[en] The aim of this work was to identify and compare, using nitrogen and carbon stable isotope data, the food sources supporting consumer communities in a Mediterranean seagrass bed (Gulf of Calvi, Corsica) with those in an adjacent epilithic algal dominated community. Isotopic data for consumers are not significantly different in the two communities. Particulate matter and algal material (seagrass epiflora and dominant epilithic macroalgae) appear to be the main food sources in both communities. Generally, the 13C of animals suggests that the seagrass Posidonia oceanica (L.) Delile represents only a minor component of their diet or of the diet of their prey, but the occurrence of a mixed diet is not excluded. P.oceanica dominates the diet of only of few species, among which holothurians appear as key components in the cycling of seagrass material.
Research center :
MARE - Centre Interfacultaire de Recherches en Océanologie - ULiège
Alcoverro T, Duarte CM, Romero J (1997) The influence of herbivores on Posidonia oceanica epiphytes. Aquat Bot 56: 93-104
Bay D (1984) A field study of the growth dynamics and productivity of Posidonia oceanica (L.) Delile in the Calvi Bay, Corsica. Aquat Bot 20: 43-64
Bunn SE, Loneragan NR, Kempster MA (1995) Effects of acid washing on stable isotope ratios of C and N in penaeid shrimp and seagrass: implication for food-web studies using multiple stable isotopes. Limnol Oceanogr 40: 622-625
Cooper LW, DeNiro MJ (1989) Stable carbon isotope variability in the seagrass Posidonia oceanica: evidence for light intensity effects. Mar Ecol Prog Ser 50: 225-229
Dauby P (1989) The stable carbon isotope ratios in benthic food webs of the gulf of Calvi, Corsica. Contin Shelf Res 9: 181-195
Dauby P, Bale AJ, Bloomer N, Canon C, Ling RD, Norro A, Robertson JE, Simon A, Théate JM, Watson AJ, Frankignoulle M (1995) Particle fluxes over a Mediterranean seagrass bed: a one year case study. Mar Ecol Prog Ser 126: 233-246
Fourqurean JW, Moore TO, Fry B, Hollibaugh JT (1997) Spatial and temporal variation in C:N:P ratios, δ15N, and δ13C of eelgrass Zostera marina as indicators of ecosystem processes, Tomales Bay, California, USA. Mar Ecol Prog Ser 157: 147-157
Fry B (1988) Foodweb structure on Georges Bank from stable C, N, and S isotopic compositions. Limnol Oceanogr 33: 1182-1190
Gobert S, Belkhiria S, Dauby P, Havelange S, Soullard M, Bouquegneau J-M (1995) Variations temporelles de la phénologie et de la composition biochimique de la phanérogame marine Posidonia oceanica en baie de Calvi. Bull Soc r Sciences Liège 64: 263-284
Havelange S, Lepoint G, Dauby P, Bouquegneau J-M (1997) Feeding of the sparid fish Sarpa salpa in a seagrass ecosystem: diet and carbon flux. Pubbl Staz Zool Napoli (I. Mar Ecol) 18: 289-297
Hecky RE, Hesslein RH (1995) Contributions of benthic algae to lake food webs as revealed by stable isotope analysis. J N Am Benthol Soc 14: 631-653
Jennings S, Renones O, Morales-Nin B, Polunin NVC, Moranta J, Coll J (1997) Spatial variation in the 15N and 13C stable isotope composition of plants, invertebrates and fishes on Mediterranean reefs: implications for the study of trophic pathways. Mar Ecol Prog Ser 146: 109-116
Jernakoff P, Brearley A, Nielsen J (1996) Factors affecting grazerepiphyte interactions in temperate seagrass meadows. Oceanogr mar Biol A Rev 34: 109-162
Kerby NW, Raven JA (1985) Transport and fixation of inorganiccarbon by macroalgae. Adv bot Res 11: 71-123
Kitting CL, Fry B, Morgan MD (1984) Detection of inconspicuous epiphytic algae supporting food web in seagrass meadows. Oecologia 62: 145-149
Lepoint G, Havelange S, Gobert S, Bouquegneau J-M (1999) Fauna vs. flora contribution to the leaf epiphytes biomass in a Posidonia oceanica seagrass bed (Revellata Bay, Corsica). Hydrobiologia 394: 63-67
Macko SA, Lee WY, Parker PL (1982) Nitrogen and carbon isotope fractionation by two species of marine amphipods: laboratory and field studies. J exp mar Biol Ecol 63: 145-149
Marguillier S, Van der Velde G, Dehairs F, Hemminga MA, Rajagopal S (1997) Trophic relationships in an inter-linked mangrove-seagrass ecosystem as traced by δ13C and δ15N. Mar Ecol Prog Ser 151: 115-121
Mariotti A, Lancelot C, Billen G (1984) Natural isotopes composition of nitrogen as tracer of origin for suspended organic matter in the Scheldt estuary. Geochim cosmochim Acta 48: 549-555
Mateo MA, Romero J (1997) Detritus dynamics in the seagrass Posidonia oceanica: elements for an ecosystem carbon and nutrient budget. Mar Ecol Prog Ser 151: 43-53
Mazzella L, Buia MC, Gambi MC, Lorenti M, Russo GF, Scipione MB, Zupo V (1992) Plant-animal trophic relationships in the Posidonia oceanica ecosystem of the Mediterranean Sea: a review. In: John DM, Hawkins SJ, Price HJ (eds) Plant animal interaction in the marine benthos. Clarendon Press, Oxford, pp 165-187
Mazzella L, Russo GF (1989) Grazing effect of two Gibbula species (Mollusca, Archeogasteropoda) on the epiphytic community of Posidonia oceanica leaves. Aquat Bot 35: 357-373
McClelland JW, Valiela I, Michener RH (1997) Nitrogen-stable isotope signatures in estuarine food webs: a record of increasing urbanisation in coastal watersheds. Limnol Oceanogr 42: 930-937
Ott JA, Maurer L (1977) Strategies of energy transfers from marine macrophytes to consumer level: the Posidonia oceanica example. In: Keegan BF, O'Ceidigh P, Boaden P (eds) Biology of benthic organisms. Pergamon Press, Oxford, pp 493-502
Pergent G, Romero J, Pergent-Martini C, Mateo MJ, Boudouresque CF (1994) Primary production, stocks and fluxes in the Mediterranean seagrass Posidonia oceanica. Mar Ecol Prog Ser 106: 139-146
Pinnegar JK, Polunin NVC (1999) Differential fractionation of δ13C and δ15N among fish tissues: implications for the study of trophic interactions. Funct Ecol 13: 225-231
Pinnegar JK, Polunin NVC (2000) Contribution of stable isotope data to elucidating food webs of Mediterrenean rocky-littoral fishes. Oecologia (in press)
Raven JA, Walker DI, Johnston AM, Handley LL, Kübler JE (1995) Implications Of 13C natural abundance measurements for photosynthetic performance by marine macrophytes in their natural environment. Mar Ecol Prog Ser 123: 193-205
Russo GF, Fresi E, Vinci D (1985) The hand-towed net method for direct sampling in Posidonia oceanica beds. Rapp P-v Réun Commn int Explor scient Mer Méditerr 29: 175-177
Wada E, Hattori A (1976) Natural abundance of 15N in particulate organic matter in the North Pacific Ocean. Geochim cosmochim Acta 40: 249-256
Wilmotte A, Demoulin V (1988) Studies of marine epiphytic algae, Calvi, Corsica. II. Seasonal variations in the populations of epiphytic blue-green algae in three harbours with different pollution loads. Br phycol J 23: 259-266
