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| Registros recuperados: 24 | |
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| Gerondeau, M; Barbraud, C; Ridoux, Vincent; Vincent, Cecile. |
| It has been suggested that the large grey seal colonies around the British Isles form local populations within a metapopulation, and that seal movements outside the breeding season lead to considerable overlap between individual home ranges. Individual behaviour and population dynamics of small peripheral colonies may also play a role in the metapopulation. We studied the French grey seal colony of the Molene archipelago, at the southern-most limit of the species' range. We analysed photo-identification data with capture-mark-recapture techniques in order to estimate the total seasonal abundance of grey seals in the archipelago and to quantify the seasonal rates of occurrence or movements of male and female seals. We found that between 58% (95% confidence... |
| Tipo: Text |
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| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-3572.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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| Mannocci, Laura; Roberts, Jason J.; Halpin, Patrick N.; Authier, Matthieu; Boisseau, Oliver; Bradai, Mohamed Nejmeddine; Canadas, Ana; Chicote, Carla; David, Lea; Di-meglio, Nathalie; Fortuna, Caterina M; Frantzis, Alexandros; Gazo, Manel; Genov, Tilen; Hammond, Philip S.; Holcer, Drasko; Kaschner, Kristin; Kerem, Dani; Lauriano, Giancarlo; Lewis, Tim; Di Sciara, Giuseppe Notarbartolo; Panigada, Simone; Antonio Raga, Juan; Scheinin, Aviad; Ridoux, Vincent; Vella, Adriana; Vella, Joseph. |
| Heterogeneous data collection in the marine environment has led to large gaps in our knowledge of marine species distributions. To fill these gaps, models calibrated on existing data may be used to predict species distributions in unsampled areas, given that available data are sufficiently representative. Our objective was to evaluate the feasibility of mapping cetacean densities across the entire Mediterranean Sea using models calibrated on available survey data and various environmental covariates. We aggregated 302,481 km of line transect survey effort conducted in the Mediterranean Sea within the past 20 years by many organisations. Survey coverage was highly heterogeneous geographically and seasonally: large data gaps were present in the eastern and... |
| Tipo: Text |
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| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00626/73789/75004.pdf |
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| Pierce, G; Santos, M; Murphy, S; Learmonth, J; Zuur, A; Rogan, E; Bustamante, Paco; Caurant, Florence; Lahaye, V; Ridoux, Vincent; Zegers, B; Mets, A; Addink, M; Smeenk, C; Jauniaux, T; Law, R; Dabin, W; Lopez, A; Farre, J; Gonzalez, A; Guerra, A; Garcia Hartmann, M; Reid, R; Moffat, C; Lockyer, C; Boon, J. |
| Concentrations of polychlorinated biphenyls (PCBs) in blubber of female common dolphins and harbour porpoises from the Atlantic coast of Europe were frequently above the threshold at which effects on reproduction could be expected, in 40% and 47% of cases respectively. This rose to 74% for porpoises from the Southern North Sea. PCB concentrations were also high in southern North Sea fish. The average pregnancy rate recorded in porpoises (42%) in the study area was lower than in the western Atlantic but that in common dolphins (25%) was similar to that of the western Atlantic population. Porpoises that died from disease or parasitic infection had higher concentrations of persistent organic pollutants (POPs) than animals dying from other causes. Few of the... |
| Tipo: Text |
Palavras-chave: Diet; Reproduction; Persistent organic pollutants; Delphinus delphis; Phocoena phocoena. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-7314.pdf |
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| Peltier, Hélène; Dabin, Willy; Dars, Cécile; Demaret, Fabien; Doremus, Ghislain; Van Canneyt, Olivier; Laran, Sophie; Mendez-fernadez, Paula; Spitz, Jérôme; Authier, Matthieu; Delphine, Pierre; Ridoux, Vincent. |
| Between the 1st of February and the March 31, 2017, 793 stranded cetaceans were found along the French Atlantic coasts. Common dolphins made up 84% of these strandings, and most of these presented evidence of death in fishing gear. The aim of this work is to test an approach that could help identify the fisheries potentially involved in a given stranding event. To do this we examined how the distributions of likely areas of mortality of bycaught dolphins, inferred from carcass drift modelling, coincide with fishing effort statistics of various fleets, generated from the Vessel Monitoring System, in the area over the same dates. Using reverse drift modelling, two main mortality areas were identified. A total of 3690 common dolphins (IC95% [2230; 6900]) were... |
| Tipo: Text |
Palavras-chave: Dolphins; Strandings; Bycatch; Fishing effort; Reverse drift; Vessel Monitoring System.. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00592/70392/68473.pdf |
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| Spitz, Jerome; Trites, Andrew W.; Becquet, Vanessa; Brind'Amour, Anik; Cherel, Yves; Galois, Robert; Ridoux, Vincent. |
