Contamination by heavy metals (Cd, Zn, Cu, and Hg) of eight fish species in the Gironde estuary (France)     

Gilles Durrieu  Régine Maury-Brachet  Michel Girardin  Eric Rochard  Alain Boudou 《Estuaries and Coasts》2005,28(4):581-591

The Gironde estuary, one of the largest in Europe, is considerated as a reference ecological system, with all the western European diadromous fish species present. The national biomonitoring program on the coastal marine environment has revealed since 1979 severe metal pollution (mostly cadmium [Cd]) in oysters collected from the estuary. No data are available on metal contamination levels in fish, despite their ecological and economic importance. We present the results from a detailed study based on 4 metals (Cd, zinc [Zn], copper [Cu], and mercury [Hg]) measured in 4 organs (gills, dorsal skeletal muscle, liver, and kidneys) from 8 fish species illustrating several ecological combinations: European eel (Anguilla anguilla), twaite shad (Alosa fallax), bass (Dicentrarchus labrax), meagre (Argyrosomus regius), flounder (Platichthys flesus),, thin-lippid grey mullet (Liza ramada), sole (Solea vulgaris), and Canary drum (Umbrina canariensis). The results show very marked differences between species and organs, as well as very significant variations between the 4 metals. Although metal concentrations measured in fish muscle are low, except in the case of Hg for theA. fallax, high levels of Cu and Cd were observed in the kidneys and livers ofL. ramada andA. anguilla. A multifactorial analysis based on rank ordered metal concentrations for the 8 fish species clearly shows 4 clusters of species assigned to the different degrees of metal contamination, from the lowest contaminated (A. regius, D. labrax, S. vulgaris, andU. canariensis), to the most contaminated group (L. ramada). The most contaminated species (L. ramada, A. angailla, andP. flesus) are characterized by long residence times in the estuary, between 3.5 and 14 yr. ForL. ramada, biofilms with high metal storage capacities would be the principal uptake route; the two other species are benthic with a carnivorous regime. Comparisons between our data and four estuaries (Seine, France; Mersey, U.K.; La Plata, Argentina; Guadalquivir, Spain), on a limited number of common species, metals and fish organs, clearly reveal higher Cd bioaccumulation levels in the Gironde estuary.  相似文献   

Sorption of Eu(III)/Cm(III) on Ca-montmorillonite and Na-illite. Part 1: Batch sorption and time-resolved laser fluorescence spectroscopy experiments     

Th. Rabung  A. Bauer  M.H. Bradbury 《Geochimica et cosmochimica acta》2005,69(23):5393-5402

Sorption of Cm(III) and Eu(III) at trace concentrations onto Ca-montmorillonite (SWy-1) and Na-illite (Illite du Puy) has been studied under anaerobic conditions by batch sorption experiments and time-resolved laser fluorescence spectroscopy (TRLFS). Comparison of the results from spectroscopic and batch sorption experiments with Cm and Eu indicates the existence of outer-sphere complexes at pH <4 in the experiments with Na-illite (0.25 g/L solid; 2.5 × 10⁻⁷ mol/L Cm; 0.1 mol/L NaClO₄). In the case of Ca-montmorillonite, (0.25 g/L solid, 2.5 × 10⁻⁷ mol/L Cm or 10⁻⁶ mol/L Eu, 0.066 mol/L Ca(ClO₄)₂), Cm/Eu outer-sphere complexes do not form at significant levels due to the Ca²⁺ competition for the clay mineral cation-exchange sites. TRLFS spectra indicate the formation of inner-sphere surface complexes at pH >5 for both clay minerals. Five H₂O/OH⁻ molecules remain in the first metal ion coordination sphere of the sorbed Eu/Cm. Measured fluorescence lifetimes of sorbed Eu/Cm and peak deconvolution of Cm-spectra are consistent with the formation of surface complexes of the form ≡S-O-Eu/Cm(OH)_x^(2−x)(H₂O)_5−x. At pH ≥ 12 Cm becomes incorporated into a surface precipitate at the Ca-montmorillonite surface presumably composed of Ca(OH)₂ or calcium silicate hydrate. A dramatic shift of the fluorescence emission band by more than 20 nm and a clear increase in the fluorescence lifetime suggests the almost complete displacement of coordinated H₂O and OH⁻. The pH dependent Eu sorption data obtained in batch experiments are consistent with spectroscopic data on Eu and Cm within experimental uncertainties thus demonstrating the validity of Eu as a homologue for trivalent actinides. Parameterization of a two-site protolysis nonelectrostatic surface complexation and cation exchange model using the batch sorption data and spectroscopic results is discussed in Part 2 of this work.  相似文献   

Caractérisation de la structure interne et de l'état hydrique de glissements argilo-marneux par tomographie géophysique : l'exemple du glissement-coulée de Super-Sauze (Alpes du Sud,France)     

