9315

• UCREFRP Catalog Number: 9315
• Author: Harvey, M. D. and R. A. Mussetter.
• Title: Evaluation of the Required Frequency of Bar Forming Events and 2-Dimensional Hydrodynamic Modeling at Colorado Squawfish Spawning Sites in the Lower Yampa Canyon, Colorado.
• USFW Year: 1996.
• USFW - Doc Type: Fort Collins.
• Copyright Material: NO

Flow meters for measuring velocity will be suspended inside the mouth of
each net, and net sets will be timed to determine volume of water sampled.
Duration of each set will be 1-2 h depending on debris load. Samples will
be fixed and preserved in 95-100V ethanol (for subsequent otolith-ageing
work). Fishes will be picked from debris in the field, returned to the
LFL, identified, measured to the nearest 0.1 mm total length, and
enumerated.
Diel abundance of drifting Colorado squawfish larvae is generally highest
at dawn, but abundance during other times of the day varies within and
between seasons (Haynes et al. 1984; Nesler 1986). Therefore, additional
diel sampling will be conducted to better estimate variation in abundance
of drifting larvae throughout the day. Every fifth day, additional
samples will be collected every 2-4 h over a 24-h period. On these days,
three nets will be set at each sampling time but only for 20-30 minutes in
order to reduce the catch of Colorado squawfish larvae. Sampling larvae
are observed to better determine Biel patterns. These data will be sued
to calibrate diel catch rates for sampling days when only dawn sets are
sued. Some cross-channel drift-net sampling may be conducted to confirm
results provided by Nesler (1986) and verify our relative-abundance
estimates.
Drift-net sampling at the lower Yampa River station will be conducted by
LFL personnel. Drift-net sampling at the lower Green River station will
be conducted by Utah DWR personnel. Sampling protocol will be the same at
both stations. LFL personnel will assist Utah DWR personnel in
establishment of the lower Green River station and will periodically check
their progress. Utah DWR will provide picked and preserved drift-net
samples to LFL for analyses. Data will be integrated with information
from Utah DWR nursery-habitat studies (SDCR Task 2) and hypotheses-testing
Task 3. Data from the drift-net and nursery-habitat studies will be used
and elaborated in hypotheses-testing study 5 (hypotheses-testing Task 5).
VI. Task Description (FY 1992)
1.) Obtain necessary equipment and personnel to sample at two stations.
2.) Collect samples according to procedures outlined in Study
Methods/Approach and in coordination with other aspects of FGFRI.
3.) Analyze samples and data.
4.) Prepare annual summary report.
VII. Study Schedule (start/end by task):
We anticipate that this study will be continued through FY 1995. Schedule
for 1991 is given.
Task M A M J J A S
1 X X X X
2 X X X
3 X X X X
4 X X
VIII. TY-1 Work:
-Description of Bork
C4