When are leatherback turtles mating? Check the DNA.

Using DNA to understand turtle mating patterns

July 5, 2019 

The DNA fingerprints of turtles

To answer the biggest questions about the world’s largest turtles, scientists have to get small: DNA small. Scientists at the National Oceanic and Atmospheric Administration are using DNA fingerprinting to find more information about leatherback sea turtles’ reproduction patterns and family groups. NOAA scientists are using similar methods that 23andMe and Ancestry use to tell us about our genealogy, except on leatherbacks.

“Hidden in a hatchling’s DNA is its entire family history, including who its mother is, who its father is, and to what nesting population it belongs,” says NOAA scientist, Peter Dutton, Ph.D. “By applying DNA fingerprinting, we can answer many elusive questions about sea turtle mating and reproduction patterns.”

When can leatherbacks start reproducing?

NOAA scientists are hoping to crack the code on how old leatherback sea turtles have to be before they can reproduce. Female leather backs lay their eggs on the beach in what are called clutches—a nest in the sand. NOAA scientists are taking the “fingerprints” of freshly-hatched leatherbacks as they make their way from the clutch to the ocean. These “fingerprints” are recorded and will be compared with first-time nesting leatherbacks. When scientists find a genetic match, they will have evidence on how long it takes a leatherback to mature.

Although we still have many questions about the leatherback sea turtles, there are some things we do know. Leatherbacks are the only turtle that don’t have a hard shell. Instead their shell looks like leather—hence the name. We also know that the temperature of the sand has an effect on the gender of hatchlings. The warmer the sand is, the more females there will be in a clutch. NOAA scientists may be able to gain insight on how global warming will affect the leatherback population overtime.

Leatherback sea turtles nest all over the world, but it is rare to see them in North Carolina. In 2018 a leatherback nested in North Carolina at Fort Fisher for the first time in six years, according to the News & Observer. We aren’t sure when they will come back to our state but with the help of NOAA’s scientists, we might just find out. 

—Zachary O. Perry 

 Zachary Perry is a writing intern for the Sci NC team, and a senior at UNC Wilmington studying professional writing.