8121

• UCREFRP Catalog Number: 8121
• Author: Williamson, J. H. and R. S. Wydoski.
• Title: Genetics Management Guidelines.
• USFW Year: 1994.
• USFW - Doc Type: Denver, CO.
• Copyright Material: NO

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

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