An adult salmon is now in the ocean free from its spawning ground. Adult salmon spend 1 to 4 years in the ocean swimming and feeding throughout the Gulf of Alaska and the Bering Sea. They grow up to there adult size and develop unique adult markings that are .
The salmon run is the time when salmon, which have migrated from the ocean, swim to the upper reaches of rivers where they spawn on gravel beds. After spawning, all Pacific salmon and most Atlantic salmon die, and the salmon life cycle starts over again.
An alternative for these salmon species would be to spend more time in the ocean, accumulating food and energy so they are then able to migrate back after spawning. But this increases their risk of dying before getting the chance to spawn and for Pacific salmon, this is is a risk too great.
It is a difficult journey from egg to spawning adult. Only about two percent of all salmon hatched will live to adulthood. There are many natural predators of salmon - birds, fish, marine mammals, and disease. Human-made obstacles include harvesting, rive blockages, pollution, and poor habitat management.