Time to Shell-ebrate the Humble Turtle!

Time to Shell-ebrate the Humble Turtle!

May 23rd is World Turtle Day so what better way to salute our favourite marine reptiles than an informative blog! There are 7 species of sea turtle in our oceans and currently six of the seven are facing extinction:

  1. Green turtles (Chelonia mydas) aren’t actually green. The carapace (shell) of a Green turtle is olive-brown in colour, marked with beautiful brown streaks and they have a smooth, bullet-shaped head. Adults weigh on average 110-200kg. It is only their body fat that is in fact green! They can also hold their breath for up to 5 hours.
  2. Hawksbill turtles (Eretmochelys imbricata) have an upper jaw that protrudes like a bird’s beak, hence the name. Their shells are often very ornate and they feed primarily on sponges and jellyfish. Mature adults weigh around 85kg and they are small in comparison to Greens.
  3. Kemp’s Ridley turtles (Lepidochelys kempii) are a similar size to a Hawksbill and have a smooth shell like the Green turtle, but it is lighter in colour. They are the smallest of all sea turtles at less than a metre, with an average weight of just 45kg.
  4. Loggerhead turtles (Caretta caretta) are most commonly found in the Atlantic and Pacific Oceans. They are the wrestler of the turtle world weighing in at an average 225kg with a long body (up to 1-5 metres), blunt large head and rough shell. Sadly they are often victims of longlines as they will scavenge on pretty much anything.
  5. Leatherback turtles (Dermochelys coriacea) are giants! Up to 500kg they have a black body and lachrymiform (teardrop) carapace which is more like leather than hard shell. This makes them most like their prehistoric cousins. They are the deepest divers and the farthest migrators. The largest ever Leatherback (900kg) was found in Wales of all places!
  6. Olive Ridley (Lepidochelys olivacea) is the second smallest sea turtle (weighing under 45kg) with an olive coloured skin and carapace. Found only in warm water they are solitary and prefer the open ocean. They are the most abundant of all turtles.
  7. Flatback turtles (Natator depressus) can be distinguished from other species by their flat pale grey-green shell. It does not favour long migrations, preferring the shallow, coastal waters of Australia and Papua New Guinea. No more than 100kg in weight they eat only soft-bodied prey. There isn’t really enough information about this species (identified only in 1988) to know if the Flatback is endangered or not.

Did you know?

  • It takes from 10 to 50 years (depending on the species) for a turtle to reach sexual maturity
  • Sea turtles return to the beach where they were born to lay their eggs, navigating via the earth’s magnetic fields
  • Females can lay up to 200 eggs in each clutch
  • The temperature of the nest determines what sex the hatchlings will be. Warmer temperatures produce more females while cooler temperatures produce more males 
  • It takes between 40-60 days for hatchlings to emerge and head for the sea
  • Only around 1 in every 1,000 marine turtle hatchlings make it to adulthood, no thanks to predators like birds and crabs, hunting by humans and also plastic pollution (like fishing nets and bags)
  • We have no idea where they go as hatchlings and for the next 20 years!
  • Turtle shells are comprised of fused bone and their beak is keratin (like your fingernails)

How you can help sea turtles?

Protecting sea turtle habitats is something you can do on a day-to-day basis. Reduce your single-use plastic waste, only have reusable shopping bags and bottles and never participate in balloon releases. Collect marine debris while diving or walking on the beach and always check when buying seafood if it has been caught responsibly. You can consult the Good Fish Guide from the Marine Conservation Society to see what the impacts are on the wider environment with their wild-caught seafood ratings. 

Get involved with a sea turtle conservation organisation such as Turtle Foundation, Seeturtle.org or any charity that helps with sea cleans and marine ecology projects like our partners Sea-Changers. As divers and snorkellers we should all be better ambassadors for the habitats of our favourite marine creatures and protect them for a healthy future.