Coral-reef restoration can be cost-effective for saving lives, money

Restoring degraded reefs can protect thousands of lives annually in Florida and Puerto Rico, new study co-led by UC Santa Cruz researchers shows

Map of south Florida coast showing reef-restoration locations
Map of Puerto Rico showing reef-restoration locations
These maps show where coral reef restoration along the coasts of Florida and Puerto Rico would protect against more than $391 million in total damage to property and lost economic activity annually. (Credit: UC Santa Cruz, J. Kendall-Bar)

A new study co-led by the Center for Coastal Climate Resilience (CCCR) at UC Santa Cruz shows coral reef restoration in Florida and Puerto Rico could save thousands of lives and prevent hundreds of millions of dollars in damage and economic interruption each year. Children, elderly, minorities, and those living below the poverty line would benefit the most from restoration.

Researchers at UC Santa Cruz and the U.S. Geological Survey (USGS) developed a modeling system to quantify the value coral reef restoration could provide to over 600 miles of coastlines in Florida and Puerto Rico. The research compared how much flooding storms would cause with and without coral reef restoration at a resolution of 10 square meters, or 108 square feet. Researchers then determined how many people and how much property and economic activity reef restoration could protect by preventing coastal flooding.

This work, published on January 15 in Science Advances, is part of a key strategic focus for CCCR on developing nature-based solutions (NBS) to reduce climate risks. “Our modeling is a major advance in characterizing the effectiveness of nature-based infrastructure for coastal protection. The approach can also be applied to other ecosystems, such as beaches, marshes, oyster reefs, and mangrove forests,” said CCCR principal investigator Borja Reguero.

“In addition, this modeling system can be used to assess the impacts of future changes in storms or sea level, helping us to measure when and how cost effective it is to adapt,” said Reguero, an associate professor in the Coastal Science & Policy Program at UC Santa Cruz.

Why we need healthy reefs

Coral reefs act as a natural barrier to coastal storms. Reefs can absorb and weaken damaging waves. As a result, waves that hit shores are smaller and cause less flooding and erosion, saving lives and money. Restoring degraded or destroyed coral reefs could protect nearly 3,000 people each year in Florida and Puerto Rico alone. Reefs would also prevent more than $391 million worth of damage to property and lost economic activity annually.   

The authors also identified where reef restoration would be cost effective on the coasts of Florida and Puerto Rico. They show that, on about 20% of the reef-lined coasts, that the value of property protected from storm damage would be greater than the cost of reef restoration.

This study only considers the economic benefits of avoided damage. But, restored reefs also benefit industries like tourism, recreation, and fisheries. As a result, the true economic value of coral reef restoration is likely much higher.  

In addition, the researchers point out that restored coral reefs can last longer than artificial defenses alone. If sea levels change, structures such as levees or seawalls would need to be raised at great expense. However, coral reefs are living organisms that can grow with changing sea levels. 

More protections for vulnerable inland communities

The results of the work show that reefs could provide some of the highest benefits to property and  vulnerable people inland of the coast. Indeed, vulnerable populations could receive two- to three times more protection from flooding relative to the general population, the study finds.

The researchers explain that properties right on the coast, like beachfront homes, will flood with or without restoration. However, reef restoration can significantly reduce the size of the flood zone behind these coastal properties, where more vulnerable people are more likely to reside, such as children, the elderly, minorities, and those living in poverty. 

This research aims to outline one method management agencies could use to mitigate coastal hazards. It also provides a framework to calculate benefit-to-cost analyses for coral-reef restoration in hazard-risk reduction. This establishes an avenue for coral-restoration projects to be considered for post-disaster mitigation funding from agencies like the Federal Emergency Management Agency or the U.S. Army Corps of Engineers, alongside traditional methods such as bulkheads or breakwaters. 

“Most hazard mitigation and disaster-recovery funding supports more artificial infrastructure such as seawalls that degrade nature. By valuing the benefits of natural infrastructure, we level the playing field and open major new funding opportunities for reef restoration, ” said CCCR Director Michael W. Beck, a co-lead on the project.

Existing coral reefs are already providing protection. A previous study led by UC Santa Cruz showed that existing reefs shield more than 18,000 people and provide more than $1.8 billion annually for the direct benefits of avoided flood damages to property in the United States.

In addition to USGS and UC Santa Cruz, the National Oceanic and Atmospheric Administration collaborated on the study, titled “Hybrid coral-reef restoration can be a cost-effective nature-based solution to provide protection to vulnerable coastal populations.”