Salmon uses magnet road map when travelling
USA: Research at the University of North Carolina, at Chapel Hill, has found that among other sea creatures, salmon uses a "magnetic map" when it migrates over large distances.
Dr. Kenneth Lohmann, professor of biology at UNC Chapel Hill is one of the researchers who have studied how ocean animals navigate when they migrate from one area to another.
The scientists have found evidence that salmon and sea turtles can read what they call the "magnetic map" of their native area and imprint it into their memories. It is believed that other species, such as whales, employ the same, or similar, techniques when they move around.
Dr. Lohmann believes that some organic regions have rocks which are rich in magnetic materials and therefore produce local magnetic anomalies. Earlier science has indicated that such magnetic activity may cause problems for some species, but now the same anomalies may serve useful for other species.
Though it's been known for a long time that the earth's magnetic field varies and each ocean has a different magnetic signature, scientists were not sure if animals could detect and use these differences.
It has been common belief that salmon utilized its smelling capabilities to find their way back to the particular river where they were born. Other theories have linked hydrodynamics to their "path finding" abilities.
As Lohmann and others are now beginning to show, many sea animals probably uses all these methods. However, they tend to lean towards magnetic navigation being the most important method.
