Ecological model of the Bay of Biscay and English Channel shelf for environmental status assessment part 1: Nutrients, phytoplankton and oxygen

• Published in: Ocean Modelling
• Main Authors: Ménesguen, Alain, Dussauze, Morgan, Dumas, Franck, Thouvenin, Bénédicte, Garnier, Valérie, Lecornu, Fabrice, Répécaud, Michel
• Other Authors: Service Hydrographique et Océanographique de la Marine (SHOM), Ministère de la Défense, Laboratoire d'Océanographie Physique et Spatiale (LOPS), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2019
• Subjects: Ecological 3D model; Continental shelf; Bay of Biscay and English Channel; Surface chlorophyll; Dissolved oxygen; MSFD; [SDU]Sciences of the Universe [physics]; [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography; North East Atlantic
• Online Access: https://insu.hal.science/insu-03683211; https://insu.hal.science/insu-03683211/document; https://insu.hal.science/insu-03683211/file/60510.pdf; https://doi.org/10.1016/j.ocemod.2018.11.002

International audience European directives (Water Framework Directive - WFD and Marine Strategy Framework Directive - MSFD) require a regular survey of several descriptors of the Environmental Status of coastal waters of the North-east Atlantic Ocean. Especially for the MSFD, which may concern large continental shelf areas where measurements are scarce, realistic ecological models can help assessing the Environmental Status. The ECO-MARS3D model of the pelagic ecosystem of the Bay of Biscay and English Channel continental shelf (NE Atlantic) has been developed for these applied purposes and validated against various types of historic data. This first paper deals with the basic biogeochemical version, which contains inorganic nutrients (NH 4 , NO 3 , PO 4 , Si(OH) 4 ), three phytoplankton bulk types (diatoms, nanoflagellates and dinoflagellates), two zooplankton bulk types, particulate detrital forms and dissolved oxygen. A second paper presents a version of this model including 3 harmful phytoplanktonic groups. A simulation covering the 2000-2010 decade is compared to satellite sea surface data for temperature and surface chlorophyll, to the Southampton-Bilbao and Ouistreham-Portsmouth ferrybox surface data for temperature, salinity, chlorophyll and nutrients, to point samples provided by the French network of phytoplankton monitoring (REPHY) for inorganic nutrients and chlorophyll, and to high frequency time series of dissolved oxygen measured by a moored automatic buoy. From a spatial point of view, the model provides realistic fields of annual means of surface temperature (but with a systematic bias of about + 1.0 °C) and phytoplanktonic biomass. From a seasonal point of view, the temperature and salinity follow correctly the observed variations. For nutrient and total chlorophyll, the model succeeds in reproducing the difference amounting to one order of magnitude between the North Sea coastal zones and the oligotrophic oceanic zone above the abyssal plain of the bay of Biscay. It also reproduces the ...