found in either season at Holdenville nor in the spring from Thunderbird (Table 2). CPUE of the "large" size class was
higher at night in the spring and during the day in the fall from Jean Neustadt (Table 2). Fall CPUE of the large"
size class was higher during the day at Thunderbird. Catch rates were higher at night for size classes combined tor all
lakes and seasons with the exception of the fall samples from Thunderbird which did not exhibit any diurnal differences
in catch rates (Table 2).
Precision of the night electrofishing samples was higher than the paired samples collected during the day (Table
2). The exceptions to this relationship were at Thunderbird for "large" saugeye and for all size classes combined in
the fall (Table 2). Ten hours of electrofishing (40 units of effort) at night would be required to ensure obtaining a
mean with a 75 % confidence interval based on data from the three lakes in this study (Table 2). By stratifying the data
by day and night, precision was not sacrificed in many cases when the data were broken out by size classes. Eleven
hours of electrofishing would meet the target of precision in 19 of the 48 sampling strata in Table 2. If only night
samples were considered, 15 of 24 strata met the target of precision with 11 hours of electrofishing.
Habitat type had little effect on day time electrofishing sampling efficiency. CPUE was higher in "saugeye"
habitat for the "intermediate" size class in spring at Holdenville and in the fall at Jean Neustadt (Table 3). CPUE of
"large" saugeye was higher in the fall at Thunderbird (Table 3). Catch rates for all size classes combined in "saugeye"
habitat were higher in the spring at Holdenville and in the fall at Jean Neustadt and Thunderbird (Table 3). All other
comparisons of habitat type by size class for each season and lake were nonsignificant. Precision of the data collected
in "saugeye" habitat was higher than the respective data collected in "bass" habitat in 17 of the 24 habitat comparisons
in Table 3. However, stratifying the data by habitat type did little to reach realistic sample size requirements.
VI. Discussion:
This study provided no clear evidence indicating that efficiency would be enhanced by limiting data collection
to a single season. Seasonal differences in catch rates and precision were inconsistent among lakes and size classes.
This is in contrast to the findings of Johnson et al. (1988) who reported higher catch rates of age-1 and older saugeye
from night electrofishing samples in spring than in fall from Pleasant Hill Reservoir, Ohio. Stratifying sampling by
habitat type during daytime electrofishing also did little to improve efficiency.
