Scientists have uncovered new details about sea turtle migrations in what could potentially be a breakthrough in the conservation of these endangered animals.
The study, published in The Journal of Experimental Biology, found that young loggerhead sea turtles use a "smart swimming" strategy to navigate the ocean waters as tiny hatchlings. By swimming only when they are in danger, and drifting at all other times, the baby sea turtles are able to conserve energy and migrate long distances, the researchers found.
The study used computer-based simulations that combined ocean currents and "virtual turtles" swimming for various period of time. The long-standing belief had been that sea turtle migration is based solely on ocean currents, but this study disproved that theory.
"Most researchers have assumed that, because ocean currents in some places move faster than young turtles can swim, the turtles cannot control their migratory paths," explains Kenneth J. Lohmann, a marine biologist at the University of North Carolina at Chapel Hill. "This study shows otherwise."
So what, then, guides the defenseless sea turtles on their epic journeys? Another recent study suggests that Earth's magnetic field, acting almost as "road signs," plays a large role in helping the animals "steer" through the ocean.
The paper, published in the Current Opinion in Neurobiology, summarizes a decade of research on sea turtle migrations and found that the animals are hard-wired from birth to migrate as an evolutionary response to escaping predators.
The findings have broader implications for the conservation of sea turtles, the authors say.
For instance, one common conservation method is to use wire cages to protect sea turtle eggs from predators like raccoons. However, these cages could interfere with the magnetic fields that sea turtles use for migration, the study found.
In addition, if one population of sea turtles were to become extinct, relocating other populations to different areas probably would be unsuccessful, because those sea turtles would be unfamiliar with the new location, making them unable to navigate the area.
Those conservation efforts are critical to the animals' survival. All sea turtles are listed as either threatened or endangered. In fact, only about one out of every 4,000 hatchlings in Florida survives into adulthood.