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Registros recuperados: 25 | |
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Silva, Alexandra; Garrido, Susana; Ibaibarriaga, Leire; Pawlowski, Lionel; Riveiro, Isabel; Marques, Vitor; Ramos, Fernando; Duhamel, Erwan; Iglesias, Magdalena; Bryere, Philippe; Mangin, Antoine; Citores, Leire; Carrera, Pablo; Uriarte, Andres. |
This work investigated adult-mediated connectivity and spatial population structure of sardine in the European Atlantic waters. The spatial and temporal progress of cohorts was modelled using abundance-at-age survey data by area in the period 2000 to 2016, covering the region from the northern Bay of Biscay to the eastern Gulf of Cadiz. A novel methodology was used to calculate indices of cohort movement between areas. Movement was relatively low between three large regions, the Bay of Biscay, the northern Spanish and Portuguese waters and the Gulf of Cadiz, each hosting a recruitment hotspot. On the other hand, one half of the sardines recruited in North Portugal and a quarter of those recruited in Southwest Portugal moved to northern Spanish waters and... |
Tipo: Text |
Palavras-chave: Metapopulation; Source-sink dynamics; Adult-mediated connectivity; Cohort dispersal; Small pelagic fishes; Stock identity; Fisheries management. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00465/57661/59856.pdf |
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Uriarte, Andres; Ibaibarriaga, Leire; Pawlowski, Lionel; Masse, Jacques; Petitgas, Pierre; Santos, Maria; Skagen, Dankert. |
La fermeture de la pêche de l’anchois (Engraulis encrasicolus) du Golfe de Gascogne entre 2005 et 2010, en raison de la faible biomasse du stock, a été une opportunité pour estimer la mortalité naturelle à partir de données de campagnes halieutiques issues de l’observation de la présence d’oeufs (DEPM) et de mesures acoustiques, utilisées pour l’évaluation de cette population depuis 1987. En considérant que la mortalité naturelle est constante au cours du temps et que la capturabilité des deux campagnes est identique pour tous les âges, la mortalité naturelle peut être estimée par des modèles log-linéaires appliquées aux séries temporelles de nombres aux âges issues des campagnes, et par des modèles d’évaluations de stock prenant en compte la saison.... |
Tipo: Text |
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Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00334/44510/45923.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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Lorance, Pascal; Pawlowski, Lionel; Trenkel, Verena. |
A database of tallybooks, from skippers' own logbooks, provided by the French industry involved in deep-water fishing to the west of the British Isles was used to standardise blue ling Landings per Unit of Effort (LPUEs). The data covered the years 1992-2008 with more extensive data for the period 2000-2007. For each haul, landings by species, tow duration, depth and location were reported. Compared to EU logbooks, this database is on a haul by haul basis instead of being aggregated by fishing sub-trips combining hauls from the same day, ICES rectangle and gear. Moreover, it includes depth, which is a major factor for catch rates in deepwater fisheries. LPUEs were estimated from Generalised Additive Models (GAMs) with depth, vessel, statistical rectangle... |
Tipo: Text |
Palavras-chave: Molva dypterygia; Abundance indices; Fishing strategy; Tweedie distribution. |
Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/00102/21330/18953.pdf |
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Véron, Matthieu; Duhamel, Erwan; Bertignac, Michel; Pawlowski, Lionel; Huret, Martin; Baulier, Loic. |
Age and size at maturation appear as key parameters governing the dynamics of a population as they affect growth rate, fecundity, and survival. The expression of such life history traits is determined by genetic make-up and modulated by environmental factors mainly through phenotypic plasticity. Moreover, fishing, besides decreasing population size and changing demographic composition can alter allelic frequencies through fisheries-induced evolution by selecting for some particular traits. In the Bay of Biscay, a decreasing trend in both sardine body condition and size-at-age has recently been pointed out at the population level. The Probabilistic Maturation Reaction Norm (PMRN) approach was applied to help disentangle phenotypic plasticity and genetic... |
Tipo: Text |
Palavras-chave: Fisheries-induced evolution; Body condition; Phenotypic plasticity; Maturation; Growth; Sardina pilchardus; Bay of biscay. |
Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00660/77203/78637.pdf |
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Pawlowski, Lionel; Lorance, Pascal. |
In the Northeast Atlantic fishery for roundnose grenadier Coryphaenoides rupestris, discards account for about 30% of the catch in weight. Data on discards are scarce; however, length distributions and discard rates appear to be relatively stable from year to year. In contrast, landings data available since 1990 show that the average pre-anal fin length has decreased from 20.7 cm in 1990 to 15.2 cm in 2008, resulting in a 58% reduction of the mean individual weight (850 g in 2008) and an increasing occurrence of overlapping class sizes between landings and discards in recent years. For stock assessment, the method of separable virtual population analysis (SVPA) was used. However, because of the lack of discard data for many of the years covered by the... |
Tipo: Text |
Palavras-chave: Stock assessment; Fishing effort; Discards; Time series; Macrouridae; Coryphaenoides rupestris; Atlantic Ocean. |
Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/00000/11175/7527.pdf |
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Veron, Matthieu; Lebigre, Christophe; Bertignac, Michel; Doray, Mathieu; Duhamel, Erwan; Huret, Martin; Pawlowski, Lionel. |
