A leatherback turtle swimming gracefully through the open ocean is arguably one of the most majestic sights in the natural world. Leatherbacks are the largest of all sea turtles, with the biggest reaching well over two metres in length and weighing over half a tonne, yet they seem to swoop effortlessly through the water as they graze on jellyfish, their favourite prey.
With their teardrop-shaped bodies and powerful front flippers, these ancient creatures are perfectly adapted to ocean life. They wander widely, migrating thousands of kilometres, and can dive to depths of over one kilometre, withstanding colder temperatures than most other reptiles.
Leatherbacks have the widest distribution of all sea turtles and have been recorded from the Arctic Circle to the southernmost tip of New Zealand. Both the eastern and western Pacific subpopulations are officially categorised as Critically Endangered on the IUCN Red List, with eastern Pacific leatherbacks considered the world’s most endangered sea turtle population. Without urgent action, they could be extinct within 60 years, according to the latest population modelling.
The leatherback is the only sea turtle that lacks a bony shell; instead, its ridged carapace is covered with leathery skin, hence the name ‘leatherback’. A leatherback’s mouth lacks teeth, but they have backward-pointing spines in their throats to help them retain and swallow prey.
The lifespan of leatherbacks is still largely a mystery, but may exceed 100 years. Males never leave the water once they have entered it as hatchlings, but each nesting season females haul themselves out of the sea and make the arduous journey across tropical beaches, where they excavate a hole in which to lay their eggs before burying them under the sand.