Sea turtle underwater

Sea turtles are ancient reptiles that have inhabited the oceans for over 100 million years, vital for the health of marine ecosystems.

About this subject

Sea turtles are reptiles of the order Testudines that inhabit all oceans except polar regions. There are seven known species, such as the green turtle, loggerhead, and hawksbill, all threatened with extinction due to human activities. These animals can weigh up to 900 kg in the case of the leatherback, the largest species, and live for over 80 years. They are highly migratory, traveling thousands of kilometers between feeding and nesting grounds.

Sea turtles depend on sandy beaches to lay their eggs, a process that usually occurs at night. Females return to the same beach where they were born to nest, a phenomenon known as philopatry. After hatching, the hatchlings face a dangerous journey to the sea, guided by the moon's reflection on the water. Only one in a thousand turtles reaches adulthood due to natural predators and human impacts.

The ecological importance of sea turtles is immense. They control jellyfish and sea urchin populations and transport nutrients between ecosystems. Their presence indicates ocean health. In Brazil, beaches such as Abrolhos in Bahia and Ilha do Cardoso in São Paulo are protected nesting sites by conservation projects like Tamar, which has been active for over 40 years.

The main threat to sea turtles is accidental bycatch in fishing nets and longlines. Plastic pollution is also fatal, as they mistake bags for jellyfish. Climate change affects sand temperature, influencing the sex ratio of hatchlings. Conservation actions, such as using turtle excluder devices in nets and beach cleanups, are crucial for the survival of these species.

Frequently Asked Questions

How many species of sea turtles are there?

There are seven species of sea turtles: green, loggerhead, hawksbill, olive ridley, leatherback, flatback, and Kemp's ridley.

Where do sea turtles nest in Brazil?

In Brazil, main nesting sites are the coasts of Bahia (Abrolhos), Sergipe, Rio Grande do Norte, Espírito Santo, and São Paulo (Ilha do Cardoso).

Why are sea turtles threatened with extinction?

Main threats include accidental bycatch, plastic pollution, nesting habitat destruction, illegal hunting, and climate change affecting sex ratios.