The green turtle is the largest hard-shelled sea turtle in the world. There are two general types of green turtles. The Atlantic Green Turtle is larger than its cousin, the Hawaiian Green Turtle. The average green turtle reaches 100cm (40in) in carapace length (top shell) and weighs 150 kg (330lbs). Hatchlings weigh about 25g (a handful of smarties). All through their life the plastron (underside) of the turtle stays a white/yellowish color, while the carapace changes from black to green, gray, or brown.

Scientists believe that hatchlings are omnivorous, but as they develop they become herbivores. The green turtle grows very slowly. Sexual maturity is not reached until they are at least 20 years old and remain sexually active until they are about 50 years old. Unlike other sea turtles, the rate of post hatchling deaths is very low. Nests are rarely disturbed.

Although it has not been proven, most people accept the idea that the females nest at the same beach that they were hatched on. Green turtles can be found in shallow, protected waters in the Gulf of Mexico and off the coast of Hawaii.

The green turtle was listed as threatened through the U.S. Endangered Species Act of 1973. However, the ones inhabiting the Pacific coast of Mexico and Florida were listed as endangered. The Green Turtle's worst enemy continues to be humans, who have destroyed their nesting sites and drown them in shrimping nets.

Until the use of Turtle Excluding Devices (TEDs) was enforced, the shrimping industry remained a threat to all marine turtles and still is to larger turtles. Garbage and plastics are a threat to any marine animal that gets tangled in it and/or mistakes it for food.