The first time I got to observe turtles up close was on our recent (April 2011) trip to Sodwana. We probably encountered ten individual Green turtles on the dives we did. I was amazed by how relaxed and calm they are underwater, and how languid their swimming style is (using the front flippers for propulsion and the rear ones as rudders). They munch at the coral, and allow you to pass by quite close without paying you the slightest bit of attention. When they swim away they look as though they’re hardly exerting themselves, but just try and keep up and you’ll see how fast they are actually moving! Five different species of turtle visit the waters of Kwazulu Natal, and Leatherbacks and Loggerheads actually nest in Sodwana, and during the summer you can go on a Turtle Tour to see the females digging nests and laying eggs on the beach.
So I’ve had turtles on the brain since earlier this year. This book was timely!
Voyage of the Turtle: In Pursuit of the Earth’s Last Dinosaur – Carl Safina
This is the second of Carl Safina’s books that I’ve read. The first, Song for the Blue Ocean, was a revelation to me – he writes beautifully, and covers so much ground that it was quite overwhelming. It was also incredibly depressing and left me feeling that, save for a few brave individuals, humanity was headed to hell in a handbasket.
This book is also beautifully written, with massive scope, mainly dealing with the massive Leatherback turtle but touching on the other six species as well (Hawksbill, Loggerhead, Green, Kemp’s Ridley, Olive Ridley and Flatback). These creatures are reptiles, but amazingly adapted to function in a range of water temperatures. Leatherbacks can swim in water so cold that it would freeze other sea creatures, thanks to special lipids in their blood. They are long distance swimmers of note, spending vast periods of time in the middle of the ocean, moving between feeding and breeding grounds. Seeing their migratory paths plotted on a world map amazed me – they cross entire oceans without a break. At some stages of their life cycle, they spend 97% of their time underwater.
Safina visits most of the primary turtle nesting sites around the world (from Florida to Papua New Guinea), and spends time in spotting planes counting turtles and nests with biologists and conservationists, and on fishing boats looking for these elusive giants out at sea. One section is particularly disturbing – he travels out with some swordfish fishermen, and describes the process of catching and killing these majestic creatures in some detail. Even though Safina is an ardent conservationist and founder of the Blue Ocean Institute, his self-confessed and very obvious enjoyment of recreational fishing – even (or specially) for big game fish – and the relish with which he describes it, is very, very disturbing to me and tends to make his other credentials ring somewhat hollow.
Turtles seem like prolific breeders to us parsimonious (well, some of us) humans. Each female makes several (five or six usually) nests during a breeding season, containing over 100 eggs. The reason for each female laying of the order of 1,000 eggs each time she breeds is because the eggs and tiny hatchlings are incredibly vulnerable to predation from crabs, birds, jackals, fish and other creatures who appreciate a concentrated dose of protein in bite-sized form. Adding to these natural threats are a multitude of dangers posed by humans, who have been on earth for a fraction of the time that these living dinosaurs have.
Human-created threats faced by turtles include entanglement in fishing line or nets, and capture on long lines. In all these instances they drown, as accidental bycatch. The lucky ones lose a flipper, or escape with a hook in their bodies and line entangling their flippers or tangled around their insides. Long lining will hopefully be completely illegal all over the world one day (it’s a brutal and wasteful way to fish), round hooks will become more prevalent, and turtle escape hatches – which are easy to fit and use on most kinds of fishing net – will become more widespread. Safina reports than locations where these hatches are law are reporting a much lower bycatch of turtles. Typically fishermen are fiercely resistant to any kind of change or advice about how to do their jobs, but there are some very persistent people working in this area.
Turtles are also eaten for food in some parts of the world, used for virility potions (can we all say it together… pathetic!) and their eggs are widely used for food as well. Their shells (this doesn’t apply to Leatherbacks, as they have tough skin stretched over bone instead of a hard carapace) are used for jewellery, dishes, and other purposes. It’s easy for poachers to observe the giant female turtles laying in full view on the beach, dig up the nests and remove all the eggs. Other man-made threats include artificial lighting that disorients hatchlings and sends them scurrying inland instead of towards the bright horizon of the ocean when they emerge from the eggs, and interference with beach contours by adding or removing sand. Turtles are particular about what kind of beach they like to nest on, and hatchlings usually return to where they were born in order to breed when their turn comes.
Their presence in the ecosystem keeps certain types of sponges, corals, sea grass and jellyfish (some of their dietary preferences) in check. There is, as Safina points out, a domino effect when the turtle numbers are dimished so much. And we can’t even see all the dominoes.
This is a more hopeful book than Song for the Blue Ocean. It’s made me want to visit Sodwana in summer to see some Leatherback turtles. These creatures have wisdom in their bones – nothing survives on earth for so long by accident. We’ll have to organise a trip there in January.
You can purchase the book here if you’re in South Africa, otherwise click here. If you want to read it on your Kindle, go here.
