This is a short but very explicit video showing how mangroves protect us from tsunamis.
My question is: Why are we destroying them?
There is growing evidence that mangroves’ dense root and branch networks are very important for protecting coastal areas, because they can absorb wave energy. Thus, they could help dissipate tsunamis, reducing their devastation.
A study found villages behind mangroves survived best (Science, doi.org/b564c7). And detailed analysis of satellite images of the west coast of Aceh by Juan Carlos Laso Bayas of the University of Hohenheim, Stuttgart, Germany, suggests that forests in front of settlements resulted in 8 per cent fewer casualties during the tsunami (PNAS, doi.org/c6wrbg).
What are mangroves?
There are about 80 different species of mangrove trees. All of these trees grow in areas with low-oxygen soil, where slow-moving waters allow fine sediments to accumulate. Mangrove forests only grow at tropical and subtropical latitudes near the equator because they cannot withstand freezing temperatures.
Many mangrove forests can be recognized by their dense tangle of prop roots that make the trees appear to be standing on stilts above the water. This tangle of roots allows the trees to handle the daily rise and fall of tides, which means that most mangroves get flooded at least twice per day. The roots also slow the movement of tidal waters, causing sediments to settle out of the water and build up the muddy bottom.
Mangrove forests stabilize the coastline, reducing erosion from storm surges, currents, waves, and tides. The intricate root system of mangroves also makes these forests attractive to fish and other organisms seeking food and shelter from predators.