New DNA test aims to tackle illegal trade in precious red coral

  • There is a significant illegal trade in valuable red corals, family Coralliidae, but law enforcement currently struggles to distinguish the commonly traded taxa.
  • The demand for corals for jewelry and decorative items has depleted some populations of these ecosystem engineers.
  • Scientists recently developed a new DNA test that could help determine if a coral object belongs to a taxon subject to international trade regulations.
  • They express the hope that the new method will “contribute to better control of international trade” and inform buyers about the species they are buying.

In a sterile room, Bertalan Lendvay wields an electric drill that projects tiny flakes of precious coral skeletons. Lendvay, a research associate at the Institute of Forensic Medicine at the University of Zurich in Switzerland, regularly works for the police at human crime scenes. But he has spent the past four years tinkering with a way to use his expertise to help law enforcement catch smugglers trying to profit from a legal coral trade worth hundreds of millions of dollars. per year.

Precious corals, also called red corals, are colonies of jellyfish-like sea creatures whose common skeleton resembles a shrunken tree stripped of its leaves and colored salmon-pink to dark vermilion. The deeper their crimson blush, the more money they fetch for sellers.

Eight species of precious corals in the family Coralliidae are most commonly found in international trade. Four are listed in Appendix III of CITES, the global wildlife trade convention, which requires that items traded internationally must be accompanied by export documents certifying that they were obtained. legally; four are not listed at all. But here’s the crux for law enforcement: Some CITES-listed and non-CITES-listed precious red coral species are nearly identical in color, especially after being polished into beads or carved into a figurine. Law enforcement cannot tell them apart.

Eight species of precious corals in the family Coralliidae are most commonly found in international trade. Image by RamiAubourg via Wikimedia Commons (CC BY-SA 4.0).

Lendvay and several colleagues have developed a new DNA test called Coral-ID that could help change that. Their study describing the new method was published in the May issue of the journal Forensic Science International: Genetics.

For the study, the Lendvay team tested Coral-ID on 20 precious coral objects seized by customs authorities when imported into Switzerland between 2009 and 2017. They drilled into the bottom of the objects or into existing holes to discreetly collect a few milligrams of coral. . Next, they used a technique originally developed to study ancient bones to extract the coral’s genetic information from the material, identifying a specific gene in mitochondrial DNA called mtMutS.

Lendvay and colleagues showed that mtMutS can serve as a genetic barcode; they identified differences in its sequence unique to six distinct taxonomic groups within the family Coralliidae. Using mtMutS, Coral-ID identified the taxonomic group of 13 of the 20 objects. For six objects with CITES documentation, Coral-ID identified a taxon different from that listed by the importer. The remaining seven unidentified objects were either too old or provided specimens too contaminated to be analyzed.

“The results are clear,” Lendvay told Mongabay. “I hope this method will contribute to a better control of international trade and that companies will become aware of the materials they use.”

Corallium japonica
Corallium japonica on display at the National Museum of Nature and Science, Tokyo, Japan. Image by Daderot via Wikimedia Commons (Public domain).

Red coral hotspots are located in the western and central Pacific Ocean, including the seas of New Caledonia, Taiwan, Japan, and the Hawaiian Islands, as well as in the Mediterranean Sea and Ocean Atlantic. The international coral trade – the “coral route” – dates back to the early 1st millennium, when people valued red coral because they believed it had powerful sacred properties. The Romans hung branches of coral around the necks of children to ward off danger, and the Egyptians decorated the tombs of pharaohs with them. Early Christians believed that red coral symbolized the blood of Christ. In Iran, people believed that coral amulets defend ships from raging storms. In Buddhism, precious coral adorned religious statues.

Red corals quickly became an iconic symbol of protection – an association that ironically reduced their numbers. The IUCN, the world conservation authority, lists a species, Corallium redas endangered. And according to the United States The National Oceanic and Atmospheric Administration“commercial beds known to corallium declined to less than 20-30% of their historical baseline. The industry is often described as “booming and declining” as coral populations, once discovered, quickly deplete. Intensive harvesting has the effect of draining coral populations of their genetic diversity and large mature colonies, leaving only small immature colonies to remain. The colonies grow so slowly – at a rate of 1 millimeter in diameter per year – that there is no feasible way to cultivate them commercially.

These days, red coral jewelry has lost its religious luster, but not its cachet, with high-quality specimens costing $10,000 per kilogram (about $4,500 per pound). Customs authorities, mainly in the United States, confiscated approximately 67,400 pieces of precious coral weighing in total 870 kilograms (1,918 pounds) between 2008 and 2015, according to a report on the CITES Trade Database by the Food and Agriculture Organization of the United Nations. But this probably does not reflect all the specimens traded illegally, let alone those harvested illegally.

In 2007, a year before the four precious coral species were added to CITES Appendix III, the United States lobbied to add all corallium genus in Appendix II, which would have imposed even greater trade restrictions. This proposal came close to being accepted, but its opponents prevailed, with the most vocal among them arguing that precious coral species are too difficult to tell apart.

Red coral jewelry.
These days, red coral jewelry has lost its religious luster, but not its cachet, with high-quality specimens costing $10,000 per kilogram (about $4,500 per pound). Image courtesy of the Swiss Gemological Institute (SSEF).

This is where Coral-ID comes in.

“This type of DNA test is essential for several reasons,” Mary Burnham Curtishead of the forensic sciences branch and supervisor of the genetics unit in the United States National Fish and Wildlife Forensic Laboratory in Ashland, Oregon, Mongabay told.

“One of the reasons, of course, is to identify protected species that appear illegally in trade. Another is the idea of ​​monitoring what is showing up in trade so that resource managers can get information on what species are in trade, temporal changes in species diversity, and changes in abundance of species. different species that can be potential indicators. overexploitation,” said Burnham Curtis, who was not involved in the study.

However, the method has limitations. Coral-ID is not specific enough to narrow down the identity of a seized item to the species level in all cases. For example, it can genetically distinguish C. rubrum (not CITES) of other species of the genus, but he cannot say C. japonicum (CITES listed) from C.nix Where C. tortuosum (none of them are CITES listed).

“Coral-ID is a useful tool, but it’s not magic,” said Lorenzo Bramantimarine scientist at the French National Center for Scientific Research (CNRS) who was not involved in the study.

“It is a weapon to add to the fight against illegal trafficking.”

But Bramanti said he believed other interventions could be more effective than enforcing international trade restrictions. He called for more protections for coral habitats. Precious corals are ecosystem engineers, forming what Bramanti called “animal forests» that significantly improve the ecological functioning of a habitat. To restore populations of precious corals, it is not enough to regulate their trade, according to Bramanti. It also calls for protecting their homeland.

Banner Image: A bracelet with figurines carved from highly prized red coral. Walters Art Museum image via Wikimedia Commons (CC BY-SA 3.0).


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