Consulta: subjectFacets:"Gironde Estuary"
Registros recuperados: 6
Data/hora: 12/06/2024 09:12:04

Impact of urban effluents on summer hypoxia in the highly turbid Gironde Estuary, applying a 3D model coupling hydrodynamics, sediment transport and biogeochemical processes
Provedor de dados: 5
Autores: Lajaunie-salla, Katixa; Wild-allen, Karen; Sottolichio, Aldo; Thouvenin, Benedicte; Litrico, Xavier; Abril, Gwenael.
Estuaries are increasingly degraded due to coastal urban development and are prone to hypoxia problems. The macro-tidal Gironde Estuary is characterized by a highly concentrated turbidity maximum zone (TMZ). Field observations show that hypoxia occurs in summer in the TMZ at low river flow and a few days after the spring tide peak. In situ data highlight lower dissolved oxygen (DO) concentrations around the city of Bordeaux, located in the upper estuary. Interactions between multiple factors limit the understanding of the processes controlling the dynamics of hypoxia. A 3D biogeochemical model was developed, coupled with hydrodynamics and a sediment transport model, to assess the contribution of the TMZ and the impact of urban effluents through wastewater...
Tipo: Text
Palavras-chave: Hypoxia; TMZ; Gironde Estuary; Wastewater; Oxygen; Modeling.
Ano: 2017
URL: http://archimer.ifremer.fr/doc/00388/49903/50475.pdf

Comportement biogéochimique d'antimoine (Sb) et de tellure (Te) dans le milieu côtier : vers des scénarios de dispersion des radionucléides de Sb et de Te en cas de rejets accidentels de centrales nucléaires
Provedor de dados: 5
Autores: Gil-diaz, Teba.
Antimony (Sb) and tellurium (Te) are relatively uncommon contaminants (stable isotopes) and may form short-lived fission products (radionuclides) released into the environment during nuclear power plants accidents. Little is known about their respective biogeochemical behaviours, necessary for general contamination studies and post-accidental radiological risk assessment.This work provides original knowledge on Sb and Te biogeochemical behaviour in highly dynamic continent-ocean transition systems: the Gironde Estuary and the Rhône River. Concentrations, spatial/temporal variations, solid/liquid partitioning (Kd), and fluxes are studied from long-term records at the watershed scale. Four estuarine sampling campaigns during contrasting hydrological...
Tipo: Text
Palavras-chave: Antimoine; Tellure; Estuaire de la Gironde; Partition solide/liquide (Kd); Extractions sélectives; Antimony; Tellurium; Gironde Estuary; Solid/liquid partitioning (Kd); Selective extractions.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00607/71891/70592.pdf

Modeling mud and sand transfers between a macrotidal estuary and the continental shelf: influence of the sediment-transport parameterization
Provedor de dados: 5
Autores: Diaz, Melanie; Grasso, Florent; Le Hir, Pierre; Sottolichio, Aldo; Caillaud, Matthieu; Thouvenin, Benedicte.
Coastal environments are directly influenced by terrigenous inputs coming from rivers through estuaries. Quantifying the amount of nutrients and contaminants transported by sediments from continental areas to the sea is crucial for marine resources protection. However, the complexity of estuarine dynamics makes it difficult to quantify sediment fluxes from field measurements alone and requires numerical modeling. Thus, using a realistic 3D hydrodynamic and sediment transport model, this study aims at evaluating the influence of model empirical parameters on sediment fluxes and estimating uncertainties on mud and sand transfers at a macrotidal estuary mouth. A sensitivity analysis, considering changes in sediment transport parameters, revealed that the...
Tipo: Text
Palavras-chave: Sensitivity analysis; Sediment fluxes; Numerical modeling; Mud; Sand; Gironde Estuary.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00617/72897/71906.pdf

Tellurium behaviour in a major European fluvial–estuarine system (Gironde, France): fluxes, solid/liquid partitioning and bioaccumulation in wild oysters
Provedor de dados: 5
Autores: Gil-díaz, Teba; Schäfer, Jörg; Dutruch, Lionel; Bossy, Cécile; Pougnet, Frédérique; Abdou, Melina; Lerat-hardy, Antoine; Pereto, Clément; Derriennic, Hervé; Briant, Nicolas; Sireau, Teddy; Knoery, Joel; Blanc, Gerard.
Tellurium (Te) is a technology critical element (TCE) with largely unknown environmental behaviour, especially in continent-ocean interface systems. The unknown behaviour results from the lack of studies in aquatic environments and from analytical challenges limiting the determination of its naturally low (ultra-trace) environmental levels. We performed a comprehensive study of Te in the Lot–Garonne–Gironde fluvial–estuarine system to better understand seasonal variations, solid/liquid partitioning (Kd), gross fluxes, estuarine dynamics, and transfer to wild oysters at the estuary mouth. A temporal record (2014–2017) of dissolved (Ted) and particulate (Tep) Te concentrations at five sites in the Lot–Garonne River system shows little differences between...
Tipo: Text
Palavras-chave: Garonne River; Gironde Estuary; Lot River; RNO; ROCCH; Technology critical element.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00505/61684/65639.pdf

Small-scale variability of zooplankton pyruvate kinase activity in the Gironde Estuary plume (Atlantic French Coast): A case study under unusually low freshwater discharge
Provedor de dados: 5
Autores: Bergeron, Jean-pierre.
Pyruvate kinase (PK) activity measurements are used to assess the role of carbohydrates in global feeding of mesozooplankton communities inhabiting an estuary plume. As a consequence of a remarkably low freshwater discharge rate, the sea surface layers of the area under estuarine influence showed a very moderate salinity fall and a nearly total depletion in nitrates, whereas higher levels of these nutrients were found in deeper, more saline, layers. Small-scale PK activity variations in mesozooplankton appear to be closely correlated to nitrate integration values within the water column. The results were analysed in comparison with literature reports. The study produced a coherent overall interpretation, which strongly supports the reliability of this new...
Tipo: Text
Palavras-chave: Gironde Estuary; Bay of Biscay; Pyruvate kinase; Pyruvate kinase; Carbohydrates; Zooplankton; Phytoplankton; Chlorophyll; Inorganic nutrients.
Ano: 2006
URL: http://archimer.ifremer.fr/doc/2006/publication-1745.pdf

First record of &lt;i&gt;Synidotea laevidorsalis&lt;/i&gt; (Miers, 1881) (Crustacea: Isopoda) in Europe (Gironde estuary, France)
Provedor de dados: 27
Autores: Mees, J.; Fockedey, N.
This note reports on the presence of a well established population of the isopod &lt;i&gt;Synidotea laevidorsalis&lt;/i&gt; (Miers) in the Gironde estuary (southwestern France). This species is new for the European fauna. &lt;i&gt;S. laevidorsalis&lt;/i&gt; is a nonendemic cool-temperate to subtropical, shallow-water species which was probably introduced into the study area from Asia. In the salinity range of 1 to 10 g l&lt;sup&gt;-1&lt;/sup&gt; of the Gironde the species constitutes an important component of the brackish-water hyperbenthic community. The population was already present in 1975 when it was misidentified as the native species &lt;i&gt;Idotea emarginata&lt;/i&gt; (Fabricius).
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Isopoda Synidotea laevidorsalis (Miers; 1881) ANE; France; Gironde Estuary.
Ano: 1993
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=2740