|   | 
Détails
   web
Enregistrements
Auteur Rouyer, T.; Bonhommeau, S.; Giordano, N.; Giordano, F.; Ellul, S.; Ellul, G.; Deguara, S.; Wendling, B.; Bernard, S.; Kerzerho, V.
Titre Tagging Atlantic bluefin tuna from a Mediterranean spawning ground using a purse seiner Type Article scientifique
Année 2020 Publication Revue Abrégée (up) Fish Res.
Volume 226 Numéro Pages 105522
Mots-Clés Eastern Atlantic and Mediterranean stock; Electronic tagging; Large Atlantic bluefin tuna; migration; Migrations; movements; population-structure; Purse seine; thermal biology; thunnus-thynnus
Résumé Atlantic bluefin tuna, Thunnus thynnus, is as an emblematic and commercially valuable large pelagic species. In the past ten years, the purse seine fishery in the Mediterranean represents more than 50 % of the catch. Nowadays, purse seines target large fish and operate during the spawning season in the spawning grounds. Electronic tagging has shed a considerable amount of light on the ecology and behaviour of bluefin tuna over the past twenty years. However, such technique has rarely been applied on large bluefin tunas caught by the Mediterranean purse seine fishery despite its major importance. The logistical constraints related to this specific fishery, combined with the timing of migration of the fish and the requirements related to the handling of big fish have made adequate tagging from purse seines complex. Here we detail such an operation, designed to bridge the knowledge gap on the migratory behaviour of tunas targeted by the purse seine fishery. Three large bluefin tunas from the same school were tagged during the fishing operation of a French purse seine, resulting in a different migration pattern than previous deployments. The fish were tagged onboard in less than 2 min and efficiently, avoiding any subsequent mortality. These results contrast with those from tagging operations carried out in the Northwest Mediterranean, which underlies the importance of tagging operations from purse seines to obtain unbiased description of the movements of the eastern Atlantic bluefin tuna stock in the context of its management.
Adresse
Auteur institutionnel Thèse
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 0165-7836 ISBN Médium
Région Expédition Conférence
Notes WOS:000525305200010 Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2771
Lien permanent pour cet enregistrement
 

 
Auteur Travassos Tolotti, M.; Forget, F.; Capello, M.; Filmalter, J.D.; Hutchinson, M.; Itano, D.; Holland, K.; Dagorn, L.
Titre Association dynamics of tuna and purse seine bycatch species with drifting fish aggregating devices (FADs) in the tropical eastern Atlantic Ocean Type Article scientifique
Année 2020 Publication Revue Abrégée (up) Fish Res.
Volume 226 Numéro Pages 105521
Mots-Clés Acoustic telemetry; behavior; Behavior; carcharhinus-falciformis; floating objects; Floating objects; obesus; pacific-ocean; patterns; Pelagic fish; Residence time; silky sharks; skipjack katsuwonus-pelamis; Tropical tuna; vertical movements; yellowfin thunnus-albacares
Résumé Several pelagic fish species are known to regularly associate with floating objects in the open ocean, including commercially valuable species. The tuna purse seine industry takes advantage of this associative behavior and has been increasingly deploying free-drifting man-made floating objects, also known as fish aggregating devices (FADs). Using passive acoustic telemetry, this study describes the associative dynamics of the main targeted tropical tuna species (Thunnus albacores, T. obelus and Katsuwonus pelamis), as well as three major bycatch species, silky shark (Carcharhinus falciformis), rainbow runner (Elagatis bipinmdata) and oceanic triggerfish (Canthidermis maculata). Short-term excursions away from the FADs were frequently performed by all tuna species as well by silky sharks. These excursions were characterized by a marked diel pattern, mainly occurring during nighttime. Rainbow runners and oceanic triggerfish were much more present at the FADs and rarely performed excursions. Average continuous residence times (CRTs) ranged from 6 days, for silky shark, up to 25 days for bigeye tuna. Similar to silky shark, average CRTs for skipjack tuna and oceanic triggerfish were less than 10 days. For yellowfin tuna and rainbow runner, CRTs averaged 19 and 16 days, respectively. Bigeye and yellowfin tuna remained associated to a single drifting FAD for a record of 55 days and 607 km traveled.
Adresse
Auteur institutionnel Thèse
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 0165-7836 ISBN Médium
Région Expédition Conférence
Notes WOS:000525305200009 Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2772
Lien permanent pour cet enregistrement
 

