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

catfish) and weights (twenty five randomly selected individuals and cumulative weights/reach)

were recorded and used characterize catch rates in all reaches (no weights were recorded by

electrofishing on 1998). Based on cost per fish removed in 1998, angling was selected as the

primary method of removal in 1999. In addition to angling in 1999, catfish collected from a

Recovery Implementation Program project in 1999 to estimate the population size of humpback

chub in Yampa Canyon were also removed.

Electrojishing

Non-motorized electrofishing rafts were used on the first trip during both years. Smith

Root electrofishing equipment with 5000 watt generators (60 - 120 Hz frequency) was used to

apply 4 - 5 amps. Two rafts (on opposing shorelines) with one person on the bow with a net

collected catfish from the entire length of shoreline along removal treatment reaches. Supply boats

occasionally collected catfish that surfaced after the electrofishing raft had passed. Number of

fishlhour caught was recorded and all fish captured were removed from the river. Due to floatation

requirements of the electrofishing raft, this method could only be used when flows exceeded

approximately 28 m3s.

Angling
Angling was used to remove channel catfish during the baseflow period in 1998 (second,

third, and eighth trip). In 1999, with the exception of a single electro fishing trip, all channel

catfish were removed by angling. Angling start and stop times, number of catfish captured, and

total weight of catfish caught were recorded by each angler on prepared data forms. Fishing time

was recorded when bait hit the water and ended with the last retrieval of line from the water and is

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