Green Sea Turtle

Chelonia mydas

One of Earth's oldest travellers, the green sea turtle navigates thousands of miles of open ocean guided by the planet's magnetic field — returning to the very beach where it hatched, decades later, to lay its own eggs.

Lifecycle stages

Stage 1

Egg

Females excavate a nest pit above the tide line at night, depositing 80–120 leathery eggs before covering them and returning to sea.

~60 days

Stage 2

Hatchling

Tiny hatchlings emerge together and race to the sea, guided by the horizon's reflected light. Most are lost to predators within hours.

Days to weeks

Stage 3

Juvenile

Survivors drift in open ocean currents, sheltering in floating sargassum mats and feeding on jellyfish and small invertebrates.

5–10 years

Stage 4

Sub-adult

Maturing turtles move to coastal feeding grounds, transitioning to a largely herbivorous diet of seagrass and algae.

10–20 years

Stage 5

Adult

Fully grown adults undertake epic migrations — sometimes 2,000 km — between feeding and breeding grounds, mating at sea every 2–5 years.

Up to 80 years

Lifespan

Up to 80 yrs

Sexual maturity

25–35 years

Clutch size

80–120 eggs

Conservation status — Endangered

Artificial lighting disorients hatchlings navigating to sea. Adults face entanglement in fishing gear, ingestion of plastic mistaken for jellyfish, and nesting beach erosion from sea level rise.