Consulta: subjectFacets:"Biogéochimie"
Registros recuperados: 12
Data/hora: 07/06/2024 06:31:48

Le mercure en milieu marin. Biogéochimie et écotoxicologie
Provedor de dados: 5
Autores: Cossa, Daniel; Thibaud, Yves; Roméo, Michèle; Gnassia-barelli, Mauricette.
This report synthesizes the knowledge on the biogeochemical cycle, bioconcentration processes and ecotoxicity of mercury in the marine environment. Man induced changes on the mercury cycle, especially along the French coasts are reviewed. Concentration levels, mechanisms and fluxes between geochemical reservoirs are assessed. Emphasis is given on sublethal effects and toxicity mechanisms. Quality standards used in European Community countries are listed. Conclusions and recommendations for environmental management and research are given.
Tipo: Text
Palavras-chave: Mercure; Biogéochimie; Contamination; Écotoxicologie; Mercury; Biogeochemistry; Contamination; Ecotoxicology.
Ano: 1990
URL: http://archimer.ifremer.fr/doc/00332/44319/43890.pdf

Dynamique du carbone et des nutriments dans la zone côtière Baie de l’Aiguillon-Pertuis Breton et influence des apports terrestres du bassin versant du Marais poitevin
Provedor de dados: 5
Autores: Lannuzel, Reva.
Coastal zones represent key systems in biogeochemical cycle couplings between continents, oceans and the atmosphere transporting considerable amounts of matter, energy and nutrients (C, N, P et Si) from land to sea. Despite its relatively modest surface area (7 % of the global ocean surface), this zone accounts for 14–30 % of all oceanic primary production. The present study deals with nutrients and carbon dynamics during a full hydrologic cycle in 2017 over the terrestrial-aquatic continuum formed by the Poitevin Marsh-Aiguillon Bay- Breton Sound to better understand terrestrial export influence on the coastal zone. Carbon and nutrient concentrations were sampled twice a month over heterogeneous sites (estuaries, channels and coastal sites) to integrate...
Tipo: Text
Palavras-chave: Zone côtière; Biogéochimie; Carbone; Nutriments; Chlorophylle a; Limitation potentielle et réelle; Dynamique.; Coastal zone; Biogeochemistry; Carbon; Nutrients; Chlorophyll a; Real and potential limitation; Spatio-temporal dynamic.
Ano: 2018
URL: http://archimer.ifremer.fr/doc/00445/55647/57299.pdf

L'étain et les organoétains en milieu marin. Biogéochimie et écotoxicologie.
Provedor de dados: 5
Autores: Alzieu, Claude.
This report synthesizes the knowledge on the biogeochemical cycle, bioconcentration processes and ecotoxicity of tin and organotins in the marine environment. Concentrations levels, biomethylation mechanisms and exchanges between sediments and water are assessed. Emphasis is given on tributyltin sublethal effects, toxicity mechanisms and no effect levels for the most sensitive organisms. Regulations on the use of organotins as antifoulants in paints are examined. Conclusions and recommendations for environmental management and research are given.
Tipo: Text
Palavras-chave: Étain; Biogéochimie; Contamination; Écotoxicologie.; Tin; Biogeochemistry; Contamination; Ecotoxicology.
Ano: 1989
URL: http://archimer.ifremer.fr/doc/00332/44314/43883.pdf

Le cadmium en milieu marin. Biogéochimie et écotoxicologie.
Provedor de dados: 5
Autores: Cossa, Daniel; Lassus, Patrick.
This report synthesizes the knowledge on the biogeochemical cycle, bioconcentration processes and ecotoxicity of cadmium in the marine environment. Man induced changes on the cadmium cycle, especially along the French coasts are reviewed. Concentration levels, mechanisms and fluxes between geochemical reservoirs are assessed. Emphasis is given on sublethal effects and toxicity mechanisms. Quality standards used in European Community countries are listed. Conclusions and recommendations for environmental management and research are given.
Tipo: Text
Palavras-chave: Cadmium; Biogéochimie; Contamination; Écotoxicologie.; Cadmium; Biogeoclzemistry; Contamination; Ecotoxicology.
Ano: 1989
URL: http://archimer.ifremer.fr/doc/00332/44312/43866.pdf

