A database with the DNA of sea turtles to identify the centers of poaching and illegal shell trafficking



  • Hawksbill turtles, a critically endangered species, have been hunted for centuries for the designs on their shells, which are used to make jewelery and special objects.
  • Exploitation and trade have pushed this species to the brink of extinction; although the killing and trade of these turtles or their body parts are banned internationally, the continuous demand continues to fuel their illegal trafficking.
  • Scientists hope that the activation of a new database containing the DNA of all the turtles on the planet, combined with forensic techniques based on wildlife DNA, could turn the situation around.
  • This new resource, called ShellBank, will allow authorized authorities to trace the place of origin of turtles from products made from their shells, in order to severely crack down on poaching and illegal trafficking in these areas.

A hawksbill turtle's protective shell is also, in some respects, its greatest weakness. The splendid patterns that decorate it and the thickness that makes it suitable for carving make it the most popular material sought after for centuries to create all types of tortoise shell objects, from jewels and pendants to eyeglass frames, up to an entire genre of the Japanese craft called bekko . Although the trade of all these products is currently prohibited by CITES, the Convention on International Trade in Endangered Species, the continued demand fuels illegal trafficking which is pushing the already critically endangered species to the brink of extinction.

So far, poachers and unscrupulous traders have managed to evade the law because it is difficult to trace the geographical origin of the thousands of turtle shell objects that are confiscated every year around the world. However, thanks to the activation of a new database containing sea turtle DNA, called ShellBank, the situation could be reversed.

ShellBank comes at just the right time. Scientists believe that over the last 180 years, humans have killed around 9 million hawksbill turtles ( Eretmochelys imbricata ), mostly for their shells. 

ShellBank is a WWF-led initiative in collaboration with government agencies, non-profit academic institutions and communities. It is billed as the first global, accessible repository of sea turtle genetic data that aims to enable authorities to crack down on poaching and illegal trade while helping researchers monitor turtle population dynamics. marine.

“In the past, this data had to be extracted from various publications and stored in individual researchers' personal spreadsheets,” Michael Jensen, marine species genetics coordinator for WWF Australia, told Mongabay. The DNA database collects genetic data from three main sources: turtle shell products, turtles at nesting sites; turtles at sea, including specimens in search of food and by-catch from fishing vessels.

By extracting DNA from contraband products, authorities will be able to use the information contained within ShellBank to trace the nesting location of the killed turtle. In fact, although they are also caught at sea, sea turtles are much more vulnerable on land, in the places where they nest. According to the WWF, once the risky nesting sites have been identified, the authorities will be able to concentrate regulations and conservation measures in these territories to crack down on illegal hunting.

The approach is similar to methods used in DNA-based forensic investigations into other major conduits of illegal wildlife trafficking, such as ivory, rhino horns and tiger bones. Some of these methods have provided damning evidence to judicial investigations.

The process used by forensic science for sea turtles is based on the work of scientists who have studied turtles caught by mistake or stranded on the coast, and focuses, in particular, on the analysis of small discrepancies in the mitochondrial DNA that distinguish different breeding populations.

“It is well known that female sea turtles return to their place of origin to reproduce and lay eggs: this process is called natal homing,” Jensen told us. “As a result, populations have a distinctive genetic trait unique to each breeding site. By mapping the distinctive genetic trait of each nesting region, the origin of turtles sampled outside the nesting beaches can be determined.”

In 2021, Jensen and his collaborators, from Australia and the United States, demonstrated that , by applying these principles to DNA extracted from tortoiseshell objects, they were able to identify the breeding site of the unfortunate owners: in fact, they managed to tracing objects taken from markets in Papua New Guinea and the Solomon Islands and discovering that the nesting site was in the Solomon Islands, where subsistence harvesting of sea turtles for direct consumption is still legal.


Francesca Roncolato, WWF Australia, curates a selection of turtle shell objects received as donations

More recently, researchers used the ShellBank database to trace the origins of hundreds of objects collected in Australia between 2020 and 2021 thanks to a WWF campaign encouraging people to hand over tortoiseshell products to the authorities. About 60% of the objects sold were made of hawksbill turtle shells (the rest were made of plastic or made with the shells of other species of sea and land turtles): half of these were traced back to populations originating from the Pacific Ocean and of the Indian Ocean and a quarter to populations of the southwestern Pacific, while smaller quantities have been attributed to Malaysia, Japan and the Caribbean.

Jensen revealed that, initially, the work to establish the ShellBank database was focused on Asia Pacific, an important hub for the illegal trade in tortoise shell products and their demand: only between 2015 and 2018 in Indonesia, Malaysia and Vietnam, more than 1,000 items and large quantities of unprocessed shells were confiscated. It should be added that turtle population numbers are dangerously low: in fact, there are supposedly fewer than 5,000 females left in this region.

So far, researchers know the distinctive genetic traits of five breeding groups of Asian Pacific hawksbill turtles based at seven individual nesting sites. Jensen said the research team wants to triple these numbers by the end of 2022, working with researchers across the region to sample even more turtles and products made from their shells, and to build their genetic profiles.

 As the database expands, we will be able to reconstruct the origin of a population with ever greater precision.


In addition to new discoveries in the field of genetics, Jensen said he has great confidence in the recent political commitment, worldwide, to combat the illegal trade in turtles. In fact, earlier this year, Cambodia, Myanmar, the Philippines and Vietnam supported a regional action plan dedicated to the protection of this species as part of their commitment to the Convention on Migratory Species. In the same period, following a severe ban on turtle shell products, the now decimated hawksbill turtles in the Seychelles have recovered.

“If the illegal trade in tortoiseshell products proceeds unchecked, it will continue to put pressure on the smallest and most vulnerable populations,” Jensen says. “We are confident that projects like ShellBank will help put an end to the illegal trafficking of turtle shell products and provide hawksbill turtles with the protection they need for their recovery.”