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| Registros recuperados: 38 | |
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| Bird, Christopher S.; Verissimo, Ana; Magozzi, Sarah; Abrantes, Katya G.; Aguilar, Alex; Al-reasi, Hassan; Barnett, Adam; Bethea, Dana M.; Biais, Gerard; Borrell, Asuncion; Bouchoucha, Marc; Boyle, Mariah; Brooks, Edward J.; Brunnschweiler, Juerg; Bustamante, Paco; Carlisle, Aaron; Catarino, Diana; Caut, Stephane; Cherel, Yves; Chouvelon, Tiphaine; Churchill, Diana; Ciancio, Javier; Claes, Julien; Colaco, Ana; Courtney, Dean L.; Cresson, Pierre; Daly, Ryan; De Necker, Leigh; Endo, Tetsuya; Figueiredo, Ivone; Frisch, Ashley J.; Hansen, Joan Holst; Heithaus, Michael; Hussey, Nigel E.; Iitembu, Johannes; Juanes, Francis; Kinney, Michael J.; Kiszka, Jeremy J.; Klarian, Sebastian A.; Kopp, Dorothee; Leaf, Robert; Li, Yunkai; Lorrain, Anne; Madigan, Daniel J.; Maljkovic, Aleksandra; Malpica-cruz, Luis; Matich, Philip; Meekan, Mark G.; Menard, Frederic; Menezes, Gui M.; Munroe, Samantha E. M.; Newman, Michael C.; Papastamatiou, Yannis P.; Pethybridge, Heidi; Plumlee, Jeffrey D.; Polo-silva, Carlos; Quaeck-davies, Katie; Raoult, Vincent; Reum, Jonathan; Torres-rojas, Yassir Eden; Shiffman, David S.; Shipley, Oliver N.; Speed, Conrad W.; Staudinger, Michelle D.; Teffer, Amy K.; Tilley, Alexander; Valls, Maria; Vaudo, Jeremy J.; Wai, Tak-cheung; Wells, R. J. David; Wyatt, Alex S. J.; Yool, Andrew; Trueman, Clive N.. |
| Sharks are a diverse group of mobile predators that forage across varied spatial scales and have the potential to influence food web dynamics. The ecological consequences of recent declines in shark biomass may extend across broader geographic ranges if shark taxa display common behavioural traits. By tracking the original site of photosynthetic fixation of carbon atoms that were ultimately assimilated into muscle tissues of 5,394 sharks from 114 species, we identify globally consistent biogeographic traits in trophic interactions between sharks found in different habitats. We show that populations of shelf-dwelling sharks derive a substantial proportion of their carbon from regional pelagic sources, but contain individuals that forage within additional... |
| Tipo: Text |
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| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00420/53141/54249.pdf |
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| Merillet, Laurene; Kopp, Dorothee; Robert, Marianne; Salaun, Michele; Mehault, Sonia; Bourillet, Jean-francois; Mouchet, Maud. |
| The development of the vessel monitoring system (VMS) in the recent years has offered high-resolution data to map the distribution and intensity of fishing activities and contributed to enhancing the potential identification of fishing impacts. However, impacts could vary at very small scale and the resolution of VMS data might not be fine enough. Other proxy could be used, such as trawl marks visible on the seabed observed by underwater video or side-scan sonar to evaluate small-scale trawling effort. In the Bay of Biscay, an underwater video survey of the Nephrops norvegicus fishing ground was conducted and provided environmental characteristics such as depth and number of trawl marks at 152 transects. The relevance of observed trawl marks as a... |
| Tipo: Text |
Palavras-chave: Bay of Biscay; Fishing intensity; Sediments; Underwater video; Vessel monitoring system. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00410/52112/52854.pdf |
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| Lefebvre, Sebastien; Giraldo, Carolina; Kopp, Dorothee; Cresson, Pierre; Travers-trolet, Morgane; Ernande, Bruno. |
| Trophic relationships play a crucial role in shaping community structure and ecological functions in marine ecosystems. Studying food-web variation along environmental gradients is still in its infancy and provides new insights in understanding how abiotic variables shape species interactions. In epicontinental seas, benthic-pelagic couplings modify predator-prey relationships and lead to entangled trophic networks. Here, we assumed that depth affects benthic-pelagic couplings’ strength and we investigated depth-related changes in the feeding patterns of fish in the whole English Channel (EC) used as a case study. Gut content and stable carbon and nitrogen isotopes of 33 fish species were collected between 5-100 m depth in 2009 and in 2014. Samples from... |
| Tipo: Text |
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| Ano: 2018 |
URL: http://archimer.ifremer.fr/doc/00455/56634/58370.pdf |
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| Kopp, Dorothee; Robert, Marianne; Pawlowski, Lionel. |
| In marine ecosystems, the study of trophic relationships has extensively benefited from the development of stable isotope analyses (SIA) as dietary tracers. SIA are particularly useful in elucidating the structure of deep sea food webs given the constraints involved in obtaining gut-content data from deep trawling. We used carbon and nitrogen stable isotope analyses and Stable Isotope Bayesian Ellipses in R (SIBER) and Stable Isotope Analysis in R (SIAR) routines, to determine the trophic ecology of five deep-sea fishes from the upper continental slope of the Celtic Sea. SIA made it possible to deduce some general tendencies in food-web structure and species trophic interactions and confirmed diet determined by gut-content analysis for the same species, in... |
| Tipo: Text |
Palavras-chave: Competition; Feeding habits; Mixing models; Stable isotope. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00410/52138/52940.pdf |
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| Morfin, Marie; Kopp, Dorothee; Benoît, Hugues P.; Méhault, Sonia. |
