Sharks use the earth’s magnetic field like a compass


Kenneth Lohmann, a professor of biology at the University of North Carolina who was not involved in the study, said: “This is a very interesting and clear proof that sharks are using the earth’s magnetic field as a kind of map.” Similar abilities are found in sea turtles. He said that this study shows that the ability to use magnetic induction navigation in seasonally migrating marine animals may be extensive.

Lohmann said: “This is equivalent to letting a child learn their home address.” When sharks are very young, they learn the magnetic “address” of their original estuary or bay. Even after walking thousands of miles, this information can help them return later. (He believes that they may not respond to the Tennessee magnetic message because it is not in the area they know.)

smallAlmon uses fragranceIn addition to magnetic data, they can also detect their spawning grounds, and sharks can do the same, especially at the end of the journey. Keller said: “For fine movement, I think smell plays an important role.” But he believes that the power of smell is not enough to guide them hundreds of miles.

exactly how is it Lohmann said it is still “a real mystery” that any animal can feel the magnetic field.One theory is that they have Magnetite crystals, It can feel the true north and it is embedded in a certain position in their brain or nervous system.The other is that the magnetic field affects the receptors in them Visual A system that superimposes colors or light patterns on its vision, such as augmented reality headsets. Maybe a light red appears in the north, and animals just follow this color.

Sharks also have pores in their snouts and noses, which are filled with Lorenzini’s ampulla, which are receptors for detecting currents in the water. Sharks search for prey by electrically inducing their heartbeat. Perhaps these receivers can also induce magnetic fields, or receive them indirectly by paying attention to their interaction with currents. No one has yet made a clear claim. Moreover, Lohman said: “There is no reason to think that all animals use only one mechanism.”

Research like Keller’s is very important because they help fill the long-term problem of how sharks achieve their massive migration and give humans a better understanding of how our ocean technology affects them. Kyle Newton, a biologist at the University of Washington in St. Louis, said: “It is indeed of great significance to the management and protection of these species.” He studied how stingrays use magnetic fields to navigate.

With the popularity of offshore wind farms, it is especially important to understand this, and it may disrupt these areas. The turbine converts wind energy into electrical energy and conducts it back to shore via underwater cables. Just as Keller’s cube uses electricity to mimic the earth’s magnetic field, underwater power cables also generate their own tiny magnetic field in the ocean. These anomalies may confuse animals, encourage them to swim the right route, or induce them to forage in an environment where there is no correct prey.

It is not clear whether any interference actually occurred. Newton said that these anomalies are small and may not have any impact at all. Or, they may make some animals more troublesome than others. But he believes that people need to study this possibility, lest we end up not derailing these important migrations. Newton said that because people cannot perceive magnetic signals, “we can easily ignore these things. They are just not within our radar range.” However, if we understand the stimuli that other animals can feel, we can be careful not to cause persistent cues Damage.

Update 5-10-2021 1:18 PM: Updated this story to correct the name of Kyle Newton University.

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