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Auteur (up) Mariani, P.; Křivan, V.; MacKenzie, B.R.; Mullon, C.
Titre The migration game in habitat network: the case of tuna Type Article scientifique
Année 2016 Publication Revue Abrégée Theor Ecol
Volume 9 Numéro 2 Pages 219-232
Mots-Clés Bluefin tuna; Game theory; Habitat selection; Ideal free distribution; Plant Sciences; Structured population; Theoretical Ecology/Statistics; Zoology
Résumé Long-distance migration is a widespread process evolved independently in several animal groups in terrestrial and marine ecosystems. Many factors contribute to the migration process and of primary importance are intra-specific competition and seasonality in the resource distribution. Adaptive migration in direction of increasing fitness should lead to the ideal free distribution (IFD) which is the evolutionary stable strategy of the habitat selection game. We introduce a migration game which focuses on migrating dynamics leading to the IFD for age-structured populations and in time varying habitats, where dispersal is costly. The model predicts migration dynamics between these habitats and the corresponding population distribution. When applied to Atlantic bluefin tunas, it predicts their migration routes and their seasonal distribution. The largest biomass is located in the spawning areas which have also the largest diversity in the age-structure. Distant feeding areas are occupied on a seasonal base and often by larger individuals, in agreement with empirical observations. Moreover, we show that only a selected number of migratory routes emerge as those effectively used by tunas.
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Langue en Langue du Résumé Titre Original
Éditeur de collection Titre de collection Titre de collection Abrégé
Volume de collection Numéro de collection Edition
ISSN 1874-1738, 1874-1746 ISBN Médium
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 1465
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Auteur (up) NIEBLAS, A.-E.; DEMARCQ, H.; DRUSHKA, K.; SLOYAN, B.; BONHOMMEAU, S.
Titre Front variability and surface ocean features of the presumed southern bluefin tuna spawning grounds in the tropical southeast Indian Ocean Type Article scientifique
Année 2014 Publication Revue Abrégée Deep-sea Research Part II-topical Studies In Oceanography
Volume 107 Numéro Pages 64-76
Mots-Clés Front detection index; Indo-Australian region; Oceanic fronts; Southern bluefin tuna Thunnus maccoyii; Spawning grounds (10 degrees S-20 degrees S 105 degrees E-125 degrees E); Tropical southeast Indian Ocean
Résumé The southern bluefin tuna (SBT, Thunnus maccoyii) is an ecologically and economically valuable fish. However, surprisingly little is known about its critical early life history, a period when mortality is several orders of magnitude higher than at any other life stage, and when larvae are highly sensitive to environmental conditions. Ocean fronts can be important in creating favourable spawning conditions, as they are a convergence of water masses with different properties that can concentrate planktonic particles and lead to enhanced productivity. In this study, we examine the front activity within the only region where SBT have been observed to spawn: the tropical southeast Indian Ocean between Indonesia and Australia (10 degrees S-20 degrees S, 105 degrees E-125 degrees E). We investigate front activity and its relationship to ocean dynamics and surface features of the region. Results are also presented for the entire Indian Ocean (30 degrees N-45 degrees S, 20 degrees E-140 degrees E) to provide a background context. We use an extension of the Cayula and Cornillon algorithm to detect ocean fronts from satellite images of sea surface temperature (SST) and chlorophyll-a concentration (chl-a). Front occurrence represents the probability of occurrence of a front at each pixel of an image. Front intensity represents the magnitude of the difference between the two water masses that make up a front. Relative to the rest of the Indian Ocean, both SST and chl-a fronts in the offshore spawning region are persistent in occurrence and weak in intensity. Front occurrence and intensity along the Australian coast are high, with persistent and intense fronts found along the northwest and west coasts. Fronts in the tropical southeast Indian Ocean are shown to have strong annual variability and some moderate interannual variability. SST front occurrence is found to lead the Southern Oscillation Index by one year, potentially linked to warming and wind anomalies in the Indian Ocean. The surface ocean characteristics of the offshore SBT spawning region are found to be particularly stable compared to the rest of the Indian Ocean in terms of stable SST, low eddy kinetic energy, i.e., low mesoscale eddy activity, and low chl-a. However, this region has high front occurrence, but low front intensity of both SST and chl-a fronts. The potential impact of these oceanic features for SBT spawning is discussed.
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Langue Langue du Résumé Titre Original
Éditeur de collection Titre de collection Titre de collection Abrégé
Volume de collection Numéro de collection Edition
ISSN 0967-0645 ISBN Médium
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 1131
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Auteur (up) Olson, R.J.; Young, J.W.; Menard, F.; Potier, M.; Allain, V.; Goni, N.; Logan, J.M.; Galvan-Magana, F.
