7406

• UCREFRP Catalog Number: 7406
• Author: Bestgen, K. R.
• Title: Status Review of the Razorback Sucker,
• USFW Year: 1990.
• Copyright Material: NO

Razorback sucker movements were studied in the Green River
with both mark-recapture and radiotelemetry methods (McAda and
Wydoski 1980, Valdez and Masslich 1989, Tyus and Karp in press).
Data suggested a mostly sedentary population with a component of
migratory individuals that have a strong fidelity for the same
spawning areas each year (Tyus and Karp in press). Movements were
associated with spring spawning and centered around a few areas,
the confluence of the Yampa and Green River and the Jensen area
between Ashley Creek and the downstream boundary of Dinosaur
National Monument. Five male razorback suckers radiotagged and
tracked for two weeks at the mouth of the Yampa River in May 1975
(McAda and Wydoski 1980) stayed within 1 km upstream of the
release site. Contact was lost with all fish within two weeks;
all were moving downstream at that time.
From 1987 to 1989, 66 of 88 razorback suckers recaptured or
radiotracked in the upper Green River remained or were recaptured
within a restricted river reach and were classed as local (Tyus
and Karp in press). Most of these fish used the Jensen area, but
six used a reach from Island Park upstream to the mouth of the
Yampa River. Migratory razorback suckers included 19 individuals
which ranged 53 to 190 km (Tyus and Karp in press). Some of these
fish moved between the Yampa River and the Jensen area (n=4, mean
one way distance = 49.6 km), and from Jensen to a composite area
including Old Charley Wash and lower Duchesne River (n=13, mean
one way distance = 94.4 km). Four fish exhibited round trip
migrations, one from upstream of Jensen and three from Jensen to
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