Mangroves Are a Critical and Threatened Marine Resource
Clearing of mangroves in the name of land reclamation — land to be used for shoreline development — is a worldwide activity. According to University of Virginia and University of Georgia scientists William Odum and R.E. Johannes, more acres of mangrove may have been cleared worldwide than any other type of area except desert, an estimated “many hundreds of thousands of hectacres.” Clearing often results in high, long-term costs of battling increased erosion.
Mangroves are not areas to be “reclaimed.” They not only belong where they are, but they are actively reclaiming and preserving land on their own. The whole process is cyclical, beginning with the mangroves’ role as recyclers, and ending with protection of the outlying coral reefs.
The Role of Mangroves in Protecting Coral Reefs
The reclaiming process is as simple as it is vital. The mangrove roots act as natural filters, trapping sediment and run off from the land, thus preventing or slowing erosion.
Removal of mangroves causes a chain reaction. If the mangroves are cleared the sediment and pollutants run unchecked into the sea grass beds. The nutrient-rich effluent promotes the growth of phytoplankton and filamentous algae, which, combined with the sediment clouds the shallow water and blocks out light necessary for sea grass beds to flourish. The environment becomes anoxic, and the sea grass ecosystem dies.
