title: n-Alkanes and stable C, N isotopic compositions as identifiers of organic matter sources in Posidonia oceanica meadows of Alexandroupolis Gulf, NE Greece.
abstract: We analyzed n-alkane contents and their stable carbon isotope composition, as well as the carbon and nitrogen isotope composition (δ(13)C, δ(15)N) of sediment organic matter and different tissues of Posidonia oceanica seagrass sampled in Alexandroupolis Gulf (A.G.), north-eastern Greece, during 2007-2011. n-Alkane contents in P. oceanica and in sediments showed similar temporal trends, but relative to bulk organic carbon content, n-alkanes were much more enriched in sediments compared to seagrass tissue. Individual n-alkanes in sediments had similar values than seagrass roots and rhizomes and were more depleted in (13)C compared to seagrass leaves and sheaths, with δ(13)C values ranging from -35‰ to -28‰ and from -25‰ to -20‰, respectively. n-Alkane indexes such as the Carbon Preference Index, carbon number maximum, and n-alkane proxy 1 (C23+C25/C23+C25+C29+C31) indicate strong inputs of terrestrial organic matter, while the presence of unresolved complex mixtures suggests potential oil pollution in some sampled areas.
authors.affiliation: Analytical, Environmental and Geo-Chemistry and Earth System Sciences Research Group, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium. Electronic address: mapostol@vub.ac.be.
authors.forename: Maria-Venetia
authors.initials: MV
authors.lastname: Apostolopoulou
authors.affiliation: Royal Belgian Institute of Natural Sciences, Operational Directorate Natural Environments, ECOCHEM, 3e & 23e Linieregimentsplein, B-8400 Ostend, Belgium. Electronic address: E.Monteyne@mumm.ac.be.
authors.forename: Els
authors.initials: E
authors.lastname: Monteyne
authors.affiliation: Freelance Statistical and Research Consultant, DatAnalysis, Ioannina, Greece. Electronic address: krikonis@yahoo.com.
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Krikonis
authors.affiliation: Department of Geography and Planning, Paris-Sorbonne University Abu Dhabi, P.O. Box 38044, Al Reem Island, United Arab Emirates. Electronic address: kosmas.pavlopoulos@psuad.ac.ae.
authors.forename: Kosmas
authors.initials: K
authors.lastname: Pavlopoulos
authors.affiliation: Royal Belgian Institute of Natural Sciences, Operational Directorate Natural Environments, ECOCHEM, 3e & 23e Linieregimentsplein, B-8400 Ostend, Belgium. Electronic address: P.Roose@mumm.ac.be.
authors.forename: Patrick
authors.initials: P
authors.lastname: Roose
authors.affiliation: Analytical, Environmental and Geo-Chemistry and Earth System Sciences Research Group, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium. Electronic address: fdehairs@vub.ac.be.
authors.forename: Frank
authors.initials: F
authors.lastname: Dehairs
mesh_terms: D035961:Alismatales / Q000378:metabolism*; D000473:Alkanes / Q000032:analysis* / Q000737:chemistry; D002247:Carbon Isotopes / Q000032:analysis; D004784:Environmental Monitoring; D019015:Geologic Sediments / Q000737:chemistry*; D006115:Greece; D009587:Nitrogen Isotopes / Q000032:analysis; D010578:Petroleum / Q000032:analysis*; D018515:Plant Leaves / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis
chemical_list: D000473:Alkanes; D002247:Carbon Isotopes; D009587:Nitrogen Isotopes; D010578:Petroleum; D014874:Water Pollutants, Chemical
keywords: Aegean Sea; Alexandroupolis Gulf; Carbon and nitrogen stable isotopes; Mediterranean Sea; Posidonia oceanica; n-Alkanes