How Much Does Coral Restoration Really Cost?
As coral reefs continue to face mounting threats from climate change, restoration has become a vital tool in our conservation toolbox. However, restoring reefs at the scale needed to make a global difference isn’t just a biological challenge; it’s a financial one.
A new study led by researchers at Ocean Revive and KAUST explores a key question for the future of coral restoration: how cost-effective are current restoration methods, and where can we improve?
This comprehensive review breaks down the real-world costs of coral nurseries, outplanting techniques, and marine operations across different countries. By comparing labour-intensive and automated approaches, it offers practical insights to help make restoration more scalable and financially sustainable.
Key Takeaways
Restoring coral reefs is expensive, with the median cost per coral outplant estimated at around 10 USD
Ocean-based nurseries are generally cheaper than land-based ones, especially in low-income countries
Cleaning frequency dramatically affects cost in ocean-based nurseries
Outplanting costs vary by technique, with some methods being 10x more expensive than others
Automating processes could reduce costs in high-income nations, but may be difficult to implement in many regions
Standardised reporting is needed to improve transparency and guide smarter investments
Restoration Methods Compared in the Study
The study focused on comparing the two most common restoration pathways:
Coral Gardening (Asexual propagation)
Coral fragments are grown in nurseries before being transplanted back onto the reef. The study assessed both:
Ocean-based nurseries - such as low-tech rope nurseries, PVC coral tables, and floating structures
Land-based aquaculture systems - usually controlled, closed-circuit environments
Direct Transplantation
Coral fragments are taken directly from donor colonies and attached to the reef without an intermediate nursery phase
Sexual Propagation Restoration Pathways
While not the study’s main focus, the researchers also looked at sexual propagation pathways, which involve collecting coral spawn, settling larvae on substrates and outplanting the recruits onto the reef to enhance genetic diversity. These methods hold huge potential for boosting climate resilience, but current methods remain technically demanding and costly, especially at scale.
Outplanting Techniques Under Review
The study also compared the cost and effectiveness of several methods for attaching corals to the reef:
Adhesives
e.g., epoxy putty, silicone, or cement
Drilling combined with adhesives
Cable ties
Nail-based solutions without adhesive
e.g. Marietchture™ reef nails or coral clips
What Were the Main Findings?
Ocean-based nurseries are more cost-effective
In Kenya, ocean-based nurseries could cost as little as $0.0004-0.059 per coral per day compared to $0.003-0.116 per coral per day in the US. The difference in these costs was mostly driven by cleaning frequency. Weekly cleaning could make nurseries up to 18x more expensive than no-cleaning approaches.
Smart site selection can help keep costs low without compromising on coral health. Restoration practitioners should aim to choose a site where:
The coral fragments will not be exposed to high levels of pollutants, sediments or competing algae
There is a healthy population of grazers to naturally reduce cleaning efforts costs low without compromising on coral health
However, ocean-based nurseries carry a higher risk as corals are exposed to open-water conditions, meaning they remain vulnerable to bleaching events and disease outbreaks, which can significantly impact survival rates.
Land-based nurseries offer control but at a price
Land-based nurseries give practitioners more control over coral-growing conditions while offering protection from external conditions, which could cause harm. Futhermore, by manipulating light levels, feeding schedules and water quality, they can boost survival and growth.
However, the upfront capital and energy costs of these systems are steep. In the US, the costs of this system were estimated at:
>$200,000 for the initial set-up
>$579,000/year for labour
>$30,000/year for energy
Consequently, these systems may be better suited for high-value species or in locations with limited access to the ocean
Outplanting costs vary widely
Depending on the technique, the cost of attaching one coral to the reef ranged from $0.84 to over $30. The fastest and cheapest techniques were:
Nail-based solutions without adhesive (e.g. Marietchture™ reef nails or coral clips) - these cost $1.37–$2.16 per coral and took ~1 minute per coral to outplant
Sexual recruits placed on tetrapods — these took just 28 seconds per coral to outplant, but had lower survival rates and have yet to be tested for asexual propagation methods
Labour costs create big global gaps
In Kenya, diver labour costs were around $6.33/hour, compared to $70.43/hour in the US. This means the same restoration project can cost 10x more in high-income countries.
Automation, such as robotic cleaning or seeding, may offer savings in the long run, especially in high-cost nations.
Why This Matters for Restoration at Scale
In a time of urgent need for reef recovery, coral restoration practices must scale up in ways that are both effective and economically viable.
This study highlights key ways to reduce costs and boost impact:
Standardising protocols and reporting to clearly identify what truly works.
Tailoring methods to local contexts — ocean-based approaches for low-income regions, and land-based approaches where infrastructure allows.
Prioritising efficiency over tradition, and embracing the opportunity to redesign restoration from the ground up.
At Ocean Revive, We’re Applying These Lessons
As a BlueTech coral restoration company, Ocean Revive is committed to developing cost-effective, scalable, and science-based solutions, building directly on insights from studies like this one.
One of the standout innovations featured in the research, the Marietchture™ reef nails, was designed by our CEO and co-founder Dr Sebastian Schmidt-Roach. Recognised as one of the fastest and most affordable outplanting techniques, these nails have become the foundation of Ocean Revive’s core technology platform, enabling faster deployment and higher survival rates in reef restoration projects worldwide.
We believe every coral counts — and every dollar must go as far as possible in protecting our reefs. By combining cutting-edge research, modular restoration tools, and global collaboration, we aim to transform coral restoration from a niche effort into a global movement.
Read the full research paper here.
Join Us in Restoring the World’s Reefs
Contact us to explore how Ocean Revive’s BlueTech solutions can help bring your reef restoration project to life.
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Biblography
Schmidt‐Roach, S., Knorr, T., Roch, C., Klaus, R., Klepac, C., Klein, S.G. and Duarte, C.M., 2025. Cost‐efficiency and effectiveness of coral restoration pathways. Restoration Ecology, 33(1), p.e14326.
