The turtle that holds up the world

archive – Marine LifeThe turtle that holds up the world

Turtles, and in particular the green turtles most commonly encountered by divers, have not been revered for nothing, says ALEXANDER KURAKIN. Photographs by ANDREY NEKRASOV

THEY SAY THERE ARE ONLY THREE things in the world that we never tire of contemplating – flames, running water and somebody else working. When I first saw a green turtle “flying” in water, not far from Marsa Alam in Egypt, I realised that this list needed to be expanded.
The grace, inner power and harmony of this animal’s movements are absorbing to an onlooker. It is like a bird’s flight but in slow motion.
The underwater world is one of silence, however, and we need not so much physical as musical terms to describe such movement.
A vague silhouette appears. It grows rapidly, separates from the blue background and transforms into a big turtle. Its front flipper/wings move up and down, showing us largo, which is slow and broad.
But here the turtle catches sight of a group of divers and loses its rhythm. Its head turns to the trouble-spot, first one eye, then the other. The flippers quiver alarmingly, the motion range decreases, tempo speeds up and we get moderato.
One of the divers moves carelessly, and an explosion in tempo is the response – despite its impressive size, the armoured creature undertakes a steep turn and quickly moves far away, using quick, powerful strokes – allegro turning into presto.
But to maintain such a rate for long does not suit the turtle’s temperament. After a dozen strokes it starts to slow down, then the blue space absorbs the silhouette again, and we’re back to the familiar largo.

IN ANTIQUITY, THE EARTH was thought to rest on the back of a giant turtle in the “world ocean”. Tribes living in what is now India believed a turtle to be one of the major figures in the universe. Legend has it that seven elephants support the Earth on their shoulders and stand on a turtle’s back. The turtle is held by a snake.
Native Americans believed that the “cosmic tree” grew from a turtle’s back and symbolised the whole universe. In Japanese legends, a turtle supports the “world mountain” that rises from the primaeval ocean to organise space and time. And back in India, the giant turtle was one of the incarnations of the god and guardian of the world Vishnu.
The lower part of its shell (the plastron) was identified with the Earth’s surface, while the upper part (the carapace) symbolised the vault of heaven.
In the folklore of many nations such concepts as Mother Earth, water, the beginning of creation, fertility, time and immortality are associated with the turtle.
Turtles have lived on our planet for a very long time. Paleontologists believe that they appeared during the Triassic period of the Mesozoic era, some 220 million years ago (compare that to our own 2-5 million-year history).
The size of today’s green turtles may be impressive (maximum carapace length more than 2m, weight 500kg), but this is nothing compared to its fossil ancestor, archelon.
This turtle, from the seas of the Cretaceous period, grew more than 4.5m long and weighed more than 2 tonnes.

NOWADAYS TURTLES ARE FOUND almost everywhere in the tropical and sub-tropical waters of the Atlantic, Indian and Pacific Oceans, but only six species of these reptiles have survived.
Most of them are predators feeding on various invertebrates and fish. And only one type follows a vegetarian diet – the green turtles most often seen by divers.
We can see them when they graze on grass in shallow coastal waters, soar over a distant reef or sleep in a sea-cave. We might get an illusion of well-being from these sightings, but the green turtle has certainly seen better times than these.
When Christopher Columbus’s ships were approaching the West Indies in the 15th century, sailors were amazed by the number of “living stones” dotting the sea surface. These were green turtles. The group of islands where this phenomenon was observed were even called Las Tortugas.
In fact there were so many turtles that they created difficulties for the ships, which had to try to get round them while trying to follow a direct course.
It would have been hard to imagine that in a few centuries turtles would be rare there. Even the name Las Tortugas would be obscured, as the islands came to be known as the Caymans.

