The
green turtle is a large, weighty sea turtle with a wide, smooth carapace, or
shell. It inhabits tropical and subtropical coastal waters around the world and
has been observed clambering onto land to sunbathe.
It is named not for the color of its shell,
which is normally brown or olive depending on its habitat, but for the greenish
color of its skin. There are two types of green turtles—scientists are
currently debating whether they are subspecies or separate species—including
the Atlantic green turtle, normally found off the shores of Europe and North
America, and the Eastern Pacific green turtle, which has been found in coastal
waters from Alaska to Chile.
Weighing up to 700 pounds (317.5 kilograms)
green turtles are among the largest sea turtles in the world. Their
proportionally small head, which is nonretractable, extends from a heart-shaped
carapace that measures up to 5 feet (1.5 meters). Males are slightly larger
than females and have a longer tail. Both have flippers that resemble paddles,
which make them powerful and graceful swimmers.
Unlike most sea turtles, adult green turtles
are herbivorous, feeding on sea grasses and algae. Juvenile green turtles,
however, will also eat invertebrates like crabs, jellyfish, and sponges.
While most sea turtles warm themselves by
swimming close to the surface of shallow waters, the Eastern Pacific green
turtle will take to land to bask in the sun. Occasionally seen sunbathing
alongside seals and albatrosses, it is one of the few marine turtles known to
leave the water other than at nesting times.
Green turtles, like other sea turtles,
undertake lengthy migrations from feeding sites to nesting grounds, normally on
sandy beaches. Mating occurs every two to four years and normally takes place
in shallow waters close to the shore. To nest, females leave the sea and choose
an area, often on the same beach used by their mothers, to lay their eggs. They
dig a pit in the sand with their flippers, fill it with a clutch of 100 to 200
eggs, cover the pit and return to the sea, leaving the eggs to hatch after
about two months. The most dangerous time of a green turtle’s life is when it
makes the journey from nest to sea. Multiple predators, including crabs and
flocks of gulls, voraciously prey on hatchlings during this short scamper.
Green turtles are listed as an endangered
species, and a subpopulation in the Mediterranean is listed as critically
endangered. Despite this, they are still killed for their meat and eggs. Their
numbers are also reduced by boat propeller accidents, fishnet-caused drowning,
and the destruction of their nesting grounds by human encroachment.