9432

• UCREFRP Catalog Number: 9432
• Author: Modde, T. and M. Fuller.
• Title: Feasibility of Channel Catfish Reduction in the Lower Yampa River.
• USFW Year: 2002.
• USFW - Doc Type: Vernal.
• Copyright Material: NO

reset the nets.

Analysis

A comparison of costs was made to determine the most effective collection method. Trip

costs for electro fishing and angling trips were determined using the 1999 salaries for a GS-13, GS-

11, two GS-Ts and one GS-5 per trip. Electro fishing trips were based on a three day trip compared

to a 5 day angling trip and average trip cost per food and supplies ( $1,100 vs $400) was greater for

angling than electrofishing trips. Netting trips were based on four day trips for a GS-7 and GS-5

($120 for food/trip).
Catch rates of channel catfish between treatment and control reaches from the last pass

were compared with a paired t-test for data collected in both 1998 and 1999. The results of the

paired t-test between catch rates from treatment and control reaches were used to indicate whether

any significant reduction was due to factors other than removal (i.e., weather, season, etc.). Linear

regression was also used to estimate the number of catfish per treatment reach at the beginning of

removal efforts. The x-intercept of the slope of catch per angler hour (dependent variable) with

cumulative catch (independent variable) was used as the estimate of the number of channel catfish

per reach at the beginning of the removal effort using a maximum likelihood regression. Standard

error for the population estimates were made with a nonparametric bootstrap method using 200

simulations (Hilborn and Walters 1992). Due to a large difference in sample size, the Kruskal

Wallis one way anova was used to compare the differences in total length of channel catfish

captured with tyke nets with those captured with angling during 1998. A GLM anova was used to

compare total lengths of fish captured by angling and electro fishing in 1999. Simple linear

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