Sharks use Earth’s magnetic field as natural GPS to navigate journeys: Scientists

A new research has found that the sharks use the Earth’s magnetic field as their natural GPS to navigate journeys covering long distances across the world’s oceans. Marine laboratory experiments with tiny sharks have found that these marine creatures use the magnetic fields that assist them to swim in vast oceans, a behaviour also observed in marine species such as sea turtles. The study was published in the journal Current Biology on May 15, and it shed light on how these gigantic creatures traversed across the oceans of the world and managed to find their way.  The experiment also outlines other survival details of the sea species such as their feeding habits, breed, and birthing, a marine policy specialist Bryan Keller, the lead author noted in the study. 

"The question has always been: Even if sharks are sensitive to magnetic orientation, do they use this sense to navigate in the oceans, and how?" researchers asked in the study published on Saturday. 

“This research supports the theory that they use the earth’s magnetic field to help them find their way; it’s nature’s GPS,"  Keller said, adding that how the sharks managed to successfully navigate during migration to targeted locations has been a decades-old question among the scientific community. The Save Our Seas Foundation project leader from the Florida State University Coastal and Marine Laboratory furthermore stated that year after year., as sharks navigated longer distances, they deployed sensitive electromagnetic fields to find their way into the ocean.

While science had long speculated the possibility, only until recently scientists were able to draw the evidence with the help of experiment in smaller sharks. “To be honest, I am surprised it worked,” Keller said. “The reason this question has been withstanding for 50 years is that sharks are difficult to study.” He further added, “The bonnethead returns to the same estuaries each year. This demonstrates that the sharks know where ‘home’ is and can navigate back to it from a distant location.”

Perceive displacement using magnetic ranges

Researchers used the magnetic displacement experiments to test 20 juvenile, wild-caught bonnetheads to be able to determine what guided their long sea journeys. While studying their behaviour scientists detected that the gigantic fished were taking cues from the magnetic fields to orient themselves and steer their course in the ocean. "sharks derive positional information from the geomagnetic field," they said, adding that their perceived displacement northward or southward was guided by the magnetic field's range that they used like the GPS.