| Understanding the mechanisms that drive prey selection is a major challenge in foraging ecology. Most studies of foraging strategies have focused on behavioural costs, and have generally failed to recognize that differences in the quality of prey may be as important to predators as the costs of acquisition. Here, we tested whether there is a relationship between the quality of diets (kJ.g(-1)) consumed by cetaceans in the North Atlantic and their metabolic costs of living as estimated by indicators of muscle performance (mitochondrial density, n = 60, and lipid content, n = 37). We found that the cost of living of 11 cetacean species is tightly coupled with the quality of prey they consume. This relationship between diet quality and cost of living appears... |
| Tipo: Text |
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| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00116/22749/20551.pdf |
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| Spitz, Jérôme; Rousseau, Yann; Ridoux, Vincent. |
| In aquatic ecosystems, competitive interactions are occasionally described. Violent attacks on harbour porpoises by bottlenose dolphins were reported and it was proposed that this behavior could result from competitive interactions for food. This hypothesis implies that the two predators should share all or part of they prey range. In this work, we describe the diets of each predator in the Bay of Biscay and adjacent areas from stomach content analysis of stranded animals. The diet of the harbour porpoise was mostly composed of small schooling fish living close to the seafloor (98 percent by mass). The diet of the bottlenose dolphin was characterised by the presence of large specimens of demersal fish (91 percent by mass) and cephalopods. Several prey... |
| Tipo: Text |
Palavras-chave: North Eastern Atlantic; Tursiops truncatus; Phocoena phocoena; Diet; Top predator; Interference competition. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-1986.pdf |
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| Kiszka, Jeremy; Macleod, Kelly; Van Canneyt, Olivier; Walker, Dylan; Ridoux, Vincent. |
| Data on the distribution and habitat utilization of oceanic marine mammals are difficult to collect and yet such information is beneficial for many conservation and management purposes. Data collected during ferry-based cetacean surveys in the English Channel and Bay of Biscay between 1998 and 2002 were analysed to investigate the distribution, encounter rate, and habitat characteristics of toothed cetaceans there. In all, 17 873 nautical miles were surveyed, and 1008 encounters of 13 identified species, including delphinids, ziphiids, harbour porpoise, and sperm whale, were recorded. The common dolphin was the commonest species, followed in decreasing occurrence by striped and bottlenose dolphins, pilot whale, harbour porpoise, Cuvier's beaked whale, and... |
| Tipo: Text |
Palavras-chave: Toothed cetaceans; Platforms of opportunity; Habitat characteristics; English Channel; Encounter rate; Distribution; Bay of Biscay; Bathymetric preference. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-3018.pdf |
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| Authier, Matthieu; Doremus, Ghislain; Van Canneyt, Olivier; Boubert, Jean-jacques; Gautier, Gerard; Doray, Mathieu; Duhamel, Erwan; Masse, Jacques; Petitgas, Pierre; Ridoux, Vincent; Spitz, Jerome. |
| Conservation has moved from species-centered to ecosystem-based approaches: the Marine Strategy Framework Directive requires the maintenance or restoration of ‘Good Environmental Status’ of all European marine waters. Monitoring biodiversity at the scale of whole ecosystems is salient, but challenging owing to the large spatial scale involved and the large spatio-temporal heterogeneity of marine ecosystems. We capitalized on the integrated ecosystemic PELGAS survey carried out in spring in the Bay of Biscay to document patterns of change in marine megafauna relative abundance at the community level over more than a decade (2004-2016). The relative abundance of the twenty three most frequently sighted species (6 cetaceans and 17 seabirds) was estimated by... |
| Tipo: Text |
Palavras-chave: Marine megafauna; Relative abundance; MSFD; Ecosystemic surveys. |
| Ano: 2018 |
URL: http://archimer.ifremer.fr/doc/00403/51405/51981.pdf |
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| Ridoux, Vincent; Spitz, J; Vincent, Cecile; Walton, M. |
| The north-east Atlantic grey seal, Halichoerus grypus, is widely distributed along the European coastline from northern Russia to France, with the core population centred around Scotland. To date, very little is known of the diet of the species at the southern margin of the species range. However, because grey seal numbers have been increasing over the last few decades in France, the issue of their potential interactions with coastal fisheries is frequently raised. The diet of grey seal in the Molene Archipelago was investigated by combining scat, stomach content and fatty acid analyses, since all three approaches have complementary potentials to reveal feeding habits of a predator. A total of 145 scats mostly of moulting adult males, 14 stomach contents... |
| Tipo: Text |
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| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-3573.pdf |
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| Martinez, Ludivine; Dabin, Willy; Caurant, Florence; Kiszka, Jeremy; Peltier, Hélène; Spitz, Jérôme; Vincent, Cécile; Van Canneyt, Olivier; Doremus, Ghislain; Ridoux, Vincent. |
| Tipo: Text |
