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Green Sea Turtle

Green Sea Turtle Facts

Size 32-60 inches (80-150 cm)
Speed 1.5 mph (2.5-3 km/h) (on average)
Weight 150-420 pounds (70-190 kg)
Lifespan 40-50 years
Food Seaweed, algae; jellyfish (as juveniles)
Predators Tiger sharks
Distribution Atlantic, Pacific
Habitat Tropical and subtropical seas
Class Reptiles
Order Turtles
Family Sea turtles
Scientific name Chelonia mydas
Characteristics Large sea turtle with a hard shell

Main Characteristics

The green sea turtle is one of seven sea turtles and considered an endangered species. Its shell is olive green to olive brown. However, it wasn't named for the color of its shell, but for its body fat. It is green because it feeds primarily on algae and seaweed.

Green Sea Turtle Green Sea Turtle - Photo: OHishiapply/Shutterstock

Distribution and Habitat

Green sea turtles live in the Atlantic and Pacific. They can even be spotted in the Mediterranean. They usually prefer warm, tropical seas. They travel across the open ocean and search for food among coral reefs.


Life Style

The green sea turtle is a diurnal solitary animal. With its paddle-shaped flippers it moves elegantly and quickly through the water. It spends a lot of time in the open sea traveling between its nesting site and feeding grounds. It feeds on coral reefs.

Anatomy and Appearance

Size and Weight

The green sea turtle weighs 150-420 pounds (70-190 kg). Its shell measures 32-60 inches (80-150 cm) in length. Unfortunately, there are no more precise figures. The size and weight of these animals are difficult to determine because they rarely come to land.


The green sea turtle has an oval to heart-shaped body. The head is rounded. There are small scutes on its flippers and its head, which are brown and have yellowish edges.


The green sea turtle has a flat and streamlined shell, with five central scutes and four lateral scutes. They blend together seamlessly, creating a smooth surface.

Green Sea Turtle Green Sea Turtle - Photo: Mark Hunter/


The Second Largest Sea Turtle

The largest is the leatherback turtle. However, due to its soft shell, it isn't classified as a sea turtle in scientific terms.

The largest loggerhead sea turtle weighed 1,200 pounds (545 kg) and its shell measured 83 inches (213 cm) in length. This puts it in first place among turtles with a hard shell.

The largest green sea turtle weighed 870 pounds (395 kg) and had a shell length of 60 inches (153 cm). It is in second place.

Normally, the animals don't grow that big. On average, the green one is slightly larger than the loggerhead. The loggerheads weigh a little more. The two species are quite similar.


The green turtle begins life as an omnivore. When young, it feeds on jellyfish, sponges, crustaceans and invertebrates. Once it grows up, it turns into a herbivore. Then, it exclusively consumes seaweed and algae, using its sharp, serrated jaws to cut through them. It can survive for long periods of time without food.

Green Sea Turtle Green Sea Turtle - Photo: SaltedLife/Shutterstock



Green sea turtles travel long distances to reach their nesting sites. Some travel more than 1,615 miles (2,600 km) to get there.


Green sea turtles usually stay underwater for five minutes and then come to the surface to take a breath. However, when they sleep they can stay underwater for several hours at a time without coming up for air.


Green sea turtles need to sleep, too. To rest in a safe place underwater they look for a cave or a ledge. They secure themselves by wedging their shells between rocks, allowing them to rest undisturbed for hours.


The green sea turtle and the yellow tang have a symbiotic relationship. The fish cleans the turtle's shell by removing algae, parasites, and barnacles, while the turtle provides food for the fish. This mutual arrangement benefits both species.

Green Sea Turtle Green Sea Turtle - Photo: Andrea Izotti/

Senses and Abilities

Magnetic Sense

The green sea turtle has the remarkable ability to detect the earth's magnetic field, which it utilizes for navigation purposes.

Sense of Sight

Green sea turtles have excellent vision and are good at perceiving the colors purple and yellow.

