Vahideh Jafari - Department of Environmental Biology, Sapienza University of Rome, Italy
Maria Letizia Costantini - Department of Environmental Biology, Sapienza University of Rome, Italy
Mostafa Jafari - TPS for LFCCs; RIFR-AREEO; and IPCC LA
Loreto Rossi - Department of Environmental Biology, Sapienza University of Rome, Italy
Edoardo Calizza - Department of Environmental Biology, Sapienza University of Rome, Italy

Stable isotope analysis has become known as important approach in ecological science but also in Geology, Biology, Climate, Organic chemistry, Botany and Zoology. The main purposes of this paper are to give a simple description of stable isotope concept, applications, and measurement method also for the animal food habits determination. The stable isotopes of Nitrogen (δ۱۵N) and Carbon (δ۱۳C) enable powerful tools for evaluating the origins of Nitrogen pollution in water systems and, associated to Bayesian Mixing Models, are the elective method to assess the trophic positions of the different taxa in a food

animal nutrition, environment, food web, stable isotope analysis, trophic position