Titre Bioenergetics, Trophic Ecology, and Niche Separation of Tunas Type Chapitre de livre
Année 2016 Publication Revue Abrégée
Volume Numéro Pages 199-344
Mots-Clés albacore thunnus-alalunga; atlantic bluefin tuna; eastern tropical pacific; fish aggregation devices; gulf-of-mexico; large pelagic fishes; oceanic top predators; predator-prey interactions; satellite archival tags; western indian-ocean
Résumé Tunas are highly specialized predators that have evolved numerous adaptations for a lifestyle that requires large amounts of energy consumption. Here we review our understanding of the bioenergetics and feeding dynamics of tunas on a global scale, with an emphasis on yellowfin, bigeye, skipjack, albacore, and Atlantic bluefin tunas. Food consumption balances bioenergetics expenditures for respiration, growth (including gonad production), specific dynamic action, egestion, and excretion. Tunas feed across the micronekton and some large zooplankton. Some tunas appear to time their life history to take advantage of ephemeral aggregations of crustacean, fish, and molluscan prey. Ontogenetic and spatial diet differences are substantial, and significant interdecadal changes in prey composition have been observed. Diet shifts from larger to smaller prey taxa highlight ecosystem-wide changes in prey availability and diversity and provide implications for changing bioenergetics requirements into the future. Where tunas overlap, we show evidence of niche separation between them; resources are divided largely by differences in diet percentages and size ranges of prey taxa. The lack of long-term data limits the ability to predict impacts of climate change on tuna feeding behaviour. We note the need for systematic collection of feeding data as part of routine monitoring of these species, and we highlight the advantages of using biochemical techniques for broad-scale analyses of trophic relations. We support the continued development of ecosystem models, which all too often lack the regional-specific trophic data needed to adequately investigate climate and fishing impacts.
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Editeur Elsevier Academic Press Inc Lieu de Publication San Diego Éditeur Curry, B.E.
Langue English Langue du Résumé Titre Original
Éditeur de collection Titre de collection Titre de collection Abrégé Advances in Marine Biology, Vol 74
Volume de collection 74 Numéro de collection Edition
ISSN ISBN 978-0-12-803607-5 Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 1661
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Auteur (up) Pecoraro, C.; Babbucci, M.; Franch, R.; Rico, C.; Papetti, C.; Chassot, E.; Bodin, N.; Cariani, A.; Bargelloni, L.; Tinti, F.
Titre The population genomics of yellowfin tuna (Thunnus albacares) at global geographic scale challenges current stock delineation Type Article scientifique
Année 2018 Publication Revue Abrégée Sci Rep
Volume 8 Numéro Pages 13890
Mots-Clés archival tag data; atlantic bluefin tuna; connectivity; conservation; divergence; fisheries management; habitat utilization; loci; pacific-ocean; relatedness
Résumé Yellowfin tuna, Thunnus albacares, is one of the most important seafood commodities in the world. Despite its great biological and economic importance, conflicting evidence arises from classical genetic and tagging studies concerning the yellowfin tuna population structure at local and global oceanic scales. Access to more powerful and cost effective genetic tools would represent the first step towards resolving the population structure of yellowfin tuna across its distribution range. Using a panel of 939 neutral Single Nucleotide Polymorphisms (SNPs), and the most comprehensive data set of yellowfin samples available so far, we found genetic differentiation among the Atlantic, Indian and Pacific oceans. The genetic stock structure analysis carried out with 33 outlier SNPs, putatively under selection, identified discrete populations within the Pacific Ocean and, for the first time, also within the Atlantic Ocean. Stock assessment approaches that consider genetic differences at neutral and adaptive genomic loci should be routinely implemented to check the status of the yellowfin tuna, prevent illegal trade, and develop more sustainable management measures.
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Editeur Lieu de Publication Éditeur
Langue English Langue du Résumé Titre Original
Éditeur de collection Titre de collection Titre de collection Abrégé
Volume de collection Numéro de collection Edition
ISSN 2045-2322 ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 2437
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Auteur (up) Rouyer, T.; Bonhommeau, S.; Giordano, N.; Ellul, S.; Ellul, G.; Deguara, S.; Wendling, B.; Belhaj, M.M.; Kerzerho, V.; Bernard, S.
Titre Tagging Atlantic bluefin tuna from a farming cage: An attempt to reduce handling times for large scale deployments Type Article scientifique
Année 2019 Publication Revue Abrégée Fisheries Research
Volume 211 Numéro Pages 27-31
Mots-Clés Electronic tagging; Farming cage; Large Atlantic bluefin tuna; Release
Résumé Our knowledge on the biology and ecology of marine species have improved greatly through the use of archival tags by enabling the collection on information from individual in the wild. This is specifically true for large pelagic species such as the Atlantic Bluefin tuna (ABFT, Thunnus thynnus) where, for the first time, it has been possible to confirm through fisheries-independent data, migration patterns, reproductive and feeding behaviours and habitat use. However, large-scale tagging experiments that would enable researchers to tackle group behaviour are difficult to set up. On the one hand, the impact of the actual tagging operation should be as minimal as possible to avoid any change in behaviour of the fish which could influence tag data analyses. On the other hand, large scale tagging experiments require handling a large number of animals in a relatively short period of time. In the present manuscript, a methodology for tagging several large ABFT with satellite tags was tested with ABFT caught from a cage of a Maltese farm. The total time of the operation, from the moment fish were caught by handline to release back to the sea lasted an average of 10 min for the 3 fish tagged. The handling of the fish on the deck lasted less than 2 min. This methodology proved successful at tagging several large (158–182 cm) fishes in a very short time, while ensuring the best conditions for the fish during tagging and subsequent release. This procedure requires substantial logistical preparation and an experienced crew team but, by reducing the time required for the operation, opens up the possibility of large scale tagging activities of large fish held in cages or caught by purse seiners.
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Editeur Lieu de Publication Éditeur
Langue Langue du Résumé Titre Original
Éditeur de collection Titre de collection Titre de collection Abrégé
Volume de collection Numéro de collection Edition
ISSN 0165-7836 ISBN Médium
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2487
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