Green Turtle in the Maldives. A green turtle (Chelonia mydas) feeds on sea grass, The Maldives is one of the countries most seriously threatened by the effects of climate change like sea level rise and erosion. Its spectacular underwater world could also soon be under threat as reef corals are extremely sensitive to rise in sea water temperatures. 10/07/2008 © Greenpeace / Paul Hilton

Sea turtles live in the ocean. They don't loiter around so much as cruise the whole sea, taking in shallow coastal lagoons, stopping by seamounts, and crossing the open ocean on high seas highways, only ever returning to land to lay eggs.

They are truly creatures of the ocean. And they are pretty special.

Today is World Turtle Day – so what better excuse to shell out a bit of love and respect to these most iconic ocean ambassadors?

Turtles are ancient creatures, largely unchanged for many millions of years. The biggest turtle roaming our seas today is the massive leatherback, a turtle with a leathery shell that can grow to be as big as a double bed. But even they start life as a ping-pong ball sized egg.

Baby turtles are both criminally cute, and phenomenally fearless. Their first trial in life is a daring dash across the beach from where their mother laid eggs. Only the most fortunate and fearless make it to the sea by dodging predators such as birds, crabs and foxes. Teeny infant hero turtles!

Young leatherback turtle in French Guiana. Leatherback turtle hatchling. French Guiana, 1980. 01/01/1980 © Greenpeace / Jacques Fretey

Today's turtles are just tiddlers when compared to the extinct species Archelon. This 'Dino-turtle' was twice as long as today’s leatherbacks, with its head alone up to a metre in length.

Some turtles are named for the way they look, the loggerhead has a big head, and the hawksbill has a very pronounced beak. Green turtles though are named for having green fat under its shell, rather than describing what colour it is outside.

Different species have different tastes in food: from somewhat dull diets of jellyfish or sea grass, to sponges to crunchy crabs. Some are even known to snack on flying fish, which is pretty impressive catching.

Like other reptiles, turtle babies' gender is influenced by temperatures: hotter temperatures produce more females. A recent study showed this is an increasing threat to turtles as a result of climate change.

Six out of the seven of the world's species of turtles are in danger, from us - entanglement in fishing gear, habitat destruction, pollution and hunting have all taken their toll. Greenpeace is working to tackle destructive methods of fishing which catches and kills turtles, as well as climate change and pollution, and we’ve campaigned against the destruction of nesting sites.

But now we need your help to protect turtles' ocean homes.

We're working to establish a global network of protected 'ocean sanctuaries' on the open seas, areas beyond any one country's own jurisdiction. From the Mediterranean to the Sargasso, the North Pacific to the Bay of Bengal, protecting these areas will help our turtles.

So, on World Turtle Day please join us by adding your name to the call for ocean sanctuaries so we can lobby governments on behalf of you, and our turtle-y awesome flippery friends.

Willie Mackenzie is an Oceans Campaigner at Greenpeace UK.