapeutic programs to engage veterans and trains divers, while working with aquariums to disseminate knowledge. Bali, Indonesia, employs innovative financing and networking to train residents, children, and operators, embedding restoration within both the economy and education to create jobs and share expertise. These approaches prove that community empowerment can transform challenges into opportunities and strengthen ecological resilience.

Conclusion: Facing Global Challenges Together

Coral reefs will face increasingly severe threats from climate change, acidification, and pollution, with profound implications for global marine biodiversity and human well-being. Without action, it is estimated that 90% of coral reefs could disappear by 2050. The 2025 Delta International Symposium on Coral Restoration, organized by Delta Electronics, is emerging as a critical hub connecting scientists, communities, governments, and businesses — key stakeholders sharing experiences, technologies, and resources to collectively advance global coral restoration. Through this platform, we not only protect local ecosystems but also breathe new hope into the world's oceans. Let us draw strength from these cases and take action together!

Further Links

• 2025 DISCR Delta International Symposium on Coral Restoration
• Delta Electronics Hosts Inaugural "International Coral Restoration Symposium," Targeting Conservation of 300 Coral Species Within Five Years

Further Reading