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Resultados 2131-2140 de 62,084
Marine litter: One of the major threats for marine mammals. Outcomes from the European Cetacean Society workshop
2019
Panti, Cristina | Baini, M | Lusher, Amy | Hernandez-Milian, Gema | Rebolledo, Elisa L. Bravo | Unger, Bianca | Syberg, Kristian | Simmonds, Mark P. | Fossi, Maria Cristina
Embargo until 09 January 2021 | Marine litter is a pollution problem affecting thousands of marine species in all the world's seas and oceans. Marine litter, in particular plastic, has negative impacts on marine wildlife primarily due to ingestion and entanglement. Since most marine mammal species negatively interact with marine litter, a first workshop under the framework of the European Cetacean Society Conference, was held in 2017 to bring together the main experts on the topic of marine mammals and marine litter from academic and research institutes, non-governmental organisations, foundations and International Agreements. The workshop was devoted to defining the impact of marine litter on marine mammals by reviewing current knowledge, methodological advances and new data available on this emerging issue. Some case studies were also presented from European waters, such as seals and cetaceans in the North, Baltic, and Mediterranean Seas. Here, we report the main findings of the workshop, including a discussion on the research needs, the main methodological gaps, an overview of new techniques for detecting the effects of marine litter (including microplastics) on marine mammals and, also, the use of citizen science to drive awareness. The final recommendations aim to establish priority research, to define harmonised methods to detect marine litter and microplastics, enforce networking among institutions and support data sharing. The information gathered will enhance awareness and communication between scientists, young people, citizens, other stakeholders and policy makers, and thereby facilitate better implementation of international directives (e.g., the Marine Strategy Framework Directive) in order to answer the question about the actual status of our oceans and finding solutions. | acceptedVersion
Mostrar más [+] Menos [-]Tools and constraints in monitoring interactions between marine litter and megafauna: Insights from case studies around the world
2019
Claro, Francoise | Fossi, Maria Cristina | Ioakeimidis, Christos | Baini, Matteo | Lusher, Amy L | McFee, Wayne | McIntosh, Rebecca Ruth | Pelamatti, Tania | Sorce, Meaghan | Galgani, François | Hardesty, Britta Denise
Embargo until 22 Feb 2021 | Adverse impacts of marine litter is documented on >1400 species, including marine megafauna (fish, birds, sea turtles and mammals). The primary impacts include ingestion and entanglement, and there is increasing concern about chemical contamination via ingestion. Numerous survey approaches and monitoring programs have been developed and implemented around the world. They may aim to provide data about parameters such as species distribution and interactions with anthropogenic activities. During the Sixth International Marine Debris Conference, a session was dedicated to the tools and constraints in monitoring interactions between litter and megafauna. In the present paper, we summarize 7 case studies which discuss entanglement and ingestion including macro- and micro-debris in several taxa and across multiple geographic regions. We then discusses the importance of tools and standardizing methods for assessment and management purposes, in the context of international environmental policies and marine litter strategies. | acceptedVersion
Mostrar más [+] Menos [-]Study of the oil interaction towards oil spill recovery skimmer material: Effect of the oil weathering and emulsification properties
2018
Farooq, Umer | Taban, Ingrid Christina | Daling, Per Snorre
The primary aim of this research was to identify the physicochemical properties of the oil and water-in-oil (W/O) emulsions used during a NOFO Oil-on-Water field trials that reduced the performance of the skimmers recovery efficacy during the trials. Extensive studies were performed at SINTEF laboratories with the residues of oil topped (i.e. evaporative loss of crude oil components by distillation process at large scale) for the field trial and compared it with different residues of oil topped by bench scale laboratory procedures. In order to obtain a sufficient stable W/O emulsion for the field trial, bunker fuel oil (IFO380) and various concentrations of an emulsifier (Paramul®) were also added to the residues of oil topped on large scale and investigated through interfacial tension, contact angle, droplet adhesion and “dip and withdraw” tests. The investigations revealed that the addition of an emulsifier lowered the interfacial tension of oil residues, which consequently reduced the adherence properties of the oil and emulsions to the surface of the skimmer material. Too high concentration of an emulsifier (>0,5%) also had a negative effect on the stability of W/O emulsion. | Study of the oil interaction towards oil spill recovery skimmer material: Effect of the oil weathering and emulsification properties | acceptedVersion
Mostrar más [+] Menos [-]Influence de pratiques réelles d’utilisations sur les émissions d’un appareil de chauffage domestique au bois
2018
Brandelet, Benoît | Rose, Christophe | Landreau, Julien | Rogaume, Caroline | Druette, Lionel | Rogaume, Yann
