Espinoza P., Lorrain Anne, Ménard Frédéric, Cherel Y., Tremblay-Boyer L., Arguelles J., Tafur R., Bertrand Sophie, Tremblay Yann, Ayon P., Munaron Jean-Marie, Richard P., Bertrand Arnaud. (2017). Trophic structure in the northern Humboldt Current system : new perspectives from stable isotope analysis. Marine Biology, 164 (4), p. art. 86 [15 p.]. ISSN 0025-3162.
Titre du document
Trophic structure in the northern Humboldt Current system : new perspectives from stable isotope analysis
Année de publication
2017
Auteurs
Espinoza P., Lorrain Anne, Ménard Frédéric, Cherel Y., Tremblay-Boyer L., Arguelles J., Tafur R., Bertrand Sophie, Tremblay Yann, Ayon P., Munaron Jean-Marie, Richard P., Bertrand Arnaud
Source
Marine Biology, 2017,
164 (4), p. art. 86 [15 p.] ISSN 0025-3162
The northern Humboldt Current system (NHCS) is the most productive eastern boundary upwelling system (EBUS) in terms of fish productivity despite having a moderate primary production compared with other EBUS. To understand this apparent paradox, an updated vision of the trophic relationships in the NHCS is required. Using delta C-13 and delta N-15 as a proxy of foraging habitat and trophic position, respectively, we focused on thirteen relevant taxonomic groups from zooplankton to air-breathing top predators collected off Peru from 2008 to 2011. Estimates of trophic position (TP) for the anchoveta Engraulis ringens were high (3.4-3.7), in accordance with previous studies showing zooplankton as a major contributor to anchoveta diet and challenging the often-cited short food chain hypothesis for this ecosystem. The squat lobster, Pleuroncodes monodon, a little studied consumer had similar delta N-15 values that of anchoveta, and thus similar trophic position. However, their differing delta C-13 values indicate that their foraging habitat do not fully overlap, which could alleviate potential competition between these species. Given the current high biomass of squat lobsters in the ecosystem, we encourage that future research focus on this species and its role in the diet of top predators. The present study provides first estimates of the relative TP of important taxonomic groups in the NHCS, which are needed to revisit anchoveta-centred ecosystem models for this region. Further work using amino acid compound specific stable isotope analyses is now required to confirm these TP estimates.
Plan de classement
Ecologie, systèmes aquatiques [036]
;
Ressources halieutiques [040]
Description Géographique
PEROU ; PACIFIQUE ; HUMBOLDT COURANT
Localisation
Fonds IRD [F B010069458]
Identifiant IRD
fdi:010069458
