Linking land use, nutrient conditions and phytoplankton abundance and diversity in the non-tidal creeks of the Neuse-Pamlico Estuarine System

This project was undertaken to determine how coastal land use and land cover affect dissolved nutrient concentration and form, phytoplankton abundance and community composition, and nitrogen buffering capacity in the non-tidal oligo- to meso-haline creeks of the Neuse Pamlico Estuarine System. The research included routine sampling of four estuarine creeks and seasonal in-situ nutrient addition bioassays designed to mimic nutrient loading events observed in the monitoring data. The results show the land use causing the greatest degree of disturbance (agriculture) resulted in the highest in-stream nutrient concentrations, the highest inorganic to organic nitrogen ratios, the lowest phytoplankton diversity, and decreased capacity to buffer the mainstem estuary from episodic nutrient loading. The findings underscore the need for watershed management designed to mitigate increased fresh water and nutrient loading from watershed modification upstream of estuarine creeks