New database helps trace marine turtle origins globally

Posted on 17 June 2024
Dr Greta Frankham drills into a tortoiseshell sample to extract genetic material for analysis; DNA data when entered into ShellBank could help trace where this turtle might have come from.
© Greta Frankham / Australian Museum

By Alexander Nicolas & Christine Madden

17 JULY 2024 If you were to travel for thousands of miles without the help of a map or GPS tracking device, do you think you would be able to navigate your way back to your point of origin? As unfathomable and difficult as that might sound, there are ancient creatures still alive today who have honed this unique ability to accomplish this incredible feat.

Marine turtles have the unbelievable ability to swim for thousands of miles after leaving the beach where they hatched from and find their way back when it is time to nest and lay their eggs. For more than 100 million years, marine turtles have covered vast distances across the world's oceans during their long lifetimes, leading to the creation of several genetically distinct marine turtle populations across each of the seven different species of marine turtle. Since all female marine turtles return to their natal (birth) beach to lay eggs, a genetic signature is passed down from mother to offspring, unique to each nesting region.

But, over the last 200 years, human activities have been impacting the survival of these ancient creatures. Over the last 30 years alone, at least 1.1 million marine turtles (not including shell products and eggs) have been illegally exploited in 65 countries
(Senko- Burgher et al., 2022). Of these, at least 22% were likely traded internationally. Global estimates of around 460,000 individual shell items were found offered for sale between 2017 - 2020 with substantial illegal markets still in existence (Nahill et al., 2020).

More than 85,000 marine turtles were caught as incidental bycatch worldwide between 1990 to 2008
(Wallace et al., 2010). It is estimated that around 80,000 turtles have been exploited legally and illegally each year over the past three decades (Senko-Burgher et al., 2022). And despite a global trade ban by the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) since 1977 and multiple policies that attempt to reduce bycatch and overexploitation of marine turtles, illegal trade of turtles, eggs, meat, and their parts has persisted.

One of the greatest challenges to tackling the illegal trade and take of turtles is the inability to identify which populations are being targeted and which are most at risk.

WWF is committed to reversing the decline of marine turtles and to recover their populations in the wild. To strengthen our efforts and many others working tirelessly to bring back turtle populations, we embarked on a mission to design a new and innovative global approach to track and trace turtles. Could tracking these genetically distinct populations hold the key to better addressing the threats marine turtles face?


Following the DNA trail

WWF created a new tool called ShellBank, which is the world’s first global traceability toolkit and global database for marine turtle DNA data. Initiated by WWF and supported by a core team of partners from the Australian Museum - Australian Centre for Wildlife Genomics, NOAA - Southwest Fisheries Science Center, and TRACE Wildlife Forensics Network, we have now taken ShellBank from pilot into practice. By extracting DNA from any marine turtle, turtle part, or product and running it through the ShellBank database, conservationists and law enforcers can now detect which populations are most at risk and make precise and targeted efforts to protect them. To celebrate World Sea Turtle Day this year, ShellBank’s database is now open-access and publicly available for data contribution from researchers, conservationists, and law enforcement agencies to help track, trace, and protect endangered marine turtles globally.

More than 13,000 samples from over 50 countries have been added to the ShellBank database, and it is already being put into action. Earlier this year, over 100 tortoiseshell items in Hong Kong’s seizure stockpile were sampled and analyzed by researchers from the University of Hong Kong, in collaboration with Hong Kong’s federal government and ShellBank. This was a key effort to better understand how to dismantle the illegal trade in marine turtles. Information, such as knowing where these marine turtles were sourced from, can help alert authorities to where marine turtles are being most rampantly taken. Additionally, for the first time in the Coral Triangle, local researchers and citizen scientists in Papua New Guinea and Indonesia have mapped seven previously unknown, genetically distinct populations of hawksbill turtles. In Indonesia’s Java Sea, a study revealed multiple unique genetic variations across just six closely situated nesting sites, surprising scientists with the diversity found in such a small area.

The lack of precise data on different, targeted marine turtle populations has been an obstacle for conservation efforts. ShellBank is a game changer in that it addresses this gap and helps governments, conservationists, and communities connect the dots to implement more targeted protection measures. The data can also enhance our understanding overall about how specific marine turtle populations forage, nest, and migrate, and whether neighboring populations interact with each other.

Marine turtles are fundamental to marine ecosystems and to cultures around the world. And the more that ShellBank grows, we will be able to better understand this fascinating, ancient animal and discover the missing pieces needed to ensure they are protected over the years to come.


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For more information, if you have data to contribute, or if you would like to support ShellBank, please visit www.shellbankproject.org or write to shellbank@wwfint.org.

About WWF
WWF is one of the world’s largest and most respected independent conservation organisations, with over 5 million supporters and a global network active in over 100 countries. WWF’s mission is to stop the degradation of the earth’s natural environment and to build a future in which humans live in harmony with nature, by conserving the world’s biological diversity, ensuring that the use of renewable natural resources is sustainable, and promoting the reduction of pollution and wasteful consumption. More: panda.org

Dr Greta Frankham drills into a tortoiseshell sample to extract genetic material for analysis; DNA data when entered into ShellBank could help trace where this turtle might have come from.
© Greta Frankham / Australian Museum Enlarge
Hawksbill turtle (Eretmochelys imbricata) swimming through a reef. Kimbe Bay, West New Britain, Papua New Guinea.
© Jürgen Freund / WWF Enlarge
WWF staff working on sea turtle in New Caledonia.
© Bastien Preuss / WWF-France Enlarge