DNA testing lays bare the networks of illegal ivory trade

A team led by scientists at the University of Washington and special agents with the US Department of Homeland Security has found genetic connections across ivory shipments seized by officials over the years. They have tested the captured material, some 11 tonnes, and uncovered “an even higher degree of organisation” among ivory smuggling networks than was known before.

The paper, “Elephant genotypes reveal the size and connectivity of transnational ivory traffickers,” was published in the journal Nature Human Behaviour. The scientists and special agents have gathered together more than 4,000 African elephant tusks from 49 different ivory seizures made in 12 African nations over a 17-year period, and tested their DNA.

According to lead author Samuel Wasser, a UW professor of biology and director of the Center for Environmental Forensic Science, exposing the connections among separate ivory seizures – made at African and Asian ports which were separated by thousands of miles – will likely boost evidence against the criminals arrested for elephant poaching and ivory smuggling, and strengthen prosecutions of the responsible transnational criminal organisations.

“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,” says Wasser.

There are two elephant species in Africa: savannah (Loxodonta africana) and forest (Loxodonta cyclotis) elephants. “Following population declines over several decades due to poaching for ivory and loss of habitat, the African forest elephant (Loxodonta cyclotis) is now listed as Critically Endangered and the African savanna elephant (Loxodonta africana) as Endangered on the IUCN Red List of Threatened Species.”

While the ivory seized by the authorities mean that the elephants they originated from are already dead, the tusks can still provide important information by shedding light on poaching, shipment activities and the connections between traffickers.

Wasser and his collaborators had written a previous paper that was published in 2018 in Science Advances. They were able to pinpoint two tusks from the same elephant that had been separated and smuggled in different shipments before being intercepted by the authorities. This allowed law enforcement to link those seizures to the same trafficking networks.

Thanks to the researchers, it was revealed that traffickers used three African ports to smuggle ivory out of: Mombasa, Kenya; Entebbe, Uganda; and Lome, Togo.

In the current research, Wasser and his colleagues cast a wider net: the DNA analysis this time includes tusks of elephants that were close relatives, such as parents, offspring, full siblings and half-siblings.

“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,” says Wasser.

The researchers write that “Analyses are drawn from 4,320 savannah (Loxodonta africana) and forest (L. cyclotis) elephant tusks, sampled from 49 large ivory seizures totalling 111 [tonnes], shipped out of Africa between 2002 and 2019.”

“Identifying close relatives indicates that poachers are likely going back to the same populations repeatedly — year after year — and tusks are then acquired and smuggled out of Africa on container ships by the same criminal network,” says Wasser. “This criminal strategy makes it much harder for authorities to track and seize these shipments because of the immense pressure they are under to move large volumes of containers quickly through ports,” he adds.

“Results suggest that individual traffickers are exporting dozens of shipments, with considerable connectivity between traffickers operating in different ports,” the researchers note.

Thanks to the researchers' analyses, the genetic data reveal a handful of interconnected smuggling networks. These large ivory shipments mainly depart from Kenya, Uganda and Nigeria.

Spreading out the DNA research from beyond individual animals to close relatives, the team was able to link seizures from a dozen countries in Central and West Africa, all the way from Cote d’Ivoire (Ivory Coast) on the Atlantic Ocean to Mozambique on the Indian Ocean.

The researchers were also able to identify how ivory shipment ports changed over time. In the 2000s smuggling networks used Tanzania; then they shifted their operations to Kenya and Uganda. Most recently ivory shipments were going out of Angola and the Democratic Republic of the Congo (DRC). In West Africa, the change was from Togo to Nigeria.

“By linking individual seizures, we’re laying out whole smuggling networks that are trying to get these tusks off the continent,” Wasser says.

Even though one illegal shipment of ivory is enough to prosecute criminals, linking multiple shipments thanks to genetic links found in the contents would lead to stronger cases and more severe penalties.

The criminals behind one ivory seizure would have been prosecuted solely for that seizure. But the genetic evidence by Wasser and his team could strengthen prosecutors’ hands.

“These tools provide a framework to combine evidence from multiple investigations, strengthen prosecutions and support indictment and prosecution of transnational ivory traffickers for the totality of their crimes,” the researchers write.