Farnaz Irandoost - Department of Environmental Biology, Sapienza University of Rome, via dei Sardi 70, 00185 Rome, Italy
Loreto Rossi - Iranian National Institute for oceanography and Atmospheric Sciences, Tehran, Iran
Homira Agah - Iranian National Institute for oceanography and Atmospheric Sciences, Tehran, Iran
Maria Letizia Costantini - Department of Environmental Biology, Sapienza University of Rome, via dei Sardi 70, 00185 Rome, Italy

Anthropogenic organic nitrogen is relatively enriched in 15N with respect to synthetic-derived nitrogen, and both of them can be distinguished from atmospheric-derived (i.e. natural) nitrogen on the basis of their δ15N signatures. According to this, stable isotopes of nitrogen have been shown to be a powerful tool to track the origin of nutrient loadings in aquatic systems. In addition, isotopic signatures of carbon and sulfur can discriminate the relative contribution of different sources to nutrients accumulated in sediments or assimilated by consumers, making it possible to describe trophic pathways and food web structure across multiple spatial and temporal scales. Isotopic signatures will be determined in primary producers, sediments and consumers collected in multiple sampling sites and occasions within each study sites. Isotopic gradients will be described and isotopic variations compared along gradients of anthropogenic pressure and with respect to reference sites.

Stable Isotope, Nutrients, Environmental pollutions