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Laser technology could help curb the illegal trade in ivory
Every year thousands of elephants are still killed for their ivory.
Part of the problem is that illegal ivory is passed off for legal ancient mammoth ivory. Now a team of researchers have developed a method that can rapidly distinguish between the two.
Distinguishing between elephant and mammoth ivory just got easier.
A new study has found that a laser technology can quickly and accurately tell the difference between ivory that came from living elephants and ivory that came from their extinct relatives, mammoths.
This could provide a major step in helping to fight the illegal trade of ivory.
Whilst it is against the law to trade in elephant ivory, it is still legal to trade in ivory from mammoths. As a result, there has been a boom in mammoth ivory sales that has resulted in a market that allows for the laundering of the illegal elephant ivory.
It can be surprisingly difficult to tell the difference between elephant and mammoth ivory in worked objects ©Ben Booth
Telling the difference can be difficult, costly and time consuming. But by using a technique known as Raman spectroscopy, researchers were able to identify if an ivory object was elephant or mammoth within just a few minutes.
Professor Adrian Lister is an expert on mammoths at the Natural History Museum. The new technique was tested by using samples of mammoth and elephant ivory in the museum’s collections.
“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,” explains Adrian. “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.”
The results have been published in the journal PLOS ONE.
Trade in ivory
Between 1979 and 1989, around half of all elephants living in Africa were killed for their ivory.
This decimated their number to around 300,000 animals, but recent conservation and law enforcement work has stopped this decline. There are now thought to be about half a million elephants spread across the continent, and the demand for ivory has dipped after countries like China made the trade illegal.
But there is still a market for the product, which threatens the remaining elephants. It is estimated that around eight percent of all elephants worldwide are killed each year to satisfy the current demand for ivory.
Elephant numbers have started to recover, but they still face threats from poaching ©Lubo Ivanko/Shutterstock
It is thought that part of the problem has been fuelled by the rise in the sale of mammoth ivory. This often comes from the countless animals found preserved in the permafrost of northern Russia. It can be argued that the sale of mammoth ivory has helped to alleviate the pressure the product has put on living species, providing a source of ivory for which no elephant was killed.
But it has also been found to be a route though which illegal elephant ivory can be passed off as legal mammoth ivory.
This has created a growing problem for customs officials, who find it near impossible to tell the difference between mammoth and elephant ivory when presented with a worked object, such as a statue.
Professor Alice Roberts from the University of Birmingham was also involved in this new study.
“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,” explains Alice. “The complete 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.”
This therefore requires the authorities to either do DNA analysis on the objects, or date them. Both these options take time and money.
This new technique can tell the difference between elephant and mammoth ivory without damaging the item ©Dr Rebecca Shepherd
Improving law enforcement
The team of scientists from the University of Bristol and Lancaster wanted to find a way to solve this issue.
They turned to a laser-based approach that is already used in the study of bone and mineral chemistry. Known more technically as Raman spectroscopy, this is a non-destructive technique that fires lasers at the surface of an object, and then measures how the light scatters. The pattern of the scattered light can reveal the chemical composition of the material being analysed.
The researchers were able to adapt the technique to accurately detect subtle chemical differences between elephant and mammoth ivory, such as finding differences in the amounts of phosphorus present.
The reasons for these differences are not really known, with the researchers suggesting that it could be related to the different diets or climates the animals had in life. Another potential reason is simply the fact that mammoth ivory has been buried in the ground for so long, allowing for subtle changes in its chemistry over time.
Regardless of the cause, the first author of the paper Dr Rebecca Shepherd is hopeful that it can be used to help curb the continued trade in endangered elephant ivory.
“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,” says Rebecca.
“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.”
