Studying our hawksbill population so we can conserve them
I study the population genetics of hawksbill turtles in Singapore and within the Indo-Pacific region. Having a good understanding of genetic diversity of our hawksbill population and their relationship with other hawksbills would really aid in their conservation management.
Genetic diversity: the total number of genetic characteristics in the genetic makeup of a species, individual differences within a species (eg. the different breeds of dogs)
How does genetics contribute to conservation?
A large male hawksbill turtle photographed around the reefs of Pulau Satumu, Singapore. (Photo by Stephen Beng)
Here is an example illustrated in the video below. Imagine 2 populations of sea turtles, of which one is extremely diverse compared to the other. A disease outbreak strikes both population and the sea turtle with the green trait is especially vulnerable to this disease, wiping out all of them from both populations. Eventually the population that had an abundance of turtles with the green trait will be at a higher risk of extinction.
A gif to illustrate the importance of understanding genetics for conservation management. (© Regine Tiong)
Having a genetically diverse population is necessary for adapting to changing environments by serving as a safety net against extinction. A higher degree of genetic diversity of a population will act as an indicator of a healthy growing population. Populations with low diversity are at a higher risk of extinction as they can be easily wiped out by diseases or environmental factors that target certain traits. Hence, genetics play a crucial role in conservation management by allowing us to focus on more isolated populations with low diversity and prioritise the distribution of limited resources for conservation.
A baby hawksbill hatchling taking its first swim in Singapore waters (Photo by Stephen Beng)
Population genetics examines the genetic variation within a population and helps to identify different populations. Differentiating populations is especially important in the marine environment where the seas are interconnected, and population boundaries are not clear. This is key especially for the hawksbill turtle, as gene flow is found to be somewhat restricted within each population, meaning that hawksbill turtles tend to mate with another individual from the same population. By being able to identify their populations and the geographical distributions of their nesting and feeding grounds, we will be able to establish more effective marine protected areas and reduce the threats to our turtles.
Through my preliminary study of the genetic diversity of hawksbill turtles nesting on Singapore’s beaches in 2019, I discovered that there were only 3 maternal lineages contributing to 9 sampled nests. Despite being a small nesting ground for hawksbill turtles, 2 out of the 3 lineages were unique to Singapore and could be critical for the conservation of their genetic diversity. I also studied their genetic relationships with hawksbill turtles within the Indo-Pacific region. The hawksbill turtles nesting in Singapore belong to a single population of low genetic diversity, which included turtles nesting in Malaysia, Northern Australia and some archipelagos in the Indian Ocean. My results also suggest that our nesting turtles nesting could have genetically originated from Malaysia and could be categorised under one management unit for conservation.
The release of Schooling, who was a premature hawksbill hatchling found in a ruptured egg and was cared for by the Wildlife Reserves Singapore’s veterinary team (Photo by Stephen Beng)
In the upcoming works of my research, I am assembling the first ever whole genome sequence of the hawksbill turtle and I plan to study the population genetics of hawksbill turtles in the Indo-Pacific region using whole genomes. This would help us better understand the population structure of the hawksbill turtles nesting in Singapore and aid in defining their conservation management unit to better protect them.