Stable isotope ratios in bentho-demersal biota along a depth gradient in the bay of biscay: A multitrophic study
|Author(s)||Schaal Gauthier1, Nerot Caroline1, Grall Jacques2, Chouvelon Tiphaine1, 3, 5, Lorrain Anne1, Mortillaro Jean-Michel2, 6, Savoye Nicolas4, Brind'Amour Anik5, Paulet Yves-Marie1, Le Bris Herve6|
|Affiliation(s)||1 : Inst Univ Europeen Mer, Lab Sci Environm Marin, IFREMER, IRD,CNRS,UMR UBO 6539, Rue Dumont dUrville, F-29280 Plouzane, France.
2 : Inst Univ Europeen Mer, Observ Domaine Cotier, UMS 3113, Rue Dumont dUrville, F-29280 Plouzane, France.
3 : Univ Rochelle, LIENSs, UMR 6250, Bat Marie Curie,Rue Paul Emile Victor, F-17000 La Rochelle, France.
4 : Univ Bordeaux 1, Lab EPOC, CNRS, Stn Marine Arcachon,UMR 5805, 2 Rue Prof Jolyet, F-33120 Arcachon, France.
5 : IFREMER, Unite Ecol & Modeles Halieut, BP21105,Rue Ile dYeu, F-44311 Nantes 03, France.
6 : Agrocampus Ouest, UMR Ecol & Sante Ecosyst 985, CS 84215,65 Rue St Brieuc, F-35042 Rennes, France.
|Source||Estuarine Coastal And Shelf Science (0272-7714) (Academic Press Ltd- Elsevier Science Ltd), 2016-09 , Vol. 179 , P. 201-206|
|WOS© Times Cited||6|
|Note||Special Issue: Functioning and dysfunctioning of Marine and Brackish Ecosystems|
|Keyword(s)||Trophic, Coastal, Bivalves, Food web, Bay of Biscay|
|Abstract||Although stable isotope ratios are increasingly used to investigate the trophic ecology of marine organisms, their spatial variations are still poorly understood in the coastal environment. In this study, we measured the stable isotope composition (δ13C, δ15N) of suspended particulate organic matter (SPOM) (primary producer), a suspension feeder, the great scallop Pecten maximus (primary consumer), megabenthic decapods and benthic fishes (secondary consumers) along a depth gradient (from 5m to 155m depth) across the continental shelf of the Bay of Biscay. Although the three trophic levels exhibited similar δ13C patterns along the gradient, the δ15N patterns varied between SPOM, scallops and carnivores. The δ15N difference between SPOM and scallops decreased with increasing depth, suggesting that non trophic factors may affect the stable isotope composition of scallops at deepest sampling stations. An opposed trend was found between scallops and carnivores, suggesting that the trophic level of these carnivores increased at higher depth, possibly as an adaptation to lower prey abundances. Although our results suggest that primary consumers are suitable to establish isotopic baselines in coastal environments, we stress the need for further studies aiming at characterizing the variability of stable isotopes in coastal biota, and the respective effects of baseline, trophic and metabolic factors in their isotopic composition.|