Scientists Crack a Mystery Surrounding Endangered Sea Turtles

By discovering where young sea turtles travel during years at sea, biologists hope they can better protect them.
(Photo: Mark Newman/Getty Images)
Apr 29, 2015· 1 MIN READ
Padma Nagappan is a multimedia journalist who writes about the environment, renewable energy, sustainability, agriculture, and biotechnology.

Hours after being hatched, baby sea turtles make their way to the ocean, and that’s the last people see of them until they return years later.

Scientists have long puzzled over where endangered turtles disappear to during these “lost years.” Now they finally have an answer: The young turtles swim hundreds of miles from their birthplace, far from the coastal waters biologists expected them to roam, according to a new study published in the journal Current Biology.

Marine biologists from the University of Central Florida and the National Oceanic and Atmospheric Administration said the discovery would help scientists predict what kind of risks sea turtles encounter during their travels as well as how to better protect them.

During an expedition to the Gulf of Mexico, Kate Mansfield, director of UCF’s marine turtle research group, and other marine biologists were surprised to find endangered Kemp’s ridley sea turtles some 800 to 900 miles from where they hatched. Scientists also discovered green sea turtles swimming 600 miles from their birthplace.

“NOAA’s interest was in the aftermath of the 2010 Deepwater Horizon oil spill and how turtles were moving around in the Gulf of Mexico,” said Nathan Putman, a NOAA marine biologist.

The scientists attached lightweight, solar-powered transmitters to sea turtles ages six to 18 months. They also deployed trackable buoys alongside the turtles to determine if the animals were drifting with ocean currents or swimming under their own power. The data showed that within days, the turtles had swum up to 125 miles away from the buoys.

“The turtles are actively selecting their habitats; they’re not simply vulnerable to ocean currents and conditions,” Putman said. “They’re choosing where they go, which complicates things in some ways, since it’s easier to map out where you’d expect them to be distributed.”

Mother turtles travel hundreds of miles to select beaches along the gulf to hatch their babies, choosing a spot based on sand quality and ocean conditions. Once they lay their eggs, they return to their foraging grounds. The eggs hatch 45 to 60 days later.

Sea turtles face threats such as rising sea levels that threaten their nesting habitats, entanglement in abandoned fishing gear and plastic, collisions with ships, and being inadvertently caught in trawling nets.