Illegal ivory DNA testing links several ivory shipments to the same resellers

International trade in elephant ivory has been illegal since 1989, but the number of African elephants continues to decline. In 2016, the International Union for the Conservation of Nature said that ivory poaching was the main reason for the appalling loss of about 111,000 elephants between 2005 and 2015 – their total number estimated at 415,000.

In an article published on September 19 in the journal Scientists progressAn international team led by scientists at the University of Washington reports that DNA testing results of large seizures of ivory by law enforcement have linked several ivory shipments over the last three years. from a handful of African ports. The researchers linked these ivory shipments after developing a rigorous DNA sorting and testing regime for tusks in different ivory shipments. This method allowed scientists to identify pairs of tusks that had been separated and shipped in different shipments to different destinations around the world, but which had been shipped from the same port, almost always within 10 months of each other, with high geographical overlap. origins of the defenses in the corresponding consignments.

"Our previous work on DNA testing of illegal ivory shipments has shown that the major" poaching "points for elephants in Africa are relatively small," said Samuel Wasser, director of the Center for Conservation Biology and professor of biology. . . "Now, we have shown that the number and location of the major smuggling networks of these large ivory shipments out of Africa are also relatively few."

Using this protocol, the team identified what appears to be the three largest ivory smuggling cartels in Africa, based in Mombasa, Kenya; Entebbe, Uganda; and Lome, Togo. Out of 38 major ivory shipments analyzed, the team was able to link 11 of these shipments by identifying pairs of tusks that had been separated after poaching, but shipped from the same port during the 2011-2014 period when the traffic was at its peak.

Large expeditions currently dominate the illegal ivory trade. According to a 2013 PLOS ONE study, about 70% of ivory seizures made between 1996 and 2011 were made on large shipments of at least half a metric tonne, or about 0.55 tonnes. Linking several large ivory shipments to the same smuggling networks will help establish evidence against the cartels responsible for most of the illicit trade and smuggling of ivory, Wasser said. These efforts could add multiple counts of trafficking to smuggling leaders, who are most often judged for unique, high-profile and sometimes controversial events; The recent acquittal of Feisal Mohamed Ali in Kenya is an example.

"We reveal links between what would otherwise be isolated ivory seizures – linking seizures not only to specific criminal networks operating in these ports, but to poaching and transport networks that carry defenses to hundreds of thousands of people. kilometers of these cartels, "said Wasser. "This is an investigative tool to help officials track these networks and gather evidence for criminal cases."

Wasser and his team had already developed DNA tests on large ivory shipments to identify the most targeted African elephant populations by poachers. To do this they created a "genetic reference map" of elephant populations in Africa, using DNA samples extracted mostly from elephant dung. Then, the team sampled the ivory of the elephant tusks seized by law enforcement and extracted DNA from it. The researchers linked the key regions of the ivory DNA samples to the genetic reference map, which allowed them to identify the region from which the elephant was coming from, often about 300 kilometers or about 186 miles. In a 2015 article published in Science, they announced that most of the seized defenses came from two "poaching hot spots" on the continent based on these DNA analyzes.

In conducting these analyzes, Wasser and his team developed a protocol to represent hundreds of defenses in a representative way as efficiently as possible.

"We have neither the time nor the money to collect samples and extract DNA from each defense," Wasser said. "We had to find a way to take only a fraction of the defenses in a cargo, but this method was also to allow us to see the diversity of elephants poached in this cargo."

In each large ivory seizure, they identified the pairs by sorting the defenses by the diameter of the base, the color and the line of the gums, which indicates where the lip was resting on the defense. . This allowed the researchers to extract DNA from a single defense in the pair. Using this sorting approach, Wasser and his team noticed that many tusks in large expeditions were orphans. The defense of the partner was not present. But comparing DNA samples from tusks between 38 large confiscated ivory shipments from 2011 to 2014, they compared 26 pairs of tusks on 11 shipments, even though they only tested on average. About one third of the defenses of each seizure.

"There is so much information in an ivory seizure – so much more than what a traditional survey can reveal," Wasser said. "Not only can we identify the geographical origins of poached elephants and the number of populations represented in a crisis, but we can use the same genetic tools to link different seizures to the same underlying criminal network."

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More information:
S.K. Wasser el al., "Combating Transnational Organized Crime by Linking Multiple Large Seizures of Ivory to the Same Reseller", Scientists progress (2018). DOI: 10.1126 / sciadv.eaat0625, http://advances.sciencemag.org/content/4/9/eaat0625