Fact: Turtles have existed for around 215 million years
Many non-divers will groan as you start telling another diving story after your diving holiday. Yet as soon as you mention the word ‘Turtle’ you will have their full attention, Even an ‘aww’ may leave their lips as you account your tale of a dive with a turtle.
There are many different types of turtles: Loggerhead, Green, Hawksbill, Leatherback, Flatback to name but a few. There are 11 families of turtle with over 200 species.
Turtles mostly eat jelly animals, and often die from eating man-made plastic bags which they mistake for food. Turtles are distributed all over the world apart from the poles; although there has been a tropical turtle fossil found in the arctic due to the warming seas. An interesting article written on the subject: (http://www.wired.com/wiredscience/2009/02/tropical-turtle/)
The world’s largest marine Turtle is the Leatherback turtle (Dermochelys coriacea) it can grow to 2.8m it is also the fourth largest modern reptile behind three crocadilians, it eats jelly animals and is listed as Critically Endangered by IUCN (International Union for Conversation of Nature).
Leatherbacks don’t have a really obvious shell, instead they have bones buried in their blackish or dark brown skin. The flexible internal shell allows Leatherbacks to withstand water pressure so they can dive deeper. They also differ to other Turtles because they do not have claws on their fins.
There is a large global decline in sea turtle numbers due to many causes including: habitat destruction, poaching of eggs and adult turtles, and coastal development. Fishing is a large contributor to Turtle deaths. Hundreds of Turtles have died due to being caught as by-catch. There are also a large number of deaths due to speedboats and water-skiers.
The year I learnt to dive in Perhentian Island, sadly I met a turtle which many divers in the area knew by the name Tripod. ‘Why did he have this name?’ I hear you ask. He only had three legs after a suspected accident with a speedboat, his shell was dented yet he seemed quite happy to let us approach and take pictures. Sea turtles come to the surface to breathe or bask in the sun and are vulnerable to passing boats. Propeller wounds and other related deaths are a major cause of sea turtle mortality, and injuries are very common.
It is a shame really, although villages on islands where the turtles are layed used to forage for turtle eggs and eat them, nowadays they set up nurseries for the eggs. Tourists can pay a small fee to release the turtles on the beach when they have hatched and are ready to enter the water. These days there are a lot of people who are helping the turtles, which could be a hopeful sign for the future.