ABSTRACT

The Pamlico Sound (PS) with its sub-estuaries is the largest lagoonal ecosystem in the United States. It exhibits periodically strong salinity stratification and an average freshwater residence time of 1 year for the sound proper. This relatively long residence time promotes effective use and cycling of nutrients, allowing the system to support high rates of primary and secondary production, and serve as a vitally important fisheries nursery. This hydrologic characteristic also makes the system highly sensitive to nutrient over-enrichment and eutrophication. The PS is experiencing ecological change in response to increasing human activity and climatic perturbations. Human impacts include a rise in nutrient, sediment, and other pollutant loads that accompany urbanization and agricultural and industrial growth in its watersheds and airsheds. Since the mid-1990s, the PS

Abstract ............................................................................................................................................ 17 2.1 Introduction ............................................................................................................................ 18 2.2 Putting Things in Perspective: Biogeochemical, Geological, and Climatological Time

Scales ...................................................................................................................................... 21 2.3 Historic Perspective on Human and Climatic Impacts...........................................................22