The key activities envisaged are: Existing data on aquifers and the water balance in Eastern African coastal areas and hydrological field data will be collected, with the aim to construct a model of groundwater outflow that will allow a prediction of the response of the hydrological system to anthropogenic disturbances. Community structures in nearshore habitats will be studied in relation to different levels of groundwater outflow and quality. The effect of different levels of groundwater outflow on the productivity and population dynamics of some species of outstanding commercial value will also be examined. Sophisticated techniques in the field of population dynamics and analytical chemistry will be applied to detect historical changes in the primary productivity and vitality of seagrass meadows and in chemical characteristics of molluscs and corals in relation to changes in groundwater outflow in recent years. Groundwater will be sampled on a seasonal basis and analysed for nutrients, polyaromatic hydrocarbons, PCB's and selected pesticides. Microbial mineralisation, community metabolism and community structures will be investigated in areas receiving pollutant inputs and control areas.