Food sources of an infaunal suspension-feeding bivalve Cerastoderma edule in a muddy sandflat of Marennes-Oléron Bay, as determined by analyses of carbon and nitrogen stable isotopes

Stable carbon and nitrogen isotope ratios were used to define the trophic base of the infaunal suspension-feeding bivalve Cerastoderma edule (L.) living on an intertidal muddy sandflat in Marennes-Oleron Bay, France. Suspended particulate organic matter (POM) collected from adjacent marine channels had a mean 6I3C value of -22 2 * 1.1 %O (n = 19). Benthic primary producers on Ronceles-Bains tidal flats had 613C values distinct from that of the POM: microphytobenthos (-16.0 * 0.6%).