Tuesday, February 24, 2009
How are mangroves destroyed and why are they destroyed?
They are drained as a sanitary measure, although the salty water doesn’t attract mosquitoes and other insects which lay their eggs in the water. Often, mangrove areas are used to dump rubbish or garbage. On islands where unoccupied land is in short supply, mangroves are often cleared to make agricultural land, or filled in for construction. Large areas have been lost to development in this way. However, such low-lying land are easily flooded during storms, so the development is not always so successful.
In some places mangroves are cleared to make aquaculture ponds for raising fish or shrimp. Ponds may also be built to treat the wastes from cities, towns or factories. Other kinds of construction can also damage mangroves. Anything that changes the way water circulates or its saltiness can kill the affected mangroves. Taking water from rivers for irrigation can reduce the amount of fresh-water available to mix with the salt-water.
Roads or construction projects like a causeway might keep out sea-water from entering the mangroves. As the sea-water is replaced by fresh-water, the mangroves will die. Mangroves are also sensitive to pollution, particularly oil pollution. If an oil spill goes into a mangrove area, the oil covers the aerial roots, and the tree roots can no longer get the air they need to live. The roots will die, and slowly, the whole forest will die too. Mangroves are also very sensitive to herbicides.
Special thanks and acknowledgements to:
http://islands.unep.ch/siemc10.htmPosted by Abigail Lim, Nicole Lim and Angelyn Ong
living nature
2:47 AM
