%0 Journal Article %T Nitrogen isotopic baselines and implications for estimating foraging habitat and trophic position of yellowfin tuna in the Indian and Pacific Oceans %+ Laboratoire des Sciences de l'Environnement Marin (LEMAR) (LEMAR) %+ Institut de Recherche pour le Développement (IRD) %+ National Institute of Water and Atmospheric Research [Wellington] (NIWA) %+ Department of Geology and Geophysics [Mānoa] %+ Pacific community (SPC) %+ Inter-American Tropical Tuna Commission (IATTC) %+ Institut méditerranéen d'océanologie (MIO) %+ Department of Earth, Ocean and Atmospheric Sciences [Vancouver] (UBC EOAS) %+ Laboratoire d'Algorithmique Complexité et Logique (LACL) %+ Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12) %+ Ecosystèmes Marins Exploités (UMR EME) %+ Griffith University [Brisbane] %+ Instituto Politecnico Nacional [Mexico] (IPN) %+ Processus de couplage à Petite Echelle, Ecosystèmes et Prédateurs Supérieurs (PEPS) %+ Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN) %+ Rhodes University, Grahamstown %A Lorrain, Anne %A Graham, Brittany S. %A Popp, Brian N. %A Allain, Valérie %A Olson, Robert J. %A Hunt, Brian P.V. %A Potier, Michel %A Fry, Brian %A Galván-Magaña, Felipe %A Menkès, Christophe E. %A Kaehler, Sven %A Ménard, Frédéric %< avec comité de lecture %@ 0967-0645 %J Deep Sea Research Part II: Topical Studies in Oceanography %I Elsevier %V 113 %P 188–198 %8 2015-03 %D 2015 %R 10.1016/j.dsr2.2014.02.003 %K Amino acids %K AA-CSIA %K ACL %K Marine top predators %K Thunnus albacares %K POM %K Barnacles %K Nitrogen stable isotopes %K Lepas anatifera %Z Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph] %Z Sciences of the Universe [physics]/Ocean, Atmosphere %Z Environmental Sciences/Biodiversity and EcologyJournal articles %X Assessment of isotopic compositions at the base of food webs is a prerequisite for using stable isotope analysis to assess foraging locations and trophic positions of marine organisms. Our study represents a unique application of stable-isotope analyses across multiple trophic levels (primary producer, primary consumer and tertiary consumer) and over a large spatial scale in two pelagic marine ecosystems. We found that delta N-15 values of particulate organic matter (POM), barnacles and phenylalanine from the muscle tissue of yellowfin tuna all showed similar spatial patterns. This consistency suggests that isotopic analysis of any of these can provide a reasonable proxy for isotopic variability at the base of the food web. Secondly, variations in the delta N-15 values of yellowfin tuna bulk-muscle tissues paralleled the spatial trends observed in all of these isotopic baseline proxies. Variation in isotopic composition at the base of the food web, rather than differences in tuna diet, explained the 11 parts per thousand variability observed in the bulk-tissue delta N-15 values of yellowfin tuna. Evaluating the trophic position of yellowfin tuna using amino-acid isotopic compositions across the western Indian and equatorial Pacific Oceans strongly suggests these tuna occupy similar trophic positions, albeit absolute trophic positions estimated by this method were lower than expected. This study reinforces the importance of considering isotopic baseline variability for diet studies, and provides new insights into methods that can be applied to generate nitrogen isoscapes for worldwide comparisons of top predators in marine ecosystems %G English %L hal-01139296 %U https://hal.science/hal-01139296 %~ SDE %~ CEA %~ INSU %~ MNHN %~ UNIV-BREST %~ UNIV-PARIS7 %~ X %~ ENS-PARIS %~ UPMC %~ UNIV-TLN %~ CNRS %~ UNIV-AMU %~ CNES %~ IFREMER %~ LACL %~ IUEM %~ X-DEP %~ LEMAR %~ OPENAIRE %~ THESES_IUEM %~ MIO %~ OSU-INSTITUT-PYTHEAS %~ GIP-BE %~ UPEC %~ LOCEAN %~ UVSQ %~ PEPS %~ PSL %~ UNIV-PARIS-SACLAY %~ UVSQ-SACLAY %~ X-SACLAY %~ UPMC_POLE_3 %~ UNIV-MONTPELLIER %~ CMM %~ SORBONNE-UNIVERSITE %~ SU-INF-2018 %~ SU-SCIENCES %~ FR-636 %~ UNIV-PARIS %~ UP-SCIENCES %~ MIO-EMBIO %~ ENS-PSL %~ UVSQ-UPSACLAY %~ CEA-UPSACLAY %~ ALLIANCE-SU %~ UM-2015-2021 %~ IPSL_LOCEAN