Sea turtles are driven by the earth's magnetic field

Sea turtles always return to familiar areas to lay eggs. On average every 4 years, they swim in the ocean without any landmarks, moving hundreds, even thousands of kilometers, between the food-seeking area and the egg-laying area. They use a relatively simple navigation system that is the earth's magnetic field. The school helps turtles find their direction despite being swept away by the waves.

In order to understand this marine reptile positioning and sensory processes, French biologists of the Montpellier Center for Functional Ecology and Evolution and Italian colleagues at the University of Pisa have released children. Chelonia Mydas green sea turtles lay eggs in the Mozambique canal, on the islands of Europa and Mayotte. They were installed with an Argos pepper plug on the shell, a powerful magnet on the head and monitored via satellite during the return trip to the spawning area.

The first test proved that despite being released anywhere and regardless of the waves, these turtles still swim towards the spawning area. However, they are unable to change the journey when drifted by the waves, some of them swimming thousands of kilometers before arriving.

According to scientists, this determines that sea turtles use magnetic fields emitted by the earth's nucleus to locate the spawning area. But this is not the only source of information used, because they can still find the spawning area despite being swept away by the waves. Sea turtles can use their sense of smell as well as some seabirds or pigeons.

Chelonia Mydas green sea turtle (Photo: zoltantakacs)

Power