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| Registros recuperados: 145 | |
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| Pelletier, Dominique; Mahevas, Stephanie; Drouineau, Hilaire; Vermard, Youen; Thebaud, Olivier; Guyader, Olivier; Poussind, Benjamin. |
| In order to provide reliable scientific advice and support for fisheries management, it is necessary to evaluate the biological and economic sustainability of complex fisheries, such as multi-species multi-fleet fisheries. Existing policy-screening modelling tools are not fully suitable in this purpose due to either an over-simplified description of population dynamics, or due to the lack of consideration of economic aspects. In this paper, we present a package that enables quantitative bioeconomic assessment of management scenarios. Population dynamics is described through spatially- and seasonally-explicit models. Exploitation dynamics is characterized by several fishing activities with specific spatial and seasonal features, and practiced by several... |
| Tipo: Text |
Palavras-chave: Policy screening; Natural resource management; Fisheries dynamics; Bioeconomic model; Population dynamics; Complex systems; Simulation tool. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6782.pdf |
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| Lopez, Romain; De Pontual, Helene; Bertignac, Michel; Mahevas, Stephanie. |
| European sea bass, Dicentrarchus labrax, is a highly valuable species in Europe, both for aquaculture in the Mediterranean Sea and for commercial and recreational fisheries in the North East Atlantic Ocean. Subjected to increasing fishing pressure, the wild population has recently experienced significant recruitment fluctuation as well as a northward extension of its distribution area in the North Sea. While the nature of the ecological and/or physiological processes involved remains unresolved, ontogenetic habitat shifts and adult site fidelity could increase the species’ vulnerability to climate change and overfishing. As managers look for expert information to propose management scenarios leading to sustainable exploitation, exploratory modelling... |
| Tipo: Text |
Palavras-chave: Population dynamics; Essential habitats; Connectivity; Bioenergetic modeling; Phenotypic plasticity; Life cycle adaptation. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00341/45258/44699.pdf |
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| Silva, A.; Skagen, D. W.; Uriarte, A.; Masse, Jacques; Santos, M. B.; Marques, V.; Carrera, P.; Beillois, Pierre; Pestana, G.; Porteiro, C.; Stratoudakis, Y.. |
| The spatio-temporal variability in the distribution, demographic structure, recruitment, and mortality of sardine within the Iberian Biscay region is described using area-disaggregated data collected during acoustic surveys and at ports since the mid-1980s. Multiple regression models were used to describe log numbers-at-age obtained annually in ten areas covered by three surveys to test the existence of geographic differences in selectivity-at-age, recruitment strength, and mortality and to infer plausible migration routes. Within Iberian waters, sardine biomass was mainly concentrated off western Portugal and the Gulf of Cadiz. In the Bay of Biscay, biomass levels were comparable with those off western Portugal. Recruitment was localized in a few areas... |
| Tipo: Text |
Palavras-chave: Stock structure; Small pelagic fish; Population dynamics; Iberian Peninsula. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6459.pdf |
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| Marandel, Florianne; Lorance, Pascal; Trenkel, Verena M.. |
| The thornback ray (Raja clavata) in the Bay of Biscay is presumed to have declined during the 20th Century. To evaluate this decline and estimate biomass trajectories, a hypothetical catch time series was created for the period 1903-2013. A Bayesian state-space biomass production model with a Schaefer production function was fitted to the hypothetical catch time series and to a shorter research vessel Catch Per Unit Eeffort (CPUE) time series (1973-2013, with missing years). A censored likelihood made it possible to obtain biomass estimates without a CPUE time series or only with an estimate of biomass depletion. A simulation-estimation approach showed a high sensitivity of results to the prior for the intrinsic growth rate. The model provided biomass... |
| Tipo: Text |
Palavras-chave: Population dynamics; Stock assessment; Data poor; Censored data; Bayes; Thornback ray; State-space model. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00359/47032/46947.pdf |
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| Daget, J.. |
| The author explains that the population dynamics study, descriptive and explicative way, the changes which happen in the structure and the parameters (growth rate, sex ratio, fecundity, mortality etc.) of a monospecific population, by the use of mathematical models which permit prediction and simulation. If the fish population is not exploited, it is necessary to sample it directly and obtain samples representative of the demographical structure by experimental fishing (like electrical fishing) or by selectivity corrections. If the population is exploited, often the exploited phasis of the stock is only studied from samples representative of the whole captures. Now it happens that there is an important difference between the demographical structure of the... |
| Tipo: Text |
Palavras-chave: Pisces; Catch statistics; Mathematical models; Population dynamics. |
| Ano: 1976 |
URL: http://archimer.ifremer.fr/doc/1976/publication-1999.pdf |
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| Barraquand, F.; Picoche, C.; Maurer, Daniele; Carassou, L.; Auby, Isabelle. |
| Phytoplanktonic communities maintain a high diversity in a seemingly homogeneous environment, competing for the same set of resources. Many theories have been proposed to explain this coexistence despite likely competition, such as contrasted responses to temporal environmental variation. However, theory has developed at a faster pace than empirical evaluation using field data, which requires inferring drivers of community dynamics from observational time series. Here, we combine autoregressive models with a data set spanning more than 20 years of phytoplankton counts every two weeks, together with nutrients and physical variables. By comparing models dominated by nutrients or physical variables (hydrodynamics and climate), we first explore which abiotic... |
| Tipo: Text |
Palavras-chave: Competition; Diatoms; Dinoflagellates; Hydrodynamics; Interactions; MAR; Mutualism; Network; Population dynamics; Seasonality; Time series. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00461/57257/59285.pdf |
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| Junquera, Susana. |
| Using the fishing records from the most relevant ports of the Cantabrian and Galician coasts, th history of the anchovy (Engraulis encrasicholus ) fishery in this area is reconstituted. The crisis observed and the variations in the fishing areas throughout the time are analyzed. An estimation of the age classes composition in the catches founded on commercial classification data can be made. The hypothesis of existence of a core population in the Southern part of the Bay of Biscay is presented and that only under certain advantageous condition the expansion of this species throughout all the Cantabrian Sea was possible. |
| Tipo: Text |
Palavras-chave: Pisces; Age composition; Population dynamics; Catch/effort; Fishery statistics. |
| Ano: 1984 |
URL: http://archimer.ifremer.fr/doc/1984/publication-1795.pdf |
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| Rochet, Marie-joelle. |
| Density dependence means that exploited fish populations exhibit earlier maturity, a faster growth rate, increased fecundity and reduced egg size. Here, the consequences of these effects on population dynamics, the estimation of spawning biomass per recruit and associated biological reference points are examined by a simulation model. The model is a self-regenerating model in which the population parameters (age at maturity, growth, fecundity, egg size) vary according to three classes of population abundance. Early life stages are characterized by a size-dependent growth and mortality model. It is concluded that spawning per recruit is an ambiguous concept because, if density dependence occurs in the adult population, the spawning biomass of a cohort is... |
| Tipo: Text |
Palavras-chave: Teleost fishes; Population dynamics; Life history; Density dependence; Biological reference points. |
| Ano: 2000 |
URL: http://archimer.ifremer.fr/doc/2000/publication-485.pdf |
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| Registros recuperados: 145 | |
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