The spatially variable effects of mangroves on flood depths and losses from storm surges in Florida
Storm surges cause billions in coastal losses, yet mangrove forests can significantly reduce damages. Using high‑resolution storm‑surge and property‑loss models, this study quantified mangrove benefits in southwest Florida during typical years and Hurricanes Irma (2017) and Ian (2022). Mangroves reduced annual damages by $67 million, cut losses by 14% during Irma and by 30% during Ian. Protection varied spatially: landward properties consistently benefited, while properties located within or seaward of mangroves sometimes faced increased exposure. Results highlight the need to understand where mangroves provide the greatest defense as coastal regions plan for climate‑driven storm intensification.
Subject Tags
- Coastal
- Mangroves
- Nature-based solutions
Abstract
Storm surges from tropical cyclones and hurricanes cause billions of dollars in coastal property damages every year. However, natural ecosystems such as mangrove forests can, by their presence on these coastlines, modify storm surges and affect property damages. Florida in the U.S. is a prime example of a state with an extensive coastline, expensive coastal properties that are exposed every year to hurricanes and bountiful coastal mangrove forests. Despite growing knowledge of the role that mangroves play in reducing storm surge damages, little is understood of how the magnitude of mangrove effects varies spatially, i.e., where and to what extent properties may benefit from mangrove presence during a storm surge. In this study, we use high-resolution storm surge and property loss models, along with data on mangrove extents in southwest Florida, to quantify the effect of mangroves on property damages annually and during recent Hurricanes, Irma (2017) and Ian (2022). We find that mangrove presence reduces property damages substantially—$67 million annually in Collier County, by 14% during Irma and by 30% during Ian. We also show a strong pattern in the spatial variability of mangrove effects—landward properties always benefit from having mangroves as a natural defense; in situations where properties are inside mangrove forests, they continue to benefit but can, in some situations, especially when they are seaward of these forests, actually face higher damages due to mangroves. These findings underline the importance of understanding the effect of mangrove presence on storm surge damages on coastlines globally, especially when considering their role as natural coastal defenses.
Citation
Narayan, S., Thomas, C. J., Nzerem, K., Matthewman, J., Shepard, C., Geselbracht, L., & Beck, M. W. (2025). The spatially variable effects of mangroves on flood depths and losses from storm surges in Florida. Cell Reports Sustainability, 2(12). https://doi.org/10.1016/j.crsus.2025.100531
TNC Authors
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Christine Shepard
Director of Science, Florida
The Nature Conservancy
Email: cshepard@tnc.org -
Laura Geselbracht
Senior Marine Scientist, Florida
The Nature Conservancy
Email: lgeselbracht@tnc.org