Sea turtle swimming sun rays

Sea turtles glide beneath sun rays piercing the surface, a display of light and motion in tropical oceans.

About this subject

Sea turtles are reptiles that have inhabited the oceans for over 100 million years. Seven species exist worldwide, all endangered, such as the green turtle (Chelonia mydas) and loggerhead (Caretta caretta). They rely on sunlight to regulate body temperature as ectotherms. Sun rays penetrating the water create visual splendor and also indicate feeding and breeding areas. At the surface, turtles often bask under the sun to warm up and absorb vitamin D, essential for calcium metabolism.

Swimming toward sunlight is particularly observed during migration. Sea turtles travel thousands of kilometers between feeding and nesting grounds, guided by Earth's magnetic field and the sun's position. Diffuse underwater sunlight helps juveniles find warmer, food-rich waters, such as jellyfish and algae. In Brazil, the northeastern coast is an important nursery, notably protected by Projeto Tamar, which safeguards nests on beaches.

Unfortunately, light pollution on beaches can disorient hatchlings, confusing artificial lights with the moon's reflection on the sea. Additionally, global warming alters sand temperature, affecting the sex ratio of hatchlings (higher temperatures produce more females). The depiction of sun rays evokes conservation needs: keeping oceans clean and beaches dark is vital for these prehistoric reptiles to continue swimming under the sun.

Frequently Asked Questions

Why do sea turtles come to the water surface?

They come to breathe as lunged reptiles and to bask in the sun, regulating body temperature and absorbing vitamin D.

How does sunlight affect sea turtles' lives?

Sunlight guides migration, helps juveniles find food, and on beaches, sand temperature (influenced by the sun) determines hatchling sex.

What can we do to protect sea turtles?

Reduce light pollution on beaches, avoid plastic bags (which can be mistaken for jellyfish), and support conservation projects like Tamar.