Mangroves and Coral Reefs Yield Positive Return on Investment for Flood Protection, Study Finds

Coastal mangroves in Everglade City, Florida. Marie Hickman / Stone / Getty Images

Using a benefit-risk analysis, researchers have found that mangroves and coral reefs can be cost-effective in reducing coastal flooding, a press release from the University of California, Santa Cruz (UCSC), said. Using risk and insurance industry techniques, the researchers were able to show that the gains from reduced damage from floods outweighed the costs of restoring the corals and mangroves, leading to a favorable return on investment.

The researchers found mangrove restoration opportunities that were cost-effective in 20 countries and territories, with Cuba, the U.S. and the Bahamas having the most coastal study units with cost-effective possibilities.

The results of the study could mean novel ways to aid restoration with funding from places like the U.S. Federal Emergency Management Agency (FEMA) that assist with disaster recovery, climate adaptation and hazard mitigation, stated the press release.

“We identify a number of funding sources that have traditionally supported artificial ‘gray infrastructure,’ such as concrete sea walls, and that could be applied to nature-based solutions,” said lead author and research professor in the Institute of Marine Sciences at UCSC Michael Beck, who holds the AXA Chair in Coastal Resilience, in the press release.

Mangroves not only provide habitat for fish species, they also serve as a natural barrier against the effects of climate change that threaten coastal communities all over the world, reported Mapping Ocean Wealth. The coastal vegetation has aerial roots that stop erosion and retain sediments. The roots and trunks, as well as the canopy, also lessen the power of waves and storm surges to diminish flooding and its resulting damages.

According to UCSC, the breakdown of many coastal wetlands and coral reefs has made many of these natural buffer zones less effective as coastal protectors, and getting funding for their restoration can be difficult.

As Beck pointed out, disaster recovery expenditure worldwide is more than 100 times the amount spent on conservation.

“Recovery funding will grow as climate change increases the impacts from storms, and environmental funding will likely shrink as national budgets are strained by natural disasters,” said Beck in the press release. “Funding for artificial infrastructure such as seawalls can be redirected to natural defenses, which provide multiple benefits beyond coastal protection.”

The demonstration that restoration has a good return on investment, shown by the study, can be key.

“This may sound esoteric, but it can be critical to getting funding for restoration projects from sources such as FEMA,” said Beck.

Cuba and Jamaica were identified by the researchers as places having the greatest number of opportunities for reef restoration that is cost-effective, the study results said.

“These benefits are critical across the Caribbean, where there have been substantial increases in storm risk and extensive habitat loss,” wrote the authors of the study.

Sign up for our newsletter