The use of hatchery technology for the conservation of Pacific and Atlantic salmon

Hatchery technology has been employed for the conservation of Pacific (Oncorhynchus spp.) and Atlantic salmon (Salmo salar) for over 140 years. The initial societal paradigm was that nature is inefficient and hatcheries could be used to conserve stocks that were over utilized or suffering habitat degradation. Although these early hatcheries failed to meet their conservation objectives, they succeeded in developing the spawning-to-swimup fry culture technology used today. In the 1930s the paradigm shifted to artificial and natural production being equally effective and led to the closure of Federal hatcheries in areas with intact freshwater habitat. Hatcheries were maintained to mitigate for habitat loss from hydropower development. With the development of cost effective smolt production technology by 1960, the paradigm returned to nature being inefficient and ushered in the massive conservation utilization production of Pacific salmon that continues to this day. The early 1990s saw another paradigm shift with nature’s inefficiency recognized as being the foundation for evolution to maintain the fitness of salmon in their natural environment. This shift gave rise to a focus for hatchery technology to preserve stocks in their native habitats. Using hatcheries for preservation–conservation has become the norm for Atlantic salmon in the USA and Atlantic Canada and for Pacific salmon stocks listed under the Endangered Species Act in the USA or as species at risk in Canada.