Sea turtle laying eggs

Sea turtles emerge at night on sandy beaches to lay eggs, an ancient ritual vital for species perpetuation.

About this subject

Sea turtles are reptiles that inhabit tropical and subtropical oceans but depend on beaches for reproduction. Females of species such as the loggerhead (Caretta caretta), green (Chelonia mydas), and leatherback (Dermochelys coriacea) migrate thousands of kilometers to the same beaches where they were born. In Brazil, the northeastern coast hosts major nesting sites, notably protected by the Tamar Project, including Praia do Forte (BA) and Comandatuba Island (BA).

Nesting usually occurs between September and March, at night. The female digs a hole with her hind flippers, deposits 80 to 200 spherical eggs, and covers the nest with sand, camouflaging it. Sand temperature determines the sex of hatchlings: higher temperatures produce females, lower temperatures produce males. This process makes turtles vulnerable to climate change, as global warming can skew sex ratios.

After about 45 to 60 days, hatchlings emerge and rush to the sea, guided by moonlight reflecting on the water. Urban light pollution disorients them, leading to predation or dehydration. Only one in a thousand hatchlings reaches adulthood. Other threats include bycatch, hunting, and habitat destruction. Conservation programs like Tamar (founded in 1980) have tagged and protected millions of nests, aiding population recovery.

Frequently Asked Questions

How many eggs does a sea turtle lay per clutch?

On average, 80 to 200 eggs per clutch, depending on species. Leatherbacks may lay up to 150, while loggerheads about 120.

Why is sand temperature important?

Temperature determines hatchling sex. Warmer sand produces more females, cooler sand more males. Global warming can skew this ratio.

Where do sea turtles nest in Brazil?

Mainly on the northeastern coast, including Praia do Forte (BA), Abrolhos (BA), and northern Espírito Santo, all protected by the Tamar Project.