8171

• UCREFRP Catalog Number: 8171
• Author: U.S. Fish and Wildlife Service.
• Title: A Study to Determine the Biological Feasibility of Pit Tags for Endangered Fishes in the Upper Colorado River Basin.
• USFW Year: 1990.
• USFW - Doc Type: Grand Junction, Colorado.
• Copyright Material: NO

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The small number of fish recovered prevented us from obtaining any
substantial data of the effects PIT tags may have had on fish growth and
survival. These small sample sizes precluded any statistical testing for
differences in tag retention, survival, and wound healing between the two test
groups, or of growth and survival between the test and control groups.
Consequently, some of the study objectives were not met.
Tagging wounds appeared to heal quickly with no deleterious effects to fish.
Although there are higher risks to injecting tags into the body cavity where an
organ may be punctured, this study demonstrated that Colorado squawfish
120-165 mm TL (11-28 g) could be successfully PIT tagged.
The scanner/decoder unit was reliable in detecting and accurately reading the
PIT tag in vivo. In most instances, the hand-held scanner detected and
decoded the tag with only one pass.
RECOMMENDATIONS
1.
For the reasons cited herein, ponds such as those used in this study were not
suitable and are not recommended for evaluating the performance of PIT tags
in the future, especially when frequent observation and determination of the
fate of the test fish are required. Attempts to recover fish from these sites
were time consuming and not cost effective. Controlled studies cannot be
adequately performed in this type of setting.
2. A suitable warmwater hatchery/research facility with personnel
knowledgeable of the cultural aspects of Colorado River endangered fishes
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