Nitrogen isotopic composition of collagen amino acids as an indicator of aquatic resource consumption: insights from Mesolithic and Epipalaeolithic archaeological sites in France created by Yuichi I. Naito, Yoshito Chikaraishi, Naohiko Ohkouchi, Dorothée G. Drucker and Hervé Bocherens

Aquatic resource exploitations in human evolution have raised many questions related to cognitive abilities and subsistence developments. It has been pointed out that the evaluation of freshwater resource consumption based on conventional stable CN isotopic composition of bulk bone collagen faces some difficulties, primarily because isotopic distinction between terrestrial and freshwater animals can be ambiguous and, even worse, can show similar values. In this study we tested the potential of nitrogen isotope analysis of individual amino acids in this evaluation. Our preliminary results for archaeological human and faunal remains from Mesolithic and Epipalaeolithic sites in France (Noyen-sur-Seine and Pont d'Ambon) show that estimated trophic positions for terrestrial animals based on δ¹⁵N of glutamic acid and phenylalanine are more precise than the bulk collagen isotopic method, allowing human aquatic resource consumptions to be identified. However, since the ability to quantify is still limited, a combination of several approaches is recommended.