 
Auteur Zhou, C.; He, P.; Xu, L.; Bach, P.; Wang, X.; Wan, R.; Tang, H.; Zhang, Y.
Titre The effects of mesoscale oceanographic structures and ambient conditions on the catch of albacore tuna in the South Pacific longline fishery Type Article scientifique
Année 2020 Publication Revue Abrégée (up) Fisheries Oceanography
Volume Numéro Pages
Mots-Clés albacore tuna; environmental conditions; hook depth; longline; ocean eddy; ocean fronts; South Pacific Ocean
Résumé Albacore tuna (Thunnus alalunga) exhibit patchy concentrations associated with biological process at a wide range of spatial scales, resulting in variations in their catchability by fishing gears. Here, we investigated the association of catch variation for pelagic longlines in the South Pacific Ocean with oceanographic mesoscale structures (in horizontal dimension) and ambient conditions (in vertical dimension). The distribution of albacore tuna as indicated by catch per unit effort (CPUE) of longlines was significantly related to the presence of mesoscale structures, with higher CPUE found at locations closer to thermal fronts and with greater gradient magnitudes, as well as areas marked by peripheral contour line of the anticyclone indicated by Sea Surface Height Anomalies 0.05 m. Surface mesoscale current velocity had the negative effect on the catch, probably as a result of decreased catchability by shoaling the hook depth. Vertical distribution of albacore in the survey region of South Pacific Ocean was hardly restricted by ambient temperature and oxygen concentration, though effect of ambient temperature was relevant and showed a negatively linear correlation with CPUE at the range of 20–24°C. On the contrary, albacore distribution was evidently dominated by the water depth and showed strong preference on water depth of 200 m, which was likely a representative feeding layer. The presence of prey resources and their accessibility by albacore revealed by mesoscale structures in the biological and physical processes, and catchability determined by the location of the baited hooks comprehensively contribute to the variability of catch.
Adresse
Auteur institutionnel Thèse
Editeur Lieu de Publication Éditeur
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 1365-2419 ISBN Médium
Région Expédition Conférence
Notes Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2732
Lien permanent pour cet enregistrement
 

 
Auteur Dagorn, L.; Holland, K.N.; Filmalter, J.
Titre Are drifting FADs essential for testing the ecological trap hypothesis ? Type Article scientifique
Année 2010 Publication Revue Abrégée (up) Fisheries Research
Volume 106 Numéro Pages 60-63
Mots-Clés ecological; Fad; hypothesis; trap; Tunas
Résumé Because tropical tunas are known to aggregate around floating objects, it has been suggested that the large number of drifting fish aggregating devices (FADS) built and deployed by purse seiners could act as an 'ecological trap'. This hypothesis states that these networks of drifting FADS could take fish to areas where they would not normally go or retain them in places that they would otherwise leave. Because the ecological trap hypothesis was first advanced for drifting FADs, some have argued that only studies using drifting FADs can test this hypothesis. However, because working with drifting FADs is difficult, accepting this precept would preclude the scientific community from providing urgently needed information to organizations charged with management of fisheries that exploit drifting FADs. We argue that because both anchored and drifting FADs alter the natural environment, the more easily accessible anchored FADs can be used to test the ecological trap hypothesis. Also, based on a comparative scientific approach, we argue that understanding the behaviour of tunas around anchored FADs can improve our general understanding of tunas around all types of floating objects and help design new, well focused studies for drifting FADs. As anchored FADs are easier to access and offer a greater potential for research, we encourage scientists to design and conduct studies (in particular on the behaviour of fish at FADS) around the moored structures.
Adresse
Auteur institutionnel Thèse
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
Région Expédition Conférence
Notes Approuvé pas de
Numéro d'Appel LL @ pixluser @ collection 66
Lien permanent pour cet enregistrement
 

 
Auteur Lucena Frédou, F.; Frédou, T.; Gaertner, D.; Kell, L.; Potier, M.; Bach, P.; Travassos, P.; Hazin, F.; Ménard, F.
Titre Life history traits and fishery patterns of teleosts caught by the tuna longline fishery in the South Atlantic and Indian Oceans Type Article scientifique
Année 2016 Publication Revue Abrégée (up) Fisheries Research
Volume 179 Numéro Pages 308-321
Mots-Clés Bycatch; Fishing impact; Tuna; Billfish; Ecosystem based fisheries management
Résumé The identification and mitigation of adverse effects of the bycatch of tuna longline fishery have been mainly developed and implemented for seabirds, sharks and turtles and, the knowledge on teleost bycatch for this fishery, remains very poor. This paper contributes to a comprehensive assessment of life history traits and fishery attributes of target and bycatch species caught by the tuna longline fishery in the South Atlantic and Indian Oceans. Data was compiled on seven life history traits and three fishery attributes for 33 and 27 teleost stocks caught by longliners in South Atlantic and Indian Oceans, respectively. In addition, each species was assigned into four categories describing the fate of the catch: target species for commercial use, bycatch species kept for consumption, bycatch species kept for commercial use and discarded bycatch. Life history traits and fishery attributes did not differ between oceans. However, non-target but commercialized species were smaller in the Atlantic Ocean. Teleosts caught by the tuna longline fishery was segregated into three main groups: (1) the fast growing species represented mainly by dolphinfishes (Coryphaena hippurus and C. equisellis), skipjack tuna (Katsuwonus pelamis), kawakawa (Euthynnus affinis), bullet tuna (Auxis rochei), snoek (Thyrsites atun) and blackfin tuna (Thunnus atlanticus); (2) target tunas and most other bycatch species which were part of an intermediate group and (3) billfishes including swordfish representing the large and slow growing species with moderate to high market values and unknown or highly uncertain stock status. Investment in some key life history traits (such as growth coefficient) and the development of quantitative or semi-quantitative approaches (stock assessment and Ecological Risk Assessment) should be priorized as precautionary management measures for these species.
Adresse
Auteur institutionnel Thèse
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
Région Expédition Conférence
Notes Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2405
Lien permanent pour cet enregistrement