Sabiia Seb
PortuguêsEspañolEnglish
Embrapa
        Busca avançada

Botão Atualizar


Botão Atualizar

Ordenar por: RelevânciaAutorTítuloAnoImprime registros no formato resumido
Registros recuperados: 9
Primeira ... 1 ... Última
Imagem não selecionada

Imprime registro no formato completo
A simulation framework to evaluate management strategies for Atlantic tunas: a preliminary example based on east Atlantic bluefin ArchiMer
Kell, Laurence T; Fromentin, Jean-marc; Gauthiez, F; Restrepo, Victor.
The Ad Hoc Working Group on the Precautionary Approach (SCRS/99/11) recommended the development of a simulation modelling framework to investigate the performance of stock specific management strategies under a variety of realistic hypothesis about population and fishery dynamics. This paper describes a preliminary simulation model based on East Atlantic bluefin tuna developed using flexible software that allows the implications for management of a variety of plausible hypotheses about stock and fishery dynamics to be explored. The intention is to illustrate the ways in which such models can be used and the types of advice that they can provide
Tipo: Text
Ano: 2000 URL: http://archimer.ifremer.fr/doc/00194/30566/28991.pdf
Imagem não selecionada

Imprime registro no formato completo
An evaluation of changes in stock productivity and consequences for management. An example based on North Atlantic albacore Thunnus alalunga ArchiMer
Kell, Laurence T; Fromentin, Jean-marc.
Reference points are important elements of fisheries management and the supporting scientific advisory frameworks. However, fish stocks can fluctuate extensively over a large range of spatial and temporal scales independent of human exploitation and there has been a classical tendency to assume a dichotomy, i.e., that changes in fish populations are primarily attributable either to exploitation or to environmental variability. Therefore we look at variability in surplus production and examine the relative impacts of the environment and exploitation on the productivity of North Atlantic albacore (Thunnus alalunga). The analysis revealed that variations were driven by environmental effects. It was also found that substantial variations in time-series of...
Tipo: Text Palavras-chave: Thunnus alalunga; Albacore; Fisheries management; FLR; Reference points; Stationary processes; Surplus production..
Ano: 2011 URL: http://archimer.ifremer.fr/doc/00192/30282/28758.pdf
Imagem não selecionada

Imprime registro no formato completo
An evaluation of the implications of population structure on the current bluefin tuna advice framework ArchiMer
Kell, Laurence T; Fromentin, Jean-marc; Bonhommeau, Sylvain.
The objectives of the comprehensive ICCAT Atlantic-Wide Research Programme on Bluefin Tuna (GBYP) are to improve data collection, knowledge of key biological and ecological processes, assessment models and management. An important element of which is to develop a robust advice framework consistent with the Precautionary Approach. The current advice framework, which is based upon Virtual Population Analysis, demonstrates how a Management Strategy Evaluation (MSE) framework can be used to evaluate the robustness of management advice to uncertainty about stock structure.
Tipo: Text Palavras-chave: Bluefin; Management Strategy Evaluation; Robustness; Stock structure; VPA.
Ano: 2012 URL: http://archimer.ifremer.fr/doc/00192/30277/28740.pdf
Imagem não selecionada

Imprime registro no formato completo
Can we detect the effects of environmental variations on fish populations through VPA outputs? the North Atlantic albacore case ArchiMer
Kell, Laurence T; Fromentin, Jean-marc; Ortiz De Zarate, Victoria; Arrizabalaga, Haritz.
Past studies have indicated that numbers-at-age 1 of albacore may be correlated with the winter NAO index in the previous year. Two main hypotheses have been stressed to explain such observation, i.e. an impact of the NAO on the recruitment or on migration patterns and consequently in the availability and catchability of specific age classes to the surface fishery. The objective of the present paper is to test whether such processes can be distinguished using VPA outputs. We first computed simple cross-correlations between the NAO at various lags, catches-at-age, Numbers-atage and F-at-age estimated in the last assessment. Since results were inconclusive, simulations were undertaken. The results showed that the probability of detecting spurious...
Tipo: Text Palavras-chave: Thunnus alalunga; North Atlantic Oscillation; Simulation model; Virtual population analysis; Correlation coefficient; NAO.
Ano: 2005 URL: http://archimer.ifremer.fr/doc/00194/30503/28913.pdf
Imagem não selecionada

