Operating Hatcheries within an Ecosystem Context Using the Adaptive Stocking Concept

Annual differences in ecological interactions between hatchery origin fish and the taxa that interact with them should be considered when managing hatcheries because of the potential for impacts to target and non‐target taxa (i.e., taxa that are not the target of a management action). A major component of the traditional hatchery paradigm is to release approximately the same number of fish of the same species every year from the same location(s) regardless of ecological conditions. This paradigm occurs in integrated and segregated hatchery programs and generally ignores ecological feedback mechanisms within the environment that can reduce survival of hatchery and wild fish. In addition, it assumes that the carrying capacity of the environment is static and underseeded, which if incorrect can result in replacement of wild fish by hatchery con‐specifics. Furthermore, practitioners of the paradigm may not consider impacts to other species that are not the target of enhancement or assumes impacts to be acceptable. To address these issues, I describe an alternative approach that prescribes stocking in places and times when: (1) ecosystem indicators suggest that risks to non‐target taxa are acceptable, (2) the environment is near or below carrying capacity or density‐dependent impacts are considered acceptable, and (3) ecological feedback mechanisms are in a desirable state. Indicators can also be used to refine fish rearing and stocking practices to enhance ecosystem benefits. According to this concept, fish would not be stocked in places and at times where ecosystem indicators are unfavorable. Although there are many potential ecological, genetic, and economic benefits of context‐specific hatchery releases, the concept should be tested before it is applied broadly. This concept may be untenable in areas with legally‐mandated release locations and numbers, or unnecessary for hatchery programs where all management goals are met.