Turtling in iSimangaliso
November in iSimangaliso Wetland Park heralds the beginning of one of the most special and awe-inspiring miracles of this world heritage site – the nesting of endangered turtles on the 220km golden shoreline. Annually, between the months of November and March, leatherback and loggerhead turtles haul their massive bodies out of the Indian Ocean and up to the base of the dunes, to lay their eggs. In this most ancient cycle of life, turtles return with almost magical accuracy to the very same beach where they hatched. Of the seven species of marine turtles worldwide, iSimangaliso’s protected coastline has five species, and its pristine beaches comprise one of the last significant laying sites in Africa for loggerheads and leatherbacks. Turtle monitoring has been undertaken in the Park since the 1960’s, with turtles being measured and tagged. The turtles of iSimangaliso have received significant conservation attention, producing a noteworthy increase in the loggerhead turtle population.
“With less than 100 laying females coming ashore each year, iSimangaliso’s leatherback turtles, the most southern population in the world, are rarer than black rhino and critically endangered. This means they could go extinct in our lifetime. Having survived aeons and ice ages along with rhinos, and at a time when over 1000 biological species are going extinct globally every year, their future survival lies with all of us,” said iSimangaliso CEO Andrew Zaloumis. “As site managers, our challenge is that once they leave our shores and swim across the high seas, they undertake epic journeys, travelling as far as Australia and India. During these journeys, which occur between nesting periods, the leatherbacks spend their time foraging. They feed on pelagic (open ocean) invertebrates such as jellyfish and this makes them extremely vulnerable to threats such as long line fishing methods and pollution. Plastic bags are often mistaken for jellyfish by these feeding animals, ultimately killing the animals that ingest them.”
A better understanding of these populations is key to their survival, and iSimangaliso has authorised and supports ongoing scientific research projects. Current work includes the satellite tagging of individual turtles, and genetic testing to determine whether known iSimangaliso nesting turtles mate with males in other populations in the Indian or Atlantic Oceans.
There is also strong collaboration with Mozambique’s Ponta do Ouro Partial Marine Reserve (PPMR) – proclaimed in 2009 – bordering iSimangaliso’s northern border. Africa’s longest trans-frontier marine protected area now offers greater protection and hope for the preservation of these species, with much improved compliance and monitoring efforts across the border. According to PPMR’s Park Manager, Miguel Goncalves: “Since 1994 a total of 5811 tracks from loggerheads and 410 from leatherbacks were recorded. An increase in the number of tracks recorded for both species in the last seven years is likely the result of a better coverage of the monitoring season, according to researchers. Since 2007, loggerheads have laid an average of 220 nests, while for leatherbacks 32 nests were recorded on average per season. The number of loggerhead turtles tagged per season has been steadily increasing, with a record 197 turtles tagged in 2013/14, with an average of 63.9 turtles tagged per season.” As conservation efforts and scientific knowledge are freely shared between the two countries, the future looks more promising for at least two of the planet’s endangered species.
The gigantic leatherback turtle can weigh over 800 kg. It has a deep, narrow, barrel-shaped shell that lacks horny scutes (horny scales), but is instead covered with thick, smooth skin like vulcanised rubber. The flippers are long and clawless, and in the adults the shell and flippers are black, usually scattered with white spots. Leatherbacks can be found nesting from Maphelane in the south all the way along the coast of iSimangaliso into Mozambique. Most breeding occurs between Manzengwenya and Bhanga Nek in the Coastal Forest Reserve section of the Park. Leatherbacks undertake long journeys and frequently enter colder currents to find food. They are adapted to conserve heat in cold water. They are the only living reptiles that are warm-blooded, generating their own heat. The adult turtles feed only on jellyfish, but the juveniles may also eat other floating organisms. They dive to feed and are able to reach depths of over 350 metres due to their flexible shells, and can stay under the water for up to 37 minutes. Long spines that project backwards cover the inside of the leatherback’s throat to stop slippery food from escaping. A leatherback turtle becomes sexually mature at between three and five years old, when the carapace is approximately 1400 mm long. Mating between leatherbacks takes place at sea. Leatherback males never leave the water once they enter it, unlike the females, which crawl onto land to nest.
The loggerhead turtle is much smaller than the leatherback turtle. It weighs between 80 and 140 kg. The large head and carapace are uniformly red-brown in juveniles and adults and their extremely strong jaws are able to crush giant clams. In southern Africa they mainly breed along the sandy shores of the iSimangaliso Wetland Park, with very small and isolated breeding patches along the coast of Mozambique. They come ashore every two to three years to lay about 500 eggs in batches of 100 to 120 every 15 days. This usually takes place at high tide during moonless nights. Both loggerhead and leatherback turtles nest in summer, generally at night. The female emerges from the surf and rests in the wash zone, looking out for danger. Then she moves above the high water mark to find a suitable site to lay her eggs. Around a thousand eggs are laid altogether during a breeding season, at nine to eleven day intervals. A high percentage (70-75%) hatch successfully.
After 60 to 70 days, the hatchlings emerge at night (usually) and make their way back to the sea. Up to 12% may be taken during this short journey by ghost crabs. For the first couple of months the tiny turtles are prey to many marine predators. It is estimated that out of every 1000 eggs only one or two hatchlings survive. Females breed every two to three years.
The green turtle is a large turtle, weighing between 125 and 200 kg. In the Atlantic, turtles of up to 300 kg have been recorded. In southern Africa they breed (in small numbers) on Bazaruto Island, Mozambique. They are found throughout the year along the coast of the iSimangaliso Wetland Park. They can be seen from vantage points on the high, forested dunes, and from Black Rock and Dog Point in the Coastal Forest Reserve section of the Park. Snorkellers and scuba divers often encounter these turtles.
This is a relatively small turtle, often weighing less than 50 kg. The beak is bird-like. In adults the upper section of the shell is translucent amber, beautifully patterned with irregular, radiating streaks of black, yellow and light red-brown. The curio trade has caused the decline of this species. The scutes are made into jewellery and sold on the black market. In countries like Singapore and the Philippines, it is estimated that up to 100 000 hatchlings are killed for the curio trade annually, highlighting the vital role that protected areas like iSimangaliso play in the conservation of such species.
The iSimangaliso Wetland Park Authority has issued contracts to authorised operators to undertake turtle tours within the Park, either by vehicle or on foot. In the St Lucia and Sodwana Bay sections of the Park, vehicular tours are offered by two concession-holders in each respective destination, while community guides are licensed to take visitors on foot patrols from the Kosi Bay area. Often hailed as a ‘bucket-list’ experience, the attraction of witnessing nesting turtles has proven to be one of the highlights of most visitors’ trips to the Park, and one of the most poignant reminders of why it is so essential that this precious area is conserved in perpetuity. iSimangaliso restricts turtle trips to licensed operators who ensure that there is minimum interference with laying turtles, including the avoidance of camera flashes or spotlights while the turtle is moving up and down the beach to lay.
For more information on the iSimangaliso Wetland Park, follow us on Twitter, Instagram, Facebook and Youtube, or visit our website at www.isimangaliso.com. Media enquiries should be directed to Media Officer Siyabonga Mhlongo at email@example.com or on 084 382 0884.