Relations milieu-ressources : impact de la conchyliculture sur un environnement lagunaire méditerranéen (Thau)
Provedor de dados: 5
Autores: Deslous-paoli, Jean-marc; Souchu, Philippe; Mazouni, N; Juge, Claude; Dagault, Francoise.
Shellfish farming leaves its mark on the environment in which it has developed, and the men who depend upon it. These changes have altogether balanced the lagoon cycle and have caused disastrous episodic events. Increased water c1arity caused by the uptake of particulate material by shellfish farming allows seagrass to grow in deeper areas of the lagoon (down to five metres). Shellfish farming nutrient transformations increase ecosystem productivity, even if the filtration pressure keeps phytoplankton biomass at a low leveI. Storage of phosphorus and nitrogen in animal tissue limits eutrophication in this ecosystem. Transfer of oysters from growout facilities increases animal and vegetal specific diversity. The presence of large amounts of shellfish allows...
Tipo: Text
Palavras-chave: Lagune; Conchyliculture; Biogéochimie; Benthos; Eutrophie; Lagoon; Shellfish farming; Biogeochemistry; Benthos; Eutrophication.
Ano: 1998
URL: https://archimer.ifremer.fr/doc/00039/15032/12365.pdf

Lagune de Salses-Leucate. II.- Contamination bactériologique et approche physico-chimique
Provedor de dados: 5
Autores: Ladagnous, Helene; Le Bec, Claude.
En complément de l'analyse bibliographique (vol. 1), une étude de la contamination bactériologique et une approche de la qualité physico-chimique des eaux de la lagune ont été menées. Réalisées aux mois de mai et juin 1996, ces études ont pour objectif d'aborder de façon prospective, la totalité de l'étang. Des secteurs contaminés bactériologiquement ont pu être mis en évidence dans la partie sud de la lagune, sans que les sources soient clairement localisées. De même, pour la partie nord, les taches de contamination mises en évidence lors de précédentes études sont confirmées dans la zone des parcs conchylicoles. Les analyses de sels nutritifs montrent l'importance des résurgences karstiques dans les apports de nutriments, sans que le facteur limitant de...
Tipo: Text
Palavras-chave: Lagune; Méditerranée; Leucate; Salses; Physico-chimie; Biogéochimie; Pollution; Bactériologie; Résurgence; Karst.; Lagoon; Mediterranean; Leucate; Salses; Physico-chemistry; Biogeochemistry; Pollution; Bacteriology; Resurgence-spring; Karst.
Ano: 1998
URL: http://archimer.ifremer.fr/doc/00073/18423/15966.pdf

Les polychlorobiphényles (PCB) en milieu marin : biogéochimie et écotoxicologie
Provedor de dados: 5
Autores: Marchand, Michel; Abarnou, Alain; Marcaillou-le Baut, Claire.
This report synthesizes the knowledge on the behaviour, bioconcentration processes and ecotoxicity ofPCB in the marine environment. Contamination levels of the French coasts are examined. Concentration levels, mechanisms andfluxes between geochemicai reservoirs are assessed. Emphasis is given on subiethai effects and toxicity mechanisms. Quality standards used in European Community countries are listed. Conclusions and recommendations for environmentai management and research are given.
Tipo: Text
Palavras-chave: PCB; Biogéochimie; Contamination; Écotoxicologie; PCBs; Biogeochemistry; Contamination; Ecotoxicology.
Ano: 1990
URL: http://archimer.ifremer.fr/doc/00148/25954/24045.pdf

Variability in benthic oxygen fluxes during the winter-spring transition in coastal sediments: an estimation by in situ micro-electrodes and laboratory mini-electrodes
Provedor de dados: 5
Autores: Lansard, B; Rabouille, C; Massias, D.
Two expeditions were achieved at the winter-spring transition in the Golfe de Fos (Mediterranean Sea) at a site situated at 21 m depth. An in situ autonomous oxygen profiler and laboratory oxygen mini-electrodes were used to measure the oxygen distribution in the sediments and calculate the diffusive oxygen fluxes. Clearer waters during the second expedition promoted a rapid shift from a net heterotrophic environment to a photosynthesis-dominated sediment. The diffusive exchange fluxes of oxygen through the sediment-water interface varied from an average consumption of 5.3 mmol m(-2) d(-1) (February) to a net production of 12 mmol m(-2) d(-1) (March). At both periods, a large spatial heterogeneity was recorded by the different electrodes, with a larger...
Tipo: Text
Palavras-chave: Oxygène; Micro-électrodes in situ; Biogéochimie; Cycle du carbone; Sédiment côtier; Oxygen; In situ micro-electrodes; Biogeochemistry; Carbon cycle; Coastal sediment.
Ano: 2003
URL: http://archimer.ifremer.fr/doc/00322/43272/43003.pdf