L’objectif de cette étude est de mettre en évidence l’influence sur les émissions et les performances d’un appareil de différents paramètres, comme l’humidité du bois, la présence d’écorce ou non, le calibre utilisé ainsi que le mode d’allumage. De nombreux résultats ressortent de cette étude. Tout d’abord, tous ces paramètres influent de manière considérable sur les émissions des appareils, notamment les émissions de particules, et ce, même à régime nominal. La présence d’écorce modifie la composition en carbone total des particules totales et implique l’émission d’un nouveau type de particule : les nano-cristaux. Une humidité élevée induit des niveaux de températures plus faibles. Ainsi, les émissions d’imbrûlés gazeux tels que les Composés Organiques Volatils vont augmenter de manière importante. Les émissions de particules, en quantité et en composition chimique, sont aussi significativement impactées par l’humidité du combustible. Deux modes d’allumage ont aussi été étudiés. Il s’avère qu’un allumage inversé permet de réduire de manière significative la globalité des émissions par rapport à un allumage classique. En effet, seules les émissions de Carbone Elémentaire sont plus importantes avec un allumage inversé. | he aim of this study is to bring to light the influence on firewood emissions and performance of several parameters like the moisture content of the fuel, the presence of bark, the caliber of the fuel but also the ignition mode. Many results emerge from this study. First of all, all these parameters significantly impact the emissions of the firewood at the nominal thermal heat output, especially the particles emissions. The presence of bark modifies the particles composition in total carbon. Moreover, the presence of bark induces the emissions of a new family of particles: the nanocrystal. A high moisture of the fuel led to a lower temperature in the combustion chamber. Then, the emissions of unburned gases, like the Volatile Organic Compounds, will considerably increase. The particles emissions and the composition of those particles were also significantly impacted by the moisture of the fuel. Two ignition modes were also studied. It appears that the top-down ignition against the traditional ignition allowed a significant decrease of all the emissions. Nevertheless, the elemental carbon emissions were more important with a top-down ignition.
Mostrar más [+] Menos [-]Microplastics in livers of European anchovies (Engraulis encrasicolus, L.)
2017
Collard, France | Gilbert, Bernard | Compère, Philippe | Eppe, Gauthier | Das, Krishna | Jauniaux, Thierry | Parmentier, Eric
peer reviewed | Microplastics (MPs) are thought to be ingested by a wide range of marine organisms before being excreted. However, several studies in marine organisms from different taxa have shown that MPs and nanoplastics could be translocated in other organs. In this study, we investigated the presence of MPs in the livers of commercial zooplanktivorous fishes collected in the field. The study focuses mainly on the European anchovy Engraulis encrasicolus but concerns also the European pilchard Sardina pilchardus and the Atlantic herring Clupea harengus. Two complementary methodologies were used to attest the occurrence of MPs in the hepatic tissue and to exclude contamination. 1) MPs were isolated by degradation of the hepatic tissue. 2) Cryosections were made on the livers and observed in polarized light microscopy. Both methods separately revealed that MPs, mainly polyethylene (PE), were translocated into the livers of the three clupeid species. In anchovy, 80 per cent of livers contained relatively large MPs that ranged from 124 μm to 438 μm, showing a high level of contamination. Two translocation pathways are hypothesized: (i) large particles found in the liver resulted from the agglomeration of smaller pieces, and/or (ii) they simply pass through the intestinal barrier. Further studies are however required to understand the exact process. © 2017 Elsevier Ltd
Mostrar más [+] Menos [-]L’agriculture entre pollution atmospherique et changement climatique
2016
Cellier, Pierre | Génermont, Sophie,
Les agroécosystèmes sont des sources et des puits de polluants atmosphériques et de gaz à effet de serre et, par là-même, ils interviennent dans les relations entre climat et pollution de l’air. Cette contribution, positive ou négative, résulte de processus complexes, à la fois directs et indirects, et prend des formes très diverses : augmentation ou diminution des émissions et dépôts, augmentation attendue de la fréquence des feux, modification de la protection phytosanitaire etc. Comme pour la plupart des processus biologiques, les incertitudes sont importantes et les verrous de connaissances restent nombreux, alors qu’une connaissance des différents facteurs d’influence, naturels et anthropiques est nécessaire pour limiter la contribution des agroécosystèmes à la fois au changement climatique et à la pollution de l’air, tout en préservant les performances économiques de l’activité agricole. Enfin, l’agriculture est concernée par tout un ensemble de politiques publiques relatives au changement climatique et à la pollution de l’air, mais également à la pollution des eaux et à la protection de l’environnement, politiques publiques qui peuvent interagir en synergie ou être antagonistes. | Interactions between climate change and air pollution in the context of agriculture. Agroecosystems are sources and sinks of atmospheric pollutants and greenhouse gases. They are therefore involved in climate change and air pollution and their cross-relations. This contribution can be positive or negative. It results from complex processes, both direct and indirect, which is related to a range of topics: increase or decrease of emission and deposition, increase in fire frequency, change in plant protection etc. As for most of biological processes, there are large uncertainties and knowledge is lacking over a range of fields. However it is necessary to have a global overview of the involved processes and drivers when trying to limit the contribution of agroecosystem both to climate change and air pollution, with attention to the economic sustainability of agriculture under global change. Moreover agriculture activities refer to public policies related not only to climate change and air pollution but also water pollution or protection of the environment. These policies may interact positively or be antagonist.
