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How do sea creatures navigate across thousands of miles of ocean with such remarkable accuracy? Scientists know that each ocean has a different magnetic signature which identifies it clearly from all the other oceans. However, scientists did not know whether sea creatures were aware of such magnetic variations. Recently, studies prove that sea turtles and salmon read a “magnetic map” of their native region and imprint it in their memories. Scientists suspect that sharks and whales use similar techniques to locate where in the ocean they are when travelling over very long distances.

Like many other sea creatures, salmon and sea turtles migrate over vast distances and over long periods of time. However, both these species always return to lay eggs in their home waters. Salmon for example, spend several years at sea but return to spawn or reproduce in the exact same river they were born in.

Researchers used to think that salmon found their way home by “smelling” through their gills. However, new systematic research now shows that this technique for identifying a location only works on a very local basis over short distances.

Scientists also speculated that marine species use hydrodynamics – or the way currents and waves create patterns in water movement when they interact with the ocean bed and shorelines – as a way of charting their position when travelling through the ocean. Again, extensive research suggests that, while useful to some species, hydrodynamics is not the key to successful ocean navigation.