Chinook salmon navigate spawning journey through internal GPS

Everybody knows about the millions of chinook salmon who fill British Columbian rivers each year on an amazing migration. They travel thousands of kilometers from feeding grounds through ocean waters before fighting against swift river currents to return to spawning grounds where they spawn new hatchlings and then die. Juvenile salmon somehow head downstream to the ocean for their new lives before repeating the final journey back to spawning grounds and death.

However, nobody knew how salmon managed to know where they were going. Until now that is as biologists this week at Oregon State University’s Department of Fisheries produced a new study suggesting that B.C. salmon use magnetic fields in their heads to find their way home in Frazier River spawning grounds.

It’s kind of like an internal GPS system. Salmon have a magnetic map in their brains that allow them to sense and navigate where they’re going by reading the Earth’s magnetic fields. This ability has been found in birds, sea turtles, and even pooping dogs previously. Salmon utilize the ability even if they’re juveniles. They’re able to sense the intensity and inclination of the magnetic field guiding them on their journey to feeding areas and spawning grounds.