Research & Impact
Tracking and conserving endangered wild turtles
Prof Jonathan Fong in the Science Unit uses new eDNA techniques to track freshwater turtles.
Freshwater turtles are going extinct across Asia because of the food and pet trade. In addition to being an important symbol in Chinese culture, turtles play an important role cycling nutrients in an ecosystem. Locating and protecting the wild populations is urgent, yet the traditional method of using traps takes a lot of time and energy, and has a low probabilityof success — like fishing in a large lake with few fish.
New eDNA techniques to locate turtles
“Hong Kong provides a unique conservation opportunity because turtle populations still exist in the wild,” said Prof Jonathan Fong, Assistant Professor in the Science Unit, who has started a four-year research project supported by the General Research Fund and the Early Career Scheme. He will use new environmental DNA (eDNA) techniques to track the existence of freshwater turtles in Hong Kong.
Compared to trapping methods, the eDNA method is described by Prof Fong as faster, cheaper and more sensitive for detection. All living things naturally release their cells (such as skin, gametes, faeces and blood) into the environment. This eDNA can be extracted, which becomes a clue of an organism’s existence and even quantity in the area. Prof Fong collects water samples, filters out the cells, and uses a standard laboratory technique called polymerase chain reaction to see if turtles live in the area. “Studies have validated eDNA approaches for many aquatic vertebrates, including turtles. The eDNA approaches have been used in other countries but have not been widely adopted in Hong Kong. My objective is to refine existing eDNA methods to locate, monitor and protect Hong Kong’s freshwater turtles,” said Prof Fong.
Conservation of native species
Prof Fong is particularly interested in locating Hong Kong’s five native species, namely the Golden coin turtle, Big-headed turtle, Chinese softshell turtle, Beal’s eyed turtle and Chinese pond turtle. The data will be used to facilitate future studies and provide baseline data for long-term monitoring. Additionally, he will track the existence of Red-eared sliders (Trachemys scripta elegans), a species native to North America that is invasive to Hong Kong. Since Red-eared sliders often compete with native species and push them to extinction, analyzing their eDNA will allow Prof Fong to track their spread and understand its impact on native species.
In the coming three years, Prof Fong will collect water and soil samples from approximately 50 sites in Hong Kong’s rivers and lakes. The samples will be processed in the new Biodiversity and Environmental Research Laboratory on campus. “One advantage of studying eDNA is that you don’t have to be an expert in science to collect the samples. I’m hoping to involve students in this project so as to give them hands-on experience of doing scientific research,” said Prof Fong. This is the first research project benefited from the establishment of the new laboratory.
Application of research outcomes
After consolidating his research data, Prof Fong will work alongside governmental and non-governmental organisations such as Agriculture, Fisheries and Conservation Department, Kadoorie Farm and Botanic Garden, and World Widlife Fund to develop appropriate conservation strategies.
Apart from protecting the habitats of turtles in Hong Kong, the research project will demonstrate the utility of eDNA for turtle conservation and serve as a model that can be scaled up to study endangered turtles across China, Asia and the rest of the world.
“I have always loved living things. I was the type of kid who would go outside to watch spiders build webs and lift up rocks to see what was underneath. Turtles have always been interesting to me because I was always amazed that they carry their home and protection with them wherever they go,” shared Prof Fong.