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Auteur 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.
Adresse
Auteur institutionnel Thèse
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
Région Expédition Conférence
Notes Approuvé pas de
Numéro d'Appel MARBEC @ alain.herve @ collection 1661
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Auteur Quispe-Ccalluari, C.; Tam, J.; Demarcq, H.; Chamorro, A.; Espinoza-Morriberon, D.; Romero, C.; Dominguez, N.; Ramos, J.; Oliveros-Ramos, R.
Titre An index of coastal thermal effects of El Nino Southern Oscillation on the Peruvian Upwelling Ecosystem Type Article scientifique
Année 2018 Publication Revue Abrégée Int. J. Climatol.
Volume 38 Numéro 7 Pages 3191-3201
Mots-Clés climate; coastal index; eastern tropical pacific; enso; Equatorial Pacific Ocean; events; ocean; Peruvian Upwelling Ecosystem; sea-surface temperature; wind
Résumé The Peruvian Upwelling Ecosystem (PUE) is one of the most productive ecosystem in the world in terms of productivity and fish catches, partly because its geographical location is affected by remote physical processes, such as the interannual climate variability of the Equatorial Pacific Ocean (EPO), whose dominant signal is El Nino Southern Oscillation (ENSO). In order to assess the thermal effects of ENSO off Peru, a Peruvian Coastal Thermal Index (PCTI) was developed representing 87.7% of the total variation of the Sea Surface Temperature (SST) anomalies of the PUE. Between 1982 and 2014, the PCTI detected 12 warm periods and 16 cold periods in the PUE. PCTI had a linear trend component, a low frequency component and a noise component, with 1.5%, 94.5% and 4% contributions to the total variance, respectively. Wavelet analysis of PCTI showed significant peaks of variability between the years 1996 and 1999 between periods of 0.4 and 6 years. A regime shift in variance of PCTI was detected in 1999, with a lower variance between 1999 and 2014 than between 1982 and 1998, which agreed with the start of a cold phase of the Pacific Decadal Oscillation. The decrease of variance of the PCTI could be linked to an increase of the local winds associated with a higher intensity of the average state of South Pacific Anticyclone. This atmospheric change might have strengthened the coastal upwelling and counteracted the intensity of warm periods in the PUE. Finally, the comparison of different indexes allowed to detect four periods where neutral conditions occurred in the EPO while warm periods occurred in the PUE (1993, 2008, 2012 and 2014); and 1 period where a warm episode occurred in the EPO (2004-2005) while a neutral condition occurred in the PUE.
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 0899-8418 ISBN Médium
Région Expédition Conférence
Notes Approuvé pas de
Numéro d'Appel MARBEC @ alain.herve @ collection 2391
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Auteur Torres-Irineo, E.; Dreyfus-Leon, M.; Gaertner, D.; Salas, S.; Marchal, P.
Titre Adaptive responses of tropical tuna purse-seiners under temporal regulations Type Article scientifique
Année 2017 Publication Revue Abrégée Ambio
Volume 46 Numéro 1 Pages 88-97
Mots-Clés atlantic; behavior; Closed season; eastern pacific-ocean; eastern tropical pacific; Fisher behaviour; Fisheries management; fishing strategies; fleet dynamics; mixed fisheries; model; Purse-seine fishing; state; trawlers; Tropical tuna
Résumé The failure to achieve fisheries management objectives has been broadly discussed in international meetings. Measuring the effects of fishery regulations is difficult due to the lack of detailed information. The yellowfin tuna fishery in the eastern Pacific Ocean offers an opportunity to evaluate the fishers' responses to temporal regulations. We used data from observers on-board Mexican purse-seine fleet, which is the main fleet fishing on dolphin-associated tuna schools. In 2002, the Inter-American Tropical Tuna Commission implemented a closed season to reduce fishing effort for this fishery. For the period 1992-2008, we analysed three fishery indicators using generalized estimating equations to evaluate the fishers' response to the closure. We found that purse-seiners decreased their time spent in port, increased their fishing sets, and maintained their proportion of successful fishing sets. Our results highlight the relevance of accounting for the fisher behaviour to understand fisheries dynamics when establishing management regulations.
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 0044-7447 ISBN Médium
Région Expédition Conférence
Notes Approuvé pas de
Numéro d'Appel MARBEC @ alain.herve @ collection 2072
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