(CNN)African elephants have drastically dwindled as targets of the illegal ivory trade, but the DNA contained within their tusks is pointing to the very criminal networks that poached them.
Tracing DNA of related elephants reveals illegal ivory trafficking networks
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Researchers used genetic testing on ivory shipments seized by law enforcement and were able to trace the international crime ring shipping the ivory from Africa.
The team tested more than 4,000 elephant tusks from 49 different seizures, made between 2002 and 2019, across 12 different African countries. The findings published Monday in the journal Nature Human Behaviour.
The study establishes familial connections between the elephants that are being poached for their ivory tusks and reveals the poaching and shipping practices and interconnectedness of the traffickers.
This kind of DNA detective work can expose the tactics employed by transnational criminal organizations, believes the research team, comprised of scientists and US Department of Homeland Security special agents. These illicit organizations have operated out of Africa for decades, leading to the heavy decline of thousands of elephants in recent years, according to the study.
"These methods are showing us that a handful of networks are behind a majority of smuggled ivory, and that the connections between these networks are deeper than even our previous research showed," said lead study author Samuel Wasser, a University of Washington professor of biology and co-executive director of the Center for Environmental Forensic Science, in a statement.
Drawing connections between the separate seizures of ivory made at ports that were thousands of miles apart can create a trail of evidence and strengthen cases against those arrested for poaching and smuggling the tusks.
This study builds on previous work, published by Wasser and his colleagues in 2018, which showed tusks from the same elephant were often separated and smuggled in different shipments before being seized. These identifications linked the trafficking networks that smuggled ivory from three African port cities in Kenya, Uganda and Togo.
The new research broadened the DNA analysis to find elephants that were related in some way, including parents, offspring and siblings. Drawing connections between families of elephants, rather than trying to match individual tusks, helped the researchers understand the scope of the trafficking network.
The three networks established in the 2018 study "are involved with many more seizures and more connected to each other than previously discovered," according to the new paper.
"If you're trying to match one tusk to its pair, you have a low chance of a match. But identifying close relatives is going to be a much more common event, and can link more ivory seizures to the same smuggling networks," Wasser said.
Special Agent John Brown, study coauthor and a criminal investigator with US Homeland Security Investigations, has worked on environmental crime issues for more than 25 years. The forensic analysis in the study can provide "a roadmap for far-reaching multinational collaborative investigations," Brown said.
The tusks came from both forest elephants and savannah elephants. Forest elephants represent about 6% of the remaining African elephant population and live in the humid forests of West Africa and the Congo Basin. Based on the tusk data from the seizures, tusks were heavily poached from Gabon and Republic of the Congo.