Sense of Hearing

They can only hear very low sounds between 200 and 700 Hz. For comparison: Humans are able to hear sounds between 16 Hz to 20,000 Hz.

Green Sea Turtle Green Sea Turtle - Photo: Laverne Nash/Shutterstock

Life Expectancy

Green sea turtles live 40-50 years.

Enemies and Threats

Natural Enemies

Adult green sea turtles only have large sharks such as the tiger shark as enemies. However, the newly hatched babies are often captured by birds or crabs on their way to the water.


In previous times, the green sea turtle was targeted for consumption in soup. Regrettably, people continue to hunt them for their meat, which is seen as a delicacy along with their eggs.

Marine Transport

Green sea turtles are often injured by ship propellers from passing ships.

Fishing Nets

The green sea turtle is not only hunted for its meat, but also dies as a so-called “bycatch”. When the fishermen cast their nets, they actually want to catch fish, but the turtles get caught in them too. Although they can stay underwater for several hours without breathing, the stress and panic causes them to lose this ability. They drown within minutes.


Sea turtles go back to the same nesting site for their entire lives. However, due to the construction of hotels and harbors, they can no longer nest there. In addition, swimming people, snorkelers and divers disturb the animals.

Plastic Waste

For turtles, plastic waste looks like food. Plastic bags look like jellyfish, for example. The turtles suffocate or die because the plastic ends up in their stomachs. Researchers believe that 90% of green sea turtles have plastic in their stomachs.

Endangered Species

The green sea turtle is considered an endangered species. According to estimates, there are only 85,000-95,000 nesting turtles left.

How Can You Help Sea Turtles?

Eat less fish

Helping sea turtles is easier than you imagine. Fishing is the biggest problem. Not just for turtles, but for all sea creatures. If you eat less fish, fewer nets will be cast. So each and every one of us can help - from the comfort of our own home. Share the importance of sea turtle conservation with your friends and let them know how they can make a difference.

Snorkeling and Diving

If you see a green sea turtle while snorkeling or diving, you're very lucky! But please keep your distance and don't try to touch them. This means great stress for the animals.

Speak to Fishermen

At the beach you can often see people casting their fishing lines into the water. Turtles frequently swallow the hooks that are attached to the lines, resulting in death. Have a friendly conversation with the fishermen and educate them about the potential consequences.

Importance for the Ecosystem

Green sea turtles help maintain the balance of underwater ecosystems by consuming seaweed and algae, preventing overgrowth of plants in the ocean.

Green Sea Turtle Green Sea Turtle - Photo: Marti Bug Catcher/Shutterstock


The Return to the Place of Birth

To lay their eggs, females return to the place of their own birth. There are many good reasons for this. There are less enemies, they get easily in and out of the water, and the sand has the right temperature. By the way: The males also return to the nesting sites to mate with the females. om 89 degrees Fahrenheit (32 degrees Celsius) only females develop. After about two months they hatch and immediately run from the nest into the water.

The Nest

To lay its eggs, the green sea turtle moves a few meters across the sand. Once it finds a suitable spot, it uses its hind flippers to dig a hole 28-56 cm deep and lays 100-200 eggs in it. It then fills the hole with sand and returns to the sea. This takes about one to 1.5 hours. Over the next few weeks, the baby turtles develop inside their eggs. Up to a temperature of up to 82 degrees Fahrenheit (28 degrees Celsius) only males develop and from 89 degrees Fahrenheit (32 degrees Celsius) only females develop. After about two months they hatch and immediately run from the nest into the water.

Green Sea Turtle Green Sea Turtle - Photo: artographer34/

Fun Facts

The scientific name of the green sea turtle is Chelonia mydas.

The Green Sea Turtle Is Related To:

  • Flatback Sea Turtle
  • Hawksbill Sea Turtle
  • Kemp's Ridley Sea Turtle
  • Leatherback Sea Turtle
  • Loggerhead Sea Turtle
  • Olive Ridley Sea Turtle

Animals in the Same Biome:

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