Mangrove forests, also called mangrove swamps, mangrove thickets or just mangroves, are wetlands in coastal intertidal zones that are typically characterized by tree species that have dense tangles of roots that make them appear to be standing on stilts above the water. These roots allow the trees to accommodate the daily rise and fall of tides, and they also slow the movement of the tidal waters, causing sediments to settle out of the water and accumulate at their muddy bottoms.
Mangrove forests occur mostly in the tropical and subtropical latitudes because mangrove trees cannot withstand freezing temperatures. The largest share of the world's mangrove forests is in Asia, at about 38 percent, followed by Latin America, the Caribbean, Africa and Oceania.
Mangrove forests are a unique and extremely important ecosystem that provides habitat for a wide variety of fish, birds, crustaceans and other organisms, many of which have evolved for living all or much of their lives in such forests. They also function to stabilize coastlines by reducing erosion from storm surges, currents, waves, and tides. Other functions include the storage and recycling of nutrients and wastes and the storing substantial amounts of carbon in the sediments at the mangrove bottoms.
Unfortunately, the world has has been experiencing extensive destruction of mangrove forests, with approximately half already lost and the destruction continuing at a rate of about one percent annually. Moreover, a substantial percentage of mangrove tree species are in danger of extinction. A major cause of this loss is pollution from oil and industrial wastes. Another is runoff from agriculture, including shrimp farming, that contains pesticides, antibiotics, disinfectants and other agricultural chemicals and wastes. This has been accompanied by the widespread draining and clearing to obtain wood and to use the land for urbanization.