We took up some basics about mangrove forests in a previous article, including how widespread and productive these ecosystems can be. Now people have begun to realize the importance of mangrove forests to the health of the planet. Not just for the obvious reasons, but for the single fact that mangroves are benevolent guardians of human civilization. They protect our property, save countless lives, and stoutly defend the world’s atmosphere from climate-changing forces of greenhouse gas.
Mangroves make up a vital part of civilization’s coastal defenses. They reduce storm surge, can even mitigate damage caused by tsunamis. Waves lose strength passing through their dense tangled roots and branches. (A joint study by Wetlands International and The Nature Conservancy found that wave heights decrease over 10% with every 100 meters/yards of mangrove forest.)
Mangroves also improve water quality by filtering soil and other substances that run off the land. The weaker waves prevent pollutants from spreading. The mangrove ecosystem’s salt beds (sabkhas) contain microbes that can absorb pollution and biodegrade oils.
Most importantly, though, these shrubs and trees constitute “blue carbon.” Mangroves are incredibly important from the climate angle because they absorb carbon dioxide in huge quantities (an average of 3,754 tons of carbon dioxide per hectare, according to one study).
“Mangroves are important carbon sinks,” says New York University marine biologist John Burt. A Thai fisher from the Andaman Coast puts it even more strongly:
“If there are no mangroves, then the sea will have no meaning. It is like having a tree without roots, for the mangroves are the roots of the sea….”
They are also its lungs, and by extension, a vital part of the world’s respiratory system. It would be hard to do without mangroves.
Creating land ideal for coastal development, these trees die from subsequent population stresses. Their abundance of sea creatures leads to overfishing. Without mangroves, “red tide” algae blooms in the water, kills sea life, and shuts down beaches. Mangrove loss exemplifies how climate change not only causes destruction, but also perpetuates and intensifies itself.
There’s a bit of hope coming for the world’s mangroves, though. Parts of the world have recognized them as species of special concern. Nations have begun to put a price tag on mangrove areas that reflects the true value of their combined benefits. Mangrove replenishment initiatives with seeds or seedlings can revive the shoreline ecosystems within 15-30 years if other conditions are suitable.
Ecological designers have even fashioned modular “nests” for mangroves to restore land lost to sea level rise. Says the Hungarian art and design collective Szövetség’3:
“We believe that, when the sea level will go beyond a critical point, the quantity of sediment trapped will form sufficiently high dams to save the current lands. The protected areas can also be used agriculturally or can be populated because their soil is rich in nutrients and they are solid enough.”
The question is not “Where would we be without mangroves?” but “Can we restore these invaluable plant communities, and increase them, more quickly than we condemn them to the speed of modern human life?”