There remains considerable uncertainty regarding the ability of artificial propagation to enhance population status and of hatchery production programs to function without adversely affecting other populations.
'Supplementation programs', on the other hand, involve the intentional demographic integration of hatchery and natural production, with the goal of improving the status of an existing natural population (Waples et al. 2007).
By any measure, the life of hatchery trout tends to be brief.
A new study suggests that large releases of hatchery steelhead salmon harm wild chinook salmon.
Steelhead from Topanga Creek and the Sweetwater River were partly, and those from San Juan Creek completely, of hatchery origin.
However, by 2006 and despite higher releases of hatchery fish from rivers in the area, the percentage of hatchery fish caught in the Strait of Georgia had dropped significantly [4].
Hatchery populations can be perpetuated solely by spawning hatchery-origin fish (segregated broodstock), or by spawning a combination of hatchery and wild fish (integrated broodstock).
Araki et al. (2007a) compared the fitness of hatchery females that mated with hatchery males versus hatchery females that mated with wild males.
With concerns over the role of hatchery programs for restoring wild populations, supplementation hatchery programs were designed to decrease negative hatchery impacts.
Furthermore, the Lake Saimaa and River Neva samples were of hatchery origin.
Recent analyses of hatchery practices have resulted in specific recommendations aimed at reducing the genetic risks associated with hatchery fish.
