Of all the animals I fed on my Marine Biologist Day at the London Aquarium, the most majestic and magnificent animals of all were the two Green Turtles, Boris and Phoenix. In the large tank of the London Aquarium, you can find sharks, rays and other interesting marine life, but most beautiful of all are these giants of the ocean. Chomping on lettuce, Monica and I fed these behemoths towards the end of the day from the open top of the tank. Green Turtles like Boris and Phoenix become vegetarian as they grow up, and so adult like them are fed lettuce, although they still try to steal food, like squids, from the others animals. In order to remain true to their natural diet, which would consist of seaweeds and kelp, the aquarium makes sure to avoid giving them any kind of meat.
Green Turtles, also known as Chelonia Mydas, are found across the globe, as far north as Britain and south Alaska, and as far down as The Cape of Good Hope. They have particularly large nesting grounds in areas of the Caribbean and Indo-Australia, where they will climb onto land to lay their eggs. Rain Island in the Great Barrier Reef is a huge hotspot for these amazing animals, with many thousands of them dragging themselves up the small strip of land in order to find the best spot to conceal their eggs. Going onto land can be vary dangerous for them, so they will make the journeys from dusk until dawn, to avoid being caught out in the baking sun. Unfortunately as the tide moves out, many turtles cannot make it back to land and are caught left as food for birds and scavengers.
Adult Green Turtles are about one and a half metres in length and can weigh up to 200kg, although certain exceptional specimens have been up to just under 400kg. Their bodies are a brownish colour, although some individuals have a more mottled pattern. Hatchling start off jet black, with a yellow or white underbelly, and as they grow, begin to develop their unique colour and pattern on the shell, that allows humans to identify individual members of the species. The tails of males are far larger and longer than those of females, which makes it easy to sex the turtles. They are rather unremarkable when compared to their close relatives, with most differences occurring around the mouth and head area, although they are the only turtle that become a herbivore when it matures. Peculiarly, the ‘green’ in the name does not feature visibly on the turtle, instead being attributed to the greenish fat layer beneath the skin. They were named by sailors who hunted and ate them on their long voyages.
The heavy shell of all larger turtles makes for a safe life of eating jellyfish and nibbling on sea kelp, but tiger sharks are still a valid threat to an adult sea turtle. The Tiger Shark has a massively powerful bite, beaten only by the Bull Shark (as well as the Nile and Saltwater Crocodile), and it more than capable or crushing through the shell of a Green Turtle in a couple of bites. As such the adult turtle will turn its body on its side in order to present as larger surface to the shark, which it cannot get its mouth around. Tiger Sharks will often wait for dead turtle bodies to be washed into the ocean of laying season, since they provide easy sources of protein. In this way, turtles are still relatively safe from these sharks, who would rather find an easier target. Juvenile turtles, however, are in much greater danger of being eaten. Eggs are dug up my land mammals as nutritious snacks, birds snatch newly hatched turtles from the sand as they run for the sea, and crabs will easily tear a baby turtle limb from limb. Luckily, with such a large number being born every year, turtles are fairly safe from their natural predator. Unfortunately, turtles are hunted for their flippers to be used as food and ‘traditional medicine’. It is a horrible waste of life, and needs to be stopped if we are to conserve these gentle giants for the future.
I had a brilliant time with Boris and Phoenix, and I must confess that I really love turtles, be they green or loggerhead. Here’s hoping that I have many more opportunities to see them in the future.