What are 10 interesting facts about Oahu’s Green Sea Turtles?

Dolphins have long amazed scientists and ocean lovers alike. They’re not just playful swimmers — they’re problem-solvers, social communicators, and fast learners. Their brains are built for more than just survival. In fact, their intelligence rivals some of the smartest animals on land. From complex tests to clever behavior in the wild, this post breaks down what makes dolphins stand out in the animal kingdom.

1. Green Sea Turtles Can Cry, But Not Because They’re Sad

You might see a green sea turtle with tears running down its face, but it’s not emotional. Those tears are actually a clever way to remove salt from their bodies.

Sea turtles live in saltwater and take in salt when they eat and drink.
Special glands near their eyes filter the extra salt from their blood.
The result? A steady stream of salty “tears” that help keep their body balanced.
These tears also help protect their eyes from sand and other debris.

2. They’re Named for Their Body Fat, Not Their Shells

Despite their name, green sea turtles don’t have green shells. Their name actually comes from something underneath the surface.

Their body fat has a greenish tint.
This green color comes from eating mostly algae and seagrass.
Scientists believe the diet changes the color of the fat over time.
Their shells can be brown, gray, or even dark olive, but not green.

3. No Teeth, But Watch Out for That Beak

Green sea turtles don’t have teeth, but that doesn’t mean they’re harmless.

They have strong, serrated beaks instead.
These beaks are built to slice through thick seagrass and soft plants.
The edges are sharp like a saw blade, perfect for grazing.
While they are not aggressive, a bite from one could hurt if provoked.

4. Their Diet Changes as They Grow

Green sea turtles start life eating one way and finish eating another.

Hatchlings are omnivores, eating small animals like jellyfish, shrimp, and sponges.
As they mature, they switch to a mostly plant-based diet.
Adults feed mostly on algae and seagrass.
This diet shift also plays a role in their digestion, behavior, and energy use.

5. They Help Keep Coral Reefs in Balance

Green sea turtles do more than just eat plants. They help protect the entire underwater ecosystem.

They eat large amounts of algae that grow on coral reefs.
Too much algae can block sunlight and suffocate coral.
By grazing, turtles keep the reef clean and healthy.
This allows fish, coral, and other marine life to thrive.

6. They’re as Heavy as a Refrigerator

These turtles are true ocean giants.

Adult green sea turtles can weigh up to 500 pounds.
Some can grow over four feet long.
Despite their size, they glide through the water with ease.
Their flippers are powerful and built for long-distance swimming.

7. They Navigate With Earth’s Magnetic Field

One of the most amazing things about green sea turtles is their ability to find their way across the ocean.

They use Earth’s magnetic field like a built-in GPS.
Hatchlings remember the magnetic signature of their birthplace.
As adults, they return to the same beach where they were born.
They can travel thousands of miles and still find their way back.

8. They Sunbathe on Land: But Only in Certain Places

Most sea turtles stay in the water, but green sea turtles in Hawaii have a special habit.

They come up onto beaches to bask in the sun.
This helps them warm up and rest safely.
Basking also saves energy by keeping their body temperature stable.
Few other sea turtle populations do this regularly.

9. Their Shells Hold Clues to Their Lives

A green sea turtle’s shell is more than just protection. It’s a record of their life.

The shell is made of scutes, or hard plates, that grow over time.
Each year, a turtle adds growth rings to these scutes.
Scientists can study the rings to estimate the turtle’s age.
Shell condition can also give clues about the turtle’s health and environment.

10. They Can’t Hide in Their Shells Like Land Turtles

If danger comes, a green sea turtle can’t tuck in its head and legs like a land turtle.

Their shells are flatter and built for speed, not defense.
They rely on swimming away quickly to escape threats.
Their flippers give them strong bursts of speed when needed.
Sea turtles evolved for life in water, not on land.

Quick Recap: Why Green Sea Turtles Are So Unique

They cry salt, not sadness
Named for their fat, not their shell
Have beaks instead of teeth
Diet shifts from meat to plants
Help coral reefs thrive
Weigh up to 500 pounds
Use magnetic fields to navigate
Bask on beaches in Hawaii
Shells grow rings like trees
Can’t pull into their shells for safety

Not Just Another Shell in the Sea

Green sea turtles are more than gentle swimmers, they are key players in marine life. With traits that range from high-tech navigation to coral reef care, they show just how incredible evolution can be. Next time you see one, remember you’re looking at millions of years of survival packed into one graceful creature.