Mangroves are short trees that grow along coastlines, having adapted to life in salt water; they reduce storm surges, prevent coastal flooding, and protect fish habitats. All told, mangroves help the world avoid some $80 billion a year in losses from floods, and they save billions more in other ways. Planting mangroves is much cheaper than building breakwaters, and the trees also improve the water quality. They’re a great investment.
