The majestic creatures we all strive to see.
Did you know that there are only seven species of sea turtles in the Earth’s seas? If you live to see a turtle on a dive you’ll be pleased to know that five of these seven species of turtles can be found in waters surrounding South Africa.
We owe the presence of turtles to the unique way our coastal waters create the ecosystems these animals prefer to be in. On the Western coast of South Africa you can find the Atlantic ocean which gets cold water from the Benguela current sweeping up from the Arctic. The Eastern side has the sub-tropical Indian Ocean which is warmed by the Agulhas current bringing heat down from the tropics. It’s these two currents that create an environment sea turtles thrive in when they come together on South African shores.
Sea turtles are categorized and belong to the super family Chelonioiidea. Don’t worry if you can’t pronounce it, but mouth ‘kel-on-ee-oy-dee-ah” and you’re half way there. Turtles are diapsids of the order Testudines characterized by a special bony or cartilaginous shell developed from their ribs that acts as a shield. “Turtle” refers to the order as a whole or to fresh-water and sea-dwelling Testudines. This means that sea turtles are classified as Testudines, as are land-dwelling tortoises, terrapins and fresh water turtles. Scientists have dated fossils of turtles which are older than other reptiles like snakes and crocodiles.
The size these turtles can grow to are intimidating. They can reach 650kg, truly gigantic when compared to other species of turtles. They nest on the beaches in KwaZulu-Natal and feed on jellyfish. These giants are crowned as the fastest reptile because they can reach speeds of 35km per hour. They can also dive to 1.5km deep, making them the deepest diving turtles. They are the only turtle with a hard carapace (the upper shell of a turtle). This defensive covering must do its job well as they can reach the geriatric age of 100 years. They navigate using the sun. Sunlight penetrates their skull and reaches the brain allowing them to know where they are and when to migrate.
Second on the list is the second largest turtle, coming in at a maximum weight of 450kg. The Loggerhead turtle, like the Leatherback, also nests in KwaZulu-Natal. They are carnivorous feeding on mollusks, sea urchins and starfish. This turtle gets its name from its large head. Its their large jaw muscles that help them crush their hard-shelled prey. Loggerhead turtles you encounter in the Atlantic or Mediterranean oceans are descendants from those found in our coastal waters.
The Green turtle resides in South African waters but they can be found around the globe, mainly in tropical and sub-tropical waters. The Green turtle is the most widely spread, nesting in 80 countries. They travel long distances to migrate to feeding grounds from the beaches they were hatched on. They use the Earth’s magnetic field to navigate. They are named for the greenish colour of their cartilage and fat, not the colour of their shells. Adults can be seen grazing on plants and algae and they can weigh up to 400kg.
Named for their narrow pointed beaks, the Hawksbill turtles enter South African waters as strays. They are easy to identify thanks to these unique beaks which they use to hunt mainly sponges, but also crabs and prawns. They can also be identified by the pattern of overlapping scales on their shells which form a zig-zag pattern on the edge.They are small turtles, reaching a maximum weight of 80kg. These turtles are immune to toxins in sponges and jellyfish. They stores these toxins in their flesh, making them poisonous to predators.
The Olive Ridley is the smallest turtle you will find in South African waters, weighing in at an average weight of 35kg. They enter our waters as strays. They get their name from the olive colour of their shells. At the moment they are the most abundant of all sea turtles. Their vulnerable status comes from the vulnerability of their nesting grounds. They nest in very few places and therefore any interference to even one nest beach could have devastating effects on the whole population. They partake in Arribada which is a mass-nesting behaviour. Hundreds of thousands of turtles nest on a beach at the same time. Have a look at these turtles nesting: