Using near-infrared reflectance spectroscopy (NIRS) to estimate carbon and nitrogen stable isotope composition in animal tissues

Francisco Javier Ancin-Murguzur; Arnaud Tarroux; Kari Anne Bråthen; Paco Bustamante; Sébastien Descamps

doi:10.1002/ece3.7851

Using near-infrared reflectance spectroscopy (NIRS) to estimate carbon and nitrogen stable isotope composition in animal tissues

Ecol Evol. 2021 Jul 5;11(15):10483-10488. doi: 10.1002/ece3.7851. eCollection 2021 Aug.

Authors

Francisco Javier Ancin-Murguzur¹, Arnaud Tarroux², Kari Anne Bråthen¹, Paco Bustamante^{3

4}, Sébastien Descamps⁵

Affiliations

¹ Department of Arctic and Marine Biology University of Tromsø - The Arctic University of Norway Tromsø Norway.
² Norwegian Institute for Nature Research Tromsø Norway.
³ Littoral Environnement et Sociétés (LIENSs) UMR 7266 CNRS-La Rochelle Université La Rochelle France.
⁴ Institut Universitaire de France (IUF) Paris France.
⁵ Norwegian Polar Institute Tromsø Norway.

Abstract

Stable isotopes analysis (SIA) of carbon and nitrogen provides valuable information about trophic interactions and animal feeding habits.We used near-infrared reflectance spectroscopy (NIRS) and support vector machines (SVM) to develop a model for screening isotopic ratios of carbon and nitrogen (δ ¹³C and δ ¹⁵N) in samples from living animals. We applied this method on dried blood samples from birds previously analyzed for δ ¹³C and δ ¹⁵N to test whether NIRS can be applied to accurately estimate isotopic ratios.Our results show a prediction accuracy of NIRS (R ² > 0.65, RMSEP < 0.28) for both δ ¹³C and δ ¹⁵N, representing a 12% of the measurement range in this study.Our study suggests that NIRS can provide a time- and cost-efficient method to evaluate stable isotope ratios of carbon and nitrogen when substantial differences in δ ¹³C or δ ¹⁵N are expected, such as when discriminating among different trophic levels in diet.

Keywords: NIRS; dietary studies; isotopic analysis.