| Two vitality index approaches have been demonstrated to be good proxies of discard survival in similar fishing and environmental conditions: Reflex Action Mortality Predictors combined with injuries (RI) scores that measure the proportion of impaired reflexes and injuries, and a simpler, quicker, but less precise approach based on ordinal categories related to fish body movements and injuries (semi-quantitative assessment, SQA). This study assessed and compared these two approaches for five species (two flatfishes, skates, a seabass and a catshark) discarded in a coastal otter trawl fishery in the Bay of Biscay. All species displayed good vitality status according to both indices and were not very sensitive to the fishing nor their biological conditions.... |
| Tipo: Text |
Palavras-chave: Discard survival; Vitality indicators; Reflex Action Mortality Predictor; Bay of Biscay; Coastal otter trawl fishery. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00466/57817/60417.pdf |
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| Giraldo, Carolina; Ernande, Bruno; Cresson, Pierre; Kopp, Dorothee; Cachera, Marie; Travers-trolet, Morgane; Lefebvre, Sebastien. |
| Depth is one of the environmental variables influencing the structure of marine food webs by directly or indirectly influencing benthic-pelagic coupling and predator-prey relationships. In shallow waters, the high degree of connectivity between pelagic and benthic networks results in complex systems with multiple interactions. Digestive tract (DT) and stable isotope (SI) analyses were used to investigate depth-related changes in feeding patterns for 33 fish species (eastern English Channel [EEC]) collected between 5 m and 80 m depth. Fish species were first arranged into functional groups based upon trophic and habitat similarities. DTs were used to determine the general topology of the food web and SIs were used to estimate the contributions of different... |
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| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00386/49711/52255.pdf |
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| Kopp, Dorothee; Lefebvre, Sebastien; Villanueva, Ching-maria; Ernande, Bruno. |
| The structure, dynamics and productivity of marine ecosystems depend mainly on their underlying food webs. In temperate marine ecosystems, specifically in the English Channel, strong seasonality, habitat diversity and variability in the sources of available organic matters are controlling factors affecting the trophodynamics of these networks. Exploitation through fisheries may also alter these food webs. During the last decade, the study of trophic ecology has greatly benefited from the use of stable isotope analysis (SIA) that integrates diet information over long time periods and complements gut content analysis. Applied in complex ecosystems, such as the English Channel, SIA may help to detect nutrient pathways and trophic links. Stable isotopic... |
| Tipo: Text |
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| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00161/27213/25412.pdf |
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| Merillet, Laurene; Kopp, Dorothee; Morandeau, Fabien; Mehault, Sonia; Rimaud, Thomas; Piton, C. |
| In the context of the reform of the Common Fishing Policy (CFP) undertaken by the European Union and implemented since 1st January 2014, the discarding of unwanted catches will gradually be forbidden. Article 15 of the CFP lays down a landing obligation for all species subject to European quotas and will come into force between 2015 and 2019 according to the species and the zones. The Regulation allows several exemptions including one for "species for which scientific proof shows high survival rates, due to the characteristics of the fishing gear, the fishing methods and the ecosystem" (EU Regulation No. 1380/2013). In particular, Nephrops were identified by the International Council for the Exploration of the Sea (ICES) as one of the species having the... |
| Tipo: Text |
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| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00378/48953/49357.pdf |
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| Walters, Andrea; Robert, Marianne; Cresson, Pierre; Le Bris, Hervé; Kopp, Dorothee. |
| Quantification of the physical and biological factors that influence the spatial structuring of food webs is central to inform effective resource management. We used baseline‐corrected stable isotope ratios (δ13C and δ15N) of 63 invertebrate and fish to investigate food web structure across a continental shelf gradient—the Celtic Sea Shelf in the Northeast Atlantic Ocean. Hierarchical clustering on δ13C and δ15N showed that the shelf food web is characterized by four trophic levels with trophic groups spread across pelagic and benthic trophic pathways. Four biomass‐weighted isotopic diversity metrics provided indicators on the status of the system, showing a relatively complex food web with high trophic redundancy at intermediate trophic levels suggesting... |
| Tipo: Text |
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| Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00693/80500/83696.pdf |
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| Syvaeranta, Jari; Martino, Aurelia; Kopp, Dorothee; Cereghino, Regis; Santoul, Frederic. |
| We tested the impacts of most common sample preservation methods used for aquatic sample materials on the stable isotope ratios of carbon and nitrogen in clams, a typical baseline indicator organism for many aquatic food web studies utilising stable isotope analysis (SIA). In addition to common chemical preservatives ethanol and formalin, we also assessed the potential impacts of freezing on delta C-13 and delta N-15 values and compared the preserved samples against freshly dried and analysed samples. All preservation methods, including freezing, had significant impacts on delta C-13 and delta N-15 values and the effects in general were greater on the carbon isotope values (1.3-2.2aEuro degrees difference) than on the nitrogen isotope values (0.9-1.0aEuro... |
