Sea turtles are graceful saltwater reptiles, well adapted to life in their marine world. The green sea turtle is a medium to large brownish sea turtle with a radiating or mottled pattern of markings on the shell. The head is small in comparison to the other sea turtles and the biting edge of the lower jaw is serrated. Adult shell lengths range in size from 0.9-1.1 meters (36-43 inches) and weights average 90-137 kilograms (200-300 pounds). The greatest cause for the decline of green turtles has been commercial harvest for eggs and food, as well as their use for leather and jewelry.