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| Registros recuperados: 202 | |
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| Carrera, Pablo; Churnside, J.h.; Boyra, G; Marques, V; Scalabrin, Carla; Uriarte, A. |
| The feasibility of using airborne lidar (Light Detection and Ranging) was studied to assess the early juvenile fractions of the main pelagic fish species of the coastal Atlantic waters of southern Europe (anchovy, sardine, mackerel, and horse mackerel). Field comparisons with more established echosounder methods were undertaken in the summers of 1998 and 1999 during the recruitment period of sardine and anchovy in the selected areas, in the presence of a variety of oceanographic and environmental conditions. Backscattered energies as well as the types of target recorded by both devices were compared. The distributions of energies and the shape of the targets were generally similar for both techniques, with moderate numerical correlation between sensors,... |
| Tipo: Text |
Palavras-chave: West Iberian Peninsula; Sardine; Recruitment; Echosounder; Bay of Biscay; Anchovy; Airborne lidar. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-2139.pdf |
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| Blanchard, Fabian. |
| Species diversity variations between the demersal fish assemblages of the Bay of Biscay (Atlantic Ocean) and of the Gulf of Lions (Mediterranean Sea) are analysed on a decade scale. The aim of this study is to interpret the dynamics of these two communities characterised by different level of fishing intensity. Data come from trawl surveys carried out for the direct evaluation of the demersal stocks abundance from 1983 to 1997. Diversity indices used are the Hill's indices N1 and N2, the species richness S, the evenness J', the K-dominance curves and the life strategy of the dominant species. Three demersal fish assemblages are defined in the community of the Bay of Biscay and in that of the Gulf of Lions: coastal, continental shelf, and continental slope.... |
| Tipo: Text |
Palavras-chave: Gulf of Lions; Bay of Biscay; Demersal fish; Community dynamics; Species diversity. |
| Ano: 2001 |
URL: http://archimer.ifremer.fr/doc/2001/publication-1393.pdf |
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| Daures, Fabienne; Planchot, Marie; Demaneche, Sebastien; Van Isenghem, Sylvie; Berthou, Patrick; Leblond, Emilie; Jezequel, Michele. |
| In order to provide economic indicators for fisheries, analysis of contribution and economic dependencies of the Bay of Biscay fishing fleets to major commercial species catching in the ICES VIII area is conducted. 9 species are considered (regarding the importance of their landings in this area): Sole, Norway Lobster, Sea bass, Hake, Anglerfish, Anchovy, Sardine, Cuttlefish and Monkfish. The landings data are provided by the Harmonie database of the Fisheries Information System of Ifremer and the analysis per specie is done for the 2005 year on one side and over the period 2000-2005 on the other side. A stock slip is built for each species and presents : - Key figures on landings in the Bay of Biscay (total landings, average price, number of vessels... |
| Tipo: Text |
Palavras-chave: Bay of Biscay; Fleet; Economic dependence; DEM; Golfe de Gascogne; Flotte de pêche; Dépendance économique. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/rapport-4697.pdf |
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| Bergeron, Jean-pierre. |
| The study examines the spatial variations over the French continental shelf of the southern Bay of Biscay (North-East Atlantic) in the nutritional condition of anchovy (Engraulis encrasicolus L.) larvae which was estimated through their DNA/C index. The same cruise yielded quantitative estimates of two metabolic descriptors of the functioning of mesozooplanktonic communities, the enzymes pyruvate kinase (PK) and trypsin, for the first time evaluated simultaneously. The aim was to appraise quality and quantity of matter assimilated by the mesozooplankton and to specify whether the main components of prey ingested by copepods are principally carbohydrates, through PK activity, or protein, under the action of the digestive endopeptidase trypsin. The larval... |
| Tipo: Text |
Palavras-chave: Anchovy larvae; Bay of Biscay; DNA/C index; Mesozooplankton; Pyruvate kinase; Trypsin. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6473.pdf |
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| Huret, Martin; Vandromme, Pieter; Petitgas, Pierre; Pecquerie, Laure. |
| Connectivity during early life stages of pelagic fish, defined here by survival probability between spawning and early juvenile habitats, depends on a combination of sufficient food availability and low predator encounter along drift trajectories. For anchovy in the Bay of Biscay, larval transport experiments throughout the spawning season suggest accumulation of early juveniles in the offshore area of the southern Bay, as well as retention over the mid-shelf at mid-latitude. However, late summer-early autumn surveys suggest presence of juveniles only in the former region. From this observation, we set up a bioenergetic individual based model to test for the effect of food availability on survival patterns. The model couples a Lagrangian transport module... |
| Tipo: Text |
Palavras-chave: Connectivity; Larval IBM; Bioenergetics; Zooplankton; Bay of Biscay; European anchovy. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00105/21655/19237.pdf |
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| Naughton, F; Bourillet, Jean-francois; Fernanda, M; Turon, J; Jouanneau, J. |
