Publications des scientifiques de l'IRD

Sardenne Fany, Diaha N. C., Amande M. J., Zudaire I., Couturier L. I. E., Metral L., Le Grand F., Bodin Nathalie. (2019). Seasonal habitat and length influence on the trophic niche of co-occurring tropical tunas in the eastern Atlantic Ocean. Canadian Journal of Fisheries and Aquatic Sciences, 76 (1), p. 69-80. ISSN 0706-652X.

Titre du document
Seasonal habitat and length influence on the trophic niche of co-occurring tropical tunas in the eastern Atlantic Ocean
Année de publication
2019
Type de document
Article référencé dans le Web of Science WOS:000454939000007
Auteurs
Sardenne Fany, Diaha N. C., Amande M. J., Zudaire I., Couturier L. I. E., Metral L., Le Grand F., Bodin Nathalie
Source
Canadian Journal of Fisheries and Aquatic Sciences, 2019, 76 (1), p. 69-80 ISSN 0706-652X
In the Gulf of Guinea, bigeye tuna (Thunnus obesus; BET) and yellowfin tuna (Thunnus albacares; YFT) are an important part of commercial fisheries and play a prominent ecological role as top predators. Using fatty acid profiles and carbon and nitrogen stable isotopes, we examined their trophic niche partitioning in this understudied region. Trophic niche overlap was high (> 70%), similar to percentages in other ocean basins. BET occupied a higher trophic position than YFT and fed on deeper prey (high delta N-15 values and high proportions of monounsaturated fatty acids). The trophic position of YFT decreased slightly in the last 15 years (delta N-15 values decreased by similar to 0.5 parts per thousand), suggesting a change in epipelagic communities, as observed in the eastern Pacific Ocean. Ontogenic changes were limited to BET. For both species, the dietary proportion of the diatom marker 20:5(n-3) increased in the seasonal upwelling area, highlighting the influence of seasonal habitat on the diet of tuna. The relatively lipid-rich muscle (similar to 6% dry mass) of Atlantic tropical tuna suggests a richer diet in this region than that of Indian Ocean tropical tuna and (or) differences in energy allocation strategies.
Plan de classement
Ecologie, systèmes aquatiques [036] ; Ressources halieutiques [040]
Description Géographique
ATLANTIQUE
Localisation
Fonds IRD [F B010074880]
Identifiant IRD
fdi:010074880
Contact