Gilles Grandjean  Céline Pennetier  Adnan Bitri  Ombeline Meric  Jean-Philippe Malet 《Comptes Rendus Geoscience》2006,338(9):587-595

Geophysical methods such as seismic surveying and electrical resistivity imaging appear to be well-adapted to investigate and understand landslide mechanisms. They allow direct and non-intrusive measurement of acoustic velocity and electrical resistivity, two fundamental parameters used to define the physical properties of the reworked moving materials. Both methods were applied at the Super-Sauze site in the French South Alps, where a typical example of an intra-material earthflow-mudslide can be observed. Measurements were taken simultaneously along two orthogonal profiles: one 325 m in length is perpendicular to the axis of the earthflow; the other 235 m in length is located along the axis of the earthflow. The results show a correlation between the seismic and electrical resistivity data, confirming that the simultaneous use of both methods gives complementary information about landslide mechanisms. The seismic data provide information on fracture density variations, whereas the electrical resistivity data provide information on water content variations. To cite this article: G. Grandjean et al., C. R. Geoscience 338 (2006).  相似文献   

Natural isotopic composition of nitrogen as a tracer of origin for suspended organic matter in the Scheldt estuary     

André Mariotti  Christiane Lancelot  Gilles Billen 《Geochimica et cosmochimica acta》1984,48(3):549-555

The natural isotopic composition of suspended particulate organic nitrogen was determined in the Southern Bight of the North Sea and in the Scheldt estuary. These data show that δ¹⁵N constitutes a convenient tracer of the origin of the suspended matter.In the winter, in the absence of intensive primary production, the suspended organic matter of the Scheldt estuary is a mixture of two components: a continental detrital component characterized by a low δ value of 1.5%. and a marine component with a mean δ value of 8%..During the phytoplankton flowering period, lasting from early May to October, intensive primary production occurs throughout the estuary giving rise to a third source of organic matter. This material is characterized by high δ values reflecting the isotopic composition of ammonia, the nitrogenous nutrient assimilated by phytoplankton in the estuary.The nitrification process occuring in the mixing area of the Scheldt estuary leads to higher downstream δ values of ammonia (>20%.) which permits the distinction between estuarine from fresh-water phytoplankton. Simple isotopic budget calculations show that, both in the upstream part and in the downstream part, autochthonous phytoplanktonic material contributes a major part of the total suspended matter in the Scheldt estuary during summer.  相似文献   

Verbessertes Unpersönliches Mikrometer für Das Zirkumzenital     

Ivo Baueršíma  Josef Šuráň 《Studia Geophysica et Geodaetica》1963,7(3):209-227

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UD-SV: Urban data services and visualization framework for sharing multidisciplinary research     

John Samuel  Vincent Jaillot  Clément Colin  Diego Vinasco Alvarez  Eric Boix  Sylvie Servigne  Gilles Gesquière 《Transactions in GIS》2023,27(3):841-858

With the widespread availability of a large volume of urban data, stakeholders from different domains require advanced tools to manage, visualize and understand cities and their evolution. During the last few years, researchers have proposed numerous research works and applications to illustrate the cities of the past and possible scenarios of the future under different conditions. However, many of these approaches are one-time solutions and not based on standards, making them obsolete and unusable for reproducible research. In this article, we present UD-SV: an Urban data-Services and Visualization open-source framework for multidisciplinary research to handle complex processing, analysis, and visualization of urban data. However, our goal is not to present a one-time monolithic software solution for urban data management and analysis, but we demonstrate the design and development of an open and interoperable software framework driven by use cases from diverse users to solve applied research challenges. The main contribution of UD-SV is that it uses open standards and open data with documented and reproducible processes with a particular emphasis on the reuse of existing open-source software components. We also show an enhanced use of standards to enable a shift toward components that are interchangeable or composable with other existing components in the GIS community.  相似文献   

New palaeontological data from the organic-rich layers of the Bathonian of the Grands Causses (France)     

Fabien Knoll  Gilles Cuny  Pierre-Olivier Mojon  Raquel López-Antoñanzas 《Proceedings of the Geologists' Association. Geologists' Association》2014

The palaeontological content (charophytes and vertebrates) of organic-rich layers from the Middle Jurassic (Bathonian) of the Grands Causses at Mostuéjouls (Aveyron, France) has been examined. It is rich in gyrogonites of Porochara douzensis. The vertebrates of the lower layer include a single hybodontiform tooth, “semionotiform” teeth and scales, and one pycnodontiform tooth whereas the upper layer has yielded one hybodontiform tooth, a variety of actinopterygian remains (mostly Caturus sp. and indeterminate pycnodontiforms) and a few possible reptile remains. The variation in fauna between the two layers is ascribed to a different degree of marine influence.  相似文献