Florida Researchers Sequence Environmental DNA for Sea Turtle Conservation

As climate change continues to impact ecosystems and animal populations across the globe, the urgency to find novel techniques that assist in protecting these species is higher than ever. Sea turtles are one such species, facing dangers such as habitat loss, disease, hunting, rising temperatures, bioplastic pollution and more. Since these creatures rely on multiple habitats, from the vast ocean waters to their preferred nesting beaches, the search for practical conservation tools to monitor the species’ growth has long remained a challenge.

To address this growing concern, researchers from the University of Florida, specifically UF’s Whitney Laboratory for Marine Bioscience and Sea Turtle Hospital, led a study investigating the environmental DNA, or “eDNA”, of several endangered sea turtle species along the coast. While eDNA was first utilized for extracting and analyzing DNA from microbes found in soil and water, scientists have since developed this technology to detect small amounts of genetic material via organisms’ skin, scales, hair, feces, or bodily fluids. 

“We wanted to test the boundaries of this technology, which hadn’t really been applied to sea turtles before and certainly not on sand,” said UF assistant professor of wildlife disease genomics, David Duffy. “This is a way to survey areas for elusive animals or species that can be hard to study otherwise. It’s essentially wildlife forensics.”

Before utilizing this technology out in the field, Duffy and his team refined their techniques with tanks and sand from turtles recuperating at the Whitney Laboratory. eDNA gathered from these turtles, plus those gathered from a network of volunteers collecting samples across the state’s beaches, indicated that the stored DNA from sand and water samples was stable for weeks to months.

“You don’t need to be a highly trained scientist to collect eDNA, which makes this technology a lot more democratic,” said Duffy. “This really opens up the ability to monitor wildlife non-invasively to a much wider pool of people.”

After testing their techniques at the Whitney Lab, Duffy and colleagues finally hit the shores. By gathering genetic material in the sand, researchers collected DNA “fingerprints” from endangered turtle species such as green turtles, known as Chelonia mydas, and loggerheads, or Caretta caretta. Their research, published in Molecular Ecology Resources, resulted in the first successful attempt at collecting animal eDNA from beach sand. These novel techniques introduce non-invasive tracing and monitoring of other kinds of endangered species, assisting in developing effective conservation strategies.

For both species’ eDNA, researchers were interested in investigating the presence or absence of the virus causing fibropapillomatosis, a form of cancer impacting nearly 50% of all green turtles along Florida beaches. This disease results in cauliflower-like tumors on the eyes, mouth, skin and internal organs, ultimately becoming so debilitating that it impacts their ability to hunt and swim effectively. eDNA shows promising potential at pinpointing where the virus’ spread and any mutations. The technique can also denote the virus’ concentration in tested water columns, giving researchers a better understanding of fibropapillomatosis’ origins and consequent spread among ecosystems.