Publications des scientifiques de l'IRD

Lorrain Anne, Graham B. S., Popp B. N., Allain V., Olson R. J., Hunt B. P. V., Potier Michel, Fry B., Galvan-Magana F., Menkes Chrisophe, Kaehler S., Ménard Frédéric. (2015). Nitrogen isotopic baselines and implications for estimating foraging habitat and trophic position of yellowfin tuna in the Indian and Pacific Oceans. In : Hobday A.J. (ed.), Arrizabalaga H. (ed.), Evans K. (ed.), Nicol S. (ed.), Young J.W. (ed.), Weng K.C. (ed.). Impacts of climate on marine top predators. Deep-Sea Research Part II : Topical Studies in Oceanography, 113 (No spécial), p. 188-198. ISSN 0967-0645.

Titre du document
Nitrogen isotopic baselines and implications for estimating foraging habitat and trophic position of yellowfin tuna in the Indian and Pacific Oceans
Année de publication
2015
Type de document
Article référencé dans le Web of Science WOS:000351978700015
Auteurs
Lorrain Anne, Graham B. S., Popp B. N., Allain V., Olson R. J., Hunt B. P. V., Potier Michel, Fry B., Galvan-Magana F., Menkes Chrisophe, Kaehler S., Ménard Frédéric
In
Hobday A.J. (ed.), Arrizabalaga H. (ed.), Evans K. (ed.), Nicol S. (ed.), Young J.W. (ed.), Weng K.C. (ed.), Impacts of climate on marine top predators
Source
Deep-Sea Research Part II : Topical Studies in Oceanography, 2015, 113 (No spécial), p. 188-198 ISSN 0967-0645
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.
Plan de classement
Ecologie, systèmes aquatiques [036]
Description Géographique
PACIFIQUE ; OCEAN INDIEN
Localisation
Fonds IRD [F B010064079]
Identifiant IRD
fdi:010064079
Contact