Stable isotope analysis offers a groundbreaking approach in the fight against wildlife poaching by providing a novel technique to differentiate between lawful mammoth ivory and unlawful elephant ivory. This method is distinguished by its speed and cost-efficiency compared to existing procedures, potentially assisting authorities in reducing the illegal slaughter of elephants by effectively identifying unauthorized ivory specimens.
The illegal elephant ivory trade has been sustained by a loophole that involves the legitimate trade of mammoth ivory. While international prohibitions limit the trade of elephant ivory, ivory sourced from the remains of ancient mammoths preserved in the Siberian permafrost is legally exchanged. Once processed, the differences between mammoth and elephant ivories are nearly invisible to the naked eye, enabling the fraudulent representation of illegal elephant ivory as legal mammoth ivory. Conventional methods, including radiocarbon dating and genetic analysis, can accurately tell the two apart but are labor-intensive and require large ivory samples.
In an effort to develop a superior technique for identifying ivory origins, researchers in Hong Kong, China, examined the stable isotope ratios of five elements—hydrogen-2, oxygen-18, carbon-13, nitrogen-15, and sulfur-34—in a study involving 79 ivory samples, comprising 44 from elephants and 35 from mammoths. The differing habitats of ancient mammoths and contemporary elephants result in significant variations in their isotopic signatures, which are influenced by diet and water consumption.
The research demonstrated that while the isotope ratios for carbon, nitrogen, and sulfur showed considerable overlaps, the ratios for hydrogen and oxygen were markedly distinct. Importantly, the hydrogen-2 isotope ratios exhibited complete non-overlap between elephant and mammoth samples. This discovery underscores the promise of stable isotope analysis as a swift, economical method, necessitating only 5mg of ivory powder and costing under $25 per sample, with results provided within hours instead of lengthy durations.
Researchers support the application of stable isotope analysis as a preliminary screening technique for identifying suspicious ivory. Specimens flagged through this analysis could then be subjected to further assessments using more advanced genetic or radiocarbon testing, bolstering enforcement efforts against illegal ivory commerce.