Flux dynamics of planktic foraminiferal tests in the south-eastern Bay of Biscay (northeast Atlantic margin)

• Published in: Journal of Marine Systems
• Main Authors: Kuhnta, Tanja, Howa, Hélène, Schmidt, Sabine, Marié, Louis, Schiebel, Ralf
• Other Authors: Bio-Indicateurs Actuels et Fossiles (BIAF), Université d'Angers (UA), Environnements et Paléoenvironnements OCéaniques (EPOC), Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de physique des océans (LPO), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2013
• Subjects: Planktic foraminifera; Bay of Biscay; Sediment traps; Particulate mass flux; 210Pb; Seasonality; Lateral advection; [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography; Inner Bay; Northeast Atlantic
• Online Access: https://hal.science/hal-00836081; https://doi.org/10.1016/j.jmarsys.2011.11.026

International audience The temporal and water depth related dynamics of planktic foraminiferal fluxes in the south-eastern Bay of Biscay are discussed for a two year sampling period (June 2006-June 2008). Two sediment traps deployed at 800 m and 1700 m water depth at a mooring in 2000 m of water depth, were analyzed for the flux of planktic foraminiferal species > 150 μm, in comparison with the total mass flux. Total flux of planktic foraminifera shows seasonal maxima in spring/early summer (> 2000 Ind. m− 2 d− 1) and minima from late summer through winter (< 10 Ind. m− 2 d− 1). The flux of planktic foraminiferal tests in the intermediate to deep water column at the inner Bay of Biscay comprises an intermittent and regionally variable signal of seasonal surface water primary productivity. Significant lateral transport and flux of particles superimposed on the downward mass flux indicate a decoupling of fluxes between the 800-m and 1700-m traps. The 210Pb budget and the presence of certain benthic foraminiferal species in the midwater column prove that the lateral flux originated from the upper continental slope. Despite the temporal and vertical variations of the particulate flux, a well-defined seasonal flux signal can be deduced from the frequency of planktic foraminiferal species.