Peu de modèles d'évaluation de stock intègrent une description fine des processus biologiques régissant les populations exploitées par la pêche au sein des écosystèmes. Ce manque est particulièrement regrettable dans le cas des petits pélagiques dont la dynamique est fortement influencée par les conditions environnementales. En effet, la pêche et les fluctuations environnementales et climatiques impactent fortement la dynamique de population de la sardine du golfe de Gascogne. Pour comprendre la dynamique de cette population au sein de l'écosystème et les effets des pêcheries, il est donc nécessaire d'identifier et de caractériser cet ensemble de pressions. Afin d'améliorer la gestion et le suivi de la dynamique de ce stock, le développement d'un modèle... |
Tipo: Text |
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Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00410/52133/52842.pdf |
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Calderwood, Julia; Robert, Marianne; Pawlowski, Lionel; Vermard, Youen; Radford, Zachary; Catchpole, Thomas L.; Reid, David G.. |
As a result of the introduction of the Landing Obligation in European fisheries there is a need to equip industry with the tools and knowledge to avoid unwanted catches. Optimising fishing practices in terms of time and location fished have been acknowledged as being important in modulating catch composition. Mapping techniques used to identify and manage the spatio-temporal nature of bycatch, however, remain underutilized. Data collected on board commercial fishing vessels by observers provides an important source of information on the component of catches discarded. Using a unique dataset, combining observer data for Irish, French and British vessels operating in the Celtic Sea between 2010 and 2015, maps were developed to identify where catches of quota... |
Tipo: Text |
Palavras-chave: Landing obligation; Discards; Consistent maps; Fishing tactics; Shiny app; Celtic sea. |
Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00590/70162/68235.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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Dube, Benoit; Pawlowski, Lionel; Biseau, Alain. |
L’étude présentée est une analyse des informations recueillies en 2011 dans le cadre du programme Obsmer en Manche Est (Division CIEM VIId) et mer du Nord (Zone IV), ainsi qu’en mer Celtique sur les chalutiers de fond. Elle complète le précédent document (juin 2011) qui présentait l’analyse des observations des captures 2009-2010 en mer du Nord – Manche Est. Ce document étend l’analyse à la pêcherie française de mer Celtique. |
Tipo: Text |
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Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00110/22172/19828.pdf |
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Silva, Alexandra; Moreno, Ana; Riveiro, Isabel; Santos, Begoña; Pita, Cristina; Garcia Rodrigues, Joao; Villasante, Sebastian; Pawlowski, Lionel; Duhamel, Erwan. |
This study describes fisheries, stock status, ICES advice and management measures for the Northern and Southern sardine stocks in EU Atlantic waters. Information on sardine biology and ecology is provided for a better understanding of stock development. Social and economic dimensions are addressed for sardine fisheries in France, Spain and Portugal. The study provides recommendations to improve knowledge on the species and indicates management measures which might be considered for the sustainability of the fisheries. |
Tipo: Text |
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Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00300/41109/40280.pdf |
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Macher, Claire; Bailly, Denis; Ballesteros, Marta; Bertignac, Michel; Collocas, Francesco; Fitzpatrick, Mike; Frangoudes, Katia; Garcia, Dorleta; Kraan, Marloes; Little, Rich; Mardle, Simon; Murillas, Arantza; Pawlowski, Lionel; Philippe, Manuelle; Prellezo, Raul; Sabatella, Evelina; Steins, Nathalie; Thebaud, Olivier; Ulrich, Clara. |
Implementation of Ecosystem Based Management in fisheries has led to higher integration of knowledge in advices and higher engagement of stakeholders in the decision support Process. As part of the process, fisheries scientists contribute in different ways and at different levels to decision support and experienced partnership approaches in the context of research projects or institutional decision support. Role of scientists in the process is however not trivial to define and operationalize. Several pitfalls can occur that scientists may have experienced through partnership projects or in the expert assessments done for authorities. A workshop was organized from 15 to 17 January 2018 as part of the ScipaDe ... |
Tipo: Text |
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Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00463/57452/59561.pdf |
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Biseau, Alain; Bellail, Robert; Bertignac, Michel; Biais, Gerard; Bigot, Jean-louis; Bouche, Ludovic; Bourjea, Jerome; Caro, Anthony; De Casamajor, Marie-noelle; Caill-milly, Nathalie; Drogou, Mickael; Duhamel, Erwan; Fifas, Spyros; Foucher, Eric; Fromentin, Jean-marc; Jadaud, Angelique; Lampert, Luis; Laurans, Martial; Lissardy, Muriel; Lorance, Pascal; Mahe, Jean-claude; Mahe, Kelig; Masse, Jacques; Morandeau, Gilles; Pawlowski, Lionel; Poisson, Francois; Reynal, Lionel; Roos, David; Verin, Yves; Vermard, Youen; Vigneau, Joel. |
Ce document présente l'état des principaux stocks exploités par les flottes françaises en termes de mortalité par pêche et de biomasse de reproducteurs. La situation fin 2010 (début 2011) par rapport aux points de référence (de précaution et Fmsy) est indiqué lorsque les indicateurs sont estimés et que les références sont définies. Les grandes tendances en matière d'évolution des mortalités et biomasses sont également indiquées. |
Tipo: Text |
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Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00035/14656/11956.pdf |
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Registros recuperados: 25 | |
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