Restoration alone isn’t saving coral reefs from climate change

Restoration of coral areas – which are under threat of bleaching – would benefit from better coordination, knowledge and data sharing, as well as from prioritising gravely affected coral areas over those that are more accessible, according to a new study published in the journal Nature Ecology and Evolution.

Carried out by the JRC, the University of Helsinki, Flinders University (AUS) and the University of Milan-Bicocca, the study reveals that, while coral restoration efforts are expanding globally, restoration alone is insufficient. Financial and logistical barriers, combined with climate change, limit the long-term goals of these efforts.

Coral reefs are not only one of the most biodiverse ecosystems on Earth, hosting 25% of marine biodiversity, they also provide countless and vital ecosystem services to around one billion people in terms of food supply (proteins), coastal protection and recreation. 

A shift in strategy is needed to ensure their survival.

Beyond restoration efforts, the study underscores the urgent need to tackle the root causes of coral reef degradation. Lasting solutions require action to curb global and ocean warming through carbon emission policies and to mitigate local threats by expanding protected areas and restricting destructive activities.

The limits of coral restoration

Efforts to restore coral reefs come with significant challenges. The study estimates that restoring just 10 % of the world’s degraded reefs would cost at least $1 billion (around €926 million) — almost four times the total investment made over the past decade. Even when restoration projects succeed, their benefits are often short-lived. 

The study shows that more than half (57 %) of restored reefs suffer bleaching events within five years of intervention, undoing long-term efforts and investments. Without addressing the root causes of coral decline, restoration will remain a temporary and small-scale solution.

Why current restoration efforts fall short

In the study, researchers assess the effectiveness of interventions by combining a comprehensive dataset documenting the success of coral restoration with current and forecasted environmental, ecological and climate data. 

Their analysis reveals that, despite significant past and ongoing coral restoration initiatives, there is still no well-coordinated, science-driven strategy to guide these efforts. In other words, restoration efforts are happening, but they do not seem to be systematically planned or properly informed by ecological and climate data.

A major issue is how restoration sites are chosen. Many projects focus on areas that are easy to access rather than on those that have the best chance of survival or are most in need of intervention. As a result, restored reefs are often located near human settlements, where they are more vulnerable to pollution and other human activities. 

Furthermore, future climate projections suggest that very few areas will remain immune to warming in the coming decades, raising concerns that restored reefs may not survive in the long term.

Another challenge is the lack of standardised data collection. Without a consistent way to measure success, it is difficult to identify which restoration techniques work best. This prevents researchers and conservationists from improving their methods and making smarter investments in coral reef recovery.

A holistic approach to reef conservation

Effective coral restoration must be integrated into a broader strategy that accounts for the complex factors affecting coral reefs. Achieving this requires global collaboration among scientists, policymakers and local communities to establish clear guidelines that consider ecological, environmental and socio-economic factors, which are currently not being taken into consideration. 

When selecting restoration sites, it is crucial to evaluate key factors such as proximity to large human settlements, the cumulative impacts of pollution and overfishing, and future climate conditions.

Enhancing data collection and sharing can also improve restoration success. Standardised monitoring would help conservationists learn from past drawbacks, but the lack of universal protocols remains a hurdle. A centralised, open-access database could consolidate diverse data, enabling better tracking, collaboration and data-driven decisions for improved outcomes.

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