Effects Of Changing Land Use On NutrientLoads And Water Quality In A SoutheasternUS Blackwater River Estuary

Nutrient enrichment in the coastal zone is a world-wide phenomenon, driven by consistent increases in population and land development. In order to counteract the effects of eutrophication, it is important to use historical records to fidetermine baseline conditions within the affected water body. Then the sometimes diffi cult and expensive process of constructing a nutrient budget must be completed, which will account for the within-basin point and nonpoint-source nutrient loads. Once this has been achieved, environmental managers will have the information to effectively target point source reductions through regulation and nonpoint-source reduction through best management practices. We take the reader through this process using the Lower St. Johns River Estuary, Florida as a model system to show degradation of water quality over time concomitant with increases in population and changes in land use, culminating in a determination of both the anthropogenic nitrogen and phosphorus loads.