Novel detection of provenance in the illegal wildlife trade using elemental data

Kate J Brandis,Phoebe J B Meagher,Debashish Mazumder,Lydia J Tong,Michelle Shaw,Daniel Ramp,Patricia Gadd

doi:10.1038/s41598-018-33786-0

Abstract

Despite being the fourth largest criminal market in the world, no forensic tools have been sufficiently developed to accurately determine the legal status of seized animals and their parts. Although legal trading is permissible for farmed or captive-bred animals, many animals are illegally removed from the wild and laundered by masquerading them as captive bred. Here we present high-resolution x-ray fluorescence (XRF) as a non-invasive and cost-effective tool for forensic classification. We tested the efficacy of this technique by using machine learning on a training set of zoo specimens and wild-caught individuals of short-beaked echidnas (Tachyglossus aculeatus), a small insectivorous monotreme in Australia. XRF outperformed stable isotope analysis (δ13C, δ15N), reducing overall classification error below 4%. XRF has the added advantage of providing samples every 200 μm on a single quill, enabling 100% classification accuracy by taking the consensus of votes per quill. This accurate and cost-effective forensic technique could provide a much needed in situ solution for combating the illegal laundering of wildlife, and conversely, assist with certification of legally bred animals.

Highlights

The international illegal wildlife trade (IWT) is the fourth largest criminal market in the world, worth between USD$7-23 billion annually[1]
Stemming the illegal trade is challenged because existing forensic tools are either inaccurate, inaccessible, or too expensive, making it difficult to confidently determine specimen identity, geographic origin, or legal status
Efforts to forensically test for geographic origin have centred on analysis of stable isotopes[29,30], relying on intrinsic tissue signatures fractionated from diets during assimilation[31,32,33]

Summary

Introduction

The international illegal wildlife trade (IWT) is the fourth largest criminal market in the world, worth between USD$7-23 billion annually[1]. Stemming the illegal trade is challenged because existing forensic tools are either inaccurate, inaccessible, or too expensive, making it difficult to confidently determine specimen identity, geographic origin, or legal status. Some success has been had with reptiles in Vietnam[22] and with fish in China, Australia, Malaysia, and Indonesia[34] Both stable isotopes and genetic testing perform best for geographically isolated species with small home ranges or with restricted ecological niches[22,25]. Both tools are expensive, require considerable sample preparation, and cannot be conducted in situ, limiting accessibility and versatility. Non-destructive, and cost-effective, no previous studies have tested the efficacy of this method as a forensic tool for combating IWT

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Conclusion