1Salmon begin their lives in small, cold rivers that flow far away from the open sea.
2When the young fish are old enough, they begin to swim downstream towards the ocean.
3In the ocean, they spend several years feeding and growing strong in the deep salt water.
4Then one season, something deep inside them tells the adult fish that the time has come to return.
5They swim thousands of kilometres back to the river of their birth.
6Along the way, they must jump up waterfalls and escape hungry bears.
7Amazingly, each fish manages to find the exact small stream where it was born years before.
8Scientists believe the salmon use the unique smell of their home water to guide them.
9Once they arrive home, the females lay their eggs in nests dug into the gravel.
10Exhausted by the journey, most of the adult fish die soon after this final effort.
11Their bodies then feed the forest, the birds, and the river that once raised them.
12It is one of the most extraordinary journeys in the natural world.