UCF marine biologist Kate Mansfield and her ongoing work with endangered sea turtles is the focus of a PBS episode of “Changing Seas,” which debuts at 8 p.m. today on WPBT2.

The show focuses on Mansfield’s breakthrough research tracking and discovering what young sea turtles do after they head to sea. The episode, called “Sea Turtles: The Lost Years,” will be available for viewing on https://youtu.be/HZW2MaVuSVk after it airs tonight in Southern Florida. The program will be distributed to public television stations around the country in November.

A PBS crew spent several days filming Mansfield as she tagged sea turtles with satellite trackers in the ocean this past year. Mansfield’s work shows that turtles are active swimmers, display certain feeding behavior and are not passive drifters as researchers previously believed.

In March 2014, Mansfield’s field research demonstrated that several long-held assumptions for sea turtles were incorrect, and since then she’s worked with other scientists around the world to test the theory on species of sea turtles. So far it appears all of the turtles studied are active swimmers, not drifters.

“There’s still so much we don’t know,” Mansfield said. “That’s why the time period is referred to as the lost years. It’s exciting to be shattering some assumptions. We need to know what the turtles are actually doing if we expect to keep them around for future generations to enjoy.”