MEPS 187:301-307 (1999)  -  doi:10.3354/meps187301

Determination of food sources for benthic invertebrates in a salt marsh (Aiguillon Bay, France) by carbon and nitrogen stable isotopes: importance of locally produced sources

P. Riera1,4,*, L. J. Stal1, J. Nieuwenhuize1, P. Richard2, G. Blanchard2,3, F. Gentil4

1Centre for Estuarine and Coastal Ecology, Netherlands Institute of Ecology (NIOO-CEMO), Postbus 140, 4400 AC Yerseke, The Netherlands
2Centre de Recherche en Écologie Marine et Aquaculture de L'Houmeau, UMR 10, CNRS-IFREMER, BP 5, Place du Séminaire, 17137 L'Houmeau, France
3Université de La Rochelle, LBBM, Pôle Science et Technologie, Avenue Marillac, 17042 La Rochelle cedex, France
4Station Biologique de Roscoff, Université Pierre & Marie Curie, CNRS UPR 9042, Place Georges-Teissier, BP 74, 29682 Roscoff cedex, France
*Address for correspondence: Station Biologique de Roscoff, Place Georges-Teissier, BP 74, 29682 Roscoff cedex, France. E-mail:

ABSTRACT: δ13C and δ15N were measured in benthic invertebrates and food sources collected in the salt marsh of the Aiguillon Bay, France. The results showed that, although Spartina anglica was dominant, this marine phanerogame did not contribute significantly to the carbon and nitrogen requirements of the invertebrates considered in this study. In fact, Macoma balthica, Scrobicularia plana and Mytilus edulis preferentially fed on a mixture of benthic diatoms and marine phytoplankton, but in different proportions, as was estimated through isotope mixing models. However, this isotopic data set revealed complex trophic relationships for the nematode community and for the crab Carcinus maenas which did not allow accurate isotopic determination of food sources.


KEY WORDS: Carbon and nitrogen isotope ratios · Muddy salt marsh · Spartina anglica · Benthic diatoms · Benthic invertebrates


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