7615

• UCREFRP Catalog Number: 7615
• Author: McAda, C. W.
• Title: Evaluation of the Interagency Standardized Monitoring Program.
• USFW Year: 1989.
• USFW - Doc Type: Grand Junction, Colorado.
• Copyright Material: NO

I
Statistical Power of the Interagency Standardized Monitoring Program
The statistical power of the ISMP was examined to determine the ability of the
program to detect future changes in the populations of the rare fishes. The
data were examined in two ways: (1) the ability to detect changes from one year
to the next (T test) and (2) the ability to detect changes over a 5-year period
(F test). Analysis was based on 'normal' (parametric) statistical tests which
have assumptions that may not be met by these data. However, the results are
sufficient to provide accurate information about the predictive ability of the
monitoring program.
The analysis was based on the mean of the three years of data collected to date.
The annual mean catch per unit effort (CPUE) and standard deviation were
calculated for each river and reach sampled in both age-0 and adult Colorado
squawfish monitoring. The three-year mean of those values was then used in the
calculations. The three-year mean was used to reduce the variability that
occurred when each year was analyzed separately and is a better variable to use
for general prediction purposes. To examine the influence of increased sample
size on the power of the program, calculations were done using the sample size
resulting from the current program and for double the sample size of the current
program. All calculations were done using the transformations described above.
Power calculations were not done for humpback chub monitoring because of the
limited data available and because changes in the ratio of humpback chub to
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