Biologists Use Tracking Devices to Uncover Early Life of Florida's Loggerhead Turtles

Biologists have used small, solar-powered tracking devices to find how Florida's loggerhead turtles spend the first few years of their life. The study challenges few commonly held notions about the turtles' infancy.

The loggerhead turtle is the most common sea turtle found in the state. These turtles nest April through September. Young loggerhead turtles begin life with a frantic race to the sea and disappear for two to three years before coming back to the beach as juveniles.

Zoologists call the first few years of the turtle's life as the "lost years" because very little is known about what happens to these turtles after their frenzied rush to the sea. The study findings challenge long-held theories of turtle behavior.

For the study, researchers at University of Central Florida, Florida Atlantic University, University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science, and University of Wisconsin attached small, solar-powered satellite tags to 17 young turtles. The turtles were tracked for 27 to 220 days.

"Before this study, most of the scientific information about the early life history of sea turtles was inferred through genetics studies, opportunistic sightings offshore, or laboratory-based studies," said Kate Mansfield, a Central Florida biologist, lead author of the research, according to a news release. "With real observations of turtles in their natural environment, we are able to examine and reevaluate existing hypotheses about the turtles' early life history."

According to a popular theory, loggerhead turtles travel with North Atlantic subtropical gyre and drift in loops around the Atlantic. The current study showed that these turtles stray away from the oceanic current.

Also, these turtles come up the oceanic surface quite often and seek refuge in Sargassum, which is a type of seaweed.

"We propose that young turtles remain at the sea surface to gain a thermal benefit," Mansfield said in a news release. "This makes sense because the turtles are cold blooded animals. By remaining at the sea surface, and by associating with Sargassum habitat, turtles gain a thermal refuge of sorts that may help enhance growth and feeding rates, among other physiological benefits."

The study is published in the journal, Proceedings of the Royal Society B.

Fun fact: The sea turtle shown in the movie "Finding Nemo" is called the Pacific Green Sea Turtle and can be found along the coasts of Alaska to Chile. In the movie, Crush, the turtle, is seen riding the East Australian Current (EAC).

Previously, researchers at James Cook University, Queensland, had tracked Australia's loggerhead turtles to find that these turtles use South Pacific gyre to reach Peru and then ride down the EAC to reach the coast of eastern Australia.