According to new research, sharks use the Earth’s magnetic field to navigate long-distance journeys across the oceans.
According to the researchers, their marine laboratory experiments with a small shark species confirm long-held speculation that sharks use magnetic fields as navigation aids – behavior observed in other aquatic animals such as sea turtles.
According to marine policy specialist Bryan Keller, one of the study’s authors, their study, published this month in the journal Current Biology, sheds light on why sharks can traverse seas and find their way back to feed, breed, and give birth.
“We know sharks respond to magnetic fields,” Keller explained. “We had no idea they had detected it to use as a navigational aid… Sharks can travel 20,000 kilometers (12,427 miles) and end up in the same location.”
For years, researchers have been intrigued by the question of how sharks perform long-distance migrations. The sharks travel in the open ocean, where few physical features, such as corals, can serve as landmarks.
In search of answers, scientists at Florida State University decided to study bonnethead sharks, a type of hammerhead that lives on both coasts of the United States and returns to the same estuaries year after year.
The researchers subjected 20 bonnetheads to magnetic conditions that simulated locations hundreds of kilometers (miles) away from where they were caught off the coast of Florida. According to the scientists, the sharks began to swim north when the magnetic cues led them to believe they were south of where they should be.
According to Robert Hueter, senior scientist emeritus at Mote Marine Laboratory & Aquarium, who was not involved in the study, the findings are compelling.
Hunter believes that more research is needed to determine how the sharks use magnetic fields to determine their location and whether larger, long-distance migrating sharks use a similar system.
“Even if sharks are sensitive to magnetic orientation, the question has always been raised. How do they use this sense to navigate the oceans? These authors have made some headway in addressing this issue, “He stated.
The study, according to Keller, could aid in the management of shark species, which are in decline. According to a recent study, the global abundance of oceanic sharks and rays decreased by more than 70% between 1970 and 2018.
Researchers believe that the bonnethead’s reliance on the Earth’s magnetic field is shared by other shark species that travel across the ocean, such as great whites. Keller believes that magnetic sensitivity evolved in bonnetheads but not in other traveling sharks.