A team of researchers from the Universities of Bristol and Lancaster, UK, developed a new laser-based approach to identify illegal ivory, which may prove vital to fight the illegal ivory trade. The work is published in the journal PLOS ONE.
Despite the ban on ivory defined by the Convention on the International Trade in Endangered Species (CITES), poaching and illegal trade continue and are responsible for 8% loss of the world’s population of elephants every year. In 2016, The African Elephant Database survey estimated that only 410,000 elephants were left in Africa, a decrease of approximately 90,000 from the previous report in 2013.
However, while trading ivory from elephants is illegal, selling ivory from extinct species, such as mammoth tusk ivory, is still possible. This type of trade is entirely legal and has become a lucrative industry. The problem is that ivory from these two sources is very similar, and it is extremely difficult to distinguish one from the other, especially in small carved items.
“There’s a real problem when it comes to stamping down on the illegal trade in elephant ivory. Because trading in ancient mammoth ivory was legal, the compete tusks of elephants and mammoths look very different, but if the ivory is cut into small pieces, it can be practically impossible to tell apart elephant ivory from well-preserved mammoth ivory. I was really pleased to be part of this project exploring a new technique for telling apart elephant and mammoth ivory. This is great science and should help the enforcers – giving them a valuable and relatively inexpensive tool to help them spot illegal ivory,” said Alice Roberts, one of the co-authors of the study.
To help with this distinction, a team of researchers from the Universities of Bristol and Lancaster wondered if Raman spectroscopy — commonly used to study bones — could be adapted to detect subtle chemical differences between mammoth and elephant ivory. Using this laser-based method, the team scanned multiple samples of mammoth and elephant tusks from London’s Natural History Museum. Results show that the technology is capable of providing accurate, quick, and non-destructive species identification.
“The gold standard method of identification recommended by The United Nations Office on Drugs and Crime for assessing the legality of ivory predominantly are expensive, destructive and time-consuming techniques,” said Dr Rebecca Shepherd from the University of Bristol. “Raman spectroscopy can provide results quickly (a single scan takes only a few minutes) and is easier to use than current methods, making it easier to determine between illegal elephant ivory and legal mammoth tusk ivory. Increased surveillance and monitoring of samples passing through customs worldwide using Raman spectroscopy could act as a deterrent to those poaching endangered and critically endangered species of elephant.”
“Stopping the trade in elephant ivory has been compromised by illegal ivory objects being described or disguised as mammoth ivory (for which trade is legal). A quick and reliable method for distinguishing the two has long been a goal, as other methods (such as radiocarbon dating and DNA analysis) are time-consuming and expensive. The demonstration that the two can be separated by Raman spectroscopy is, therefore, a significant step forward; also, this method (unlike the others) does not require any sampling, leaving the ivory object intact,” concluded Professor Adrian Lister, one of the study’s co-authors from the Natural History Museum.
Shepherd RF, Lister AM, Roberts AM, Taylor AM, Kerns JG (2024) Discrimination of ivory from extant and extinct elephant species using Raman spectroscopy: A potential non-destructive technique for combating illegal wildlife trade. PLoS ONE 19(4): e0299689. https://doi.org/10.1371/journal.pone.0299689