Green Seaturtle / Tortue verte
Click on photograph for more information about sea turtles.
The Green Turtle can reach 1.5 m
carapace length but is typically less than 1 m. It is characterized by a broad and
flattened carapace with no keel and only slight serrations along the back edge. It is
olive to brown or black in colour and may be mottled. The
plastron is clear white or
yellowish. The skin is brown or grey to black and the paddle-like forelimbs have only
one claw which is long and curved in males. Males also have prehensile tails with a
flattened nail at the tip. Green Turtles can be distinguished from other seas turtles
by their four costal scutes the
first of which does not touch the nuchal scute and the pair of prefontal scales
between the eyes.
The Green Turtle is similar to the other hard-shelled sea turtles and is intermediate
in size between the Loggerhead Turtle and the
Kemp's Ridley Turtle. Both of the other
turtles have coarse serrations along the back edge of the carapace and sculpting along
the centre line -- a keel in the Loggerhead Turtle and five raised knobs in the Kemp's
Ridley. The shape of the carapace also differs.
Green Turtles are found in both the Atlantic and Pacific oceans. In Canada they have
been seen on the west coast of Vancouver Island. Their distribution on the Pacific
coast is influenced by El Nino weather events. It ranges throughout tropical portions
of the Atlantic, Pacific and Indian oceans.
Although it has been seen up to 160 km from land and can migrate across 2,000 km of
open ocean feeding occurs in water as little as 3-5 m deep. Reefs and rocky areas are
used for resting. Hatchlings may use floating mats of sargassum algae. Nesting occurs
on flat continental or island beaches with little wave action.
reen Turtles may take from 19-24 years to reach sexual maturity. Nesting in Pacific
populations occurs in winter or spring on beaches in areas such as Hawaii, Mexico
and central America. Most females breed every three years and lay several clutches
of up to 238 eggs. Hatchlings from a nest emerge together after dark. Sex of hatchlings
is determined by incubation temperature.
The Green Turtle is the only sea turtle that commonly leaves the water to bask
although they also bask on the surface of the water -- sometimes providing a landing
site for seabirds. Adult Green Turtles prefer to feed on algae or sea grasses while
juveniles eat a variety of invertebrates.
Green Turtles and their eggs have long been harvested by humans for food and are
an important source of protein in some third world countries. Populations have
declined dramatically over the last 50 years although not to the same degree as
other species of marine turtles. Other threats to the species are exploitation of
the nesting and feeding grounds.