Imprime registro no formato completo
Evaluation of the performance and robustness of VPA-based stock assessment and MSY-based management strategy to process error: the Atlantic bluefin tuna case study ArchiMer
Fromentin, Jean-marc; Kell, Laurence T.
An integrative simulation framework was built to evaluate the consequences of variability attributable to changes in carrying capacity or the stock’s migration pattern of Atlantic bluefin tuna on the ICCAT stock assessment and management procedures. We also evaluated the performances of stock assessment methods with respect to their ability to provide good estimates of MSY, FMSY and BMSY and tested the robustness of the current ICCAT management strategy to uncertainty about the true dynamics and historical exploitation levels. The results clearly indicate that the VPA performances were seriously impaired if the long-term variations in catches are due to changes in migration/availability. There is further considerable confounding between the underlying...
Tipo: Text Palavras-chave: Thunnus thynnus; Stock assessment; VPA; Biological reference points; MSY; Management strategy; Simulation model.
Ano: 2009 URL: http://archimer.ifremer.fr/doc/00192/30295/28786.pdf
Imagem não selecionada

Imprime registro no formato completo
Length based catch analysis for east Atlantic Mediterranean bluefin tuna ArchiMer
Kell, Laurence T; Bonhommeau, Sylvain; Fromentin, Jean-marc.
Although the bluefin assessment is based on catch-at-age data, ageing using hard parts is an expensive and d{fficult process. Therefore length data are converted into age for bluefin using a growth curve, i.e. age slicing. Where age is predicted from length using the inverse of the von Bertalanffy growth curve. Here we show how a simple method based on length data alone can be used to estimate population parameters such as total mortality (Z).
Tipo: Text Palavras-chave: Bluefin; Catch curve analysis; Growth; Length; Mortality.
Ano: 2013 URL: http://archimer.ifremer.fr/doc/00191/30274/28734.pdf
Imagem não selecionada

Imprime registro no formato completo
Online collaborative environment to run Stock Assessment work ow: an option for IOTC? ArchiMer
Imzilen, Taha; Bonhommeau, Sylvain; Rouyer, Tristan; Kell, Laurence T; Chassot, Emmanuel; Barde, Julien.
In this note, we present an approach which has been recently used to execute online the set of codes used for eastern blue_n tuna (BFT-E) stock assessment at ICCAT. We aim at discussing the possible interest of the approach to the IOTC Community for focusing on Indian ocean tuna and tuna-like stocks and running other assesment models such as Stock Synthesis 3 (SS3). In 2014, ICCAT BFT-E working group has been able to execute thousands of model runs by using parallelization of R and Fortran codes on a supercomputer. This approach has a lot of scienti_c bene_ts, in particular for better including the multiple sources of uncertainty in assessment results and associated scienti_c advice. However, very few participants would be able to reproduce it without...
Tipo: Text
Ano: 2016 URL: http://archimer.ifremer.fr/doc/00360/47135/47084.pdf
Imagem não selecionada

Imprime registro no formato completo
Online collaborative environment to run the eastern bluefin tuna stock assessment workflow ArchiMer
Imzilen, Taha; Bonhommeau, Sylvain; Rouyer, Tristan; Kell, Laurence T; Barde, Julien.
In this note, we describe an approach which makes possible to execute online the set of codes used for eastern bluefin tuna (BFT-E) stock assess-ment at ICCAT. In 2014, ICCAT BFT-E working group has been able to execute thousands of model runs by using parallelization of R and Fortran codes on a supercomputer. This new approach has a lot of scientific benefits, but very few participants would be able to reproduce it without specific skills. Since november 2015, the H2020 BlueBridge project is funding an engineer to set up a WebSite (or VRE for Virtual Research Environment) where users will be able to parametrize and execute various steps of the BFT-E stock assessment workflow. By repackaging codes provided by ICCAT BFT-E working group the same codes are...
Tipo: Text Palavras-chave: Bluefin tuna; Scientific cloud; Stock assessment; Grid computing; Online processing.
Ano: 2017 URL: http://archimer.ifremer.fr/doc/00403/51471/52042.pdf
Imagem não selecionada

Imprime registro no formato completo
Projections for east Atlantic and Mediterranean bluefin tuna ArchiMer
Kell, Laurence T; Bonhommeau, Sylvain; Fromentin, Jean-marc; Ortiz, Mauricio; Walter, John.
The management plan for East Atlantic and Mediterranean bluefin tuna is based on the Kobe II strategy matrix (K2SM), which indicates the probability of SSB>BMSY and F <FMSY for different levels of catch projections. In this paper we document the projections for eastern Atlantic and Mediterranean bluefin tuna.
Tipo: Text Palavras-chave: Stock assessment; Bluefin tuna.
Ano: 2013 URL: http://archimer.ifremer.fr/doc/00192/30276/28739.pdf
Registros recuperados: 9
Primeira ... 1 ... Última
 

Empresa Brasileira de Pesquisa Agropecuária - Embrapa
Todos os direitos reservados, conforme Lei n° 9.610
Política de Privacidade
Área restrita

Embrapa
Parque Estação Biológica - PqEB s/n°
Brasília, DF - Brasil - CEP 70770-901
Fone: (61) 3448-4433 - Fax: (61) 3448-4890 / 3448-4891 SAC: https://www.embrapa.br/fale-conosco

Valid HTML 4.01 Transitional