6028

• UCREFRP Catalog Number: 6028
• Author: Wick, E. J., D. L. Stoneburner and J. A. Hawkins.
• Title: Observations on the Ecology of Colorado Squawfish ‎(
• USFW Year: 1983.
• Copyright Material: NO

5
Two techniques of monitoring were used, general survey and continuous
diel monitoring patterned after USFWS studies (Miller et al., 1982b,c;
Tyus et al., 1982a). The general survey method was an attempt to locate
a maximum number of radiotagged fish at random times throughout a 3 to 5
day period. The diel technique was an effort to monitor fish activities
continually during three time periods, 0800-1600, 1600-2400, 2400-0800
hr. All radiotagged fish were monitored systematically according to a
study plan. The two monitoring systems were usually conducted
concurrently by two field teams. The procedure for data collection was
the same for both methods. The general location of a fish was first
determined using a Custom Electronics receiver with an omni-directional
whip antenna, with a nominal range of 800 meters (m). When a fish was
located a directional loop antenna was used to triangulate the actual
position of the fish. The nominal range was 250 m. When the position
of a fish had been determined, the river (km), movement pattern, habitats
utilized, river substrate, river water temperature and transmitter pulse
frequency data were recorded. Habitat was identified according to
modified definitions used by the CDOW (Wick et al., 1981; Appendix A).
Intensive monitoring of the radiotagged fish began on April 26 and
continued until August 28, 1982. In addition, the general survey
technique was used during late August, early October, and November to
obtain postspawn data.
Squawfish Sampling During Migration
When squawfish began extensive migrations and spawning was likely,

potential spawning sites and areas inhabited by radiotagged fish were
sampled with trammel nets. When conditions permitted, trammel nets were