Facts on the world's favourite ocean reptiles
Sea turtles (cheloniidae, Dermochelyidae) are a big favourite around the world. Even having their own day 'world turtle day' which is celebrated on the 23rd of May each year, and was started in 2000 by American Tortoise Rescue to raise awareness.
Turtles are omnivores, and grow between 2 to 7 feet long, weighing anything between 70 to 2,000 pounds.
There are seven species of sea turtles, six of which swim all around the Earth's waters. These are:
Green turtle (Chelonia mydas)
Hawksbill turtle (Eretmochelys imbricata)
Leatherback turtle (Dermochelys coriacea)
Loggerhead turtle (Caretta caretta)
Olive Ridley turtle (Lepidochelys olivacea)
Kemp's Ridley sea turtle(Lepidochelys kempii)
The seventh specie is the Flatback turtle (Natator depressus), which only lives in the waters around Australia.
The leatherback can weigh up to 2,000 pounds, making it the largest sea turtle. The leatherback is the only turtle that doesn't have a bony shell, with their carapaces (the upper shell) being fairly flexible and quite rubbery to touch. Other sea turtle shells are made of thick plates called scutes.
Did you know?
Leatherback turtles were around when the T-rex was alive - that's over 200 million years ago.
Warmer temperatures actually cause more female turtles to be born.
Unlike other turtles, sea turtles can't actually pull their head and limbs inside their shells, a turtle's shell is actually part of it's skeleton and it made up of over 50 bones including their spine and ribcage.
Turtle's return to the same beaches they were born on to lay their eggs. They are extremely sensitive to the earth's magnetic field. In a magnetic field, there is the strength of the field, and the angle of which the field lines cross the earth. Turtles can detect both components and figure out where in the ocean they are.
A turtle's journey
Turtle's make incredibly long journeys, migrating thousands of miles between feeding and breeding areas. The leatherback turtle travels on average 3,700 miles each way. Sea turtles mate at sea, and then return ashore on the beaches they were born to lay their eggs. Female's dig a hole in the sand, then deposit their clutch of eggs (which can be up to 100), cover it back up and return to sea.
60 days later, the eggs hatch and the tiny turtles make their way to the water at night. This can be a deadly journey as predators such as seabirds and crabs, prey on the young turtles. Coastal development also causes a threat for the hatchlings. Natural light at the horizon guides the hatchlings to the ocean, lights from buildings can cause confusion for the turtles, causing them to head the wrong direction.
Threats they face
Heartbreakingly six of the seven turtle species are classified as endangered, threatened or critically endangered. A large cause of threat comes from human activity and impact, acts such as climate change, hunting, pollution, and by-catch in fishing nets. Climate change is warming temperatures, affecting sand temperature, which causes the sea turtle eggs laid to be affected, meaning more females are born.