Estuaries of the south Atlantic coast of North America: Their geographicalsignatures

Estuaries of the southeastern Atlantic coastal plain are dominated by shall ow meso-tidal bar-built systems interspersed with shallow sounds and both l ow flow coastal plain and high how piedmont riverine systems. Three general geographical areas can be discriminated: the sounds of North Carolina; the alternating series of riverine and ocean dominated bar-built systems of So uth Carolina, Georgia, and northeast Florida, and the subtropical bar-built estuaries of the Florida southeast coast. The regional climate ranges from temperate to subtropical with sea level rise and hurricanes having a major impact on the region's estuaries because of its low and relatively flat ge omorphology. Primary production is highest in the central region. Seagrasse s are common in the northern and southern most systems, while intertidal sa lt marshes composed of Spartina alterniflora reach their greatest extent an d productivity in South Carolina and Georgia. Nuisance blooms (cyanobacteri a, dinoflagellates, and cryptomonads) occur more frequently in the northern and extreme southern parts of the region. Fishery catches are highest in t he North Carolina and Florida areas. Human population growth with its assoc iated urbanization reaches a maximum in Florida and it is thought that the long-term sustainability of the Florida coast for human habitation will be lost within the next 25 years. Tidal hushing appears to play an important r ole in mitigating anthropogenic inputs in systems of moderate to high tidal range, i.e., the South Carolina and Georgia coasts. The most pressing envi ronmental problems for the estuaries of the southeastern Atlantic coast see m to be nutrient loading and poor land use in North Carolina and high human population density and growth in Florida. The future utilization of these estuarine systems and their services will depend on the development of impr oved management strategies based on improved data quality.