F.M. Utter C.C. Krueger R.R. Reisenbichler 2003 <p><span>Genetic considerations can be crucially important to the success of reintroductions&nbsp;of lotic species. Current paradigms for conservation and population genetics provide guidance&nbsp;for reducing uncertainties in genetic issues and for increasing the likelihood of achieving&nbsp;restoration. Effective restoration is facilitated through specific goals and objectives developed&nbsp;</span><span>from the definition that a restored or healthy population is (i) genetically adapted to the local&nbsp;environment, (ii) self-sustaining at abundances consistent with the carrying capacity of the&nbsp;</span><span>river system, (iii) genetically compatible with neighboring populations so that substantial outbreeding&nbsp;depression does not result from straying and interbreeding between populations,&nbsp;</span><span>and (iv) sufficiently diverse genetically to accommodate environmental variability over many&nbsp;decades. Genetic principles reveal the importance of describing and adhering to the ancestral&nbsp;</span><span>lineages for the species to be restored and enabling genetic processes to maintain diversity and&nbsp;fitness in the populations under restoration. Newly established populations should be protected&nbsp;from unnecessary human sources of mortality, gene flow from maladapted (e.g., hatchery)&nbsp;or exotic populations, and inadvertent selection by fisheries or other human activities.&nbsp;</span><span>Such protection facilitates initial, rapid adaptation of the population to its environment and&nbsp;should enhance the chances for persistence. Various uncertainties about specific restoration&nbsp;</span><span>actions must be addressed on a case-by-case basis. Such uncertainties include whether to allow&nbsp;natural colonization or to introduce fish, which populations are suitable as sources for reintroduction,&nbsp;appropriate levels of gene flow from other populations, appropriate levels of artificial&nbsp;production, appropriate minimum numbers of individuals released or maintained in the population,&nbsp;and the best developmental stages for releasing fish into the restored stream. Rigorous&nbsp;evaluation or experimental management is necessary to reduce uncertainty in our knowledge&nbsp;</span><span>so that future conservation and restoration activities can be more effective.</span></p> application/pdf en American Fisheries Society Genetic concepts and uncertainties in restoring fish populations and species chapter