Modelling the eutrophication of the Seine Bight (France) under historical, present and future riverine nutrient loading

Because of the occurrence of episodic blooms of toxic dinoflagellates, eutrophication of the Seine Bight is a subject of growing concern. In order to better understand the relationships between these processes and human activity in the Seine watershed, two models have been used in connection: [cirf ] A model describing nutrient (N, P, Si) transfer processes at the scale of the whole Seine Basin (RIVERSTRAHLER [Billen, G., Gamier, J., Ficht, A., Cun, C., 2001. Modelling the response of water quality in the Seine River Estuary in response to human activity in the watershed over the last 50 years. Estuaries 24, 977-993]), allowing human activity (agricultural practices, waterscape management, urban wastewater management, etc.) to be related to fluxes delivered to the sea. [cirf ] A model of 3D hydrodynamic and ecological model of the Seine Bight (SiAM-3D/ELISE [Cugier, P., 1999. Modélisation du devenir à moyen terme dans l'eau et le sédiment des éléments majeurs (N, P, Si, O) rejetés par la Seine en baie de Seine. Thèse de doctorat, Univ. de Caen, p. 241; Cugier, P., Le Hir, P., 2000. Modélisation 3D des matières en suspension en baie de Seine Orientale (Manche, France). C. R. Acad. Sci. Paris, Sciences de la Terre et des planétes 331, 287-294]), capable of reproducing the spatio-temporal variations of sediment transport, thermo-haline stratification and phytoplanktonic development in the plume of the Seine river.