by In recent years, the global trade in elephant ivory has faced significant restrictions in an effort to protect dwindling elephant populations. Many countries have strict controls on the trade in elephant ivory. However, the sale of mammal ivory, which comes mainly from extinct species, remains unregulated.
But it is a significant challenge for customs and law enforcement agencies to distinguish between ivory from extinct mummies and living elephants. This is a process that takes time and requires the destruction of the ivory.
Now our new study, published in PLOS ONE, presents a major breakthrough – using a known laser technique to separate mammalian and elephant ivory.
Our results couldn’t come soon enough. The number of African elephants has declined significantly from about 12 million a century ago to about 400,000 today.
Annually, more than 20,000 elephants are poached for ivory, mainly in Africa. This reduction not only affects the ecological balance, but also reduces biodiversity. Ultimately, it highlights the urgent need for conservation efforts to protect these species.
Hunting for ivory mammals is also a problem. The new regulations have resulted in the rise of the “mammoth hunter” today. These are people who deliberately tried to dig up the remains of mammals from the permafrost of Siberia in the summer months.
Driven by the lucrative market for giant ivories, these hunters venture into remote Arctic regions, where climate change has accelerated the melting of permafrost. Because of this, huge tusks that were previously inaccessible are more accessible.
This activity does not only have commercial implications. It also raises significant ethical and environmental concerns. This is because it affects preserved ecosystems and involves the extraction of resources of great value to the science of paleontology.
Laser insights
Our study from the University of Bristol, in collaboration with Lancaster University and the Natural History Museum, introduces a possible method of change. We use a non-invasive laser technique called Raman spectroscopy to identify the origin of a piece of ivory.
The method works by analyzing the biochemical composition of the ivory, which is mainly composed of mineral tissue composed of collagen (the flexible organic component) and hydroxyapatite (a hard inorganic mineral, containing calcium).
Raman spectroscopy is a well-established technique. Applications related to identifying whiskey, studying archaeological human bones from the Mary Rose ship, understanding how turkey tendons develop and even identifying the purity of meat sold by the food industry have already been demonstrated.
The technique works by focusing laser light on the ivory sample. The light energy is temporarily absorbed by the bonds between the molecules in the sample, and then re-released almost immediately. This emitted light scatters back with more or less energy than the initial laser light sent to the sample.
This carries information about the molecular vibrations within the material – providing a unique pattern of light for each type of ivory. The analysis involves studying the differences between these unique fingerprints.
Our study analyzed elephant and mammoth samples provided by the Natural History Museum, London. He showed that not only could the technique differentiate between mammalian and elephant ivory, it could also see differences in ivory from living elephant species.
In fact, we succeeded in distinguishing ivory from the extinct woolly mammal (Mammuthus primigenius) and two species of elephants that still walk the Earth today (Loxodonta and Elephas maximus).
Important implications
This method has several advantages over traditional techniques for ivory analysis. Raman spectroscopy is non-destructive and can be performed quickly. It is therefore a great tool for customs officers who need to make quick decisions. Our study was conducted on a bench spectrometer (a device that breaks light into wavelengths) within a laboratory. But research suggests that a cheaper and more portable handheld Raman spectrometer may offer equivalent results.
Further research will be needed to refine the technique and expand the database of ivory signatures. We are working with Worldwide Wildlife Hong Kong and the Overseas and Commonwealth Development Office to develop this technique.
More data will ultimately increase the accuracy of species identification. It could help us detect even finer distinctions – such as the age of the ivory or the particular environmental conditions in which the elephants or mammals lived.
There are also other non-destructive techniques, such as X-ray fluorescence spectroscopy, which could be used as a complementary method to identify the geographical region from which the ivory was taken.
As this technique becomes more accessible and widely accepted, it can be instrumental in global conservation efforts, helping to prevent the illegal trade in elephant ivory.
This article from The Conversation is republished under a Creative Commons license. Read the original article.
Rebecca Shepherd receives funding from the EPSRC and the FCDO.
