Study: Salmon Inherit A Magnetic GPS Map

Salmon Maps

New studies are indicating that salmon use the Earth’s magnetic field to position themselves and navigate in their respective waters.

According to Nathan Putman, along with colleagues from Oregon State University, the University of Washington, the University of North Carolina, and the Oregon Hatchery Research Center Chinook salmon can use this internal map to route themselves either back home or to migrate to their new homes. Whether they are directing themselves out into the seas and oceans or back into the freshwater streams, they always seem to know which way is the right way. It seems to be an unusual quality.

These salmon use this internal system by sensing changes in the intensity and the angle of the poles. Researchers proved this by putting salmon in buckets and changing their magnetic fields manually. If they simulated a northern change in magnetism, the salmon would change their direction south. Conversely, if they imitated a southern change, the salmon would change to a northern direction.

According tot he paper:

Migratory marine animals exploit resources in different oceanic regions at different life stages, but how they navigate to specific oceanic areas is poorly understood. A particular challenge is explaining how juvenile animals with no prior migratory experience are able to locate specific oceanic feeding habitats that are hundreds or thousands of kilometers from their natal sites. Although adults reproducing in the vicinity of favorable ocean currents can facilitate transport of their offspring to these habitats, variation in ocean circulation makes passive transport unreliable, and young animals probably take an active role in controlling their migratory trajectories.

Scientists also believe this sense is instinctive and it is some sort of internal map. Of all the salmon that were introduced into this experiment, none had been introduced into actual migration. All tests were simulated and showed they changed direction in relation to magnetism. Whether trying finding their way back home or finding spawning grounds, this is a skill that is not learned. They are born with it.

On The Web:
Pacific salmon migrate with a ‘magnetic map’
http://www.bbc.co.uk/news/science-environment-26067065

Putnam, N. F., Scanlan, M. M., Billman, E. J., O’Neil, J. P., Couture, R. B., Quinn, T. P., Lohmann, K. J., and Noakes, D. L. G. (2014). An Inherited Magnetic Map Guides Ocean Navigation in Juvenile Pacific Salmon. Current Biology 24: 1-5. doi: 10.1016/j.cub.2014.01.017.