Top 10 facts about marine turtles

1. There are seven species of marine turtle

Marine turtles were around more than 100 million years ago - and lived alongside dinosaurs. These days, scientists recognise seven species of marine turtle: 

1. Hawksbill
2. Loggerhead
3. Leatherback
4. Olive ridley
5. Green
6. Flatback 
7. Kemp's ridley

Six of these are threatened with extinction, and there's simply not enough information on the flatback to know how at risk they are.

2. Turtles don’t have teeth

They use their beak-like mouth to grasp their food. This beak is made of keratin (the same stuff your fingernails are made of).

3. They’re well ‘ard

Turtle shells are made of over 50 bones fused together - so they're literally wearing their bones on the outside.  

They also have light, spongy bones that help them float.

4. Their young lives are a mystery

The first few years of a marine turtle’s life are known as the ‘lost years’. That’s because the time between when the hatchlings emerge until they return to coastal shallow waters to forage is incredibly difficult to study. The lost years they spend at sea – which can be up to 20 years – largely remain a mystery to us.

5. They can be ginormous

Marine turtle species vary greatly in size. The smallest, Kemp’s ridley, measure around 70cm long and weigh up to 40kg, whilst the leatherback can reach up to 180cm long and weigh 500kg. That’s over 10 times heavier!  

Amazingly, Wales holds the world record for the largest marine turtle ever found. In 1988, a leatherback was found ashore measuring 2.5 m long, 2.5 m from flipper to flipper, and weighing over 900kg (that’s more than 140 stone)!

6. It’s survival of the fittest

It's estimated that only around 1 in 1,000 marine turtle hatchlings make it to adulthood. This is down to the long time it takes for them to reach maturity and the many dangers faced by hatchlings and juveniles – from predators to marine plastics. 

7. They make some interesting noises

Female leatherbacks make some strange noises when they’re nesting – some of which sound similar to a human belch.

8. Sad but less salty

Turtles may sometimes look as if they're crying - but they're actually getting rid of excess salt (from swallowing salty seawater) through a 'salt excretion gland' near the corner of their eye. The salt excreted from this gland can have a salt concentration twice that of seawater.

9. Life ain’t a track meet, it’s a marathon

Marine turtles can migrate incredibly long distances – the longest known record is for a female leatherback who swam nearly 13,000 miles over 647 days from Indonesia to the west coast of America. That’s over 20 miles a day.

10. They always return home

Females return to the same beach they hatched on, to lay their own eggs and bury them in sand ‘nests’. Marine turtles’ amazing ability to navigate comes from their sensitivity to the Earth's magnetic fields.

Photo credit: Olive ridley turtle returning to the sea after an "arribada" (mass nesting of females at the same time), Costa Rica © Carlos Drews / WWF