9 INCREDIBLE FACTS ABOUT GREEN SEA TURTLES

Green sea turtles are one of the largest sea turtle species – and among the most remarkable animals in the ocean.

They are as old as dinosaurs and as heavy as motorbikes. They love swimming through tropical and warm subtropical ocean waters, feasting on seagrass and holding their breath for hours at a time. And they can be found right here in the warm coastal waters of Australia.

Fast Facts – What makes the green sea turtle unique

• They descend from an ancient lineage – sea turtles have existed for more than 120 million years, since the age of the dinosaurs!
• They can migrate extraordinary distances, swimming up to 2,600km between nesting and feeding grounds.
• Female sea turtles return to the same beach where they were born (or very close by) to lay their eggs.
• Sand temperature determines whether hatchlings are male or female, with warmer sand producing females.

Let's dive into nine incredible facts about the green sea turtle.

1. What do green sea turtles eat?

They say you are what you eat, and green sea turtles take that seriously. Unlike most sea turtles, adult green sea turtles are herbivorous and eat mostly seagrass and algae. In fact, their diet is so rich in greens that their fat turns green. It’s the green colour of their fat, not their shells – which are often brown or olive in colour – that gives them their name.

2. Where do green sea turtles live?

Green sea turtles can be found in tropical and subtropical waters around the world, often in coastal areas rich in seagrass and coral reefs. They nest in over 80 countries and live in the coastal areas of more than 140!

They love travelling so much that they can swim as far as 2,600km between feeding and nesting grounds. That’s like driving from Canberra to Alice Springs to grab lunch!

3. How long can green sea turtles stay underwater?

Incredibly, green sea turtles can stay underwater for up to five hours while resting, by slowing their heart rate to conserve oxygen. While they spend most of their lives beneath the surface, they do need to come up to breathe every 20 minutes or so. Only females will return to land, and only when it’s time to lay their eggs.

4. Do green sea turtles return to the same beach where they hatched?

Female green sea turtles are incredible navigators and return to the beach where they were born (or a nearby beach) to lay their own eggs. This usually occurs once they reach maturity, at about 20 to 35 years of age. Once there, they use their flippers to dig a hole in the sand and lay about 115 eggs (that’s about nine dozen for the eggheads among you).

5. How does temperature affect baby green sea turtles?

Whether a green sea turtle is born male or female depends on the temperature of the sand. Warmer sand – typically 29°C or higher – tends to produce females while cooler sand produces males. This is because of something called temperature-dependent sex determination, a type of sex determination found in many reptiles and some fish.

Unfortunately, as climate change causes temperatures around the world to rise, it is also creating a dangerous imbalance in the sex ratio of green sea turtles. Research has found that green sea turtles in the northern part of the Great Barrier Reef are almost entirely female, outnumbering males by at least 116 to 1. If this trend continues, too few males could limit breeding opportunities and put the species at risk.

6. How do green sea turtles hatch from their eggs?

Green sea turtles are born with a small, temporary ‘egg tooth’ (or caruncle) to help them break out of their shells. They then leave their nesting beach and make the often perilous journey across the sand to the ocean.

7. How long have sea turtles existed?

Sea turtles have existed for more than 120 million years – their ancestors swam alongside the dinosaurs.

8. How long do green sea turtles live?

Although we are still uncertain, it seems green sea turtles are in it for the long haul, with records of some living for at least 70 years, even a few reaching over 100.

No birthday letters from the King, however. As migratory animals, they have no fixed address!

9. Are green sea turtles endangered?

While no longer classified as Endangered globally, some populations of green sea turtles remain threatened. In Australia, they are still listed as Vulnerable, meaning they are at risk of becoming endangered. Climate change, habitat loss, pollution, unsustainable fishing practices and invasive species all put pressure on green sea turtles.

These ancient mariners survived millennia of natural environmental changes – from mass extinctions to ice ages and shifting coastlines. However, centuries of human pressure, as turtles were hunted for their fat, meat and eggs, led to major declines by the mid-20th century.

Fortunately, conservationists and communities have been working to help sea turtle populations bounce back by protecting nesting beaches, reducing bycatch and restoring vital habitats. In a major milestone, green sea turtles were globally reclassified on the IUCN Red List of Threatened Species, from ‘Endangered’ to ‘Least Concern’ in 2025.

Nevertheless, pollution remains a key threat, with turtles often mistaking plastic bags for food – sometimes with devastating consequences. One study estimated that at least 1,000 sea turtles die each year from plastic entanglement, though the true number is likely far higher.

In Australia, green sea turtles are still listed as 'Vulnerable' under the EPBC Act 1999. Global heating, habitat destruction, unsustainable fishing practices, invasive species, and pollution are pushing Australia’s globally significant wildlife, land and seascapes to breaking point, causing animals like the green sea turtle to be at risk of extinction.

How Australia’s new nature laws could protect green sea turtles

In November 2025, the Australian Government passed the biggest reforms to Australia’s nature laws in over 20 years, introducing stronger environmental protections and oversight, that should help us better preserve important feeding and migration habitats for species like green sea turtles.

Among other things, these reforms have tightened loopholes around land clearing, particularly in Great Barrier Reef catchments. This allows the government to enforce tougher environmental restrictions, helping reduce sediment and pollution runoff from land clearing that can smother the seagrass beds sea turtles rely on for feeding.

We can further safeguard important feeding and migration habitats for species like green sea turtles by creating highly protected marine sanctuaries. WWF is calling on the Australian Government to ensure a future for sea turtles by honouring its commitment to protect at least 30% of our oceans in marine sanctuaries by 2030.

You can show your support for this important goal below.

What is WWF doing to protect green sea turtles?

As the new nature laws are finalised throughout 2026, WWF-Australia is keeping pressure on the government to ensure these reforms result in meaningful change.

We are also advocating for governments to set more ambitious targets and accelerate action on climate change, as warmer water, severe weather and rising sea levels threaten sea turtle habitats and breeding patterns.

We are working to protect the reefs, islands and seagrass beds where green sea turtles feed and breed, keeping these habitats free from destructive fishing nets, plastic and chemical pollution. The Australian Government’s commitment to protect 30% of Australia’s oceans as marine sanctuaries by 2030 is an important step, but protections must be applied in the right places.

WWF-Australia is working with the government to provide data-backed research on sea turtles to ensure new legislation and policy decisions deliver the greatest impact. For example, our Blue Corridors for Turtles project connects turtle movement with genetics (using ShellBank), allowing us to map turtle migration routes from nesting sites to feeding grounds, and identify important marine turtle areas that matter most for protection.

We are also working to keep oceans free of the deadly plastic pollution that kills so much of our ocean wildlife, pushing governments to phase out single-use plastics and accelerate the transition to a circular economy for packaging.

How you can help protect green sea turtles

• Sign the petition for marine sanctuaries in 30% of our oceans, to urge the government to follow through on their commitment to fully protect critical habitats by 2030.
• Donate to protect sea turtles and our blue corridors.
• Adopt a turtle to protect spectacular sea turtles and their ocean home.
• Tune in to Scat Chat with WWF to learn about the weird and wonderful ways that animal scat is being used to help wildlife conservation.