Marine Biology

, Volume 153, Issue 4, pp 673–688

Stable isotopes (δ13C, δ15N) and modelling as tools to estimate the trophic ecology of cultivated oysters in two contrasting environments

  • Julio César Marín Leal
  • Stanislas Dubois
  • Francis Orvain
  • Robert Galois
  • Jean-Louis Blin
  • Michel Ropert
  • Marie-Paule Bataillé
  • Alain Ourry
  • Sébastien Lefebvre
Research Article

DOI: 10.1007/s00227-007-0841-7

Cite this article as:
Marín Leal, J.C., Dubois, S., Orvain, F. et al. Mar Biol (2008) 153: 673. doi:10.1007/s00227-007-0841-7

Abstract

Food sources for cultivated marine bivalves generally are not well identified, although they are essential for a better understanding of coastal ecosystems and for the sustainability of shellfish farming activities. In addition to phytoplankton, other organic matter sources (OMS), such as microphytobenthos and detritus (of terrestrial or marine origins), can contribute significantly to the growth of marine bivalves. The aim of this study was to identify the potential food sources and to estimate their contributions to the growth of the Pacific oyster (Crassostrea gigas) in two contrasting trophic environments of Normandy (France): the Baie des Veys (BDV) and the Lingreville area (LIN). Two sites were studied in the BDV area (BDV-S and BDV-N) and one in the LIN area. To estimate the contribution of each type of OMS, we used a combination of stable natural isotope composition (δ13C, δ15N) analysis of OMS and oyster tissue together with a modelling exercise. Field sampling was conducted every 2 months over 1 year. The sampled sources were suspended particulate organic matter from marine (PhyOM) and terrestrial (TOM) origins, microphytobenthos (MPB), detrital organic matter from the superficial sediment (SOM), and macroalgae (Ulva sp., ULV). A statistical mixing model coupled to a bioenergetic model was used to calculate the contributions of each different source at different seasons. Results showed that isotopic composition of the animal flesh varied with respect to the potential OMS over the year within each ecosystem. Significant differences were also observed among the three locations. For instance, the δ13C and δ15N values of the oysters ranged from −20.0 to −19.1‰ and from 6.9 to 10.8‰ at BDV-S, from −19.4 to −18.1‰ and from 6.4 to 10.0‰ at BDV-N, and from −21.8 to −19.4‰ and from 6.3 to 8.3‰ at LIN. The contributions of the different sources to oyster growth differed depending on the ecosystem and on the period of the year. Phytoplankton (PhyOM) predominated as the principal food source for oysters (particularly in the LIN location). MPB, TOM, and ULV detritus also possibly contributed to oysters’ diet during summer and autumn at the BDV-S and BDV-N sites. SOM was not considered an OMS because it was already a mix of the other four OMS, but rather a trophic reservoir that potentially mirrored the trophic functioning of marine ecosystems.

Copyright information

© Springer-Verlag 2007

Authors and Affiliations

  • Julio César Marín Leal
    • 1
    • 2
  • Stanislas Dubois
    • 1
  • Francis Orvain
    • 1
  • Robert Galois
    • 3
  • Jean-Louis Blin
    • 4
  • Michel Ropert
    • 5
  • Marie-Paule Bataillé
    • 6
  • Alain Ourry
    • 6
  • Sébastien Lefebvre
    • 1
  1. 1.Laboratoire de Biologie et Biotechnologies MarinesUMR 100 IFREMER-Université de Caen Basse-Normandie “Physiologie et Ecophysiologie des Mollusques Marins (PE2M)”Caen CedexFrance
  2. 2.Departamento de Ingeniería Sanitaria y Ambiental, Escuela de Ingeniería Civil, Facultad de IngenieríaLa Universidad del ZuliaMaracaiboVenezuela
  3. 3.Centre de Recherche sur les Ecosystèmes Littoraux Anthropisés (CRELA)UMR 6217 CNRS-IFREMER-Université de La RochelleL’HoumeauFrance
  4. 4.Syndicat Mixte pour l’Équipement du Littoral (SMEL)Blainville sur MerFrance
  5. 5.Laboratoire Environnement Ressources de NormandieIFREMERPort-en-BessinFrance
  6. 6.UMR 950 INRA-Université de Caen Basse-Normandie “Écophysiologie Végétale, Agronomie et Nutrition N.C.S. (EVA)”Caen CedexFrance