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. DRAF1- . continued to use water depths similar to those used in ice-free conditions, indicating that razorback suckers do not use ice as a cover element. 6.2 GENERAL HABITAT USE 6.2.1 Colorado Squawfish . During the fi rst year of this investigation, the 10 radiotagged Colorado squawfish were observed in three habitat types; runs, eddies, and backwaters. Of the total observation time, the fish occupied these habitats approximately 77, 10 and 7% of the time, respectively (Figure 16A). . During the second year of the investigation, a second group of 10 radiotagged squawfish, during ice-free conditions, were observed in runs, slackwaters, and eddies, approximately 46, 46, and 7% of the time, respectively (Figure 16B). The new habitat designation of slackwater is defined as an area of very low downstream velocity created by an instream structure, such as a sand shoal, emergent island, or at the lower end of an eddy. We referred to this habitat in year 1 as a slow run, but a distinction is necessary because many of the radiotagged fish were observed using this very specific habitat. The habitat designations used in year 1 will be reexamined, and it is expected that the 77% run habitat will roughly divide in half into runs and slackwaters resulting in about the same habitat use during both years of the study. . . The same 10 fish monitored under iced conditions during year 2 occupied runs, slackwaters, and backwaters approximately 67, 17, and 17% of the time, respectively (Figure 16C). Their use of ice-covered backwaters and relatively shallow areas is believed to be a behavioral response to surface ice as a cover element. The difficulty in assessing habitats associated with fish under ice probably explains the descrepancy between habitat use in ice-free vs ice- covered water. Instream features that create slackwaters are difficult to see with ice cover, and so, most habitats with downstream flow were designated as runs, but may have been slackwaters. . . The habitat used by Colorado squawfish in the winter characteristically had moderate depth (except under ice), low velocity, and was often downstream of some instream structure such as a sand shoal or emergent island. The troughs located just downstream of these features were often used by squawfish. Their sedentary behavior in these slackwaters suggests that the fish use these as resting habitat. Their selection for these areas, once a minimum depth criterion is met, appears to be driven by low near-bottom velocity. Although deep pools and deep fast runs were available, the fish consistently used areas of low bottom velocity which were not necessarily in the deepest parts of the river channel. Since the turbidity of the river never allowed us to observe the position of a fish in the water colUIlU1, we believe that the fish were positioned near the bottom where velocities were always low. Additional discussion on use of depth, velocity and substrate is presented in the section on HSI Curve Development. . . Squawfish were also found, although less commonly, in eddies and backwaters. Often, when fish were located in these habitats, they were exhibiting localized movement wi thin the confines of the habitat type, suggesting a foraging 33 .