10 Incredible Sea Turtle Facts to Celebrate World Sea Turtle Day

Slow and steady wins the race. It’s a sentiment that has shadowed turtles for years, and perhaps, for good reason. Turtles are slow, but wise. Sea turtles, however, are nothing short of amazing. Sea turtles begin life with a single tooth. If they survive the journey to the ocean, they travel incredible distances, losing that tooth along the way before appearing in locations around the world.

Sea turtles are part of the order Testudines. Within that grouping (the superfamily Chelonioidea) are seven sea turtle species, including the green sea turtle, leatherback turtle, and loggerhead sea turtle.
They are one of the most widely distributed creatures on the planet, traveling thousands of miles between breeding and nesting grounds. Due to climate change and overfishing, however, six of the seven sea turtle species are considered threatened with extinction, according to the IUCN Red List. In honor of World Sea Turtle Day, let’s learn 10 amazing facts about these graceful swimmers and boost the profile of a precious, endangered creature.

Temperature Gender Reveal

Once the deed is done, female sea turtles return to land and lay between 50 and 350 eggs in a grouping called a clutch. The gender of those soon-to-be-born sea turtles depends on temperature-dependent sex determination. If the temperature is warm, the eggs will produce female hatchlings. If temperatures are on the cooler side, the eggs will produce male hatchlings. Once they hatch, baby sea turtles leave their shells behind, crawl across the beach, and disappear into the sea. It should be noted, however, that fluctuating temperatures will produce a mixture of male and female sea turtles.

The Lost Generations

Scientists are good at studying baby sea turtles and mature sea turtles, but they struggle with those intermediate years. For a long time, tracking younglings as they made their way through the ocean proved incredibly difficult. Known as the “lost years,” the juvenile period of sea turtles, which can last up to twenty years, remained a mystery.

At best, scientists assumed that young sea turtles simply drifted with the ocean currents. A recent study published in Proceedings of the Royal Society B, however, challenged that assumption. The study tracked 114 wild-caught juvenile turtles between 2011 and 2022. The authors found that instead of drifting with the currents, juvenile turtles often moved between shallow and deep parts of the ocean. As such, the authors recommended defining these lost years as spanning from the “oceanic stage” to the “dispersal stage” to better reflect the turtles’ adaptive behaviors.

Deep Sea Divers

As reptiles, sea turtles breathe air. But that doesn’t mean they can’t forgo oxygen for extended periods of time. Sea turtles with hard shells can dive to depths of 980 feet or more. It’s leatherback sea turtles, however, that beat out any of their relatives for diving prowess. Leatherback sea turtles can dive down to 3,280 feet, where pressures are brutal and temperatures are freezing cold. Sea turtles can accomplish these deep dives thanks to special adaptations that allow them to hold their breath for long periods. Leatherback sea turtles, in particular, can store oxygen in their blood and tissues, which lets them stay down in the murky depths for up to 85 minutes.

You Are What You Eat

As the saying goes, “You are what you eat.” This is especially true for the green sea turtle, a type of turtle that’s found in subtropical and temperate regions of every ocean. Adult green turtles are mostly herbivores. While they sometimes eat invertebrates and animal matter, they mostly subsist on plants like seagrass and algae. Their shells might be green, but green sea turtles get their name from their green-colored fat, which is believed to be colored by all the green plant matter that they eat. Whatever the case, green turtles live up to their name by chowing down on all the best plant matter the ocean has to offer.

No Teeth, No Problem

Most animals are born without much in the way of teeth, which develop as they age. Sea turtles, however, take the opposite approach. Baby sea turtles are born with a single tooth called a caruncle. This helps them break out of their shell and dig through the sand on a perilous journey toward the ocean. The caruncle, an upper jaw extension, falls off soon after they’re born. It’s there just long enough to help the babies get into the water.

Adult sea turtles have no teeth. Instead, they use their beaks to break up food. Green sea turtles have serrated edges inside their beaks that function similarly to teeth. Leatherback turtles, on the other hand, grab and break up food using their sharp beaks. Inside their mouths and throats, they have backward-pointing spines that help hold food, such as salps and jellyfish.

Massive Migration

Sea turtles are the most widely distributed marine reptiles on Earth. They accomplish this breadth with the spirit of a marathon runner. Sea turtles are known to travel thousands of miles during migration seasons. For a species like the leatherback turtle, these migrations can take them as far as 3,700 miles between breeding and feeding locations. What’s more, one female leatherback turtle holds the record.

While tracking the migration of leatherback turtles, scientists discovered one individual that truly went an amazing distance. In 2008, a female leatherback was tracked by a trans-Pacific satellite as it made an arduous 12,774-mile journey from Papua, Indonesia, to the coast of Oregon in the United States. The signal was subsequently lost, so there is a good chance this female traveled even farther. What’s even more amazing is that this female likely navigated her way across the world by detecting the Earth’s magnetic field and using it for navigation.

Manicure Magic

As previously mentioned, scientists struggled with tracking juvenile sea turtles for decades. These younglings were simply too small to tag in an effective, long-lasting manner. To solve this problem, scientists took a page out of Cosmopolitan Magazine: they discovered that a neoprene-silicon attachment with an acrylic base-coat kept tags on young turtles for over two months. This is the same chemical mixture used to make fake fingernails.

Plastic Problems

Everyone knows that plastic pollution is a big issue in the ocean. The Great Pacific Garbage Patch is a testament to the sheer amount of non-degradable material thrown into the water. The numbers are humbling; scientists estimated that about 8 million metric tons of plastic waste entered the ocean in just 2010.

This poses a serious problem for sea turtles, who often mistake plastic waste for food. Scientists estimate that about 52% of the world’s sea turtles have eaten plastic. This isn’t just an inconvenience; it’s a serious and sometimes fatal health risk for turtles. To make matters worse, plastic waste often traps sea turtles. Scientists estimate that at least 1,000 sea turtles die each year due to entanglement in plastic, though the actual number may be higher.

Exoskeleton Shells

A glance at sea turtles would make you think that their shells are separate from their bodies like snails. In truth, sea turtles are more like insects with amazing swimming capabilities. Sea turtles are classified into two categories: hard-shelled and soft-shelled. A turtle’s hard shell consists of up to 50 bones, with their ribs, shoulder blades, and vertebrae fused together to form an amazing piece of armor.

The only soft-shelled sea turtle is the leatherback turtle. It is distinguished by its hardy, leather-like shell replete with tiny bone deposits like those found in lizard scales. Scientists believe that leatherbacks have more flexible shells to meet the demands of deep-sea diving. While leatherback shells are made up of scale-like bony deposits, hard-shelled turtles have shells composed of beta-keratin, the same protein found in fingernails.

Long Lives

Say what you will about turtles, they are built for longevity. No other type of turtle lives longer than sea turtles. They have lifespans similar to humans, with many individuals living up to fifty years or longer. That’s likely because their maturation process is slow and steady. It takes sea turtles between two and three decades to mature. After that, they can continue to reproduce for another ten years or more. Keep in mind, however, that 50 years is just a rough estimate. One sea turtle named Myrtle had an impressively long life. She was estimated to be over 50 years old (some estimates put her closer to 90 years old), but there is no public record confirming her death or exact age.

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