7282

• UCREFRP Catalog Number: 7282
• Author: U.S. Fish and Wildlife Service, R. I. P.
• Title: Final Recovery Implementation Program for Endangered Fish Species in the Upper Colorado River Basin.
• USFW Year: 1987.
• USFW - Doc Type: Denver, Colorado.
• Copyright Material: NO

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4.3.1 Hatchery Research
A hatchery program should be conducted to determine: (a) whether hatchery-
reared populations will survive over the long term after being stocked into
the wild; and (b) whether there are hatchery capabilities to raise needed
quantities of rare species. If results show that healthy, genetically viable
hatchery-reared fish will survive and reproduce successfully over the long
term in the wild, a hatchery production program will be designed and
implemented (see Section 4.3.4).
Research will include controlled and monitored introductions of individuals of
rare species from a hatchery or from grow-out ponds (see Section 4.3.2) to
perform studies on migration behavior, imprinting/homing, spawning, long-term
survival and reproduction, interaction with wild populations, age of
introduction, etc.
In addition, fish culture research is needed to determine appropriate hatchery
loading densities, water requirements, water quality, and feeding rates for
the rare fish. An effort should be made to take advantage of the multiyear
research and production that has occurred in the Service's Dexter and Willow
Beach hatcheries (also see Section 4.3.3).
4.3.2 Rearing Areas (Grow-out Ponds)
1 Rearing areas for fry and young-of-the-year could be artificially created
through the use of grow-out ponds instead of hatcheries to accelerate growth
and increase survival. Such areas could be developed by altering existing
ponds. For example, in gravel pits near Grand Junction, Colorado squawfish
' have been raised in 1 year to a size that would take 3 years in the wild. The
Service is also successfully raising razorback suckers in grow-out ponds.
Sources of larval fish may include: (a) fertilized eggs, fry, and young-of-
the-year, obtained from hatcheries; (b) adult fish captured from the wild;
(c) eggs and milt obtained from wild adult fish; or (d) hatchery-stocked adult
' females and reintroduced milt from wild males. Predatory fish occurring in
these ponds would be removed prior to stocking of the rare species. After the
fish have been reared to the desired size, they would be released into the
nearby river through a channel. Different sizes of marked fish could be
released from the grow-out ponds to determine the relationship between size of
introduced fish and survival in the upper basin.
' 4.3.3 Hatchery Capabilities
Existing hatchery facilities will be evaluated to determine if they can
provide the number of hatchery-reared fish needed for the research program.
The numbers and ages of hatchery-reared rare fishes needed to conduct research
are listed in Appendix 6.4. These facilities must be capable of raising
disease-free, genetically healthy rare fish. If sufficient capability is not
available, modification of an existing hatchery facility could be feasible.
However, grow-out ponds may significantly reduce the need and costs for
hatchery facilities, since grow-out ponds would create habitat for the rearing
of rare fishes while decreasing the need for rearing ponds at a hatchery.

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