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