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Canadian Amphibian and Reptile Conservation Network - Réseau Canadien de 
Conservation des Amphibiens et des Reptiles

Chelonia mydas
Green Seaturtle / Tortue verte


Green Seaturtle
Click on photograph for more information about sea turtles.

Description
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.

Confusing Species
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.

Distribution
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.

Habitat
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.

Reproduction
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.

Natural history
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.

Conservation Concerns
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.