Researchers at the universities of Bristol and Lancaster have used laser-based Raman spectroscopy to distinguish between illegal elephant ivory and legal mammoth tusk ivory.
As the sale of ivory from extinct species, such as mammoths, is legal it can be very hard for customs services to identify illegal ivory.
The illegal ivory trade is estimated to cause an 8% loss in the world’s elephant population each year.
Modifying Raman spectroscopy
The researchers have published their findings in PLOS ONE.
They sought to establish whether Raman spectroscopy could be modified to accurately detect differences in the chemistry of mammoth and elephant ivory.
Raman spectroscopy is already used in the study of bone and mineral chemistry.
Dr Rebecca Shepherd with mammoth ivory samples obtained from the Natural History Museum. In the background, the benchtop Raman spectrometer is shown. Credit: Dr Rebecca Shepherd
Non-destructive technology
The non-destructive technology, which involves shining a high-energy light at an ivory specimen, can detect small biochemical differences in the tusks from elephants and mammoths.
They scanned samples of mammoth and elephant tusks from London’s Natural History Museum using the laser-based method of Raman spectroscopy.
Results from the experiment found the technology provided accurate, quick and non-destructive species identification.
Providing results quickly
Dr Rebecca Shepherd, formerly of Lancaster Medical School and now at the University of Bristol’s School of Anatomy, explained:
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.
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.
Important development
Dr Jemma Kerns of Lancaster Medical School, added:
The combined approach of a non-destructive laser-based method of Raman spectroscopy with advanced data analysis holds a lot of promise for the identification of unknown samples of ivory, which is especially important, given the increase in available mammoth tusks and the need for timely identification.
Great science
Alice Roberts, Professor of Public Engagement in Science, from the University of Birmingham and one of the study’s co-authors, said:
There’s a real problem when it comes to stamping down on the illegal trade in elephant ivory. Because trading in ancient mammoth ivory is 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.
Quick and reliable method
Professor Adrian Lister, one of the study’s co-authors from the Natural History Museum, added:
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.
Addressing problems of global significance
Professor Charlotte Deane, Executive Chair of the Engineering and Physical Sciences Research Council (EPSRC), said:
By offering a quick and simple alternative to current methods, the use of Raman spectroscopy could play an important role in tackling the illegal ivory trade.
The researchers’ work illustrates how the development and adoption of innovative new techniques can help us to address problems of global significance.
Top image: A selection of elephant and mammoth tusk samples. Credit: Ben Booth