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1 <br /> <br /> <br /> <br />i <br />t <br /> <br />F <br /> <br />1 <br />1 <br /> <br /> <br /> <br /> <br />1 <br />Box 4. Genetic risks, hatchery activities causing such risks, and genetic <br />processes related to these risks (expressed ad changes from natural <br />patterns). Modified from Kapuscinski et al. (1993). <br />Genetic risk Hatchery activity causing risk Genetic process <br />Extinction Excessive numbers of adults removed from Increases in <br />wild stock or population for development genetic drift <br />of broodstocks. and inbreeding <br />Loss of genetic Low number of parents mated. Increases in <br />diversity with- genetic drift <br />in stocks or Inappropriate breeding design. and inbreeding <br />populations <br />Inappropriate fertilization method. <br />Captive breeding changes the natural <br />genetic diversity in families. <br /> Founders for broodstocks differ from wild <br /> or supplemented stocks or populations in <br /> genetic diversity, life history patterns, <br /> or ability to adapt to environmental <br /> changes. <br />Loss of genetic Broodstock collected from stocks or Immigration: <br />diversity among populations that are genetically Changes in <br />stocks or popu- unrelated to wild or supplemented genetic <br />tions interbreeding stocks or populations. patterns; <br /> Outbreeding <br /> depression <br />Inadvertent Broodstock not collected throughout Artificial <br />artificial of the spawning season. selection: <br />selection Disrupted <br />Mated adults are from a nonrandom patterns of <br />sample of their cohort with respect natural <br />to genetic performance traits because selection; <br />of nonrandom mortality during incuba- Changes in <br />tion, rearing, or holding. amounts of <br /> natural <br />Genetic swamping of wild stocks through selection <br />stocking of large numbers of closely <br />related individuals or unequal family lots. <br />25 <br />s