8058

• UCREFRP Catalog Number: 8058
• Author: Wydoski, R. S.
• Title: Annual Propagation Operation Plan 1996.
• USFW Year: 1996.
• USFW - Doc Type: Denver.
• Copyright Material: NO

of unknown pedigrees that are presently in captivity may be used
for broodstock.
In addition, 6,000 larval fishes were placed in a pond at the Ouray
Endangered Fish Facility to obtain razorback suckers for stocking
to stabilize and increase the numbers of the Middle Green River
stock to 1,000 adults. The larvae that were placed in the pond
include a mixture of species, including the flannelmouth and
bluehead suckers. Based on expected survival rates and proportions
of previous sampling and identification efforts, it is estimated
that about 25 razorback suckers would survive until October, 1996.
Some of the surviving razorback suckers will be maintained and
reared to be spawned for developing the Middle Green River
broodstock if the DNA fingerprinting technique can be used to show
that they are unrelated. The remainder of the razorback suckers
will be reared to an appropriate size for augmentation stocking in
the Middle Green River.
B. Razorback Sucker - Upper Colorado River Stock. Razorback suckers
from Upper Colorado River, Etter Pond, Colorado River Arm of Lake
Powell, and San Juan River Arm of Lake Powell will be used to
develop a broodstock for the Upper Colorado River. There are too
few fish remaining in the wild to develop a broodstock from the
Upper Colorado River. The consensus of the Genetics Panel and
upper basin biologists during a meeting held on razorback suckers
in September, 1994 was that the broodstock should be developed from
a mixed stock (Wydoski 1994b). Eighteen wild adult razorbacks are
in captivity at the Grand Junction facility.
Progeny that are excess to broodstock development will be used for
augmentation stocking in Colorado River reaches that still contain
razorback suckers and for restoration stocking in river reaches
above barrier dams where the species has been extirpated.
During 1996, attempts will be made to obtain additional wild adult
razorback suckers from the Upper Colorado River and Lake Powell
that are suitable for continued development of the Upper Colorado
River broodstock. On January 23, 1996, the Biology Committee
members agreed that wild adult fish could be collected by Recovery
Program participants during Program funded studies so additional
funds from Recovery Program Project No. 29e would not be needed.
The FY 1996 scope-of-work for Project No. 29e has been revised
accordingly. The Bureau of Reclamation and National Park Service
are tracking sonic-tagged razorback suckers in Lake Powell. If
they discover that these tagged fish are congregating in the spring
of 1996 during the spawning season, they will inform the Utah
Division of Wildlife Resources personnel who will attempt to
collect fish to determine if wild adult razorbacks are among the
sonic-tagged fish. If wild razorbacks are collected, they will be
held at the Wahweap State Fish Hatchery until they can be
transferred to the refuge ponds at the Horsethief State Wildlife
Area. These fish will be used for broodstock development of the
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