A total of 55 large tanks were reported at seven land-based hatchery locations, i.e., averaging 7.9 (range of 4 12) large tanks per land-based site.
Indeed, the location of hatcheries in the lower half of most of the rivers studied here likely separates many hatchery (which rarely swim upstream of the hatcheries) and wild spawners spatially.
For Chinook salmon in the Wenatchee River (case study 1), the distribution of spawning location differed between hatchery fish and wild fish and was negatively correlated with reproductive success.
In the case of Wenatchee River hatchery spring Chinook salmon, spawning location is likely to be largely determined by where the hatchery fish are released as juveniles, which is an environmental factor.
A within-population outbred cross was created by mating a single F1 male with one F1 female from Grovers Creek hatchery population within the Puget Sound in Washington State (location: 47.791016°N, 122.557983°W).
For example, hatchery fish might tend to return to spawning locations near their point of release, and if these locations happen to be in poor quality spawning habitat then the relative fitness of the hatchery fish would be reduced compared to wild fish spawning in higher quality habitat.
White embarked upon a search for potential locations for a state fish hatchery, and in the summer of 1877, he purchased the Maguire Springs and 2.5 acre near Romney from Charles Harmison of Valley View.
The reduced fitness of hatchery fish was consistently documented despite differences in geographic location, study species, hatchery practices, and analytical approaches.
It is possible that the original hatchery stock was established from individuals collected from multiple locations or that the effective population size of the wild population decreased following the establishment of the domesticated strain.
Details of the experiment location and initial set up of family crosses and hatchery procedure can be found in de Eyto et al. (2007).
