Tracking the provenance of octopus using isotopic and multi-elemental analysis

Abstract

Octopus are an increasingly important seafood commodity, yet traceability techniques to validate the origins of octopus products are sorely lacking. For the first time, we investigate whether chemical profiling can identify geographical origins of octopus on international and domestic scales. Our samples consisted of wild-caught octopus from south-east Asia and southern Australia, regions with high seafood trade. We used a novel combination of stable carbon (δ13C) and oxygen (δ18O) isotope analyses (Isotope-Ratio Mass Spectrometry) of internal calcified structures called statoliths, with elemental analyses (X-Ray Fluorescence using Itrax) of muscle tissue. We found that multivariate profiles had distinctive regional signatures, even across species, with high classification success (∼95%) back to region of origin. This study validates isotopic and multi-elemental profiling as an effective provenance tool for octopus, which could be used to support transparency and accountability of seafood supply chains and thus encourage sustainable use of ocean resources. © 2021 Elsevier Ltd.