How Environmental DNA Is Helping Sea Turtle Conservation

As animals travel throughout the environment, they leave behind their DNA in a variety of ways. Whether it’s skin cells and bodily fluids left in the track of a nesting sea turtle, or whale feces floating on the surface of the ocean, or fish scales in a lake, all contain the animal’s DNA. By collecting soil, water, and even air samples, scientists can extract this environmental DNA (eDNA) to study a wide variety of wildlife. One team from the University of Florida’s Whitney Laboratory in St. Augustine is analyzing eDNA to learn more about sea turtles and help protect them.

In April 2022, Dr. David Duffy and his team at Whitney Lab were the first to successfully obtain eDNA of sea turtles from samples of ocean water and beach sand. The team developed specific eDNA analysis techniques to:

• Identify both green and loggerhead sea turtles.
• Determine their area of origin and their subpopulation.
• Verify areas where sea turtles are living.
• Determine how their range and population numbers are changing.
• Identify sea turtle pathogens such as fibropapillomatosis (FP).

Studying eDNA versus traditional DNA collection directly from the animal has several advantages. Since the samples are collected after the sea turtles have nested, researchers do not have to stress nesting females or emerging hatchlings to take blood and tissue samples. Also, after the eDNA is collected and properly stored, it is stable for weeks to months. This allows the researchers to receive samples collected from different locations all over Florida. Furthermore, citizen scientists can be trained to collect the samples which makes it more cost effective.

In the future, the Whitney Lab team is planning to use eDNA to determine how many sea turtles live in specific areas and to analyze their genetic diversity (to help conservation efforts). They also are hoping that eDNA can help identify variants of the FP virus so they can track the spread of the disease and possibly develop treatments.

Sources:

• Wikipedia: “Environmental DNA”
• University of Florida News website: “Sea Turtle Conservation Gets Boost from New DNA Detection Method” (May 2022)
• University of Florida video: “UF Researchers Are the First to Collect Animal DNA from Beach Sand” (May 2022)
• Wiley Online Library: “Detection and Population Genomics of Sea Turtle Species Via Noninvasive Environmental DNA Analysis of Nesting Beach Sand Tracks and Oceanic Water” (April 2022)

Additional Information:

Use these links to learn more about the study of eDNA.

• Science News: “Stray DNA is All Around Us. It Could Revolutionize Conservation” (November 2024)
• ASBMB Today Magazine: “Environmental DNA Is Everywhere” (April 2024)
• PBS NOVA: “Hunt for the Oldest DNA” (February 2024)