title: The allochthonous material input in the trophodynamic system of the shelf sediments of the Gulf of Tigullio (Ligurian Sea, NW Mediterranean).
abstract: The organic allochthonous material input in the benthic system of a NW Mediterranean shelf area was studied using a three-pronged approach, focusing firstly on the evaluation of the sedimentary stable isotope ratios and organic matter (OM) composition, then on the OM recycling processes performed by the microbial organisms, and finally on the potential trophic relationships between the macrobenthic organisms. The highest allochthonous signal, indicating continental input, was observed within the 50-m isobath, while at the 80-m isobath the marine signal was higher, pointing to a rather low continental influence approximately 5 km from the shore. Heavier rainfall, often generating abrupt allochthonous inputs by river outfalls, led to a wider spread of fine sediment particles. Carbohydrates were the compounds that best represented the continental input and these compounds were associated with potential recycling activities by microbiota, pointing to the entry of these C-containing allochthonous materials into the microbial food web. The macrofaunal deposit-feeders used sedimentary OM characterised by a continental signature as a food source, although the isotopic ratios of the organisms also pointed to selective feeding on materials that had a marine signature, especially at our offshore sampling stations. Predators fed on deposit- or suspension-feeders, with a potential selection of the latter during the highest inputs of continental materials occurring in winter.
authors.affiliation: Dipartimento di Scienze Della Terra, Dell'Ambiente e Della Vita (DiSTAV), Università di Genova, C.so Europa 26, 16132 Genova, Italy. Electronic address: misic@dipteris.unige.it.
authors.forename: Cristina
authors.initials: C
authors.lastname: Misic
authors.affiliation: Dipartimento di Scienze Della Terra, Dell'Ambiente e Della Vita (DiSTAV), Università di Genova, C.so Europa 26, 16132 Genova, Italy.
authors.forename: Luigi
authors.initials: L
authors.lastname: Gaozza
authors.affiliation: Dipartimento di Scienze Della Terra, Dell'Ambiente e Della Vita (DiSTAV), Università di Genova, C.so Europa 26, 16132 Genova, Italy.
authors.forename: Mario
authors.initials: M
authors.lastname: Petrillo
authors.affiliation: Dipartimento di Scienze Della Terra, Dell'Ambiente e Della Vita (DiSTAV), Università di Genova, C.so Europa 26, 16132 Genova, Italy.
authors.forename: Anabella
authors.initials: A
authors.lastname: Covazzi Harriague
mesh_terms: D004784:Environmental Monitoring; D020387:Food Chain; D019015:Geologic Sediments / Q000032:analysis*; D008522:Mediterranean Sea; D045483:Rivers / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D014874:Water Pollutants, Chemical
keywords: Continental input; Enzymatic activity; Ligurian Sea; Macrofauna; NW Mediterranean; Organic matter; Sediments