Food source of intertidal nematodes in the Bay of Marennes-Oléron (France), as determined by dual stable isotope analysis

Abstract

Nematodes living on an intertidal mudflat of the Marennes-Oleron Bay (France) were assayed for 6I3C and 6IsN ratios together with their potential food resources be- tween July 1992 and May 1993. Results suggest that nematodes do not exploit all the components of the sedlrnented organic matter (SOM) pool at the same rate. Furthermore, based on coefficients of average trophic enrichment found in the literature for both C and N, the enrichment of nematodes in 13c and their depletion in I5N relative to SOM suggest that microphytobenthos constitutes their main food source in this particular environment.