| Tipo: Text |
Palavras-chave: Formalin; Freezing; Ethanol; Preservation; Stable isotope analysis. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00021/13192/10271.pdf |
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| Vogel, Camille; Kopp, Dorothee; Mehault, Sonia. |
| On January 1st, 2016, the French mixed Nephrops and hake fishery of the Grande Vasière, an area located in the Bay of Biscay, fell under the discard ban implemented as part of the new European Common Fisheries Policy. The fleet records historically high levels of discard despite numerous gear selectivity studies. Together with high discards survival, new technological solutions to minimize catches of undersized individuals could justify local exemptions from the discard ban. Our study focuses on the effects of two selective devices, a square mesh cylinder (SMC) and a grid, on the escapement of undersized individuals and discard reduction. Relative catch probability of the modified gear compared with the traditional gear was modelled using the catch... |
| Tipo: Text |
Palavras-chave: Nephrops; European hake; Discard ban; Gear technology; Catch comparison; Selectivity. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00356/46717/46906.pdf |
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| Vogel, Camille; Kopp, Dorothee; Morandeau, Fabien; Morfin, Marie; Mehault, Sonia. |
| In the English Channel and Southern Bight, French demersal trawlers target a mix of demersal species including whiting (Merlangius merlangus). The discard ban to be implemented in January 2016 motivated fishermen to look for technical measures to reduce unwanted catches of undersized individuals (<27 cm). From 2008–2014, 18 different gear configurations were tested for bycatch reduction on board fleets of vessels of 16–20 m and 20–24 m. Selective devices tested included grids, square mesh panels (SMP), square mesh cylinders (SMC), various combinations of these devices and large mesh trawls. Using the catch comparison method, our results focus on six devices that proved efficient to reduce catches of undersized whiting, equally divided between the two... |
| Tipo: Text |
Palavras-chave: Square mesh; Sorting grids; Fishing gear technology; Merlangius merlangus; Catch comparison; GLMM. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00384/49553/50079.pdf |
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| Issac, Pierre; Robert, Marianne; Le Bris, Hervé; Rault, Jonathan; Pawlowski, Lionel; Kopp, Dorothee. |
| We used stable isotope ratio and gut content analyses to determine and compare the feeding ecology of two commercially important predator species, Lophius piscatorius and Lophius budegassa in the Celtic sea, where data concerning their trophic ecology remain sparse. This study included two areas and two size-classes, showing that anglerfish in the Celtic sea are mainly piscivorous top predators as observed in other marine waters. However, a substantial part of the diet of the fish in the small size classes consists of benthic macro-invertebrates, mainly Crustaceans. Despite the common knowledge that they are opportunistic predators that display a low degree of prey selectivity, our results suggest that the two species have different trophic niches when... |
| Tipo: Text |
Palavras-chave: Lophius; Gut content; Stable isotopes; Trophic niche; Trophic segregation; Top predator. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00395/50614/51326.pdf |
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| Kopp, Dorothee. |
| Le problème de la dégradation des récifs coralliens est actuellement au centre de nombreuses recherches en écologie. Le présent travail apporte des résultats concernant le rôle des poissons herbivores dans la dynamique des récifs et a permis d’évaluer l’importance de ces poissons pour la résilience des communautés benthiques récifales de Guadeloupe. Le peuplement de poissons herbivores a été étudié en plongée à l’aide de relevés visuels quantitatifs sur plusieurs platiers et pentes externes repartis autour de la Guadeloupe. Les données recueillies ont été analysées par le calcul de descripteurs synthétiques de la biodiversité, par des méthodes d’ordination et de groupement et à l’aide d’autocorrélogrammes. L’étude temporelle éalisée sur une période de 18... |
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| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/00177/28780/27259.pdf |
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| Vincent, Benoit; Simon, Julien; Vacherot, Jean-philippe; Morandeau, Fabien; Larnaud, Pascal; Kopp, Dorothee; Mehault, Sonia; Morfin, Marie; Savina-rolland, Marie; Marc, Emilie. |
| The Lorient flume tank is an hydrodynamic facility available for any qualification and observation of submerged objects in still or moving water. It is a closed loop circulating tank filled with fresh water. The fluid is moved with a 70 kW pump-motor with a velocity between 0 and 1 m/s and homogenized with a series of pressure drop systems. The overall dimensions are 24.50 m long, 7.50m wide and 3.30 m high. The part where experiments can be set up is 12m long, 2.6 m wide and 1.5 m deep. A mobile bottom belt can be synchronized with the water flow velocity and enables to simulate the seabed velocity relatively to a towed object. The overall process of the facility is controlled by a user friendly interface. |
| Tipo: Text |
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| Ano: 2018 |
URL: http://archimer.ifremer.fr/doc/00436/54803/56299.pdf |
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| Registros recuperados: 38 | |
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