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

acute or chronic bioassays, homing (i.e., olfaction and chemoreception
studies), fish passage, taxonomy, anatomy, and physiology as well as
performance, fitness, and hereditary trials. Endangered fish specimens are
needed for use in public relations programs and to educate the public about
reasons for the fish being listed as endangered and the program to recover
declining populations. Augmentation stocking may be required to provide a
"jump-start" mechanism to supplement fish in habitats where the wild
populations are very depressed. Restoration stocking will be necessary in
river reaches where stocks have been extirpated. Such stocking will be
required to reestablish the bonytail in the upper basin and may be needed to
reestablish other endangered fishes in unoccupied river reaches within their
historic range.
Immediate (1 year) and short-term (2-5 years) needs for captive-reared
endangered fishes were identified for the Upper Colorado River Basin.
Long-term (5 years or longer) endangered fish needs could not be identi-
fied with certainty at the present time. Immediate needs involve
protection of wild stocks from becoming extinct. Short-term fish and
propagation facility needs involve development and maintenance of
genetically sound broodstocks in refuges and the production of captive-
reared fish for field and laboratory experiments. Long-term fish and
hatchery needs involve anticipated augmentation and restoration stocking.
Biologists agree that augmentation and restoration stocking should be
done as planned field experiments and approved by the appropriate Program
committees to ensure that the objectives for stocking are clear and
measurable with an identified timeframe and potential genetic risks to
wild fish are carefully evaluated.
The uncertainty for long-term needs is due, in part, to the fact that large-
scale stocking of hatchery-reared endangered fish to augment wild stocks has
not been well defined. Some of the unknown factors are the numbers of
captive-reared fish to be stocked, the size of the fish at release,
location(s) of releases, frequency of releases, and habitat requirements of
early life stages. Large-scale stocking may adversely affect the genetic
diversity in remaining wild stocks. In addition, vital information from the
ongoing genetics and systematic studies to identify genetically different
stocks will not be available until 1994 for razorback suckers and Colorado
squawfish. An interim report on the genetics and systematics of the Gila
chubs will be prepared in 1995 and a final report is scheduled for 1997.
Propagation and stocking should be considered only as an interim tool in
recovery programs since recovery, by definition, implies that the populations
or stocks will be self-sustaining. Past stocking of endangered Colorado River
fishes in the upper and lower basins have resulted in poor success.
Therefore, it is imperative to proceed cautiously with stocking. Many
biologists believe that it would be premature to conduct large-scale
augmentation or restoration stocking before genetics data are available, the
ecological requirements of the fish are understood, and the response of
existing fish stocks to streamflows, habitat restoration, and fish passage are
evaluated.
Biologists agree that the development of broodstocks with genetic diversity
similar to wild stocks and production of captive-reared fish for field and
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