Mostrar más [+] Menos [-]DECOMBIO - Contribution de la combustion de la biomasse aux PM10 en vallée de l’Arve : mise en place et qualification d’un dispositif de suivi
2016
Chevrier, Florie | JEžEK, Irena | Brulfert, Guillaume | MOčnik, Grisa | Marchand, Nicolas | Jaffrezo, Jean-Luc | Besombes, Jean-Luc
Caractéristiques et origines principales des épisodes de pollution hivernaux aux PM10 en France | Main properties and origins of winter PM10 pollution events in France
2012
Favez, Olivier | Petit, Jean-Eudes | Bessagnet, Bertrand | Meleux, Frédérik | Chiappini, Laura | Lemeur, Sébastien | Labartette, Claire | Chappaz, Claire | Guergnion, Pierre-Yves | Saison, Jean-Yves | Chretien, Eve | Pallares, Cyril | Verlhac, Stéphane | Aujay, Robin | Malherbe, Laure | Beauchamp, Maxime | Piot, Christine | Jaffrezo, Jean-Luc | Besombes, Jean-Luc | Sciare, Jean | Rouil, Laurence | Leoz-Garziandia, Eva
This paper aims at gaining an insight into the PM10 daily threshold (50 micro g/m3) exceedances measured by French regional air quality monitoring networks for the last four years. As almost three quarter of these exceedances happens to occur between November and April, we focus here on such winter (broadly speaking) pollution episodes. The deployment of monitoring devices allowing for a proper account of semi-volatile material within PM10 was achieved concomitantly to the development particulate pollution episodes largely influenced by ammonium nitrate (which is semi-volatile) in March-April 2007. Since then, such pollution events are frequently observed at this period of the year, notably due to stable meteorological conditions favoring the condensation of semi-volatile material into the particulate phase along with the resumption of manure spreading, which constitutes a major source of ammonium nitrate gaseous precursors (at least at some points of the year). Such pollution events, which are also related to combustion emissions (among which mobile sources) are typically preceded, from November to February, by frequent daily threshold exceedances with potentially significant influences of biomass burning (e.g. residential wood burning). The winter period is also impacted by long range transport episodes, corresponding notably to increases of ammonium sulfate relative abundances within PM10. Moreover, as traffic sites are generally the first ones showing PM10 exceedances due the increment of direct emissions and resuspension processes, mobile sources are also considered as a major target for action plans. Finally, it is underlined that the occurrence of daily threshold exceedances is highly influenced by meteorological conditions, so that the yearly number of these exceedances shows well-marked inter-annual variations, with 2009 and 2011 (and 2012, but not shown here) being significantly more polluted than 2008 and 2010. The on-going development of efficient forecasting systems still suffer lacks of detailed emission inventories and strong knowledge on the physical and chemical transformation processes of particles and their gaseous precursors within the boundary layer. | Cette synthèse dresse une analyse non exhaustive des dépassements du seuil réglementaire journalier de 50 micro g/m3 pour les PM10 mesurés au niveau national par les Associations Agréées de Surveillance de la Qualité de l'Air (AASQA) au cours des quatre dernières années. Près des trois quarts de ces dépassements étant observés entre fin novembre et début avril, nous nous intéressons plus particulièrement ici à ces épisodes hivernaux (au sens large). La mise en oeuvre de techniques analytiques permettant une prise en compte correcte des espèces semi-volatiles dans la composition des PM10 a coïncidé en mars-avril 2007 à la survenue de nombreux dépassements de seuil journalier s'accompagnant d'importants niveaux de nitrate d'ammonium (composé semi-volatil). Ce type d'épisode est régulièrement observé à cette période. Il s'explique notamment par la conjonction de conditions atmosphériques stables et propices à la condensation en phase particulaire des espèces labiles, et de la reprise des épandages agricoles, constituant une source majeure, au moins ponctuellement, de précurseurs gazeux azotés du nitrate d'ammonium. Ce type d'épisode, mettant également en cause les émissions anthropiques de combustion (dont les