Palavras-chave: Golfe de Gascogne; Mammifères marins; Activités anthropiques; Pressions; Menaces. |
| Ano: 2012 |
URL: https://archimer.ifremer.fr/doc/00330/44070/43641.pdf |
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| Martinez, Ludivine; Dabin, Willy; Caurant, Florence; Kiszka, Jeremy; Peltier, Hélène; Spitz, Jérôme; Vincent, Cécile; Van Canneyt, Olivier; Doremus, Ghislain; Ridoux, Vincent. |
| Tipo: Text |
Palavras-chave: Méditerranée; Mammifères marins; Activités anthropiques; Pressions; Menaces. |
| Ano: 2012 |
URL: https://archimer.ifremer.fr/doc/00331/44254/43823.pdf |
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| Martinez, Ludivine; Dabin, Willy; Caurant, Florence; Kiszka, Jeremy; Peltier, Hélène; Spitz, Jérôme; Vincent, Cécile; Van Canneyt, Olivier; Doremus, Ghislain; Ridoux, Vincent. |
| Tipo: Text |
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| Ano: 2012 |
URL: https://archimer.ifremer.fr/doc/00329/43985/43557.pdf |
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| Certain, G.; Masse, Jacques; Van Canneyt, O.; Petitgas, Pierre; Doremus, G.; Santos, M. B.; Ridoux, Vincent. |
| The present study is a general multivariate analysis of the spatial association between small pelagic fishes and their predators (seabirds, marine mammals and fisheries), using 6 yr (18000 km) of transects surveyed in spring in the Bay of Biscay, France. We describe 4 groups of prey-predator association, with explicit distinction of prey size: (1) terns and anchovies (10 to 15 cm), (2) common dolphins, common murres, sprat and sardine (<20 cm), (3) gannets, horse mackerel and mackerel (15 to 25 cm) and (4) bottlenose dolphin, horse mackerel and mackerel (25 to 40 cm). Our analysis also illustrates the great variability in these associations, with years of strong prey-predator associations followed by years of weak relationships. The analysis allows us... |
| Tipo: Text |
Palavras-chave: Marine top predators; Small pelagic fishes; Spatial associations; Temporal variability; Pelagic ecosystem; Bay of Biscay. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00031/14257/11540.pdf |
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| Spitz, Jerome; Ridoux, Vincent; Brind'Amour, Anik. |
| 1. Understanding ‘Why a prey is a prey for a given predator?’ can be facilitated through trait-based approaches that identify linkages between prey and predator morphological and ecological characteristics and highlight key functions involved in prey selection. 2. Enhanced understanding of the functional relationships between predators and their prey is now essential to go beyond the traditional taxonomic framework of dietary studies and to improve our knowledge of ecosystem functioning for wildlife conservation and management. 3. We test the relevance of a three-matrix approach in foraging ecology among a marine mammal community in the northeast Atlantic to identify the key functional traits shaping prey selection processes regardless of the taxonomy... |
| Tipo: Text |
Palavras-chave: Foraging strategy; Fourth-corner method; Functional ecology; Marine mammals; Prey selection; RLQ analysis. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00189/30047/29495.pdf |
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| Lassalle, G.; Lobry, J.; Le Loc'H, F.; Bustamante, Paco; Certain, Gregoire; Delmas, Daniel; Dupuy, C.; Hily, Christian; Labry, Claire; Le Pape, O.; Marquis, Elise; Petitgas, Pierre; Pusineri, Claire; Ridoux, Vincent; Spitz, J.; Niquil, Nathalie. |
| The Bay of Biscay (North-East Atlantic) has long been subjected to intense direct and indirect human activities that lead to the excessive degradation and sometimes overexploitation of natural resources. Fisheries management is gradually moving away from single-species assessments to more holistic, multi-species approaches that better respond to the reality of ecosystem processes. Quantitative modelling methods such as Ecopath with Ecosim can be useful tools for planning, implementing and evaluating ecosystem-based fisheries management strategies. The aim of this study was therefore to model the energy fluxes within the food web of this highly pressured ecosystem and to extract practical information required in the diagnosis of ecosystem state/health. A... |
| Tipo: Text |
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| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00057/16851/14329.pdf |
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| Martinez, Ludivine; Dabin, Willy; Caurant, Florence; Van Canneyt, Olivier; Doremus, Ghislain; Peltier, Hélène; Spitz, Jérôme; Vincent, Cécile; Ridoux, Vincent; Kiszka, Jeremy. |
| Tipo: Text |
Palavras-chave: Golfe de Gascogne; Mammifères marins; Conservation; Caractéristiques démographiques; Suivi; Espèces; Rôle dans les écosystèmes. |
| Ano: 2012 |
URL: https://archimer.ifremer.fr/doc/00329/44030/43602.pdf |
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| Martinez, Ludivine; Dabin, Willy; Caurant, Florence; Van Canneyt, Olivier; Doremus, Ghislain; Peltier, Hélène; Spitz, Jérôme; Vincent, Cécile; Ridoux, Vincent; Kiszka, Jeremy. |
| Tipo: Text |
Palavras-chave: Manche; Mer du Nord; Mammifères marins; Conservation; Caractéristiques démographiques; Suivi; Espèces; Rôle dans les écosystèmes. |
| Ano: 2012 |
URL: https://archimer.ifremer.fr/doc/00327/43845/43419.pdf |
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| Registros recuperados: 24 | |
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