8123

• UCREFRP Catalog Number: 8123
• Author: Wydoski, R. S.
• Title: Coordinated Hatchery Facility Plan
• USFW Year: 1994.
• USFW - Doc Type: Need for Captive-Reared Endangered Fish and Propagation Facilities.
• Copyright Material: NO

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Diversion Dam and Delta, Colorado) and where the endangered fish have
become extirpated because of habitat alterations (e.g., Colorado
squawfish in historic habitat upstream from the Highline Irrigation
Diversion Canal to Rifle, Colorado and bonytail throughout its historic
range in the upper basin).
Box 2. Opportunities for effective management of genetic resources in
endangered fish stocks in the Upper Colorado River Basin.
(These opportunities are listed by priority; Modified from
Riggs 1990).
Conserve endangered fish populations or stocks in the upper basin
for their genetic potential for recovery, applicable legal mandate,
or social or cultural values.
2. Facilitate natural recruitment of endangered fishes in the upper
basin to develop self-sustaining populations.
3. Maintain natural
situations where
necessary in the
genetic diversity of endangered fish stocks in
supplementation with captive-reared fish is
upper basin.
4. Employ breeding strategies that will result in genetic diversity
similar to wild stocks where stocking of captive-reared endangered
fish is intended to complement natural recruitment.
5. Augmentation or restoration stocking of endangered fish will
supplement or reestablish stocks in waters where little or no
recruitment occurs by native or naturalized populations.
6. Thoroughly evaluate the success of experimental stocking of
endangered fish prior to any large-scale augmentation or
restoration stocking.
E. Reasons for Maintaining Genetic Diversity in Captive Propagation Programs.
The major objective in captive propagation of threatened and endangered fish
species is to develop broodstocks and to produce offspring that have genetic
characteristics similar to those of the founding population. Two additional
objectives for captive propagation of endangered fishes are (1) to use
captive propagation and stocking when necessary as temporary fishery
management tools to facilitate recovery (i.e. development of self-
sustataining populations) of endangered fishes in their natural habitats in
the upper basin while preserving the genetic diversity of wild endangered
fish stocks and (2) to maintain genetic refugia for endangered fish species
or stocks that may be susceptible to extinction from declining numbers and
from catastrophic risk in the wild, until such risks are removed.
Breeding, rearing, and maintaining captive stocks such that genetic
diversity similar to wild stocks is maintained in each generation is
important in achieving this objective. Managing captive populations to
maintain existing natural genetic diversity preserves future options for
effective management and recovery of the taxon by fish and wildlife managers
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