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

Abstract

International audienceThe 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

Population dynamics of modern planktonic foraminifera in the western Barents Sea

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Calcareous nannoplankton and foraminiferal response to global Oligocene and Miocene climatic oscillations: a case study from the Western Carpathian segment of the Central Paratethys

“…The co-occurrence of the planktonic species Globigerina bulloidespraebulloides, Globigerinella regularis, Globigeri noides spp., and Orbulina suggests a seasonal succession of assemblages characterized by the alternation of warm seasons with a stratified oligotrophic water and cool seasons with a mixed upper water column (e.g., Reynold & Thunell 1985;Rigual-Hernandez et al 2012;Kuhnt et al 2013;Salmon et al 2014). Similarly, the co-occurrence of large Helicosphaera spp.…”

“…The surface water is characterized by Paragloborotalia mayeri, Globigerinoides spp., Orbulina suturalis, five-chambered Globigerina ottnangiensis and Turborotalita quinqueloba. The coexistence of these taxa also indicates a seasonal succession of assemblages (e.g., Reynold & Thunell 1985;Rigual-Hernandez et al 2012;Kuhnt et al 2013;Salmon et al 2014), but substitution of Globigerina bulloides, dominating during the MM-1 interval, by Turbo rotalita quinqueloba means cooling during the cold and high-nutrient season. The lower abundance of Globigerinella and its replacement by Globigerinoides spp.…”

Recostruction of the unusual Mid Miocene (Badenian) palaeoenvironment of the Carpathian Foredeep (Lomnice/Tišnov denudational relict, Czech Republic)

“…with Globigerina spp. sug gest a sea sonal suc ces sion of as sem blages (e.g., Reynold and Thunell, 1985;Rigual-Hernandez et al, 2012;Kuhnt et al, 2013;Salmon et al, 2014). The phytoplankton is dom i nated by Reticulofenestra minuta char ac ter iz ing en vi ron men tal stress with rapid changes within that en vi ron ment, in clud ing os cil la tions of sa lin ity (Wade and Brown, 2006), and nu tri ent con tent (Flores et al, 1997;Wells and Okada, 1997;Kameo, 2002) con sis tent with the varied test size of the Globigerina bulloides/praebulloides group.…”