Early September brings coho salmon (Oncorhynchus kisutch) gathering in nearshore waters throughout Puget Sound and coastal areas, staging before entering rivers for their fall spawning runs. These "silver salmon" congregate in bays, estuaries, and along the coast, feeding intensively to build energy reserves for their upstream migration. Coho are distinctive with their bright silver sides, metallic blue-green backs, and small black spots on the upper tail fin. Most coho spend 18 months in freshwater streams as juveniles before migrating to the ocean, where they typically spend 18 months before returning to spawn. Peak coho runs occur from September through November, with fish entering rivers in waves following rain events. Coho populations have declined significantly from historical levels due to habitat loss and degradation, making many runs listed as threatened under the Endangered Species Act.