Using laser technology to stem the international flow of illegal ivory
Bristol led research identifies new method of differentiating legal from illegal ivory, offering hope to elephant conservation efforts
Trade in elephant ivory is a global issue, the biggest contributor to the 98% decline in population since 1500. A new use for existing technology, developed by researchers at the Universities of Bristol and Lancaster, could make detecting illegal ivory easier for customs officials, and harder for traffickers to trade.
In recent years, many countries have restricted their laws on ivory trade, and most have banned all trade. But, there are often exceptions for antique items or objects of cultural significance, meaning these pieces can still be traded and sold legally. Key markets in China and the Far East have seen an increase in demand in recent years, where it is seen as a luxury status symbol.
These restrictive rules often do not apply to extinct species, such as mammoth, which creates complications for officials seizing samples without a straightforward identification process. Techniques currently used often require damage to property which may have been legal to trade.
An influx of mammoth ivory has exasperated the issue. As increasing in global temperatures thaw permafrost in the Siberian arctic, near perfectly intact specimens emerge, leading to the rise of a generation of ‘mammoth hunters’, undertaking expeditions to harvest newly exposed mammoth ivory, leading to an influx on trade routes.
This legal and increasing source of ivory poses an enforcement problem for border protection and customs teams across the globe, as ivory products of these two different types of tusk can be difficult to distinguish from one another, particularly once it has been carved or sculpted.
At a microscopic level however, there are differences in ivory between species and genus, which can be identified in the dentinal tubules – the channels from the pulp on the inside of the ivory to the external dentine layer. Dr Rebecca Shepherd from the University’s School of Anatomy, in collaboration with the University of Lancaster, has been working with Raman spectroscopy, which uses a laser to identify biochemical differences in bone and minerals to identify these subtle differences, and to build a database of Raman ‘fingerprints’ for each species. Unlike traditional methods used to differentiate between types of ivory, such as DNA analysis, Raman spectroscopy is non-destructive, and does not require any preparation of the material prior to analysis.
"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."
Dr Rebecca Shepherd
Modern Raman spectrometers are relatively simple to operate. They use a laser to measure and quantify changes in wavelength as it is scattered from a material. They are also non-destructive to biological specimens. As the light (photons) interact with molecular bonds, providing energy for them to vibrate, energy is lost or gained, which results in a shift in wavelength. The output data, containing information about the different changes in light, is referred to as a Raman ‘fingerprint’ or ‘a spectrum’
A major benefit of using Raman Spectroscopy devices is that they are commonly found in airports, with officials trained to utilise the machines to identify illegal drugs. By training customs officials on how to use the devices to tell the difference between legal and illegal forms of ivory, illegal shipments can be stopped. This will make trade in elephant ivory more difficult and risky for traffickers leading to a drop in profits. Researchers hope that this will ultimately have a positive influence on elephant populations
"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."
Professor Adrian Lister, Natural History Museum
The impact of Dr Shepherds work is being felt across the globe. In summer 2024, she was invited to China by WWF China to carry out workshops for customs and border force officials. As a result of this trip, Dr Shepherd is in talks with the USA’s homeland security to explore the use of Raman Spectroscopy to identify species of bird eggs, which are smuggled into the country from Mexico.
The stakes are high. The 2016 African Elephant Database survey revealed a decline of 90,000 elephants in just three years, leaving an estimated population of only 410,000. While the decline in Asian elephants is slower due to the lack of tusks in females, their numbers have still dropped by 50% over the past three generations. As increasing pressures from habitat decline, climate change and the expansion of human populations threaten elephant populations across the world, ending the illegal ivory trade offers some reduction of threat to these majestic creatures.
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