EVEN WITHOUT HUMAN intervention, nature is quite severe to these shelled wanderers. Young green turtles spend their youth among algae accumulations floating at the ocean’s surface, eating jellyfish, crustaceans and molluscs. They are tasty prey for sharks and other predatory fish.
Only when they are five years old and have attained a respectable size do they dare to return to shallow coastal waters.
Here they change their diet, the main dish becoming sea-grasses. For the next 10-20 years, they keep travelling in search of new pastures.
Then the eternal procreative instinct leads turtles back to the very beach where they hatched from an egg years before. Scientists have yet to discover exactly how turtles find the way to their birthplaces.
Some believe they move towards the smell of a “home bank” spread by ocean currents, others that they navigate using the sun and stars, and a third group insists that it is terrestrial magnetic fields that guide them on their way.
One way or another, the turtles cross vast distances to find some island they left two or three decades earlier. In one officially registered case, a turtle swam 1250 miles to get home!
In the waters of their cherished island, turtles find partners that have made the same difficult journey. Some time after mating, the females crawl ashore at night. Turtles may be active and graceful in the deep blue but they’re clumsy on land, so each movement is performed with great difficulty.
And there is much to be done: to find a place above the splash zone, and dig a fairly deep hole with flippers designed not for digging but swimming.
The mother turtle oviposits 100-200 eggs in the two to five nests she makes in a season. She covers them with sand and carefully disguises them – though how can a creature succeed in hiding something when it leaves its caterpillar track-like “footprints” in the sand?

WITH A SENSE OF RELIEF the female finally returns to the sea while, in the deep, warm sand, the turtles’ hard life begins. Many nests are ruined during the six to eight weeks of incubation, as snakes, raccoons, ocelots, jaguars, stray dogs and other predators enjoy a nutritious diet of turtle eggs.
Eventually the small (about 5cm-long) hatchlings dig their way out of the sand and head towards the sea. Few make it through the gauntlet of predators awaiting an easy profit – those already mentioned are joined by huge flocks of birds of prey.
And those tiny turtles that get to the water can’t celebrate their victory yet, because shoals of hungry fish are loitering beyond the splash zone. Scientists estimate that the hatchling survival rate can be measured in hundredths of a percentage point.
But everything is balanced in nature. Until humans meddled in this cruel arithmetic, turtles could weight the scales on their own behalf.
A green turtle lives for about 80 years, giving it the chance to produce so many eggs that even under the most unfavourable conditions a positive balance of the species numbers is guaranteed, as was shown by Columbus, Cook and other explorers of the Age of Discovery.
Unfortunately, the explorers looked at turtles not from an aesthetic but from a gastronomic point of view. After all, the journey lasted for months, and long-term storage of products was very limited, so turtles were regarded only as a reliable source of fresh meat.
Over the years, as communication between the Old and New Worlds increased, so did the rate at which turtles were consumed.
The green was also known as the edible turtle, and it should be noted that “green” describes not the colour of the animal (which can be green, brown or dark brown) but that of the fat scraped from inside the upper shell.
The so-called calipee, a tender cartilaginous tissue, was cut from the lower part of the shell, and this and the fat were the most important ingredients of the famous turtle soup.
Sadly, turtle soup remains popular, and turtle eggs are widely used in cookery and confectionery all over the world. So the number of these reptiles has reduced, and turtles, which still can be found on Turkey’s Mediterranean coast or in the vicinity of the Egyptian resorts of Marsa Alam and Abu Dabab, are hardly a thriving maritime tribe.
Fortunately, many coastal countries have realised that attracting tourists who want to enjoy seeing the turtles in their native environment can be much more profitable than eating them.

WE VISITED MALAYSIA’S east coast, where in 1991 nine offshore islands were united as a marine park, Pulau Redang. One of the world’s largest turtle “kindergartens” is located on Redang Island.
The staff ensure that nobody bothers the armoured mothers during egg-laying, and guard the precious sets until the babies start hatching.
Human intervention at this stage is useful, because it enhances survival rates dozens of times over. On summer evenings, when a great number of small turtles appear out of the sand, the conservationists roam over the beach, collecting the “harvest” in large plastic buckets.
These turtles spend a night safe in the buckets during their predators’ most active hunting period, and are released in the morning, not on the beach but out in the deep sea. This doesn’t guarantee that all will survive, but their chances are significantly increased. The work done by the marine park is important, but every one of us can protect the turtles.
If we refrain from buying turtle souvenirs made of carapace and don’t order turtle soup, it all goes towards limiting the profitability of the turtle business, and the more people who follow this line, the more chance we have of saving these amazing animals and preserving the beauty and diversity of the world.
After all, our world rests on a turtle.

Appeared in DIVER May 2017

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