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Resultados 1-4 de 4
Microplastic inputs to the Mediterranean Sea during wet and dry seasons: The case of two Lebanese coastal outlets
2024
Sawan, Rosa | Doyen, Périne | Viudes, Florence | Amara, Rachid | Mahfouz, Céline | Laboratoire d’Océanologie et de Géosciences (LOG) - UMR 8187 (LOG) ; Institut national des sciences de l'Univers (INSU - CNRS)-Université du Littoral Côte d'Opale (ULCO)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Nord]) | BioEcoAgro - UMR transfrontalière INRAE 1158 ; Université d'Artois (UA)-Université de Liège-Université de Picardie Jules Verne (UPJV)-Université du Littoral Côte d'Opale (ULCO)-Université de Lille-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-JUNIA (JUNIA) ; Université catholique de Lille (UCL)-Université catholique de Lille (UCL) | Biochimie des Produits Aquatiques (BPA) ; Université du Littoral Côte d'Opale (ULCO)-BioEcoAgro - UMR transfrontalière INRAE 1158 ; Université d'Artois (UA)-Université de Liège-Université de Picardie Jules Verne (UPJV)-Université du Littoral Côte d'Opale (ULCO)-Université de Lille-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-JUNIA (JUNIA) ; Université catholique de Lille (UCL)-Université catholique de Lille (UCL)-Université d'Artois (UA)-Université de Liège-Université de Picardie Jules Verne (UPJV)-Université du Littoral Côte d'Opale (ULCO)-Université de Lille-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-JUNIA (JUNIA) ; Université catholique de Lille (UCL)-Université catholique de Lille (UCL) | Université du Littoral Côte d'Opale (ULCO) | National Center for Marine Sciences [Lebanon] ; National Council for Scientific Research = Conseil national de la recherche scientifique du Liban [Lebanon] (CNRS-L)
International audience | This paper presents a new Remote Hyperspectral Imaging System (RHIS) embedded on an Unmanned Aquatic Drone (UAD) for plastic detection and identification in coastal and freshwater environments. This original system, namely the Remotely Operated Vehicle of the University of Littoral Côte d’Opale (ROV-ULCO), works in a near-field of view, where the distance between the hyperspectral camera and the water surface is about 45 cm. In this paper, the new ROV-ULCO system with all its components is firstly presented. Then, a hyperspectral image database of plastic litter acquired with this system is described. This database contains hyperspectral data cubes of different plastic types and polymers corresponding to the most-common plastic litter items found in aquatic environments. An in situ spectral analysis was conducted from this benchmark database to characterize the hyperspectral reflectance of these items in order to identify the absorption feature wavelengths for each type of plastic. Finally, the ability of our original system RHIS to automatically recognize different types of plastic litter was assessed by applying different supervised machine learning methods on a set of representative image patches of marine litter. The obtained results highlighted the plastic litter classification capability with an overall accuracy close to 90%. This paper showed that the newly presented RHIS coupled with the UAD is a promising approach to identify plastic waste in aquatic environments.
Mostrar más [+] Menos [-]Large-scale geographic patterns of mercury contamination in Morocco revealed by freshwater turtles
2018
Slimani, Tahar | El Hassani, Mohamed Said | El Mouden, El Hassan | Bonnet, Marine | Bustamante, Paco | Brischoux, Francois | Brault-Favrou, Maud | Bonnet, Xavier | Faculté des Sciences Semlalia [Marrakech] ; Université Cadi Ayyad [Marrakech] (UCA) | Centre d'Études Biologiques de Chizé - UMR 7372 (CEBC) ; Institut National de la Recherche Agronomique (INRA)-La Rochelle Université (ULR)-Centre National de la Recherche Scientifique (CNRS) | LIttoral ENvironnement et Sociétés (LIENSs) ; La Rochelle Université (ULR)-Centre National de la Recherche Scientifique (CNRS)
International audience | Mercury (Hg) is a toxic contaminant present in most aquatic ecosystems. High concentrations pose serious threats to organisms and to human health. Because previous studies focused on few countries, environmental hazard due to Hg contamination remains obscure in many geographic areas, and for example limited information is available in North Africa. We examined total Hg contamination in 13 sites in Morocco (12 rivers and one lake) spread over a large area, 400 km north–south and 350 km west–east, that encompasses different biogeographic zones separated by the Atlas Mountains. Due to their longevity and sedentary habits, we used freshwater turtles as biological probes to monitor Hg exposure. Keratinized tissues reflect long-term Hg exposure; thus, we assayed Hg concentration in the claws of > 200 individuals and supplemented these data with blood Hg concentrations of > 60 individuals (a tissue that provides shorter term Hg exposure integration). The results provide the first large-scale picture of Hg contamination in the aquatic freshwater systems of Morocco. Comparisons with previous studies revealed that some of the sites were highly contaminated (e.g. mean Hg concentrations were above 5 μg g⁻¹, a very high level in keratinized tissues) whereas other sites presented moderate or baseline levels. Unexpectedly, all highly contaminated sites were found in less densely populated areas, while more densely urbanized northern sites, even the sewers of large cities, were not highly contaminated. We hypothesize that silver mining activities in the southern High Atlas and in the Anti-Atlas contaminate rivers of the catchment basins over long distances. These findings indicate that fish, water consumption and contamination levels in local people should be further scrutinized.
Mostrar más [+] Menos [-]Mercury transfer (Hg) localization using bryophytic bioindicators as describers of the hydrological functioning (river - groundwater exchange) in the plain of the upper Rhine in Alsace (France) [principal component analysis, multiple correspondence factor analysis]
1995
Roeck, U. (Universite de Strasbourg 1, Illkirch Graffenstaden (France). Departement Hydrologie et Environnement) | Glasser, N. | Tremolieres, M.
Measurement of MFO [mixed function oxidase] levels in roach as a biomarker of PAH [polycyclic aromatic hydrocarbons] levels in freshwater systems in UK
1995
O'Hare, D.B. (University of Derby (Royaume Uni). School of Environmental and Applied Sciences, Department of Biology) | Siddall, R. | Gill, R.A. | Robotham, P.W.J.