They may seem like nothing more than lifeless, immobile rocks. But these tiny creatures, no bigger than the tip of your finger, build the largest animal structures on Earth — visible even from space! Coral reefs, the « rainforests of the sea, » cover less than 1% of the ocean floor but host more than a quarter of all marine life, protect over a quarter of coastal infrastructure, and provide services valued at nearly 10 trillion dollars per year.
Under perfect conditions, researchers believe coral reefs could live forever. But today, we are on track to lose up to 90% of them by 2050 — and possibly all coral reefs by the end of the century.
This article highlights four initiatives endorsed by the United Nations Decade of Ocean Science for Sustainable Development 2021-2030 (the “Ocean Decade”) that are leading innovative solutions through science, technology, financing mechanisms, and community engagement to conserve and restore these “bustling underwater cities.”
Professor John Charlie Veron has spent his life beneath the waves. A pioneer of coral science, he once described the Great Barrier Reef as a “world beyond imagination.” Now 80 years old, with decades of diving behind him, Charlie has seen many changes since those early days. “My heart is broken to see the Great Barrier Reef now because it is nothing like what it was.”
On the other side of the world, marine biologist John Christopher Fine, during his time in the Cayman Islands, discovered a similar story unfolding underwater: “Huge heads of stony corals were dead, and algae and gorgonians were growing over mounds of dead coral.”
From the Pacific to the Caribbean, warming waters, pollution, ocean acidification, overfishing, and physical destruction are killing one of the planet’s richest and most biologically productive ecosystems every day. Saving reefs requires combining the best scientific innovation with well-funded, well-designed, and rapidly executed strategies backed by political and social commitments. This type of action is gaining momentum globally. Last June, the 2025 United Nations Conference concluded with a strong call from 11 world leaders to prioritize resilient reef systems in national policies and integrate reef protection into climate and biodiversity roadmaps.
The four successes below show how the Ocean Decade is crafting a survival plan for coral reefs, from mobilizing funds to engaging local communities.
Have you ever imagined 2,500 New York subway cars or a Boeing 747 resting on the seafloor? Or wondered why huge blocks of concrete are deliberately thrown into the ocean?
These structures are used to restore damaged marine ecosystems and encourage repopulation or create new ecosystems where none existed before.
With its 3D Purpose Built Reefs for Marine Restoration project (Coast3D Reefs), Coastruction perfects 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 Lake Oostvoornse, 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 integrated shelters, they are designed to boost biodiversity and coastal resilience.
In early 2025, the project reached a major milestone with the installation of three custom 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, divers used a small boat, throwing components overboard and assembling them directly on the seabed.
Coastruction founder Nadia Fani has 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 toward a more sustainable and circular use of raw materials for the good of our environment.”
Each Coastruction creation is specifically designed for its target ecosystem and closely monitored. Coastruction aims to revolutionize the conservation and restoration of marine life, offering a holistic 360° solution for artificial reefs and coastal installations.
Reef Recovery 2030: generating science to save the Great Barrier Reef
Bigger than the UK, 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 coral types, 1,500 fish species, and 4,000 mollusc types. But this vast ecosystem is in crisis: since 1995, the reef has lost over half its coral cover, with ocean warming taking a devastating toll.
Reef Recovery 2030 — led by the Great Barrier Reef Foundation, a member of the Ocean Decade Alliance — aims not only to restore the reef but to build a global blueprint for coral reef conservation. Over 350 scientists are involved in this R&D effort, the world’s largest to protect an ecosystem from climate change impacts.
Researchers have developed techniques to grow coral larvae and deploy them en masse using innovative seeding methods. One such technique, Coral IVF, involves collecting coral spawn from healthy reefs and raising millions of baby corals in specially designed floating pools and tanks. These pools encourage higher fertilization rates. Once mature, the corals are delivered to damaged reefs where they can attach and grow.
Corals depend on beneficial bacteria to thrive, much like humans. But stress can disrupt this fragile balance. Research supported by the initiative shows corals can be given probiotics to improve their health and resilience to climate stresses like rising water temperatures.
But long-term success depends not only on lab innovation; it also requires the knowledge, leadership, and experience of those who have cared for these ecosystems for generations.
Great Barrier Reef Foundation Managing Director Anna Marsden says Traditional Owners are central to conservation efforts. “We know genuine co-design and partnerships with Traditional Owners and Reef communities result in better, stronger, and more lasting outcomes. It’s vital to weave innovative science with ancient wisdom, and we’re grateful that Reef Traditional Owners continue to generously share their knowledge to protect our iconic Reef.”
Global Fund for Coral Reefs: turning coral reefs into a decisive climate investment
Many of the world’s key reef systems are in countries facing steep barriers to climate finance due to debt burdens and high risk. 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), UN Environment Programme (UNEP), and UN Development Programme (UNDP), unlocks funding via a blended investment approach to “protect-transform-restore-recover,” focusing on vulnerable regions. This means layered interventions addressing multiple causes of reef degradation, from global to local, direct to indirect.
By the end of 2024, GFCR was active in over 20 reef nations, backing more than 150 reef-positive enterprises and financial solutions. These include sustainable fisheries, eco-tourism, reef restoration, and marine protection innovations. The investments have improved the livelihoods of over 30,000 people, nearly half of new jobs filled by women. Overall, more than 4.15 million people have benefited through better food security, ecosystem services, and economic resilience.
“In addition to being critical ecological treasures, coral reefs are economic lifelines for millions,” said Susan Gardner, Director of UNEP’s Ecosystems Division. “By positioning them as smart, sustainable investments, GFCR channels finance to achieve global impact, supporting vulnerable communities on nature loss and climate change frontlines.”
Today, reef-positive projects supported by GFCR cover 4% of the world’s remaining coral reefs and safeguard over 10.88 million hectares of marine and coastal areas.
Seatrees: community-powered coral reef restoration
Citizen science takes many forms — coral planting, reef monitoring, predator removal, photogrammetry, education, and coordinating local conservation. This democratizes marine science by turning observers into active participants, building local knowledge and strengthening community bonds with the ocean.
The Ocean Decade project Seatrees focuses on community-led coral restoration, empowering locals to protect ecosystems sustaining their lives.
In partnership with Samsung, Seatrees combines mobile innovation, marine science, and community action. Using Samsung smartphones and advanced imaging, scientists and local conservationists monitor coral health with precision. Samsung’s Ocean Mode app, developed by the Center for Health Design at UC San Diego, replaces bulky underwater cameras, making reef tracking more accessible even in remote areas.
At restoration sites in Fiji, Indonesia, and Florida, over 11,000 coral fragments were planted in the first year alone. In Florida, 3,000 additional micro-fragmented corals are grown in tanks until strong enough for planting in the wild. To date, Seatrees projects, including those supported by Samsung, have restored more than 10,000 square meters of damaged coral reefs worldwide. Direct predator control efforts have removed over 2,300 crown-of-thorns starfish, giving young corals a better chance to survive.
“Local communities are not just participants, they are the driving force behind our restoration efforts,” said Michael Stewart, Seatrees co-founder. “By providing tools, training, and technology, we are turning coral restoration into a scalable global movement rooted in local leadership, capable of regenerating reef ecosystems worldwide.”
The challenges facing coral reefs demand urgent, coordinated action. The Ocean Decade provides a vital framework to align scientific research, funding, and policy to protect these ecosystems, which are integral to marine life and human communities around the world.
