Food sources used by sediment meiofauna in an intertidal Zostera noltii seagrass bed: a seasonal stable isotope study

Benoit Lebreton (1) , Pierre Richard (1) , Robert Galois (1) , Gilles Radenac (1) , Amel Brahmia (1) , Géraldine Colli (1) , Marig Grouazel (1) , Cyril André (1) , Gaël Guillou (1) , Gérard Blanchard (1)

1 LIENSs - LIttoral ENvironnement et Sociétés

In an intertidal Zostera noltii Hornem. seagrass bed, food sources used by sediment meiofauna were determined seasonally by comparing stable isotope signatures (δ13C, δ15N) of sources with those of nematodes and copepods. Proportions of different carbon sources used by consumers were estimated using the SIAR mixing model on δ13C values. Contrary to δ15N values, food source mean δ13C values encompassed a large range, from -22.1‰ (suspended particulate organic matter) to -10.0‰ (Z. noltii roots). δ13C values of copepods (from -22.3 to -12.3‰) showed that they use many food sources (benthic and phytoplanktonic microalgae, Z. noltii matter). Nematode δ13C values ranged from -14.6 to -11.4‰, indicating a strong role of microphytobenthos and/or Z. noltii matter as carbon sources. The difference of food source uses between copepods and nematodes is discussed in the light of source accessibility and availability.

Domaines: Sciences de l'environnement

Benoit Lebreton, Pierre Richard, Robert Galois, Gilles Radenac, Amel Brahmia, et al.. Food sources used by sediment meiofauna in an intertidal Zostera noltii seagrass bed: a seasonal stable isotope study. Marine Biology, 2012, 159, pp.1537 - 1550. ⟨10.1007/s00227-012-1940-7⟩. ⟨hal-01080696⟩