7639

• UCREFRP Catalog Number: 7639
• Author: Langlois, D., T. Lytle and C. Haynes.
• Title: Colorado Squawfish Propagation Study.
• USFW Year: 1980.
• USFW - Doc Type: \
• Copyright Material: NO

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COLORADO SOUAWFISH PROPAGATION STUDY
David Langlois, Tom Lytle, and Charles Haynes
PROGRAM NARRATIVE OBJECTIVES
To design Colorado squawfish propagation facilities for construction
at the Rifle Falls fish hatchery capable of producing 100,000 juvenile
Colorado squawfish yearly; and, to begin construction of such facilities
by June 30, 1979.
INTRODUCTION
With the knowledge that Colorado squawfish can be successfully propagated
in a hatchery (Toney 1979), the State of Colorado decided to investigate
and refine production technology. Spawn-taking techniques, handling of
brood fish, and rearing methods for progeny are some of the research
unknowns which must be answered to maximize production of fingerling
squawfish on an annual basis. It was also decided that a facility devoted
totally to Colorado squawfish production and research would enhance the
chances of large-scale success. The Rifle Falls State Fish Hatchery
became a candidate site for a feasibility study on the following criteria:
1) it appeared to have land and water available to develop the facility;
2) it is adjacent to the historical habitat of the Colorado squawfish,
i.e., the Colorado River and, 3) the existing hatchery and regional staff
had shown an interest in the culture of endangered species.
While hatchery propagation alone will not result in the declassification
of the species, such a source of young fish will aid the recovery effort
in several ways. Fish of a uniform size and age are needed for bioassay
work, including salinity, pesticide, and heavy metal toxicity studies.
This knowledge would supplement (not replace) habitat requirement studies
using wild fish. Taxonomic work with larval squawfish would facilitate
field identification of wild fish, making it easier to monitor annual
reproduction. Life history studies could also be conducted using hatchery
fish both in the hatchery environment and in historic habitat. Squawf ish
are needed to investigate competition and predation with other fishes,
migration, growth, and survival. Such uses of hatchery - reared squawfish
demonstrate the value of the hatchery product on the squawfish recovery effort.
SYNOPSIS OF PROGRESS
On August 2, 1978 personnel from the Division of Wildlife and the U.S.
Fish and Wildlife Service met at the Rifle Falls hatchery to tour the
unit, evaluate potential construction sites, and discuss the operation of
the squawfish facility. Three possible sites were discussed and it was
decided that the Division Engineering Section should design a construction
plan. The regional office made the engineering request. As a result, an
on-site inspection was completed by the engineering section and three
alternative hatchery plans were prepared for review during the winter months.