Sharks use Earth’s magnetic field to navigate
Just how do sharks navigate in their long-distance migrations? Scientists at Florida State University, USA, recently tried to find out. Bryan Keller, one of the study authors, said that sharks could respond to magnetic fields, but it was not known whether they could use this as an aid in navigation.
To test if sharks use the earth’s magnetic field to navigate, the team captured 20 juvenile bonnethead sharks (Sphyrna tiburo) off Florida. These hammerhead-like sharks return to the same estuaries every year. Placed in tanks, they were exposed to an altered magnetic environment. This tricked them into thinking they were hundreds of kilometres south from their capture location. So, the sharks tried to swim home by swimming north.
As the research paper stated: “Navigating thousands of kilometres to a target location through a three-dimensional ocean is among the most impressive feats in nature.” The sharks must first have built-in biological ‘hardware’ to detect the field. Then, they need sophisticated programming or ‘software’ to use it to navigate. For humans, the same feat would require high intelligence, learning, and directed application.
Unsurprisingly, the paper credited undirected evolution for these amazing abilities, rather than the supremely intelligent designer God of the Bible.
- Keller, B.A. and 4 others, Map-like use of the Earth’s magnetic field in sharks, Current Biology 31(Issue 13):2881–2886.e3, 12 Jul 2021.
- Whittle, P., Sharks use Earth’s magnetic field as a GPS, scientists say; apnews.com, 16 May 2021.
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