| Vegetation and quantitative climate reconstructions from a northwestern France shelf core (VK0358Bis) show orbital and suborbital climate variability for the last 8850 years in this region. A long-term cooling trend in summer temperatures, marked by gradual temperate and humid forest decline, parallels cooling in Greenland and the decrease of mid-latitude summer insolation reduction until at least 2000 cal. yr BP. At the long-term scale, the lowering in seasonal contrast revealed by vegetation changes follows the increase of precession. Corylus woodlands spread at the expense of deciduous Quercus forest, between 8740 and 8390 cal. yr BP, linked with the high seasonality conditions that, counterbalancing the long-term astronomical forcing trend, were... |
| Tipo: Text |
Palavras-chave: Bay of Biscay; France; Europe; Vegetation; Marine core; Corylus; 8.2 kyr event; Millennial scale climate variability; Long term cooling; Holocene. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-4205.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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| Huret, Martin; Bourriau, Paul; Doray, Mathieu; Gohin, Francis; Petitgas, Pierre. |
| Fishery annual surveys are shifting towards integrated ecosystem surveys. However, monitoring the whole ecosystem once a year entails special attention to the interpretation of observations, because they only represent a snapshot in the seasonal dynamics of the environment, of a species, or any dynamic process of interest. The dependency of this snapshot to the timing, but also to the duration, of the survey with respect to this seasonal dynamics needs to be considered. Fish stock assessment is only little impacted by the observed timing within a given season, whereas warming, stratification, plankton bloom occurrence, or fish fecundity, are processes rapidly changing especially in spring. Firstly, from independent satellite data, we described the seasonal... |
| Tipo: Text |
Palavras-chave: Ecosystem survey; Anchovy; Sardine; Spawning; Sea surface temperature; Degree day; Bay of Biscay. |
| Ano: 2018 |
URL: http://archimer.ifremer.fr/doc/00394/50584/51483.pdf |
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| Labry, Claire; Herbland, Alain; Delmas, Daniel. |
| More and more studies emphasize the status of phosphorus (P) as the principal limiting nutrient of phytoplankton growth, especially in coastal waters under the influence of freshwater discharges. The purpose of the present paper is to investigate the role of P on planktonic production in the waters influenced by the Gironde discharges; the Gironde being one of the two largest rivers on the French Atlantic coast. The survey is based on several cruises made in 1998 and 1999. Two different patterns were observed for waters with salinity below and above 34.5. For waters with salinity <34.5. P was found to be the first limiting nutrient of winter and spring phytoplankton blooms, based on undetectable phosphate (<20 nM), high NO3 : PO4 ratios, typically... |
| Tipo: Text |
Palavras-chave: Bay of Biscay; River plume; Salinity; Water quality analysis; Phytoplankton; Planktonic production. |
| Ano: 2002 |
URL: http://archimer.ifremer.fr/doc/2002/publication-690.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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| Petitgas, Pierre; Renard, Didier; Desassis, Nicolas; Huret, Martin; Romagnan, Jean-baptiste; Doray, Mathieu; Woillez, Mathieu; Rivoirard, Jacques. |
| This paper presents a novel application of the geostatistical multivariate method known as min–max autocorrelation factors (MAFs) for analysing fisheries survey data in a space–time context. The method was used to map essential fish habitats and evaluate the variability in time of their occupancy. Research surveys at sea on marine fish stocks have been undertaken for several decades now. The data are time series of yearly maps of fish density, making it possible to analyse the space–time variability in fish spatial distributions. Space–time models are key to addressing conservation issues requiring the characterization of variability in habitat maps over time. Here, the variability in fisheries survey data series is decomposed in space and time to address... |
| Tipo: Text |
Palavras-chave: MAF; Space-time; Habitat; Mapping; Sardine; Bay of Biscay. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00599/71157/69915.pdf |
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| Woillez, M; Poulard, Jean-charles; Rivoirard, Jacques; Petitgas, Pierre; Bez, Nicolas. |
| A series of candidate statistical indices is used in an attempt to capture spatial patterns of fish populations from research survey data. To handle diffuse population limits, indices are designed not to depend on arbitrary delineation of the domain. They characterize the location (centre of gravity and spatial patches), the occupation of space (inertia, isotropy, positive area, spreading area, and equivalent area), statistical dispersion (Gini index and coefficient of variation of strictly positive densities), and microstructure. Collocation between different ages and years is summarized by a global index of collocation. Indices are estimated for hake from a bottom-trawl data series in the Bay of Biscay in autumn of 1987-2004. The study provides a... |
| Tipo: Text |
Palavras-chave: Spatial indices; European hake; Bay of Biscay. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-2671.pdf |
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| Registros recuperados: 202 | |
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