title: The effects of nitrogen pollutants on the isotopic signal (δ15N) of Ulva lactuca: Microcosm experiments.
abstract: Effects of two chemical forms of Nitrogen (NH4+and NO3-) on δ15N in Ulva lactuca were analysed separately and in mixture at two concentrations. We assessed whether the δ15N values of U. lactuca discriminate between Nitrogen from synthetic fertilisers (inorganic) and from fresh cow manure (organic), and the isotopic ability of the macroalga to reflect Nitrogen concentrations. Isotopic signature and N content of the macroalga reflected different nitrogenous sources and their concentrations after 48h. The inorganic Nitrogen source (NH4NO3) altered the isotopic values of the macroalgae more than Nitrogen from fresh cow manure (NO3-). δ15N values observed in the mixed solution did not differ from those displayed in NH4NO3treatment alone. We conclude that stable isotope analysis of U. lactuca collected in an unpolluted site and experimentally submerged in sites suspected of being affected by disturbance is a useful tool for rapid monitoring of anthropogenic discharges of Nitrogen pollutants.
authors.affiliation: Sapienza University of Rome, Department of Environmental Biology, via dei Sardi 70, 00185 Rome, Italy.
authors.forename: Lucia
authors.initials: L
authors.lastname: Orlandi
authors.affiliation: Sapienza University of Rome, Department of Environmental Biology, via dei Sardi 70, 00185 Rome, Italy; CoNISMa - Consorzio Nazionale Interuniversitario per le Scienze del Mare, Piazzale Flaminio 9, 00196 Rome, Italy.
authors.forename: Edoardo
authors.initials: E
authors.lastname: Calizza
authors.affiliation: Sapienza University of Rome, Department of Environmental Biology, via dei Sardi 70, 00185 Rome, Italy; CoNISMa - Consorzio Nazionale Interuniversitario per le Scienze del Mare, Piazzale Flaminio 9, 00196 Rome, Italy.
authors.forename: Giulio
authors.initials: G
authors.lastname: Careddu
authors.affiliation: Sapienza University of Rome, Department of Environmental Biology, via dei Sardi 70, 00185 Rome, Italy.
authors.forename: Pasquale
authors.initials: P
authors.lastname: Carlino
authors.affiliation: Sapienza University of Rome, Department of Environmental Biology, via dei Sardi 70, 00185 Rome, Italy; CoNISMa - Consorzio Nazionale Interuniversitario per le Scienze del Mare, Piazzale Flaminio 9, 00196 Rome, Italy. Electronic address: marialetizia.costantini@uniroma1.it.
authors.forename: Maria Letizia
authors.initials: ML
authors.lastname: Costantini
authors.affiliation: Sapienza University of Rome, Department of Environmental Biology, via dei Sardi 70, 00185 Rome, Italy; CoNISMa - Consorzio Nazionale Interuniversitario per le Scienze del Mare, Piazzale Flaminio 9, 00196 Rome, Italy.
authors.forename: Loreto
authors.initials: L
authors.lastname: Rossi
mesh_terms: D000818:Animals; D002417:Cattle; D004784:Environmental Monitoring; D008372:Manure; D009584:Nitrogen; D009587:Nitrogen Isotopes; D044445:Ulva / Q000737:chemistry*; D014874:Water Pollutants, Chemical
chemical_list: D008372:Manure; D009587:Nitrogen Isotopes; D014874:Water Pollutants, Chemical; D009584:Nitrogen
keywords: Bioindicator; Macroalgae; Mixed N sources; Nitrogen source; Pollution; Stable isotopes