Human Impacts

While much of the South Florida coastline was covered in mangrove forest at one time, only a few hundred-thousand hectares remain today. Much of the original forest was destroyed by human activity before the value of these unique ecosystems was fully realized. As populations increased in Florida and land was developed along the coastlines, dikes and impoundments were built to control flooding. Dredge and fill operations were used in many areas to drain land for homes and businesses. Not only were many mangrove trees removed but the roots of many others were covered by deep mud, constant flooding, and excess sediment which eventually killed the trees. Since mangrove forests are very important to stabilizing the land, removal of mangrove trees results in increased erosion of coastlines and increased risk to coastal homeowners.

Run-off from upland and inland areas may also cause problems to these sensitive ecosystems. Pollutants may be washed into mangrove waters and threaten the health of plants and trees. Petroleum from crude-oil spills can clog the lenticels of tree roots and interfere with oxygen intake. Mangrove trees are also very sensitive to herbicides and pesticides that may run-off from urban or agricultural areas farther inland.