ABSTRACT
In sheer numbers, Pacific salmon are among the most widely cultivated fish on Earth, with approximately 4 to 5 billion fry and juveniles reared each year by various state, federal, and private hatcheries and farms. Most of these fish are reared to the smolt stage, at which time they are physiologically and behaviorally prepared to migrate from fresh water to the sea. After release, the salmon grow to adulthood in the North Pacific Ocean. As the fish approach maturity, they undertake a second migration to nearshore areas, where most enter capture fisheries. Capture fisheries are managed to permit sufficient escapement of mature fish to rivers where they spawn to perpetuate the year-class.
