Green sea turtle (Chelonia mydas)

Taxonomy and identification

Adults have a streamlined carapace and paddle-like forelimbs adapted for swimming. The common name refers to the greenish color of the fat beneath the carapace, not the shell. Juveniles often have different coloration and diet compared with adults, and the species has been studied for regional variation in size and shell pattern.

Distribution, habitat and diet

Green turtles use a range of habitats: open ocean for pelagic juveniles, coastal seagrass beds and algal flats for adults, and sandy beaches for nesting. Adults are largely herbivorous, feeding mainly on seagrasses and marine algae, which helps maintain healthy seagrass ecosystems.

Life cycle and behavior

Females return to sandy beaches to lay multiple clutches of eggs, often showing natal homing to the region where they hatched. Incubation conditions can affect hatchling sex, and hatchlings face high natural mortality. Sexual maturity is reached only after many years, making populations slow to recover from declines.

Threats and conservation

Populations have declined due to threats such as fisheries bycatch, coastal development that degrades nesting habitat, pollution, illegal harvesting of eggs and turtles, and climate change affecting beaches and sex ratios. The species is protected by national laws and international agreements in many places; conservation actions include protected nesting sites, fisheries bycatch mitigation, habitat restoration, and coordinated monitoring.

Further information

• Ecological role: grazing on seagrass helps maintain coastal habitats.
• Conservation requires international cooperation because of long migrations.
• Research and monitoring guide management of nesting beaches and fisheries.

For more general taxonomic and conservation resources see relevant species summaries and family accounts at further reading.