N. J. Bax, The significance and prediction of predation in marine fisheries, ICES Journal of Marine Science, vol.55, issue.6, 1998.
DOI : 10.1006/jmsc.1998.0350

S. Bearhop, C. E. Adams, S. Waldron, R. A. Fuller, and H. Macleod, Determining trophic niche width:??a novel approach using stable isotope analysis, Journal of Animal Ecology, vol.75, issue.5, pp.1007-1012, 2004.
DOI : 10.1111/j.0021-8790.2004.00861.x

A. L. Bond and A. W. Diamond, Recent Bayesian stable-isotope mixing models are highly sensitive to variation in discrimination factors, Ecological Applications, vol.21, issue.4, pp.1017-1023, 2011.
DOI : 10.1111/j.1365-2435.2009.01529.x

L. W. Botsford, J. C. Castilla, and C. H. Peterson, The Management of Fisheries and Marine Ecosystems, Science, vol.277, issue.5325, pp.509-515, 1997.
DOI : 10.1126/science.277.5325.509

A. Buchheister and R. J. Latour, Turnover and fractionation of carbon and nitrogen stable isotopes in tissues of a migratory coastal predator, summer flounder (Paralichthys dentatus), Can. J. Fish. Aquat. Sci, vol.67, pp.445-461, 2010.

H. N. Cabral and B. Ohmert, Diet of juvenile meagre, Argyrosomus regius, within the Tagus estuary, Cahiers Biol. Mar, vol.42, pp.289-293, 2001.

S. Caut, E. Angulo, and F. Courchamp, C): the effect of diet isotopic values and applications for diet reconstruction, Journal of Applied Ecology, vol.75, issue.2, 2009.
DOI : 10.1111/j.1365-2664.2009.01620.x

Y. Cherel and K. A. Hobson, Geographical variation in carbon stable isotope signatures of case of an open ecosystem: The Bay of Biscay (North-East Atlantic), Progr. Oceanogr, vol.101, pp.92-105, 2007.

M. R. Clarke, A handbook for the identification of cephalopod beaks, 1986.

R. Curtin and R. Prellezo, Understanding marine ecosystem based management: A literature review, Marine Policy, vol.34, issue.5, pp.821-830, 2010.
DOI : 10.1016/j.marpol.2010.01.003

URL : http://commons.wmu.se/cgi/viewcontent.cgi?article=1046&context=lib_articles

A. M. Davis, M. L. Blanchette, B. J. Pusey, T. D. Jardine, and R. G. Pearson, Gut content and stable isotope analyses provide complementary understanding of ontogenetic dietary shifts and trophic relationships among fishes in a tropical river, Freshwater Biology, vol.89, issue.10, pp.2156-2172, 2012.
DOI : 10.1111/j.1365-2427.2012.02858.x

M. J. Deniro and S. Epstein, Mechanism of carbon isotope fractionation associated with lipid synthesis, Science, vol.197, issue.4300, pp.261-263, 1977.
DOI : 10.1126/science.327543

R. L. France, Carbon-13 enrichment in benthic compared to planktonic algae:foodweb implications, Marine Ecology Progress Series, vol.124, pp.307-312, 1995.
DOI : 10.3354/meps124307

K. T. Frank, B. Petrie, J. S. Choi, and W. C. Leggett, Trophic Cascades in a Formerly Cod-Dominated Ecosystem, Science, vol.308, issue.5728, pp.1621-1623, 2005.
DOI : 10.1126/science.1113075

R. González-quirós, J. Del-Árbol, M. Del-mar-garcía-pacheco, A. J. Silva-garcía, J. M. Naranjo et al., Life-history of the meagre Argyrosomus regius in the Gulf of C??diz (SW Iberian Peninsula), Fisheries Research, vol.109, issue.1, pp.140-149, 2011.
DOI : 10.1016/j.fishres.2011.01.031

M. H. Griffiths, (Sciaenidae) in the Great Fish River estuary, with notes on the diet of early juveniles from three other estuarine systems, South African Journal of Marine Science, vol.18, issue.1, pp.137-145, 1997.
DOI : 10.2989/025776197784161153

J. Guelinckx, J. Maes, P. Van-den-driessche, B. Geysen, F. Dehairs et al., Changes in ??13C and ??15N in different tissues of juvenile sand goby Pomatoschistus minutus: a laboratory diet-switch experiment, Marine Ecology Progress Series, vol.341, pp.205-215, 2007.
DOI : 10.3354/meps341205

T. J. Härkönen, Guide to the otoliths of the bony fishes of the northeast Atlantic, 1986.

K. A. Hobson and R. G. Clark, C in Tissues, The Condor, vol.94, issue.1, pp.181-188, 1992.
DOI : 10.2307/1368807

L. Meynier, C. Pusineri, J. Spitz, M. B. Santos, G. J. Pierce et al., Intraspecific dietary variation in the short-beaked common dolphin Delphinus delphis in the Bay of Biscay: importance of fat fish, Marine Ecology Progress Series, vol.354, pp.277-287, 2008.
DOI : 10.3354/meps07246

R. Michener and K. Lajtha, Stable Isotopes in Ecology and Environmental Science, 2008.
DOI : 10.1002/9780470691854

M. Minagawa and E. Wada, Stepwise enrichment of 15N along food chains: Further evidence and the relation between ??15N and animal age, Geochimica et Cosmochimica Acta, vol.48, issue.5, pp.1135-1140, 1984.
DOI : 10.1016/0016-7037(84)90204-7

B. Morales-nin, A. J. Geffen, S. Pérez-mayol, M. Palmer, R. González-quirós et al., Seasonal and ontogenic migrations of meagre (Argyrosomus regius) determined by otolith geochemical signatures, Fisheries Research, vol.127, issue.128, pp.154-165, 2012.
DOI : 10.1016/j.fishres.2012.02.012

