Sea turtles are mostly observed as either hatchlings or adults. A new study investigates what happens to young turtles after they head out to open waters, shedding light on the "lost years" they spend out at sea.
In a study published in the journal Current Biology, researchers from the National Oceanic and Atmospheric Administration and the University of Central Florida tagged green and Kemp's ridley turtle toddlers caught in the wild along the Gulf of Mexico, tracking 44 turtles by satellite for two to three months.
While they only obtained a glimpse of those lost years, it still gave researchers enough information to show that the sea turtles were not simply going with the flow of the current.
Once sea turtles hatch and head for the water, their movements show different paths from passive drifting. The research team used modeled and observed conditions in ocean currents and employed carefully designed buoy drifters for comparison. The researchers found that in the first few days out in the water, sea turtles can have up to a 125-mile difference in distance from drifters.
What's even more remarkable is that in almost every instance, the young sea turtles swam in such a way that they always reached or stayed in favorable ocean habitats.
"The results of our study have huge implications for better understanding early sea turtle survival and behavior, which may ultimately lead to new and innovative ways to further protect the imperiled animals," said Kate Mansfield, Marine Turtle Research Group director at the University of Central Florida and an author of the study.
The researchers are excited about the findings as this is the first time that drifters were released with small neonate or yearling sea turtles caught in the wild, which allowed them to directly test out the "passive drifter" hypothesis. They discovered that even the slightest degree of active orientation or swimming can spell the difference in how sea turtles disperse in the water.
Previous studies have suggested that at least some hatchlings spend their time in mats of seaweed called Sargassum, where they find shelter after entering the water. Otherwise, sea turtles were believed to simply follow ocean currents, not playing active roles in plotting out their destinations.
Every species of sea turtle is either threatened or endangered, so knowing how they move once they are in the water will have a hand in protecting them.
Photo: Jan Smith | Flickr
