title: Spatial variations in feeding habits and trophic levels of two small pelagic fish species in the central Mediterranean Sea.
abstract: Trophic ecology of adults of European sardine (Sardina pilchardus) and anchovy (Engraulis encrasicolus) was examined and compared among various regions of central Mediterranean Sea. Carbon and nitrogen stable isotope analyses (δ(13)C and δ(15)N) were adopted as a tool to determine changes in feeding behaviour of adults of sardines and anchovies. In the study period (summer) a clear geographical pattern was recognized in the isotopic composition of both species, with an increasing trend northward. The highest variations in isotopic signal were linked to the geographical positions of the samples and, especially, between pairs of areas: South Sicily/South Campania and Gulf of Gaeta/South Elba. Higher isotope values were found in the anchovies and sardines caught in northern Tyrrhenian Sea, while lower values were mostly estimated in the southern region. Higher carbon and nitrogen isotopes may reflect a more coastal behaviour of both species, being (13)C-enriched source from benthic primary producers in addition to phytoplankton. Variations in the nitrogen isotope ratio may reflect not only differences in the trophic level of prey species, but also variations in the baseline level of food webs. Our results support the hypothesis that feeding behaviour of both species is directly or indirectly influenced by local factors, or by resource partitioning based on zooplankton size. Findings can supply knowledge needed for improving fish stock management and promoting plans able to take into account also local ecosystem analysis.
authors.affiliation: Istituto per l'Ambiente Marino Costiero, Consiglio Nazionale delle Ricerche, Calata Porta di Massa, 80100, Naples, Italy.
authors.forename: P
authors.initials: P
authors.lastname: Rumolo
authors.affiliation: Istituto per l'Ambiente Marino Costiero, Consiglio Nazionale delle Ricerche, UOS di Capo Granitola, Via del Mare, 3 Torretta Granitola, 91021, Campobello di Mazara, Italy. Electronic address: angelo.bonanno@iamc.cnr.it.
authors.forename: A
authors.initials: A
authors.lastname: Bonanno
authors.affiliation: Istituto per l'Ambiente Marino Costiero, Consiglio Nazionale delle Ricerche, Calata Porta di Massa, 80100, Naples, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Barra
authors.affiliation: ENEA, Marine Environment Research Centre, Santa Teresa Pozzuolo di Lerici, 19100, La Spezia, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Fanelli
authors.affiliation: Istituto per l'Ambiente Marino Costiero, Consiglio Nazionale delle Ricerche, UOS di Capo Granitola, Via del Mare, 3 Torretta Granitola, 91021, Campobello di Mazara, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Calabrò
authors.affiliation: Istituto per l'Ambiente Marino Costiero, Consiglio Nazionale delle Ricerche, UOS di Capo Granitola, Via del Mare, 3 Torretta Granitola, 91021, Campobello di Mazara, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Genovese
authors.affiliation: Istituto per l'Ambiente Marino Costiero, Consiglio Nazionale delle Ricerche, UOS di Capo Granitola, Via del Mare, 3 Torretta Granitola, 91021, Campobello di Mazara, Italy.
authors.forename: R
authors.initials: R
authors.lastname: Ferreri
authors.affiliation: Istituto per l'Ambiente Marino Costiero, Consiglio Nazionale delle Ricerche, UOS di Capo Granitola, Via del Mare, 3 Torretta Granitola, 91021, Campobello di Mazara, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Mazzola
authors.affiliation: Istituto per l'Ambiente Marino Costiero, Consiglio Nazionale delle Ricerche, UOS di Capo Granitola, Via del Mare, 3 Torretta Granitola, 91021, Campobello di Mazara, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Basilone
mesh_terms: D000818:Animals; D002247:Carbon Isotopes / Q000032:analysis; D017753:Ecosystem; D005247:Feeding Behavior; D005399:Fishes / Q000502:physiology*; D020387:Food Chain; D008522:Mediterranean Sea; D009587:Nitrogen Isotopes / Q000032:analysis
chemical_list: D002247:Carbon Isotopes; D009587:Nitrogen Isotopes
keywords: Engraulis encrasicolus; Feeding behaviour; Mesozooplankton; Sardina pilchardus; Stable isotopes; Trophic ecology; Tyrrhenian Sea