C. Nerot, A. Lorrain, J. Grall, D. P. Gillikin, J. Munaron et al., Stable isotope variations in benthic filter feeders across a large depth gradient on the continental shelf, Estuarine, Coastal and Shelf Science, vol.96, pp.228-235, 2012.
DOI : 10.1016/j.ecss.2011.11.004

URL : https://hal.archives-ouvertes.fr/hal-00660783

A. C. Parnell, R. Inger, S. Bearhop, and A. L. Jackson, Source Partitioning Using Stable Isotopes: Coping with Too Much Variation, PLoS ONE, vol.5, issue.3, p.9672, 2010.
DOI : 10.1371/journal.pone.0009672.g002

URL : http://doi.org/10.1371/journal.pone.0009672

S. Pasquaud, P. Elie, C. Jeantet, I. Billy, P. Martinez et al., A preliminary investigation of the fish food web in the Gironde estuary, France, using dietary and stable isotope analyses, Estuarine, Coastal and Shelf Science, vol.78, issue.2, pp.267-279, 2008.
DOI : 10.1016/j.ecss.2007.12.014

B. J. Peterson and B. Fry, Stable Isotopes in Ecosystem Studies, Annual Review of Ecology and Systematics, vol.18, issue.1, pp.293-320, 1987.
DOI : 10.1146/annurev.es.18.110187.001453

P. Petitgas, Life cycle spatial patterns of small pelagic fish in the Northeast Atlantic, 2010.

G. J. Pierce and P. R. Boyle, A review of methods for diet analysis in piscivorous marine mammals. Oceanogr, Mar. Biol, vol.29, pp.409-486, 1991.

J. K. Pinnegar and N. V. Polunin, Differential fractionation of delta13C and delta15N among fish tissues: implications for the study of trophic interactions, Functional Ecology, vol.13, issue.2, pp.225-231, 1999.
DOI : 10.1139/cjfas-54-5-1142

M. J. Polito, W. Z. Trivelpiece, N. J. Karnovsky, E. Ng, W. P. Patterson et al., Integrating Stomach Content and Stable Isotope Analyses to Quantify the Diets of Pygoscelid Penguins, PLoS ONE, vol.6, issue.10, 2011.
DOI : 10.1371/journal.pone.0026642.s002

D. M. Post, USING STABLE ISOTOPES TO ESTIMATE TROPHIC POSITION: MODELS, METHODS, AND ASSUMPTIONS, Ecology, vol.83, issue.3, pp.703-718, 2002.
DOI : 10.4319/lo.1994.39.5.1030

C. Pusineri, Y. Vasseur, S. Hassani, L. Meynier, J. Spitz et al., Food and feeding ecology of juvenile albacore, Thunnus alalunga, off the Bay of Biscay: a case study, 2005.

J. Quéro and J. Vayne, Le Maigre, Argyrosomus regius (Asso, 1801) (Pisces, Perciformes, Sciaenidae) du Golfe de Gascogne et des eaux plus septentrionales, pp.35-66, 1985.

R. Development and C. Team, R: A language and environment for statistical computing, 2011.

J. C. Reynolds and N. J. Aebischer, Comparison and quantification of carnivore diet by faecal analysis: a critique, with recommendations, based on a study of the Fox Vulpes vulpes, Mammal Review, vol.32, issue.3, pp.97-122, 1991.
DOI : 10.2307/3544695

J. Spitz, T. Chouvelon, M. Cardinaud, C. Kostecki, and P. Lorance, Prey preferences of adult sea bass Dicentrarchus labrax in the northeastern Atlantic: implications for bycatch of common dolphin Delphinus delphis, ICES Journal of Marine Science, vol.70, issue.2, pp.452-461, 2013.
DOI : 10.1093/icesjms/fss200

URL : https://hal.archives-ouvertes.fr/hal-00815475

T. M. Sutton, M. J. Cyterski, J. J. Ney, and M. C. Duval, Determination of factors influencing stomach content retention by striped bass captured using gillnets, Journal of Fish Biology, vol.33, issue.4, pp.903-910, 2004.
DOI : 10.1006/jfbi.2001.1746

K. W. Suzuki, A. Kasai, K. Nakayama, and M. Tanaka, ) juveniles: implications for analyzing migration, Canadian Journal of Fisheries and Aquatic Sciences, vol.62, issue.3, pp.671-678, 2011.
DOI : 10.1139/f04-231

C. J. Sweeting, J. Barry, C. Barnes, N. V. Polunin, and S. Jennings, Effects of body size and environment on diet-tissue ??15N fractionation in fishes, Journal of Experimental Marine Biology and Ecology, vol.340, issue.1, pp.1-10, 2007.
DOI : 10.1016/j.jembe.2006.07.023

C. J. Sweeting, J. T. Barry, N. V. Polunin, and S. Jennings, Effects of body size and environment on diet-tissue ??13C fractionation in fishes, Journal of Experimental Marine Biology and Ecology, vol.352, issue.1, pp.165-176, 2007.
DOI : 10.1016/j.jembe.2007.07.007

. Fig, Relationships between ? 13 C values (left) or ? 15 N values (right) (?) and total length (TL, cm) in meagre collected in 2010 for SIA (N=21) and presenting a wide range of individual sizes. Results from the GGAM models (fitted to individual ? 13 C or ? 15 N values to identify size-related trends) are plotted on raw isotope data (i.e. 70% ethanol preserved) and TL data in the form of a smoother, illustrating the modelled relationships between parameters

. Sia, Data corrected from the effect of ethanol preservation were used (see text and supplemental material. A) Models applied on all individuals analysed for