Every year during our warm summer months(October – March), some of the world’s most endangered animal species, loggerhead and leatherback turtles, slowly struggle up the beaches of the northern KwaZulu-Natal coastline to nest.
All of the world’s seven species of marine turtles have unique lifestyles in that they travel great distances and take decades to mature. This makes turtles important indicators of ocean health.
Of the five species found off the KwaZulu-Natal Coast, only the loggerhead and leatherback turtle females nest along our shores at night.
They use the medium to coarse-grained sandy beaches that are backed by high dunes with well-developed primary vegetation. Steep beach faces make it easy for loggerhead turtles to swim through the surf over low-lying rock ledges. The females emerge from the surf and rest in the wash zone on the beach. It is here when they assess the beach for any danger by lifting their heads and scanning the beach. Satisfied that there is no danger they then proceed up the beach to well above the high water mark.
All of the world’s seven species of marine turtles have unique lifestyles in that they travel great distances and take decades to mature. This makes turtles important indicators of ocean health.
Of the five species found off the KwaZulu-Natal Coast, only the loggerhead and leatherback turtle females nest along our shores at night.
They use the medium to coarse-grained sandy beaches that are backed by high dunes with well-developed primary vegetation. Steep beach faces make it easy for loggerhead turtles to swim through the surf over low-lying rock ledges. The females emerge from the surf and rest in the wash zone on the beach. It is here when they assess the beach for any danger by lifting their heads and scanning the beach. Satisfied that there is no danger they then proceed up the beach to well above the high water mark.
Having found a suitable site at the vegetation edge, the female commences by excavating a body pit with her fore flippers. This enables her to lie with the top of her carapace level with the beach. She then digs an egg cavity with her hind flippers. The egg pit is a flask-shaped hole about 50 – 80 cm deep. A normal clutch constitutes 100 – 120 soft white-shelled eggs. The female then fills the hole with sand and kneads and presses the surface until the sand is packed hard. She disguises the nest by throwing loose sand over the nesting area with her fore flippers. Satisfied that her nest is safe, she returns to the sea.
Leatherback turtles can return up to seven times to lay eggs, while Loggerhead turtles return up to four times in a single season.
The eggs take between 55 and 65 days to mature. Once ready to emerge, the hatchlings cut their way out of the egg with a special egg tooth on the end of their beaks. After the bulk of the eggs have hatched the hatchlings start digging at the sides of the nest. The nest collapses and fills up with sand. This enables the hatchlings to push and climb to the surface.Image
They will normally rest until nightfall when the temperature of the surface sand drops and the sprint down to the sea. The hatchlings are guided towards the water’s edge by the lighter sea horizon. During this run to the water about 4 out of every 100 are taken by ghost crabs or other predators.
Once in the ocean, they go on a swimming frenzy in the Agulhas current that lasts for a few days. They are then swept down the east and south coasts of South Africa, most of them ending up in the Southern Indian Ocean where they spend at least three years drifting in the open sea. Predation is very high during these first few years, and it is estimated that only 1 to 2 hatchlings of every 1 000 that enter the sea will reach maturity.
During this phase the young sea turtles feed on bluebottles, jellyfish and storm snails that drift on the surface. Following the currents, they are eventually brought back to the coasts where they change their diets. Loggerheads feed on sea organisms that inhabit reefs, i.e. urchins, mussels and crabs. Leatherback turtles maintain an exclusive diet of jellyfish and they only enter coastal water to breed.
Females reach nesting maturity between 12 and 20 years, when they return to the beaches where they were born to restart the life cycle.
In South Africa harvesting of all sea turtles was banned in 1916, and from the early 1960’s concerted efforts were made to enforce legislation banning egg collection and the harvesting of adults for their meat. In 1963 a turtle conservation and monitoring program was initiated along the north-eastern coast of KwaZulu-Natal, which is now the Greater St Lucia Wetland Park, declared a World Heritage Site by UNESCO in December 1999. Since the inception of the program 16 local community members have been trained as monitors, and they gather valuable data over the nesting period.
A turtle walk concession at Kosi Bay/Bhanga Nek has been granted to local community guides to take small groups to walk along the beach to watch turtles nesting. Apart from this, five turtle concessions have been granted to independent eco tourism operators in the Greater St Lucia Wetlands Park.
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