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| Registros recuperados: 16 | |
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| Drouineau, Hilaire; Lobry, Jeremy; Delpech, C.; Bouchoucha, Marc; Mahevas, Stephanie; Courrat, A.; Pasquaud, S.; Lepage, M.. |
| In the context of the European Water Framework Directive (WFD), monitoring programs and related indicators have been developed to assess anthropogenic impacts on various components of aquatic ecosystems. While great precautions are usually taken when selecting and calculating relevant core metrics, little attention is generally paid to the generation of the multimetric indicator, i.e. the combination of the different core metrics. Indeed, most multimetric indicators are generated by simply averaging or summing metrics, without taking into account their sensitivity and their variability. Moreover, few indicators provide a rigorous estimate of the uncertainty of the assessments, while this estimation is essential for managers. In this context, we developed a... |
| Tipo: Text |
Palavras-chave: Multimetric fish-based indicator; Bayesian method; Pressure-impact models; Water Framework Directive; Anthropogenic pressure; Monitoring program; Transitional waters. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00049/16037/13572.pdf |
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| Gascuel, D.; Bez, Nicolas; Forest, Andre; Guillotreau, P.; Laloe, F.; Lobry, Jeremy; Mahevas, Stephanie; Mesnil, Benoit; Rivot, Etienne; Rochette, S.; Trenkel, Verena. |
| We, members of the Association Francaise d'Halieumetrie, share the conviction that European fisheries have a future. It is time to get off the wrong track. Radical change is required to embark on the path of sustainable development and truly implement the ecosystem approach to fisheries. Today, high fishing pressure is deployed to catch a rare resource, which in return is responsible for the rarity. We must reverse the situation: an abundant resource that affords high catches applying moderate fishing pressure. All management tools and especially all actors must be mobilized. The transition is not simple, and European solidarity must accompany the changes. It is well worth the effort. By reducing fishing pressure, it will be possible in the medium term to... |
| Tipo: Text |
Palavras-chave: Access regulation; Ecosystem approach to fisheries; European Common Fishery Policy; ITQ; MPA; MSY; Management plan; Overcapacity; Subsidies. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00035/14598/11947.pdf |
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| Chevillot, Xavier; Pierre, Maud; Rigaud, Arthur; Drouineau, Hilaire; Chaalali, Aurelie; Sautour, Benoit; Lobry, Jeremy. |
| For decades, global climate change has directly and indirectly affected the structure and function of ecosystems. Abrupt changes in biodiversity have been observed in response to linear or sudden modifications to the environment. These abrupt shifts can cause long-term reorganizations within ecosystems, with communities exhibiting new functional responses to environmental factors. Over the last 3 decades, the Gironde estuary in southwest France has experienced 2 abrupt shifts in both the physical and chemical environments and the pelagic community. Rather than describing these shifts and their origins, we focused on the 3 inter-shift periods, describing the structure of the fish community and its relationship with the environment during these periods. We... |
| Tipo: Text |
Palavras-chave: Ecosystem state; Fish diversity; Estuary; Generalised linear mixed models; GLMM; Time series; Shift; Inter-shift periods. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00334/44567/44282.pdf |
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| Lassalle, Geraldine; Gascuel, Didier; Le Loch, Francois; Lobry, Jeremy; Pierce, Graham John; Ridoux, Vincent; Santos, Maria Begona; Spitz, Jerome; Niquil, Nathalie. |
| A number of marine mammal populations is currently threatened by their interactions with fisheries. The present study aimed to provide insights into the severity of potential impacts of operational and biological interactions between top predators and fisheries, in the Bay of Biscay region. Our approach was to modify an Ecopath with Ecosim (EwE) model describing the overall structure and function of the ecosystem by including landings and discards of exploited stocks and estimations of the bycatch of non-target compartments. Second, a set of ecological indices and a trophic level (TL)-based model (EcoTroph, ET) were derived from the EwE model. ET was used to simulate the effects of increasing fishing pressure on the ecosystem and, more particularly, on top... |
| Tipo: Text |
Palavras-chave: Ecopath; Ecosystem modelling; EcoTroph; Fisheries impacts; Marine mammals; Trophic level. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00087/19855/17541.pdf |
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| Courrat, A.; Lobry, Jeremy; Nicolas, D.; Laffargue, Pascal; Amara, R.; Lepage, M.; Girardin, M.; Le Pape, O.. |
| Estuaries serve as nursery grounds for many marine fish species. However increasing human activities within estuaries and surrounding areas lead to significant habitat loss for the juveniles and decrease the quality of the remaining habitats. This study is based on the data of 470 beam trawls from surveys that were conducted in 13 French estuaries for the purpose of the European Water Framework Directive. It aimed at testing the effects of anthropogenic disturbances on the nursery function of estuaries. With a multispecific approach based on ecological guilds, two fish metrics, abundance and species richness of Marine juvenile migrant fishes, were used as proxies for the estuarine nursery function. Indices of heavy metal and organic contaminations were... |
| Tipo: Text |
Palavras-chave: Contamination; Anthropogenic disturbances; Fish indicators; Estuaries; Nursery grounds; Essential fish habitat. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6291.pdf |
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| Brind'Amour, Anik; Lobry, Jeremy. |
| When reviewing the various fish-based community indicators aiming at assessing the ecological status of marine communities and/or ecosystems, a typology consisting of three major components emerges. The first component highlights the choice of relevant metrics associated with a level of organization (e. g. population or community). The second relies on the method used to combine the metrics (an aggregated indicator or a synoptic table). The third refers to the type of analysis (direct or indirect) that is used to establish the link between the metrics and a given pressure. In this paper we use the Vilaine coastal-estuarine fish communities as a case study to discuss and relate two different approaches to the suggested typology. The first approach... |
| Tipo: Text |
Palavras-chave: Coastal ecosystems; Fish communities; Indicators; Integrated approaches; Metric; Typology of fish indicators. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/00000/11174/7532.pdf |
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| Lobry, Jeremy; David, V; Pasquaud, S; Lepage, M; Sautour, B; Rochard, E. |
| Estuarine areas provide highly valuable ecosystem benefits for human populations, despite being under intense demographic, economic and ecological pressures. Hence, an understanding of the structure and function of estuarine ecosystems is essential for understanding the persistence and stability of these ecosystems and their response to perturbations. This study synthesises available data and knowledge about the Gironde estuary (SW France) in a mass-balanced trophic model to illustrate potential key patterns in the functioning of the estuarine ecosystem and key elements of its stability. In order to evaluate the total direct and indirect impact on the whole community of the 2 main sources of anthropogenic perturbations in the estuarine area, mortalities... |
| Tipo: Text |
Palavras-chave: Gironde estuary; Ecopath; Diversity; Stability; Network analysis; Food web; Estuarine ecosystem. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-4290.pdf |
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| Tecchio, Samuele; Chaalali, Aurelie; Raoux, Aurore; Rius, Armonie Tous; Lequesne, Justine; Girardin, Valerie; Lassalle, Geraldine; Cachera, Marie; Riou, Philippe; Lobry, Jeremy; Dauvin, Jean-claude; Niquil, Nathalie. |
| During 2002–2005, a new container terminal in the commercial harbour of Le Havre, named “Port2000”, was built on the northern flank of the Seine estuary, northern France. This extension is already known to have modified the estuary current and sediment dynamics, as well as reducing biomass of the suprabenthos assemblage, for the whole downstream part of the system. However, studies on other biotic communities were largely inconclusive, and an ecosystem-wide analysis was still lacking. Here, we performed a before/after study of ecosystem dynamics of the different habitats of the Seine estuary, using a Linear Inverse Modelling technique (LIM-MCMC) to estimate all flows occurring in the food web. Ecological Network Analysis indices were calculated,... |
| Tipo: Text |
Palavras-chave: Linear inverse model; Estuarine ecosystem; Seine estuary; English Channel. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00288/39916/44274.pdf |
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| Pasquaud, Stéphanie; Lobry, Jeremy; Elie, Pierre. |
| Estuarine areas are sites of human pressures and degradation. In order to maintain and/or restore the quality of estuarine ecosystems, it is necessary to describe their structure and functioning. For that reason, many recent scientific works focus on food webs, which are depicted as being good indicators of the functioning of aquatic ecosystems. Hence it is necessary to question how estuarine food webs can be described. This paper proposes a pragmatic and practical review of the most widely used techniques (stomach/gut content analysis, stable isotope ratios and biochemical markers) with emphasis on their main advantages, drawbacks and bias according to possible ecological goals (ecological quality objectives). These approaches, although quite different,... |
| Tipo: Text |
Palavras-chave: Trophic model; Biochemical marker; Stable isotope; Stomach/gut content analysis; Estuarine food web. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-2784.pdf |
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| Lobry, Jeremy; Lepage, Mario; Rochard, Eric. |
| Detecting changes in animal communities suggests that a reference situation exists. It is a particularly difficult task in estuarine environments that are complex and fluctuate with time. Effects of human pressures are difficult to assess due to the scarcity or even the lack of evaluation and monitoring systems. In order to detect anomalies in the functioning of the system and to identify effects of perturbations upon populations and communities, it is necessary to analyse the dynamics in order to infer a reference state. This work aims to describe an approach based on K-Tab analyses and allows to define an average situation called "compromise" which is then compared to a single year of data. In this situation, the Gironde estuary, which has been monitored... |
