Detecting Leatherbacks From a Water Sample Alone

This May, CFF joined collaborators in North Carolina to collect environmental DNA (eDNA) samples in waters where leatherback sea turtles forage. The goal: to test whether a turtle's presence can be confirmed from a water sample alone — no sighting required.

Every animal leaves traces of itself behind. Skin cells, mucus, and waste all carry DNA, and when that material ends up in the water, it can be collected and analyzed. That's environmental DNA, or eDNA — and it offers a way to detect an animal without ever seeing it.

That matters for leatherbacks, which are notoriously hard to study. They travel vast distances, dive deep, and surface unpredictably, so finding them by eye or boat is slow and difficult. Screening a water sample for leatherback DNA could sidestep that problem entirely: if the genetic traces are there, the turtle was too.

The May trip was a step in testing how well the method works in the field. If it proves reliable, eDNA could become a powerful, non-invasive tool for tracking leatherbacks across their range — one of the ocean's most elusive species, monitored from nothing more than the water it swims through.

The work was conducted in collaboration with Acbotics, NEFSC, and SEFSC.

Photo taken under ESA Permit #23639