Nature Calls: Sea Turtles

A few days ago I was caught in the Internet Vortex of Strange And Useless Stuff (familiar with this place?) when I stumbled across a charming sea-turtle’s-eye-view clip. I realized that everything I knew about sea turtles was gleaned from Crush in Finding Nemo. I figured most of them don’t speak like surfer dudes, so I wanted learn more about these venerable reptiles that have been around for 150 million years.

Sea turtles inhabit all salt water areas of the world, traveling thousands of miles between foraging areas and nesting sites. One female logged a 12,000-mile roundtrip from Papua New Guinea to the Northwestern US. How they migrate is still a mystery. One theory suggests they use the earth’s magnetic fields.

 

Green Sea Turtle

A green sea turtle at the New England Aquarium. © Lorianne DiSabato

There are seven species of sea turtles: green, hawksbill, loggerhead, leatherback, olive ridley, Australian flatback, and Kemp’s ridley. All are endangered or threatened. More on this in a moment.

Leatherbacks (Dermochelys coriacea), the largest of all sea turtles, can weigh nearly 1,000 pounds and measure more than 60 inches, but most are in the 100-pound range.

They eat mainly jellyfish and seaweed, but also feast on squid, barnacles, and sea anemones. Adult green turtles (Chelonia mydas) are solely herbivores, eating seagrass and algae.

 

Hawksbill Sea Turtle

Hawksbill Sea Turtle. © Caroline Rogers for US Fish & Wildlife Service

 

Non-exclusive arrangements

Sea turtles live anywhere from 50-80 years, but don’t become mature until 20 or 30 years old. Males never leave the ocean, while females come ashore only to lay eggs on beaches. (Except green sea turtles. Occasionally they can be seen sunbathing near albatross nesting sites.)

As nesting season begins, females often mate with several males. She stores the sperm for several months, meaning the eggs will be fertilized by many different males. In one season, she may lay between 65-180 eggs. This sounds like a lot of eggs, but many of the tiny hatchlings won’t survive the short but treacherous journey from sandy nest to the sea. Predators, from gulls to crabs to humans, lie in wait.

Leatherback hatchlings

Leatherback hatchlings at the Mabibi Beach, South Africa. © Jeroen Looyé

Endangered

The recent past has not been kind to sea turtles. Humans have built condos on their nesting sites, then installed glaring lights, disturbing their rhythms. (Beach lights are disorienting to hatchlings, causing them to stray inland instead of going to the sea.)  Fishing nets continue to ensnare them. Sea turtles face a unique kind of threat from climate change. It alters sand temperatures at turtle nesting sites, which affects the sex of hatchlings. The warmer it is, the more females in that clutch of eggs.

But…a small victory!  On April 4, the status of green sea turtles in Florida and Mexico was downgraded from endangered to threatened. I know this isn’t much, but it’s a step in the right direction. The population has rebounded from a handful to just over 2,200. This increase took nearly 40 years, so they’re not out of the woods. Efforts are being made to protect nesting grounds and reduce the use of fishing nets along coastlines worldwide. In the Mediterranean, South Pacific, and West Pacific, green sea turtles are still endangered.

Now for the clip that inspired this post…this female green sea turtle will take you on a quick tour of the Great Barrier Reef.

To learn more about sea turtles, visit the Sea Turtle Conservancy.

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34 comments

    1. This innate drive to head to the sea is indeed amazing. Given their tiny bodies, it’s quite a trek. I read that once they reach the water, they spend most of their time hiding in kelp and seaweed patches. It isn’t until they grow much bigger that they head out into the open water.

      Liked by 1 person

  1. Hi there! When I went to Edisto Island, SC a few summers ago, I learned from a local biologist all the efforts they are making in that beach area for hatchlings as well. In fact, rental units all include HUGE signs indicating that beach lights on at night during certain times of the year are strictly prohibited AND illegal — and that prosecution will ensue if the rules aren’t followed. While the plight of SO many animals hangs in this precarious balance — breaking my heart daily — I AM happy to see that mankind is trying to reverse some of these alarming trends.

    Liked by 1 person

    1. Thank you for sharing that story, Melissa. I’m so glad to know that beach communities are making these efforts to help the hatchlings. They are so delicate. And it’s really such a minor — inexpensive and not inconvenient — measure to take.

      Like

  2. Include me in the choir that loves that video! Was that sea turtle wearing a Go Pro camera? I hope things continue to move in the direction of their survival. They are magnificent creatures. If Lin Manuel Miranda could create a musical about them, possibly he could work his magic on their survival? I think Hamilton is staying put on the ten spot thanks to him.

    Liked by 2 people

  3. That video is absolutely amazing. It’s remarkable how effortless it looks — have to say it makes me wish I could swim that way for that long underwater. It’s been a long time dream to see hatching turtles on a beach, to watch the hatchlings make that journey. Enjoyed this post so much, Jackie!

    Liked by 1 person

  4. Love turtles–land and sea! 🙂 This reminded me of a long, wonderful passage from Will Harlan’s bio of Carol Ruckdeschel, UNTAMED. She played a big part in helping preserve land on Cumberland Island off the coast of Georgia where many sea turtles nest. There’s a section of the book that explores sea turtle migrations, touches on the theories of magnetic pulls for their navigation that you mentioned, and other interesting tidbits.

    Liked by 1 person

  5. Dude! That video is amazing! I was snorkeling in the Great Barrier Reef and saw all kinds of cool animals, had I seen this turtle I would have flipped my lid! They are such amazing creatures and so beautiful I love checking them out whenever we go to the aquarium. Lovely post my friend.

    Liked by 1 person

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