9667

• UCREFRP Catalog Number: 9667
• Author: Brouder, M. J. and T. L. Hoffnagle.
• Title: Paria River Native Fish Monitoring - 1996-1997 Annual Report.
• USFW Year: 1997.
• USFW - Doc Type: Flagstaff, AZ.
• Copyright Material: NO

• 1997 Paris River Native Fish Monitoring
was followed by the appearance of YOY being recruited into the population through August.
Of special note is the capture of two large bluehead suckers at RK 0.8 in the Paris River in
1997. Weiss (1993) reported the capture'of three bluehead suckers in the Paris River. A total of
111 juvenile bluehead suckers were captured by AGFD (unpublished data) on l5 June 1994,
mostly in the mouth, but as faz upstream as Site 1 (RK 4.8). Cazothers and Hinckley (198I)
reported the presence of bluehead suckers in the Paris River during the summer of 1978. It is
possible that small numbers of bluehead suckers use and may even spawn in the Paris River.
However, recruitment for this species is also low, since no bluehead suckers were captured by
AGFD in the Colorado River below the Paris (AGFD 1996).
~ Of special concern is the catch of 18 redside shiners in the mouth of the Paris River on 1 l
July. Redside shiner is an exotic species which may compete with or prey on YOY flannelmouth
sucker for habitat and/or food. Hinckley (.1973) reports that redside shiner are piscivorous and
are a particular threat to native fishes. With low levels of recruitment having been reported in
past studies, the presence of this exotic species may have negative effects on recruitment and
ultimately survival of native fishes. In addition, two bluehead suckers were caught at RK 0.8 in
1997. Although not the first time this species has been caught in the Paris River (Weiss 1993;
AGFD unpublished data), numbers of bluehead sucker have been low.
The excellent rearing conditions present in 1996 were not observed in 1997; however,
catches of YOY flannelmouth sucker were relatively high early in the summer. These results and
those of Thieme (in preparation) show that successful recruitment of flannelmouth sucker is
dependent on more than just Paria and Colorado River dischazge. The timing of events such as
high and low flows in the Paris and Colorado Rivers are just as important as the magnitude of
these flows. Continued monitoring of the Paris River and its use by all life stages of flannelmouth
~ sucker and speckled dace is necessary to understand the relationship of Paris River dischazge and
Glen Canyon Dam operations to recruitment of flannelmouth sucker. With low levels of
recruitment having been reported in past studies, monitoring the abundance and distribution of
redside shiners and other exotics in and around the Paris River is also important. Lastly, the
capture of bluehead suckers in the Paris River in 1997 means that YOY sucker species must be
accurately identified so that any changes in abundance and/or distribution of bluehead suckers
may also be detected.
Brooder and Hoffnagle, 1997 Annual Report
Arizona Game & Fish Depanmern 13