Modélisation des contaminants en milieu aquatique: Module MET&amp;OR
Provedor de dados: 5
Autores: Thouvenin, Benedicte.
The MET&amp;OR module is a model, written in FORTRAN 90, which calculates the biogeochemical reactions between variables such as trace metal, radioactive tracers, organic or bacterial contaminants (biodegradation, decay, adsorption / desorption, photolysis, hydrolysis, volatilization, partition at equilibrium ..). It groups together classical reactions, described in the literature, to evaluate the source and sink terms which are integrated into the transport equations solved by a hydrodynamic model. It is intended more particularly for marine and coastal waters. This technical documentation aims to present the MET&amp;OR module and the way in which it was coupled to the hydrodynamic model, in particular to MARS-3D.
Tipo: Text
Palavras-chave: Modelisation; Biogéochimie; Contaminants métalliques; Organic contmainants; Contaminants bactériens; Modeling; Biogeochemical; Trace metals; Contaminants organiques; Bacterial contaminant.
Ano: 2021
URL: https://archimer.ifremer.fr/doc/00688/79972/83002.pdf

Biogeochemical markers of organic matter along the Wight-Cherbourg transect (central English Channel)
Provedor de dados: 5
Autores: Ismaili, Mm; Serve, L; Gadel, F; Lafite, R; Texier, H.
Three cruises on the Wight-Cherbourg transect were undertaken during the FluxManche II Programme in order to study the origin, nature and behaviour of organic matter inputs to the waters of the English Channel. Suspended particulate material (SPM) collected from surface and deep waters at each station was analysed at elemental level for Particulate Organic Carbon and Particulate Organic Nitrogen (POC, PON), at molecular level for main classes of organic compounds using Pyrolysis-Gas Chromatography coupled with Mass Spectrometry (Py-GC-MS) and for phenolic compounds, particularly lignin-derived phenols, using High Performance Liquid Chromatography (HPLC). The SPM content increases from the French (south) to the English coast (north) with the lowest values...
Tipo: Text
Palavras-chave: Matière particulaire en suspension; Composés organiques; Marqueurs phénoliques; Biogéochimie; Manche; Suspended particulate matter; Organic compounds; Phenolic markers; Biogeochemistry; English Channel.
Ano: 1999
URL: http://archimer.ifremer.fr/doc/00325/43603/43922.pdf

Importance de la spéciation des métaux et composés organométalliques pour une bonne évaluation des risques environnementaux en milieu marin. Cas du mercure, de I'arsenic et de l'étain
Provedor de dados: 5
Autores: Michel, Pierre.
Methylmercury toxicity for sea-food consumers is well known long time ago. Tributyltin used as antifouling in paints is toxic at a level as low as 1 ng/l for oysters gastropod. At the opposite, organoarsenic compounds and especially arsenobetaine from fishes are much less toxic than inorganic species. Moreover, besides toxicological considerations, the biogeochemical fates of these elements need a good knowledge of the chemical forms of environmental inputs and of their behaviour in the various compartments (waters, sediments, biota). These phenomenons will be better understood by discussing typical applications.
Tipo: Text
Palavras-chave: Composés organométalliques; Mercure; Arsenic; Étain; Biogéochimie; Organometallic compounds; Mercury; Arsenic; Tin; Biogeochemistry.
Ano: 1992
URL: https://archimer.ifremer.fr/doc/00480/59138/61766.pdf

L'arsenic en milieu marin. Biogeochimie et ecotoxicologie
Provedor de dados: 5
Autores: Michel, Pierre.
Arsenic levels of in the marine environment are high in comparison with other contaminants. Over the past twenty years, a large number of arsenic organic compounds have been identified in the water, sediments and living species. This document constitutes a synthesis of current knowledge on arsenic sources, and contamination levels, on its biogeochemical cycle as well as its toxic effects on human and marine fauna. This paper highlights in particular the effects of phosynthesis on arsenic speciation and its distribution throughout the marine environment. Problems of toxicity in the case of certain phyto- and zooplankton species are identified. Bioaccumulation in seaweeds, molluscs and fishes is documented as well, with special attention to the species...
Tipo: Text
Palavras-chave: Ecotoxicology; Contamination; Biogeochemistry; Arsenic; Ecotoxicologie; Contamination; Biogéochimie; Arsenic.
Ano: 1993
URL: http://archimer.ifremer.fr/doc/1993/rapport-1448.pdf