transports), est typiquement précédé entre novembre et février de fréquents dépassements pour lesquels le rôle des combustions de biomasse (incluant notamment le chauffage au bois individuel) peut être important. La période hivernale est également marquée par l'occurrence de phénomènes de transport longue distance se caractérisant par une augmentation des contributions du sulfate d'ammonium. Les sites de proximité automobile étant généralement les premiers concernés par les dépassements du seuil journalier en raison du surplus de concentrations provenant des émissions à l'échappement et des phénomènes de remise en suspension, le transport routier est également considéré comme un levier incontournable pour le respect des valeurs limites. Enfin, il est souligné que l'occurrence des différents types d'épisodes de dépassements dépend fortement des conditions météorologiques, de sorte qu'on observe une forte variabilité interannuelle du nombre de dépassements hivernaux ? : 2009 et 2011 (et 2012) étant significativement plus impactées que 2008 et 2010. Une bonne prévision de ces épisodes passe encore par l'affinage des cadastres d'émission et une meilleure compréhension du devenir dans l'atmosphère des émissions primaires (gazeuses et particulaires).
Mostrar más [+] Menos [-]Inter-species differences for polychlorinated biphenyls and polybrominated diphenyl ethers in marine top predators from the Southern North Sea: Part 1. Accumulation patterns in harbour seals and harbour porpoises
2009
Weijs, Liesbeth | Dirtu, Alin C | Das, Krishna | Gheorghe, Adriana | Reijnders, Peter | Neels, Hugo | Blust, Ronny | Covaci, Adrian | MARE - Centre Interfacultaire de Recherches en Océanologie - ULiège
peer reviewed | Harbour porpoises (Phocoena phocoena) and harbour seals (Phoca vitulina) are two representative top predator species of the North Sea ecosystem. The median values of sum of 21 polychlorinated biphenyl (PCB) congeners and sum of 10 polybrominated diphenyl ether (PBDE) congeners were 23.1 mg/g lipid weight (lw) and 0.33 mg/g lw in blubber of harbour seals (n ¼ 28) and 12.4 mg/g lw and 0.76 mg/g lw in blubber of harbour porpoises (n¼ 35), respectively. For both species, the highest PCB concentrations were observed in adult males indicating bioaccumulation. On the contrary, the highest PBDE concentrations were measured in juveniles, likely due to better-developed metabolic capacities with age in adults. A higher contribution of lower chlorinated and non-persistent congeners, such as CB 52, CB 95, CB 101, and CB 149, together with higher contributions of other PBDE congeners than BDE 47, indicated that harbour porpoises are unable to metabolize these compounds. Harbour seals showed a higher ability to metabolize PCBs and PBDEs.
Mostrar más [+] Menos [-]Inter-species differences for polychlorinated biphenyls and polybrominated diphenyl ethers in marine top predators from the Southern North Sea: Part 2. Biomagnification in harbour seals and harbour porpoises
2009
Weijs, Liesbeth | Dirtu, Alin C | Das, Krishna | Ghorghe, Adriana | Reijnders, Peter | Neels, Hugo | Blust, Ronny | Covaci, Adrian | MARE - Centre Interfacultaire de Recherches en Océanologie - ULiège
peer reviewed | Harbour porpoises (Phocoena phocoena) and harbour seals (Phoca vitulina) were found to differ in the ability to metabolize polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs). Biomagnification factors (BMFs), calculated between both predators and their prey (sole – Solea solea and whiting – Merlangius merlangus), had a large range of variation (between 0.5 and 91 for PCBs and between 0.6 and 53 for PBDEs). For the higher chlorinated PCBs and the highest brominated PBDEs, the BMF values in adult males were significantly higher than in the juvenile individuals of both species. BMF values of hexa- to octa-PCBs were the highest, suggesting reduced ability to degrade these congeners. Harbour porpoises had higher BMFs for lower chlorinated PCBs and for all PBDEs compared to harbour seals. Other factors, which may influence biomagnification, such as the octanol–water partition coefficients and the trophic level position measured through stable isotope (d15N) analysis, were found to be of lesser importance to predict biomagnification in the studied food chain.
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