WSP00173

• File Number: 8240.200.10.A
• Description: UCRBRIP Habitat Restoration
• Basin: Colorado Mainstem
• Date: 10/8/1997
• Author: UCRBRIP
• Title: Final Habitat Restoration Program FY 1998 Work Plan Part 2
• Water Supply Pro - Doc Type: Publication

OS/22/98

spawning will be able to sustain the populations when other Recovery Program elements are implemented.

Primary Refu!!es. Two primary refuges are needed for broodstock development: one for the Green River
and one for the Upper Colorado River. The Ouray National Fish Hatchery will be fully operational in FY98
to meet immediate and short-term captive-reared endangered fish as a primary refuge and is considered the
primary refuge for the Green River. Ouray National Fish Hatchery being constructed will consist of a
hatchery building, ozone water treatment building, 36 ponds with 10.8 acres of surface area and a
consitioning pond. The Grand Valley Endangered Fish Facility has been designated as the primary refuge
for endangered fish stocks from the Upper Colorado River. This facility is composed of a hatchery building
with a reuse water supply, 3.5 acres of ponds at the HorsethiefState Wildlife Area, and a 5.0 acre growout
pond near the confluence of the Gunnison River wi.th the Colorado River (Clymer's Pond).

Primary refuges are intended for developing and maintaining brQodstocks and for production of fish for
priority research experiments. These refuges should have the capability to maintain wild adult endangered
fish and spawn these fish using breeding strategies identified in the Genetics Management Guidelines to
produce pedigreed family lots. Pedigreed family lots from paired matings requires the construction of small
ponds (0.2-acre) to rear the fish until they are large enough for PIT-tagging when family lots can be
combined. Small ponds (0.2-acre) are considered optimal for rearing endangered fishes in pedigreed family
lots to maintain genetic diversity. Growth rates of razorback suckers, bonytail, and Colorado squawfish have
about twice the growth rate offish cultured in raceways. However, raceways or other propagation facilities
may be needed to physically condition captive-reared endangered fishes so that they are able to cope with the
riverine environment and to escape predators. A primary refuge would also be used to rear larvae until the
paired fms have developed for stocking into growout ponds since this strategy increases the survival of fish.

Back"" Refu!!es. The main purpose of backup refuges is to maintain priority endangered fishes to prevent
catastrophic loss of an Upper Basin stock or to maintain broodstocks or fish for long-term research
experiments such as the chemoreception study to determine if Upper Basin stocks imprint. Endangered fish
that are maintained in backup refuges would not be handled very often.

Although there is concensus that priority captive-reared fish should be maintained in backup refuges as a
safety precaution against catastrophic loss, a backup refuge could be simply a pond with a reliable water
supply in a secure area. Modification of existing ponds for ease of collecting endangered fishes can be
accomplished inexpensively by sloping the pond bottom and installing a fish trap.

Therefore, various sites could serve as backup refuges. The ponds should be located above the 50-year
floodplain to prevent the uncontrolled loss offish from overbank flooding. Small ponds are not necessary as
backup refuges because all of the fish will be PIT-tagged for future recognition. Ponds that are 0.5-acre to
multiple-acres in size with sloped bottoms that empty into a kettle or fish trap would be ideal for backup
refuges. The pond bottom does not have to be lined in backup refuges.

The backup refuge for Green River stocks and upper Colorado River stocks will be Wahweap State Fish
Hatchery UT.

Growout or Production Ponds. The Recovery Program participants have established a high priority for
stabilizing the razorback sucker stock in the Middle Green River and for reintroduction of the razorback
sucker in the Upper Colorado River. The excellent growth exhibited by this species in predatory-free off-
channel impoundments along Lake Mohave (T. Burke and G. Mueller, 1995, Personal Communication),
Wahweap State Fish Hatchery (L. Lentsch, 1995, Personal Communication), and gravel-pit ponds along the
Colorado River in the Grand Valley (Osmundson and Kaeding 1989) demonstrates that elaborate
propagation facilities are not required to produce fish for reintroduction stocking in the Upper Colorado'
River Basin.

The potential sites for growout production ponds on the Green River are being explored. Potential sites for
growout or production for the Upper Colorado River include the Ouray National Fish Hatchery, ponds on the
HorsethiefState Wildlife Area, gravel-pit ponds along the Colorado and Green rivers, and Wahweap State
Fish Hatchery. The immediate and short-term needs for growout is 3.5 acres of additional ponds for
production of razorback suckers to be stocked in the Upper Colorado River. The same amount of space (3.5
acres) would be required for rearing razorback suckers for stocking the Green River. Larger ponds (e.g. 1.0
to 3.0 acres) can be used for growoutproduction facilities and it is nut necessary for the ponds to be lined.
However, it may be desirable for these ponds to have a sloped bottom and a fish trap at the outlet to collect

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