Leatherback Turtle

VIRTUAL ANIMAL IN AUGMENTED REALITY

The leatherback turtle is one of the impressive figures that you will be able to discover in the Grand Large experience.

At birth, the little turtles make their way to the ocean and on the way between the nest and the ocean, these 7 cm turtles become an easy prey for birds, crabs or dogs that feast on them.

Where is the animal to be found?

They can be found in all the oceans of the world except the Arctic and Antarctic oceans.

It is a pelagic species that lives on the high seas and can dive to depths of more than 1,300 metres and stay at that depth for 85 minutes before coming back up to the surface to breathe.

How can it be recognised?

• The leatherback turtle, Dermochelys coriacea, which can be as long as 2 metres and weigh 500 kg, is the largest of the sea turtles and of tortoises in general.
• It is characterised by a carapace without scales that is formed by a thin skin covering a thick layer of fat, coloured grey or dark blue with light patches.
• It has seven ridges running lengthways. So it does not have a hard bony shell like the other turtles. It is also called the lute turtle or leathery turtle.
• Leatherback turtles mainly feed on jellyfish, notably the lion’s mane jellyfish, Cyanea capillata, but they also consume pelagic tunicates, fish, sea urchins, crustaceans, molluscs and some seaweeds and plants.
• Juvenile leatherback turtles must consume the equivalent of their bodyweight in jellyfish every day to meet their food needs.
• The shape of its body means it has excellent hydrodynamic properties making it the fastest turtle when swimming under water with bursts of speed of up to 40 km/h.
• Their front flippers are proportionally longer than those of the other sea turtles and their rear flippers are paddle-shaped, allowing them easily to cover long distances.

What is distinctive about it?

• They can live for up to 50 years, and reach sexual maturity between 9 and 20 years of age.
• Every 2 to 4 years, the females come to lay their eggs, always on the same beach located in the tropical or subtropical zone.
• They lay 2 or 3 times in the space of 10 to 15 days and each time they lay 100 to 200 eggs whose incubation period varies between 60 and 70 days.

Threat and protective measure

The leatherback turtle population is declining in several parts of the world, particularly in the Pacific. Turtles are under threat both on their nesting beaches and in the sea.

• The urbanisation of the coastline has an impact on the state of the beaches where the turtles nest: the amount of dry sand on the beaches decreases, the street lighting upsets the turtles that come to lay there, and disorients the young when they try to get to the ocean.
• The rising sea levels linked to climate change cause an erosion of the beaches and a reduction in the area where the females come to nest.
• Likewise, the temperature of the sand has an impact on the survival of the eggs and on the male / female distribution because the determination of their sex depends on the temperature of the nest.
• Lastly, the warming of the water also has an impact on the abundance and distribution of their food causing the turtles to change their migratory routes, and also variations in the nesting season.
• Turtle poaching and the consumption of their eggs by humans are having an impact on the survival of the species despite their protected-species status in many countries.
• At sea, plastic pollution is a cause of death for the turtles which confuse plastic bags with jellyfish and choke on them.
• Bycatch in fishing nets is also a cause of death by drowning for turtles further to the injuries they suffer, as are collisions with ships when the turtles are close to the surface.