Modern salmon hatcheries in Alaska were established in five regions of the state in the 1970s, when wild runs of salmon were at record low levels. Initially conceived as a state-run system, the Alaska program has evolved in the private sector and is centered on private, non-profit, regional aquaculture associations run by fishermen and other stakeholders. Presently, Alaska has 33 production hatcheries (14 hatcheries have closed). Many release over 100 million young salmon annually; between 1.3 and 1.4 billion are released in total. In 1975, hatcheries produced fewer than 20,000 adult salmon. During the 1990s, the Alaska program produced 27-54 million adult salmon annually, which accounted for 14-37% of the annual common-property salmon harvest. It is second in size and productivity to the Japanese ocean ranching program (approximately 2 billion fry released annually, 50-70 million salmon harvested). Pink salmon (Oncorhynchus gorbuscha) and chum salmon (O. keta), which are species released into the oceanic environment as postlarvae, comprise >80% of the hatchery production. Protection of wild-salmon fitness and rigorous evaluation of hatchery contribution to fisheries have been emphasized throughout the development of the Alaska ocean ranching program. Strict regulation by public-agency geneticists, pathologists, and fishery managers of hatchery siting, hatchery capacity, and transport of salmon between streams has reduced risks to wild-salmon fitness. Recent implementation of mass-marking technology has enabled harvest managers to protect wild salmon in mixed-stock fisheries from unsustainable fishing mortality. Both hatchery and wild stocks have experienced high marine survivals since the late 1970s, resulting in record salmon harvests through the 1990s.
