Sea Turtles
Prehistoric species visiting our beaches
Sea turtles are large, air-breathing reptiles that live in tropical and subtropical seas throughout the world. Their shells consist of an upper part (carapace) and a lower section (plastron). Hard scales (also called ‘scutes’) cover all species except the leatherback, and the number and arrangement of these scutes can be used to help determine the species.
Sea turtles do not have teeth, but their jaws have modified “beaks” suited to their particular diet. They do not have visible ears but have eardrums covered by skin. They hear 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 maintain close ties to land.
Females must come ashore to lay their eggs in the sand; therefore, all sea turtles begin their lives as tiny hatchlings on land. Research on marine turtles has uncovered many facts about these ancient creatures, and most of this research has been focused on nesting females and hatchlings emerging from the nest, largely because they are the easiest to find and study.
Most scientists recognize seven species of sea turtles around the world, with three species regularly nesting on our beach in St. Johns County - the Loggerhead, Green, and Leatherback.
Loggerhead Sea Turtle
Caretta caretta
IUCN Red List: VULNERABLE (worldwide)
Loggerhead sea turtles are the most widespread sea turtle species in the world, and the most abundant of all sea turtle species in the United States. You can recognize them by their reddish-brown carapace (upper shell), yellow underbelly and their strong jaws that they use to crunch through the hard shells of crustaceans and mollusks. The mouth of the loggerhead sea turtle is actually where they get their name! Some people think their massive head is as big and sturdy as a log. Learn more.
Green Sea Turtle
Chelonia mydas
IUCN Red List: ENDANGERED (worldwide)
Green turtles are endangered around the world, but they are nesting in increasing numbers on the east coast of Florida. The green sea turtle was listed as endangered under the Endangered Species Act in the United States in 1978. Green sea turtles are unique—they are one of the largest species of turtle and the only turtle that is strictly herbivorous as an adult (although juvenile green sea turtles will also eat crabs, sponges, and jellyfish). Green sea turtles eat sea grasses and algae, which results in the green-colored fat and cartilage that inspired their name. Learn more.
Leatherback Sea Turtle
Dermochelys coriacea
IUCN Red List: VULNERABLE (worldwide)
The leatherback is the largest of all turtles, dives the deepest, and travels the furthest of all sea turtles. Leatherback sea turtles are the largest sea turtles in the world! They can grow up to seven feet and weigh more than 2,000 pounds. While all other sea turtles have a hard body shell, leatherback sea turtles do not. You can recognize them by their soft carapace (top shell). Leatherback sea turtles have a top shell that is smooth, bluish-black leathery skin with small white spots that cover a matrix of bones with seven ridges (keels). Their back is where they get their name—since it’s smooth and leathery! Learn more.