Francine Taylor-Campbell, Contributor
WETLANDS ARE areas of land where the water table is at or near the surface, making them intermittently or permanently flooded by shallow water. They are seen as nature's water filters as they are able to intercept pollutants from the upper land areas before they reach the coast. This is achieved in a number of ways. Wetland vegetation reduces the velocity of the inflowing water and aids in the settling of suspended particles, nutrients in the water are used by the plants to help them grow, and pollutants such as pesticides, metals and nutrients, when their concentrations are high, can be absorbed onto the trapped sediment. In these ways wetlands are able to improve the quality of the water that pass through them. This, however, depends largely on the storage volume, the time it takes for the water to move through the wetland, the types of soils involved, and the species and number of aquatic plants. In addition, however, is how the people living in and near the wetlands use the areas and dispose of their wastes - we should be managing our activities so as to ensure that the wetlands can continue to act as nature's filters
DEFORESTATION AND DRAINAGE
Wetlands occupy about six per cent of the world's land surface but are being lost through deforestation and drainage for agricultural and commercial purposes. The challenge is therefore to develop means of protecting the wetland areas still available to us and, if possible, restoring those that have been destroyed. This means designing programmes which highlight the human and ecological benefits that can be derived from wetlands and supporting this with scientific data. An important first step is to obtain baseline data on the quality of the waters flowing into, within and from the wetlands, and then to regularly monitor these waters to determine whether the wetlands are continuing to perform their environmentally important functions.
The Black River Morasses, the largest wetland area in Jamaica, have been recognised for their role in enhancing the water quality of the Black River. The Lower Morass is recognised as a wetland of international importance under the Ramsar Convention of 1971. Ongoing studies being conducted by the UWI Chemistry Department in the Black River Upper Morass seek to understand how that wetland functions. Initial water quality data show that the morass does reduce the concentrations of nitrogen and sediment from the Black River. The data are now being used to develop a mathematical model that can explain how the morass removes nutrients and predict how changes in the way we use the morass will affect the water quality. This work is being funded by the Environmental Foundation of Jamaica (EFJ) and is being conducted with the assistance of St. Elizabeth Environmental Protection Association (SEEPA) and the staff and students at Maggotty High School. The knowledge gained from this project will provide a basis for assessing proposed conservation and restoration efforts for the Black River Morasses.
Francine Taylor-Campbell is a PhD student.
