FN Archimer Export Format PT J TI Long-term water quality in the lower Seine: Lessons learned over 4 decades of monitoring BT AF ROMERO, Estela LE GENDRE, Romain GARNIER, Josette BILLEN, Gilles FISSON, Cedric SILVESTRE, Marie RIOU, Philippe AS 1:1;2:2;3:1,3;4:1,3;5:4;6:5;7:6; FF 1:;2:PDG-RBE-LEADNC;3:;4:;5:;6:;7:PDG-ODE-LITTORAL-LERN; C1 Univ Paris 06, UMR Metis 7619, F-75005 Paris, France. IFREMER, Unite Rech Lagons Ecosyst & Aquaculture Durable, Noumea 98848, New Caledonia. CNRS, UMR Metis 7619, F-75005 Paris, France. Grp Interet Publ Seine Aval GIP Seine Aval, Pole Reg Savoirs, F-76100 Rouen, France. CNRS, FR3020, Federat Ile De France Rech Environm FIRE, F-75005 Paris, France. IFREMER, Lab Environm & Ressources Normandie, F-14520 Port En Bessin, France. C2 UNIV PARIS 06, FRANCE IFREMER, FRANCE CNRS, FRANCE GIP SEINE-AVAL, FRANCE CNRS, FRANCE IFREMER, FRANCE SI NOUMEA PORT-EN-BESSIN SE PDG-RBE-LEADNC PDG-ODE-LITTORAL-LERN IN WOS Ifremer jusqu'en 2018 copubli-france copubli-univ-france IF 3.751 TC 83 UR https://archimer.ifremer.fr/doc/00311/42202/41541.pdf LA English DT Article DE ;Seine River;Water quality;Nutrients;Long-term trends;WFD;Policy AB The Seine River is a highly artificialised catchment in Europe, comprising both productive agricultural areas and intense industrial and commercial activity. Due to its strategic importance, monitoring programs in the river started as early as the 1970s. The present study compiles and analyses this valuable data set (1970–2014), thoroughly describing the riverine section downstream of Paris and the estuary. We identify long-term trends and shifting patterns in nutrients and oxygen, and pay special attention to the river’s evolution after the year 2000, when the European Water Framework Directive came into force. The study has a manifest management perspective, and the results are discussed on the basis of the environmental quality standards proposed in current environmental regulations. The data show that water quality has improved remarkably over the past two decades, with sharp reductions of ammonium and phosphate and a progressive increase of dissolved oxygen levels. The amelioration is prominent in the estuary, where summer anoxic episodes have nearly disappeared. As a result, these three parameters are nowadays in good or very good condition throughout the year. The successful abatement of point sources contrasts, however, with the low effectiveness of the measures provided for the control of nutrients from diffuse sources. Nitrate concentration has increased by 150% since the early 1980s, and only very recently has the upward trend been reversed. Bold agri-environmental management measures are required if we are to prevent chronic pollution problems and truly restore the good ecological status of rivers. PY 2016 PD APR SO Environmental Science & Policy SN 1462-9011 PU Elsevier Sci Ltd VL 58 UT 000370900400015 BP 141 EP 154 DI 10.1016/j.envsci.2016.01.016 ID 42202 ER EF