1103

• UCREFRP Catalog Number: 1103
• Author: Holden, P. B.
• Title: Study of The Habitat Use and Movement Of The Rare Fishes In The Green River From Jensen To Green River, Utah, August and September, 1977
• USFW Year: 1977.
• USFW - Doc Type: Final Report.
• Copyright Material: NO

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Rare Fish Movements

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The original plan of this study called for sampling one section of
the Green River (Jensen to Ouray) several times, continuously marking
rare fishes and hopefully recapturing some. The study was changed when
young-of-the-year squawfish were not found in the original study area.
Therefore, emphasis was placed on locating young-of-the-year squawfish
rather than recapturing marked juveniles from the primary study area.
The marking of rare fishes continued throughout the study with the antici-
pation that future studies may recapture some of the fishes.
Twenty juvenile squawfish were tagged, 13 more were anal fin clipped.
Four subadult squawfish were also tagged. One tagged juvenile was recap-
tured at the site of release 4-1/2 hours later.
Young-of-the-year squawfish were larger than anticipated (35-55 mm)
when encountered in Gray Canyon. A solution of Bismark brown Y dye was
tryed on two squawfish. One showed signs of stress in 5 minutes, the
other in 15 minutes. Partial anal fin clipping was also tryed as a po-
tential marking technique. Two squawfish were clipped and observed for
30 minutes. No ill effects were noted. Although the samples were small
in both tests, it was decided that a partial fin clip appeared the better
technique.
Movement of young-of-the-year squawfish was studied in detail in
one backwater (see Appendix IV, upper photo). The area was seined five
different times during a two-day period (Data sheets 77-293, 294, 300,
301, 302) and 4,31,29, 11, and 12 young-of-the-year squawfish were

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