This article was originally shared by the Ocean Decade

They may seem like nothing more than still, lifeless rocks. But these tiny creatures, no bigger than your fingertip, are building the largest animal-made structures on Earth, visible even from space! Coral reefs, the “rainforests of the sea,” cover less than 1% of the ocean floor but support over a quarter of all marine life, protect over a quarter of coastal infrastructure, and provide services worth nearly US$10 trillion a year.

Under perfect conditions, researchers believe they could live forever, but today we’re on track to lose up to 90% by 2050, and possibly all coral reefs by the end of the century.

In this article, we highlight four initiatives endorsed by the UN Decade of Ocean Science for Sustainable Development 2021-2030 (‘Ocean Decade’) that are pioneering innovative solutions through science, technology, funding mechanisms, and community engagement to conserve and restore these “busy underwater cities.”

Professor John Charlie Veron has spent a lifetime beneath the waves. A pioneer in coral science, he once described the Great Barrier Reef as a “world beyond imagination.” Now in his 80s, with decades of diving behind him, Charlie has seen a lot of changes since those early days. “My heart breaks to see the Great Barrier Reef now because it is nothing like it used to be.” Half a world away, marine biologist John Christopher Fine, during his stay in the Cayman Islands, finds a similar story unfolding underwater: “Huge heads of stony coral were dead, and algae and gorgonian seafans grew on mounds of dead coral.”

From the Pacific to the Caribbean, warming waters, pollution, ocean acidification, overfishing, and physical destruction are killing one of the most biologically rich and productive ecosystems on earth every day. Ways to save the reefs combine the best scientific innovation with a well-funded, well-designed, and rapidly executed strategy with political and social commitments. Momentum for this kind of action is building on the global stage. Last June, the 2025 United Nations Conference concluded with a strong call from 11 global leaders to prioritize resilient reef systems in national policies and to incorporate reef protection into climate and biodiversity roadmaps.

The four success stories below highlight how the Ocean Decade is designing a blueprint for coral reef survival from the mobilization of funding to the engagement of local communities.

Coast3D Reefs: How 3D printing is reviving the ocean’s key ecosystems

Have you ever imagined 2,500 New York City subway cars or a Boeing 747 resting on the seafloor? Or wondered why massive concrete blocks are being deliberately tossed into the ocean? These structures are being used to restore damaged marine ecosystems and encourage repopulation or to create new ecosystems in areas where none previously existed.

With its project 3D Purpose Built Reefs for Marine Restoration (Coast3D Reefs), Coastruction is perfecting this approach by creating a symbiosis between nature and technology. Working closely with local communities and environmental experts, Coastruction designs 3D-printed reef modules tailored to specific species and environments, using local materials like recycled concrete or beach sand.

In the Netherlands, over 100 reef units were given a second life in Oostvoornse Lake, forming the new “Goby Reef.” Inspired by Pacific atolls and tested in wave simulations at Deltares, the structures now sit 4 to 6 meters deep, attracting mussels, algae, and fish. With porous surfaces and built-in shelter spaces, they’re designed to boost biodiversity and coastal resilience.

In early 2025, the project marked a major milestone with the installation of three custom-designed reefs in the Red Sea. Each reef, standing 1.7 meters tall and covering 15 square meters, was carefully assembled underwater by a dive team and placed next to natural coral formations to support fish and coral repopulation. Thanks to a modular system designed and 3D printed for easy deployment, the divers were able to use just a small diving boat, throwing the components overboard and assembling them directly on the seabed.

Coastruction founder Nadia Fani always dreamed of making the world a more beautiful place. “As a mother, I believe we need to act now and change our attitude toward our oceans. We need to protect and restore what we have. That is why I work towards a more sustainable and circular way of using raw materials for the good of our environment.”

Each Coastruction creation is specifically designed for its target ecosystem and carefully monitored. Coastruction aims to bring a revolution in the approach to the conservation and restoration of marine life, while providing a holistic 360° solution for artificial reefs and coastal installation manufacturing.

Reef Recovery 2030: Generating science to save the Great Barrier Reef

Bigger than the United Kingdom, Switzerland, and the Netherlands combined, Australia’s Great Barrier Reef is one of the world’s natural wonders. Inscribed on UNESCO’s World Heritage List in 1981, it hosts the world’s largest collection of coral reefs, with 400 types of coral, 1,500 species of fish and 4,000 types of mollusc. But this vast ecosystem is in crisis: since 1995, the reef has lost more than half of its coral cover, with ocean warming taking a devastating toll.

Reef Recovery 2030 – led by the Great Barrier Reef Foundation, an institutional member of the Ocean Decade Alliance – aims not only to restore the reef but also to build a global blueprint for coral reef conservation. More than 350 scientists are involved in this R&D initiative, which is the world’s largest effort to protect an ecosystem from the impacts of climate change.

