Nitrogen (N) limitation is a common feature of estuaries worldwide. Excessive man-made N loading from unprecedented urban, agricultural and industrial growth in the Neuse River estuary watershed has led to accelerating primary production (eutrophication), including harmful algal blooms. Blooms produce large amounts of organic matter, which fuels excessive oxygen consumption. This condition, hypoxia, reduces habitats, causes disease, suffocates fish and shellfish and disrupts ecosystem function. National expansion of hypoxia is of prime concern. "Nitrogen is nitrogen" is commonly assumed when relating N inputs to ecosystem structure and function. We hypothesize that diverse algal groups use various anthropogenic inorganic and organic N sources differentially, leading to distinct algal bloom responses, food web alteration, oxygen depletion, water quality and habitat changes in the estuary. The responses of natural algal communities to specific N compounds and their impacts on altered estuarine function (e.g., hypoxia and nurient cycling) is the focus of this research.
