Collaborative Research: Across the Salinity Transition -- Changes in N and P Biogeochemistry Along an Estuarine Salinity Gradient

University Of Maryland Center For Environmental Sciences, Cambridge MD

Investigators

Abstract

Aquatic ecosystems are threatened by over enrichment with nitrogen (N) and phosphorus (P). For unclear reasons, P enrichment generally has the greatest impact in freshwater while N enrichment has the greatest impact in saltwater. The goal of this study is to understand how the biogeochemistry of N and P change along the transition from freshwater to saltwater in an estuary. The project will measure inputs and removals of N and P along the salinity transition of the Patuxent River estuary, investigate the importance of watershed-derived particulate P, and test hypotheses about interactions of N, P, iron and sulfur cycles. Transformations and releases of N and P will be measured by incubating sediment cores from along the salinity gradient. The mechanisms of salinity effects will be investigated by experimentally altering concentrations of seawater, sea salts, sulfate, and nitrate over incubated cores. The results will help guide nutrient management in coastal ecosystems. This is a collaborative project with Thomas Jordan (DEB-0212543)