Once sea-turtle
hatchlings hit the surf, they vanish for up to five
years. Where the half-dollar-size tots spend these
“lost years“ while
ballooning to the size of dinner plates has been a mystery, until now.
According to LiveScience.com, new research indicates the green sea
turtles (Chelonia mydas) hide out in the open ocean, where they feast
on jellyfish and other marine creatures.
Not only did the researchers spot their short-lived sea homes, but they
discovered that these reptiles, thought to be lifelong vegetarians, are
actually meat eaters as juveniles.
The results help to solve a 50-year-old mystery about the hideouts.
“This has been a really intriguing and embarrassing problem for
sea-turtle biologists, because so many green-turtle
hatchlings enter
the ocean, and we haven’t known where they go,“ said study team member
Karen Bjorndal, a
zoologist and director of the University of Florida’s
Archie Carr Center for Sea Turtle Research.
Before this study, scientists had two snapshots that provided scant
clues about the missing information on the lives of green turtles: When
they hatch, the 2-inch-long (5-centimeters) sea turtles push through
seemingly colossal surf. Then, between three and five years later, the
now juveniles reappear closer to shore.
“Literally, when green turtles run off their nesting beach and into the
ocean as little hatchlings, they disappear. And nobody sees them again
,“ Bjorndal told LiveScience.
The scientists collected samples from the shells of 44 green sea
turtles at a site near Great Inagua in the Bahamas. They analyzed heavy
and light stable isotopes of carbon and nitrogen from both the oldest
(earliest-grown) and newest sections of the shells. The isotopes act as
fingerprints for an animal’s diet (carnivore or herbivore) and where in
the ocean the animal lived.
The results indicated the green sea turtles spent their lost years in
the deep ocean, feeding as carnivores, before moving closer to shore
and switching to a vegetarian diet of sea grasses.
The findings have implications for conservation of the green turtles,
because as Bjorndal explained, “you can’t protect a species if you
don’t know where it is.“