Trophic ecology of European sardine Sardina pilchardus and European anchovy Engraulis encrasicolus in the Bay of Biscay (north-east Atlantic) inferred from δ13C and δ15N values of fish and identified mesozooplanktonic organisms

Abstract : European sardine (Sardina pilchardus) and European anchovy (Engraulis encrasicolus) are two species of economical and ecological significance in the Bay of Biscay (north-east Atlantic). However, the trophic ecology of both species is still poorly known in the area, and more generally, few studies have considered the potential trophic overlap between sardines and anchovies worldwide. This study aims to highlight the trophic links between the mesozooplankton and adults of these two pelagic fish in the Bay of Biscay, through carbon and nitrogen stable isotopes analysis (SIA). Mesozooplankton and individuals of sardines and anchovies were collected during one season (spring 2010), over spatially contrasted stations within the study area. First, the potential effect of preservation (ethanol vs. freezing) and of delipidation (by cyclohexane) on mesozooplankton δ13C and δ15N values was assessed. Results demonstrated the necessity to correct for the preservation effect and for lipid contents in mesozooplankton for further analyses of sardines' and anchovies' diet through SIA. Next, this study highlighted the interest of working on identified mesozooplanktonic organisms instead of undetermined assemblages when unravelling food sources of planktivorous fish using stable isotopes. The inter-specific variability of isotope values within a planktonic assemblage was effectively high, probably depending on the various feeding behaviours that can occur among mesozooplankton species. Intra-specific variability was also significant and related to the spatial variations of baseline signatures in the area. To investigate the foraging areas and potential diet overlap of S. pilchardus and E. encrasicolus, mixing models (SIAR) were applied. Both fish species appeared to feed mainly in the neritic waters of the Bay of Biscay in spring and to select mainly small- to medium-sized copepods (e.g. Acartia sp., Temora sp.). However, E. encrasicolus showed a greater trophic plasticity by foraging more offshore and on a wider range of prey sizes, while S. pilchardus seemed more limited to coastal areas and the mesozooplanktonic species of these waters for feeding.
Type de document :
Article dans une revue
Journal of Sea Research, Elsevier, 2014, 85, pp.277-291
Liste complète des métadonnées

Littérature citée [76 références]  Voir  Masquer  Télécharger

https://hal.archives-ouvertes.fr/hal-00903728
Contributeur : Paco Bustamante <>
Soumis le : samedi 28 juin 2014 - 01:18:49
Dernière modification le : mardi 3 juillet 2018 - 11:32:52
Document(s) archivé(s) le : dimanche 28 septembre 2014 - 10:40:35

Fichier

Chouvelon_et_al_2014_JSR.pdf
Fichiers produits par l'(les) auteur(s)

Identifiants

  • HAL Id : hal-00903728, version 2

Collections

Citation

Tiphaine Chouvelon, Alexis Chappuis, Paco Bustamante, Sébastien Lefebvre, Françoise Mornet, et al.. Trophic ecology of European sardine Sardina pilchardus and European anchovy Engraulis encrasicolus in the Bay of Biscay (north-east Atlantic) inferred from δ13C and δ15N values of fish and identified mesozooplanktonic organisms. Journal of Sea Research, Elsevier, 2014, 85, pp.277-291. 〈hal-00903728v2〉

Partager

Métriques

Consultations de la notice

511

Téléchargements de fichiers

269