Latest study reveals new genetic insights into Indonesia's critically endangered Hawksbill turtles

Posted on April, 30 2024

A ground-breaking study sheds new light on the genetic diversity of critically endangered hawksbill sea turtles, uncovering new and unique genetic variation across six nesting sites in Indonesia’s Java Sea.
The pioneering research led by IPB University marks Indonesia’s first comprehensive genetic analysis of hawksbill turtles, revealing five new genetically distinct population groups that were previously unknown to researchers and conservation practitioners.

"Our research indicates that hawksbill turtles in the Java Sea display remarkable genetic diversity, particularly on small islands. We believe that similar diversity patterns may be observed in other parts of Indonesia, given its abundance of small islands and dense coral reef habitats, but more studies are needed to understand their genetic variability,” said lead author Iqbal Sani, Master’s student in the Marine Science Programme at Indonesia’s IPB University (Bogor).

The study was made possible through collaboration among several universities and conservation groups in Indonesia and the wider region. In the study, researchers collected small tissue samples from nesting hawksbill turtles on isolated islands in the Java Sea. The samples were then shipped to the genetics laboratory at IPB’s Department of Marine Science and Technology, where DNA was extracted to examine the turtles' mitochondrial DNA d-loop, a key genetic marker. 

These findings offer a fresh perspective on how hawksbill turtles are genetically distributed, suggesting that the Java Sea region may have some of the highest genetic diversity for hawksbill turtles compared to other regions globally. 

“Since 1998, our team at YPLI/ELNA has been monitoring hawksbill populations across five locations in the Java Sea. In recent years, we started collecting tissue samples for genetic analysis, and it's fantastic to now collaborate with local universities on this crucial aspect. The genetic diversity we've discovered among hawksbill turtles in what might seem like a small area has been surprising. This information is vital for the conservation and management of these turtles and highlights the need for continued protection of individual nesting beaches", said Ema Herma from YPLI, one of the local organisations monitoring these populations.

Such unexpectedly fine scale population structure across relatively short distances revealed in this study emphasizes the importance of independently managing and developing localized conservation strategies. This would ensure management efforts are tailored to the specific needs and genetic contexts of each hawksbill turtle population.

Supported by ShellBank – the world’s first global database for marine turtle DNA - this study has filled a vital gap in marine turtle genetic data, contributing essential insight for turtle conservation and management.
“With more fine-tuned genetic data, we can empower conservationists and law enforcement agencies to pinpoint and combat threats such as overexploitation, bycatch, and the illegal trade of marine turtles more effectively,” said Christine Madden, WWF’s Global Marine Turtle Lead at WWF, Co-Founder of ShellBank, and one of the study’s authors.

As the first comprehensive genetic analysis of hawksbill turtles in Indonesia, the study highlights an urgent need for further research throughout Indonesia and Asia Pacific. Deeper understanding of marine turtle populations’ connectivity is essential for governments and communities to better protect this critically endangered species. 
The study was a successful collaboration between universities, conservation groups and communities including IPB University, Yayasan Penyu Laut Indonesia (YPLI), Everlasting Nature of Asia (ELNA), Oceanogen, ShellBank, University of Kyoto, and World Wide Fund for Nature (WWF).
Key Highlights
  • Unveiling Genetic Diversity: The research reveals significant genetic diversity, highlighting the existence of five new genetically distinct stocks or management units crucial for hawksbill turtle conservation.
  • Conservation Milestone: The study's findings reveal an unexpectedly high-resolution population structure across relatively short distances within Indonesia, underscoring the need for independently managed and protected hawksbill populations even within proximate geographical areas. This nuanced understanding of population differentiation emphasizes the importance of localized conservation strategies, ensuring that management efforts are tailored to the specific needs and genetic contexts of each hawksbill turtle population.
  • Collaborative Endeavour: The study exemplifies successful collaboration among various organizations, including Yayasan Penyu Laut Indonesia (YPLI), Everlasting Nature of Asia (ELNA), the University of Kyoto, the World Wildlife Fund (WWF), IPB University, and Oceanogen, all dedicated to the study and conservation of endangered hawksbill turtles.
Gabby Ahmadia, senior marine scientist at WWF sees a hawksbill turtle whilst surveying a reef in the Selat Dampier MPA, Raja Ampat, West Papua, Indonesia
© James Morgan / WWF-US
Huge schooling bumphead parrotfish (Bolbometopon muricatum) with a passing hawksbill turtle (Eretmochelys imbricata), Sipadan Island, Sabah, Malaysia.
© Jürgen Freund / WWF