| Tipo: Text |
Palavras-chave: Fish and shrimp assemblages dynamics; Gironde estuary; Correspondence analysis; Spatial pattern; STATIS. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-1989.pdf |
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| Morin, Jocelyne; Bertrand, Jacques; Cochard, Marie-laure; Coppin, Franck; Leaute, Jean-pierre; Lobry, Jeremy; Mahe, Jean-claude; Poulard, Jean-charles; Rochet, Marie-joelle; Schlaich, Ivan; Souplet, Arnauld; Trenkel, Verena; Vaz, Sandrine; Verin, Yves. |
| Since about twenty years, Ifremer have carried out fishery surveys along the French coasts. A dynamic indicator-based approach to the assessment of multi-stock fisheries has been applied to these data series. Reference points for non-commercial populations and community indicators are seldom available, but reference directions are well established: it is known whether fishing will increase or decrease the indicator, hence the direction that should be avoided. A set of simple indicators of fishing impacts on fish populations and communities were estimated from time-series data provided by scientific surveys (population abundance and average length, community total biomass and number, average length and weight, and size spectrum). Trends in these indicators... |
| Tipo: Text |
Palavras-chave: Communauté; Population; Indicateurs; Campagnes scientifiques; Pêcheries multi spécifiques; Approche écosystémique pour la gestion des pêches. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/rapport-7293.pdf |
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| Bertrand, Jacques; Cochard, Marie-laure; Coppin, Franck; Leaute, Jean-pierre; Lobry, Jeremy; Mahe, Jean-claude; Morin, Jocelyne; Poulard, Jean-charles; Rochet, Marie-joelle; Schlaich, Ivan; Souplet, Arnauld; Trenkel, Verena; Verin, Yves; SIH-C. |
| The integration of fishing management into the ecosystemic approach has been recommended for many years by international consultative bodies; it is also written into international conventions and agreements. The implementation of the ecosystemic approach involves the development of programmes for monitoring exploited ecosystems in order to measure the effects of management steps. Plotting the results of these observations for operational reasons requires formalizing summary performance indicators. IFREMER has carried out halieutic observation campaigns for some twenty years along the coasts of France from oceanographic ships and chartered ships. The objective of these campaigns is to produce abundance indices of species that are of halieutic interest.... |
| Tipo: Text |
Palavras-chave: Ecosystem; Indicating; Scientific survey; Scientific research; Fishing; English Channel; Bay of Biscay; France; Shellfish; Fish; Invertébrés; Poissons; Ecosystème; Indicateur; Campagne océanographique; Recherche scientifique; Pêche halieutique; Pêche; Mer du nord; Golfe de gascogne; Manche; France. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/rapport-2327.pdf |
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| Tecchio, Samuele; Rius, Antonio; Dauvin, Jean-claude; Lobry, Jeremy; Lassalle, Geraldine; Morin, Jocelyne; Bacq, Nicolas; Cachera, Marie; Chaalali, Aurelie; Villanueva, Ching-maria; Niquil, Nathalie. |
| Ecological network analysis was applied in the Seine estuary ecosystem, northern France, integrating ecological data from the years 1996 to 2002. The Ecopath with Ecosim (EwE) approach was used to model the trophic flows in 6 spatial compartments leading to 6 distinct EwE models: the navigation channel and the two channel flanks in the estuary proper, and 3 marine habitats in the eastern Seine Bay. Each model included 12 consumer groups, 2 primary producers, and one detritus group. Ecological network analysis was performed, including a set of indices, keystoneness, and trophic spectrum analysis to describe the contribution of the 6 habitats to the Seine estuary ecosystem functioning. Results showed that the two habitats with a functioning most related to a... |
| Tipo: Text |
Palavras-chave: Trophic network; Estuary; Ecological network analysis; Ecopath with Ecosim; Food web; Ecosystem health indicators. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00270/38154/42026.pdf |
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| Drouineau, Hilaire; Lobry, Jeremy; Bez, Nicolas; Travers-trolet, Morgane; Vermard, Youen; Gascuel, Didier. |
| In this introductory paper we highlight key questions that were discussed during the symposium on “Status, functioning and shifts in marine ecosystems” organized by the Association Française d’Halieutique (French Association for Fisheries Sciences, Montpellier, France, July 2015). This symposium illustrated that fisheries science is now working at multiple scales and on all dimensions of socio-ecosystems (ecological, political, sociological, and economic), with a great diversity of approaches and taking into account different levels of complexity while acknowledging diverse sources of uncertainty. We argue that we should go one step further and call for a protean fisheries science to address the deteriorated states of aquatic ecosystems caused by... |
| Tipo: Text |
Palavras-chave: EAFM; Fisheries management; Fisheries science; Marine resources; Models; Uncertainty. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00359/46990/46921.pdf |
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| Registros recuperados: 16 | |
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