Mangroves are pretty incredible. They are the only type of trees capable of living in saltwater and perform a ton of beneficial services for the environment and humans like providing critical habitat to important fish species and reducing the amount of carbon dioxide in the atmosphere. Now, thanks to new research published in the Proceedings of the National Academy of Sciences, we can add “protecting coastal economies” to the list. 

Coastal mangrove forests serve as a barrier between oceans and human settlements on land. In the midst of tropical storms, mangroves buffer shorelines from damage by reducing wave action and storm surges. As the strength and frequency of hurricanes increases as a result of climate change, scientists and economists have been wondering just how much economic value these barrier forests provide as they protect us from storms. 

To find out, researchers studied how coastal areas in Central America fared during hurricanes from 2000 – 2013. Unfortunately, it can be difficult to get a full picture of the economic impacts of storms so researchers relied on an interesting indicator of economic activity: the appearance and amount of lights visible in an area in satellite imagery at night. More lights in an area equates to more infrastructure and activity, which tends to correlate to higher income and economic activity. By comparing the images of lights in an area before and after storms, scientists were able to judge just how much damage the area had sustained and how long the area was likely facing an economic downturn post-hurricane. 

In areas with relatively narrow bands of mangrove forests (less than 1 km wide), there was around a 24% decrease in lighting at night after a category 3 hurricane. But areas that had larger bands of mangroves buffering them from storms were unaffected! 

Unfortunately, mangroves risk deforestation from threats like human development, pollution, and overharvesting. While scientists have been trumpeting the phenomenal benefits we receive from having healthy and intact mangrove ecosystems for a while, it is still shocking to see how this service impacts the bottom line for so many coastal communities. When you see the numbers, you really can’t deny how important it is for us to focus on conserving these important habitats.