Sea turtles are huge, air-breathing reptiles that dwell in tropical and subtropical seas all over the world. Their shells consist of an upper part and a lower section. Hard scales cover all but the leatherback, and the number and collection of these scutes can be used to decide the species.

Sea turtles available in different sizes, shapes and colors. The olive ridley is usually less than 100 pounds, while the leatherback normally ranges from 650 to 1,300 pounds! The upper shell, or carapace, of each sea turtle species ranges in length, color, shape and collection of scales. Sea turtles do not have teeth, but their jaws have modified "beaks" suited to their fastidious diet. They do not have noticeable ears but have eardrums covered by skin. They listen to best at low frequencies, and their sense of smell is excellent. Their vision underwater is good, but they are nearsighted out of water. Their streamlined bodies and large flippers make them remarkably adapted to life at sea. However, sea turtles continue close ties to land.

Females must appear on shore to lay their eggs in the sand; therefore, all sea turtles begin their lives as tiny hatchlings on land. Research on marine turtles has revealed many facts about these ancient creatures. Most of this study has been focused on nesting females and hatchlings promising from the nest, largely because they are the easiest to find and study.

Thousands of sea turtles around the world have been label to help collect information about their development rates, reproductive cycles and migration routes. After decades of studying sea turtles, much has been learned. However, many mysteries still remain.