Salmon have a complex life cycle with several distinct stages. After hatching from eggs laid in freshwater, the young salmon, called fry, remain in the river for several months. They then undergo a physiological change known as smoltification, which prepares them for life in the ocean.

Once adult salmon have begun their migration back to freshwater, their bodies undergo more changes to prepare for spawning. Spawners adapt to freshwater, their coloring changes, and some grow humped backs or hooked jaws.

Click on the following numbered steps to read about the different components of the salmon life cycle: 1. Salmon eggs, 2. Alevins, 3. Coho fry, 4. Smolts, 5. The Elwha River draining into the Strait of Juan de Fuca, 6. Coho migrating to spawn, 7. Sockeye spawning, 8. Dead salmon after spawning.

When they reach sexual maturity, the adults return to the upstream rivers to reproduce. Usually they return with uncanny precision to the natal river where they were born, and even to the very spawning ground of their birth.

The spawning stage is the start of the salmon lifecycle. Adult salmon return to their birthplace in freshwater. Here, females create gravel nests to lay eggs. Males then fertilize these eggs. Both females and males ensure the continuity of their species. After spawning, most salmon die.