The salmon’s ability to smell out different kinds of water helps it to find the same fiver where it was born.

The journey of the Pacific salmon from its ocean home back to the freshwater stream at its birth is legendary.

The salmon spends most of its life in the ocean.  When the time comes for the salmon to spawn (lay its eggs), it leaves the sea and returns to the same river, to the very place it was hatched years before.

How does the salmon find its way home?

It follows its nose! It can smell the difference between the water in one stream and the water of another stream nearby.  (That scent is produced by dissolved materials in the water.)

“Remembering” the odor of the stream in which it was born, the salmon smells its way home, tracking the familiar scent like a bloodhound.

Battling swift river currents and facing many other dangers, the bruised and weary salmon finally reaches the spawning ground.  Here it lays its own eggs, then dies, and the Pacific salmon story begins again.  – Dick Rogers