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| Registros recuperados: 11 | |
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| Rodríguez‐ezpeleta, Naiara; Díaz‐arce, Natalia; Walter, John F; Richardson, David E; Rooker, Jay R; Nøttestad, Leif; Hanke, Alex R; Franks, James S; Deguara, Simeon; Lauretta, Matthew V; Addis, Piero; Varela, Jose Luis; Fraile, Igaratza; Goñi, Nicolas; Abid, Noureddine; Alemany, Francisco; Oray, Isik K; Quattro, Joseph M; Sow, Fambaye N; Itoh, Tomoyuki; Karakulak, F Saadet; Pascual‐alayón, Pedro J; Santos, Miguel N; Tsukahara, Yohei; Lutcavage, Molly; Fromentin, Jean-marc; Arrizabalaga, Haritz. |
| Effective sustainable management of marine fisheries requires that assessed management units (that is, fish stocks) correspond to biological populations. This issue has long been discussed in the context of Atlantic bluefin tuna (ABFT, Thunnus thynnus) management, which currently considers two unmixed stocks but does not take into account how individuals born in each of the two main spawning grounds (Gulf of Mexico and Mediterranean Sea) mix in feeding aggregations throughout the Atlantic Ocean. Using thousands of genome‐wide molecular markers obtained from larvae and young of the year collected at the species’ main spawning grounds, we provide what is, to the best of our knowledge, the first direct genetic evidence for “natal homing” in ABFT. This has... |
| Tipo: Text |
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| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00595/70710/68917.pdf |
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| Restrepo, Victor; Arrizabalaga, Haritz; Ortiz De Urbina, J M; Fromentin, Jean-marc. |
| A standard yield per recruit (YPR) analysis is used to analyse the effects of minimum size regulations on bluefin tuna from the Eastern stock (East Atlantic and Mediterranean). Analyses were based on a selectivity vector computed over the period 1990- 1994 for which data were more reliable and VPA (performed during the 2002 stock assessment) showed a relatively good convergence. This selectivity vector was modified according to different minimum size regulations and implementation error levels. It is concluded that: (i) perfect implementation of the size limit regulation adopted in 2004 would increase YPR by 4.3% relative to the size limit adopted in 2002, and by 8.8% relative to the pattern realized in the early 1990s; (ii) YPR is however expected to... |
| Tipo: Text |
Palavras-chave: Yield/recruit; Yield predictions; Size limit regulations; Bluefin tuna.. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/00194/30545/28964.pdf |
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| Restrepo, Victor R; Ortiz De Urbina, J; Fromentin, Jean-marc; Arrizabalaga, Haritz. |
| Knowledge of gear-specific selectivity patterns can be useful in age-structured analyses. In recent assessments of eastern Atlantic bluefin tuna, Thunnus thynnus, the SCRS has derived selectivity estimates from the results of virtual population analyses. This document proposes an alternative approach, based on equilibrium catch curves, that is simple to apply and that relies on a smaller set of assumptions. The study uses the catch-at-age data from the last assessment conducted in 2002, and estimates recent and historical selectivity patterns for the total stock as well as some of the major gears (trap, baitboat, purse seine and longline). The resulting estimates seem reasonable for the various gears, given prior knowledge. The document also presents... |
| Tipo: Text |
Palavras-chave: Gear selectivity; Stock assessment; Bluefin tuna. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/00192/30326/28800.pdf |
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| Fromentin, Jean-marc; Arrizabalaga, Haritz; Restrepo, Victor R; Ortiz De Urbina, J. |
| The 2004 data exploratory meeting concluded that it was no longer defensible to assess the East Atlantic and Mediterranean population using methods that assume that the catch-atsize/age is known exactly, until extensive improvements in fisheries statistics are made. For these reasons, we here investigated the potential benefits of the year-class curve analysis. The robustness and consistency of our results tend to advocate that this method is, in the present situation, a good alternative to ADAPT (among others). As a whole, the estimates of Z from the year-class curve analyses applied on the Spanish trap and Japanese long line fishery data appear indeed to be in good or excellent agreement with ADAPT outputs for the same period and same age-classes. This... |