The researchers have already developed techniques to grow coral larvae and deploy them en masse through innovative seeding methods. One such technique is Coral IVF. The team collects coral spawn from healthy reefs and rears millions of baby corals in specially designed floating pools and tanks. These pools encourage higher fertilization rates, and once the corals are mature enough, they are delivered to damaged reefs where they can attach and grow.

Corals depend on friendly bacteria to thrive, much like we do. Yet in times of stress, this fragile balance can easily be thrown off. Research supported by the initiative has shown that corals can be given probiotics to improve their health and increase their resilience to climate-related stresses such as rising water temperatures.

But long-term success depends not only on innovation in the lab; it also requires the knowledge, leadership, and lived experience of those who have stewarded these ecosystems for generations.

Great Barrier Reef Foundation Managing Director Anna Marsden says Traditional Owners are at the heart of conservation efforts on the Great Barrier Reef. “We know that genuine co-design and co-delivery partnerships with Traditional Owners and Reef communities result in better, stronger and more enduring outcomes. It’s vital to weave together innovative science with ancient wisdom, and we’re grateful that Reef Traditional Owners continue to generously share their knowledge to help protect our iconic Reef.”

Global Fund for Coral Reefs: Turning coral reefs into a decisive climate investment

Many of the world’s most important reef systems are in countries that face steep barriers. These regions face steep barriers to accessing climate finance due to debt burdens and high-risk perceptions. As a result, the traditional global financial architecture often overlooks those most in need.

The Global Fund for Coral Reefs (GFCR) led by the UN Capital Development Fund (UNCDF), the United Nations Environment Programme (UNEP), and the United Nations Development Programme (UNDP), unlocks funding via a blended investment approach to ‘protect-transform-restore-recover,’ focusing on vulnerable regions. This means layered interventions to address the multiple drivers of degradation from global to local, and from direct to indirect causes.

By the end of 2024, GFCR was active in more than 20 reef nations, backing over 150 reef-positive enterprises and finance solutions. These range from sustainable fisheries and eco-tourism ventures to innovations in reef restoration and marine protection. The investments have directly improved the livelihoods of over 30,000 people, with nearly 50% of new jobs filled by women. In total, more than 4.15 million people have benefited through improved food security, ecosystem services, and economic resilience.

“In addition to serving as critical ecological treasures, coral reefs are economic lifelines for millions. By positioning them as smart, sustainable investments, the Global Fund for Coral Reefs is channeling finance  to achieve impact at a global scale, by supporting vulnerable communities on the frontlines of nature loss and climate change.” - Susan Gardner, Director, Ecosystems Division, United Nations Environment Programme.

Today, reef-positive initiatives supported by GFCR touch 4% of the world’s remaining coral reefs and help safeguard over 10.88 million hectares of marine and coastal areas.

Seatrees: Community-powered coral reef restoration

Citizen science can take many forms, from coral planting and reef monitoring to predator removal, photogrammetry, education, and coordinating local conservation efforts. This democratization of marine science turns passive observers into active participants, builds local knowledge, and strengthens the bond between communities and the ocean they depend on.

The Decade Project Seatrees focuses on community-led coral restoration, empowering local people to take charge of protecting the ecosystems that sustain their lives.

By joining forces with Samsung, Seatrees brings together mobile innovation, marine science, and community action to restore coral reefs. Using Samsung smartphones and their advanced imaging, scientists and local conservationists can now monitor coral health with precision. Samsung’s Ocean Mode app developed by the center for health design at UC San Diego, is replacing bulky, expensive underwater cameras, making professional-grade reef tracking more accessible even in remote areas.

Across restoration sites in Fiji, Indonesia, and Florida, over 11,000 coral fragments were planted in the first year alone. In Florida, an additional 3,000 microfragmented corals are being grown in tanks until they’re strong enough to be outplanted into the wild. To date, Seatrees projects, including those supported by Samsung, have helped to restore more than 10,000 square meters of damaged coral reefs worldwide. Direct predator control efforts have also removed more than 2,300 destructive Crown-of-Thorns Starfish, helping give young coral a fighting chance to survive.

“Local communities aren’t just participants – they’re the driving force behind our restoration efforts. By empowering them with tools, training, and technology, we’re turning coral restoration into a global movement, one that’s scalable, rooted in local leadership, and capable of regenerating reef ecosystems around the world.” - Michael Stewart, Co-Founder of Seatrees.

The challenges facing coral reefs demand urgent, coordinated action. The Ocean Decade provides a vital framework for aligning scientific research, funding, and policy to protect these ecosystems, which are integral to both marine life and human communities worldwide.

For more information, please contact:
Ocean Decade Communications Team ([email protected])

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