7739

• UCREFRP Catalog Number: 7739
• Author: Muth, R. T. and T. P. Nesler.
• Title: Associations Among Flow and Temperature Regimes and Spawning Periods and Abundance of Young of Selected Fishes, Lower Yampa River, Colorado, 1980-1984 - Final Report.
• USFW Year: 1993.
• USFW - Doc Type: \
• Copyright Material: NO

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17

Table 6.-Correlations (pearson r) among years between total catch-per-unit-effort (number of fish
collected per area sampled) and percentage of occurrence (percentage of aU samples in which each taxon
occurred) of age-O or older fish for selected flShes,lower Yampa River, Colorado, 1980-1984. Coefficients
in bold type followed by an asterisk (*) are statisticaUy significant (r ~ 0.878; df = 3; P $ 0.05). Strong
correlations (r = 0.778-0.877) are indicated by coefficients in bold type not followed by an asterisk.

Correlation coefficient

Taxon

AeeO
NATIVES
0.235
0.867
0.973*
0.593

NONNATIVES
0.857
0.833
-0.326
0.981*

Ale 1+

Gila sp.
Rhinichlhys oscu/us
Catostomus discobolus
C. latipinnis

Cyprinella /utrensis
Notropis stramineus
Pimephales prome/as
Richardsonius baIleatus

0.273
0.010
0.377
0.852

highest in reaches 1 and 3 and lowest in reach 5 (similar to natives). For sand shiner and fathead minnow,
CPUE was highest in reaches 3 and 4 and lowest in reach 2. CPUE for redside shiner was highest in reach
4 and lowest in reach 1.
From percent contribution per year of each taxon to the total annual CPUE for age-O fish (aU taxa
combined), slightly different patterns emerge, especially for native fIShes (Figure 6). Among native fishes,
highest percent contnbution by taxon occurred in either 1983 or 1984, and lowest percent contribution,
except for Gila sp., occurred in 1981; for Gila sp, lowest percent contribution occurred in 1984. Among
nonnative species, highest percent contribution by taxon occurred in either 1980 or 1981, and lowest
percent contribution occurred in 1984.
Patterns of total relative abundance among years and relative abundance among reaches over all
years for age-l + fish of nonnative species were somewhat predictable given the patterns exhibited by age-O
fish of these species (Table 8). Total values from both relative-abundance indices for age-l + fish of each
species were smallest in 1984, and, except for redside shiner, CPUE of age-l + fish for each species was
highest in 1982 (for redside shiner, greatest values of CPUE and PO for age-l + fish occurred in 1983).
Over all years, reaches with greatest CPUE values for age-l + fish were the same as those with highest
CPUE for age-O fISh.
Correlations among years between values of total relative abundance for age-O fish with annual
spawning-period parameters by taxon were somewhat similar among most fishes, natives and nODnatives
(Table 9). For all fIShes, correlation coefficients were positive for CPUE compared with SPAWN-T and,
except for Dannelmouth sucker, negative for CPUE compared with SPAWN-I. The degree of association
was generally stronger for non natives than natives. Similarly, for all fIShes except tlannelmouth sucker and