| Tipo: Text |
Palavras-chave: Fishing and natural mortalities; Year-class curves; Stock assessment. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/00192/30325/28799.pdf |
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| Arrizabalaga, Haritz; Dufour, Florence; Kell, Laurence; Merino, Gorka; Ibaibarriaga, Leire; Chust, Guillem; Irigoien, Xabier; Santiago, Jose Luis; Murua, Hilario; Fraile, Igaratza; Chifflet, Marina; Goikoetxea, Nerea; Sagarminaga, Yolanda; Aumont, Olivier; Bopp, Laurent; Herrera, Miguel; Fromentin, Jean-marc; Bonhomeau, Sylvain. |
| In spite of its pivotal role in future implementations of the Ecosystem Approach to Fisheries Management, current knowledge about tuna habitat preferences remains fragmented and heterogeneous, because it relies mainly on regional or local studies that have used a variety of approaches making them difficult to combine. Therefore in this study we analyse data from six tuna species in the Pacific, Atlantic and Indian Oceans in order to provide a global, comparative perspective of habitat preferences. These data are longline catch per unit effort from 1958 to2007 for albacore, Atlantic bluefin, southern bluefin, bigeye, yellowfin and skipjack tunas. Both quotient analysis and Generalized Additive Models were used to determine habitat preference with respect to... |
| Tipo: Text |
Palavras-chave: Habitat; Tuna fisheries; Catch/effort; Environmental conditions; Quotient analysis; Generalised Additive Models; Ecosystem Approach to Fisheries Management. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00201/31190/29589.pdf |
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| Druon, Jean-noel; Fromentin, Jean-marc; Hanke, Alex R.; Arrizabalaga, Haritz; Damalas, Dimitrios; Ticina, Vjekoslav; Quilez-badia, Gemma; Ramirez, Karina; Arregui, Igor; Tserpes, George; Reglero, Patricia; Deflorio, Michele; Oray, Isik; Karakulak, F. Saadet; Megalbfonou, Persefoni; Ceyhan, Tevfik; Grubisic, Leon; Mackenzie, Brian R.; Lamkin, John; Afonso, Pedro; Addis, Piero. |
| An ecological niche modelling (ENM) approach was used to predict the potential feeding and spawning habitats of small (5-25kg, only feeding) and large (> 25kg) Atlantic bluefin tuna (ABFT), Thunnus thynnus, in the Mediterranean Sea, the North Atlantic and the Gulf of Mexico. The ENM was built bridging knowledge on ecological traits of ABFT (e.g. temperature tolerance, mobility, feeding and spawning strategy) with patterns of selected environmental variables (chlorophyll-a fronts and concentration, sea surface current and temperature, sea surface height anomaly) that were identified using an extensive set of precisely geo-located presence data. The results highlight a wider temperature tolerance for larger fish allowing them to feed in the northern –... |
| Tipo: Text |
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| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00308/41953/41803.pdf |
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| Brophy, Deirdre; Haynes, Paula; Arrizabalaga, Haritz; Fraile, Igaratza; Fromentin, Jean-marc; Garibaldi, Fulvio; Katavic, Ivan; Tinti, Fausto; Karakulak, F. Saadet; Macias, David; Busawon, Dheeraj; Hanke, Alex; Kimoto, Ai; Sakai, Osamu; Deguara, Simeon; Abid, Nouredinne; Santos, Miguel Neves. |
| Two stocks of bluefin tuna (Thunnus thynnus) inhabit the north Atlantic; the western and eastern stocks spawn in the Gulf of Mexico and the Mediterranean Sea respectively. Trans-Atlantic movements occur outside spawning time whereas natal homing maintains stock structure. Commercial fisheries may exploit a mixed assemblage of both stocks. The incorporation of mixing rates into stock assessment is precluded by uncertainties surrounding stock discrimination. Otolith shape descriptors were used to characterise western and eastern stocks of Atlantic bluefin tuna in the present study and to estimate stock composition in catches of unknown origin. Otolith shape varied with length and between locations and years. Within a restricted size range (200-297-cm fork... |
| Tipo: Text |
Palavras-chave: Elliptical Fourier analysis; Population structure; Stock mixture analysis. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00346/45745/45381.pdf |
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| Registros recuperados: 11 | |
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