Publications des scientifiques de l'IRD

Carlier A., Chauvaud L., van der Geest M., Le Loc'h François, Le Duff M., Vernet M., Raffray Jean, Diakhate D., Labrosse P., Wague A., Le Goff C., Gohin F., Chapron B., Clavier J. (2015). Trophic connectivity between offshore upwelling and the inshore food web of Banc d'Arguin (Mauritania) : new insights from isotopic analysis. Estuarine Coastal and Shelf Science, 165, p. 149-158. ISSN 0272-7714.

Titre du document
Trophic connectivity between offshore upwelling and the inshore food web of Banc d'Arguin (Mauritania) : new insights from isotopic analysis
Année de publication
2015
Type de document
Article référencé dans le Web of Science WOS:000367119500017
Auteurs
Carlier A., Chauvaud L., van der Geest M., Le Loc'h François, Le Duff M., Vernet M., Raffray Jean, Diakhate D., Labrosse P., Wague A., Le Goff C., Gohin F., Chapron B., Clavier J.
Source
Estuarine Coastal and Shelf Science, 2015, 165, p. 149-158 ISSN 0272-7714
Banc d'Arguin (BA), Mauritania, is a nationally protected shallow gulf > 10,000 km(2) between the Sahara desert and the upwelling system off the Mauritanian coast. In the southeast, BA consists of a 500 km(2) tidal flat, the most important wintering site for shorebirds using the East Atlantic Flyway. The Mauritanian upwelling-driven phytoplankton production supports the most productive fisheries worldwide, but little is known about its trophic role in the functioning of the inshore BA food web. Using stable isotopes as trophic tracers to distinguish between upwelling-driven phytoplankton, open ocean phytoplankton, and benthic primary producers, we assessed the spatial extent to which the inshore BA food web is fuelled by upwelling-driven phytoplankton production. The delta C-13 and delta N-15 signals were characterized in dominant primary producers, benthic invertebrate taxa, and various fish species along an offshore inshore (northwest southeast) gradient. We also monitored the spatial and temporal extent of upwelling entering BA during 2008 with remote sensing of sea surface temperature and chlorophyll a data. The results suggest that benthic invertebrates and fishes living in the northwestern part of BA depend on the nearby upwelling phytoplankton production, but this food source does not support the intertidal benthic community in southeast BA. Furthermore, the isotopic signatures of fishes suggest weak trophic connectivity between the northern subtidal and southeastern intertidal BA. Our results support the hypothesis that the southeastern tidal flat region functions as a distinct ecosystem with a food web supported mainly by local benthic primary production, which is crucial knowledge for effective management of the pristine BA national park.
Plan de classement
Ecologie, systèmes aquatiques [036] ; Etudes, transformation, conservation du milieu naturel [082] ; Télédétection [126]
Description Géographique
MAURITANIE ; BANC D'ARGUIN
Localisation
Fonds IRD [F B010066033]
Identifiant IRD
fdi:010066033
Contact
  • Coordonnées :
    IST / IRD Ile-de-France
    32 avenue Henri Varagnat
    93140 Bondy Cedex
    France
    Horizon Pleins textes
  •