Fish Use Magnets to Guide Their Journey
A recent study conducted by Oregon State University has found that Chinook salmon are born knowing exactly how to navigate back to their ancestral feeding grounds. Guided by the earth’s magnetic field, an inborn GPS-like sense of direction leads them back home when the time comes.
Science has shown that many animals use Earth’s magnetic field to navigate. However, only Chinook salmon and loggerhead turtles are thus far the only one’s scientists have found to have such impressive GPS-like directional awareness. Many migratory animals, like geese, learn the routes they take on their yearly migrations by following adults during adolescence. Though impressive, these multi-thousand mile trips are more learned behavior than instinct.
Testing the theory involved placing hundred of juvenile salmon in test tanks, after which researchers manipulated the magnetic field using electromagnetic coils. It was discovered that most of the salmon would orient themselves toward the magnetic source that most closely corresponded to their natural feeding territories. The researchers’ next step will be to determine just how precise the fishes’ internal navigation systems are; they hypothesize that these abilities are weaker in adolescence, and improve as the fish age. But, can their built-in GPSs get them within miles of their feeding grounds, or inches? Further studies hope to determine this.
The results, and the rarity of these magnetic field-guided traits, lead researchers to believe the other marine animals may also possess these unique migratory abilities.