Chinook salmon ‘internal GPS’ guides migration

VANCOUVER (NEWS1130) – A new study says Chinook salmon hatch with a kind of inherited magnetic map that allows them to find their way to ocean feeding grounds and back to their freshwater birthplaces to spawn.

Researchers wanted to know how juvenile fish find their way to specific areas of the ocean where they’ve never been before, but where their ancestors have foraged for generations.

It’s been a widely held belief that ocean currents carry salmon to these spots, but lead author Nathan Putman says that doesn’t appear to be the case.

Electrical currents, simulating Earth’s magnetic field, were placed around large buckets containing fish, and researchers found the salmon detect subtle changes and can use the magnetic fields like an internal GPS.

A previous study found that migrating sea turtles rely on magnetic fields, which Putman says shows how sensitive marine creatures are to even the smallest shift in magnetic pull.

Read more via Current Biology.