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1 1 1 1 I t that ice thickness (including frazil) was greatest in pools and eddies (mainly pools). In spite of differences in flow, the maximum normalized value for depth in BA EM habitat was consistent at 2 feet for 8 of 12 trips in which these habitats were used during both winters (Appendix D). This indicates a preference for this depth in these habitat types, especially since a wide range of depths was available. Effective depth tended to remain constant during Winter 2 because as water surface elevation increased with increased discharge, the ice thickened. Analysis of RU SH data showed that shallower shoreline habitat was used most frequently early and late in the winter. Squawfish mowed into the shoreline areas at ice formation, possibly to take advantage of the cover ice provided. The advantage of this behavior may decrease as winter progresses. Use of shallow shoreline areas also increased just prior to ice-out in Winter 1. Fish could have been seeking the C7mllpaMtlvely low velocities in response to higher discharges during this time. Depth utilization in run habitat was greater in mid-December than during January and early February. Velocity utilization over time Biweekly means for velocity (Appendix E) were averaged for both years for the period during ice cover. This gave equal weight to each trip and reflected average velocities utilized most frequently throughout the winter. Averages were calculated for each habitat group. Therefore, velocities reported in this section differ from overall averages reported previously for each separate habitat type. Negative velocities were converted to positive values for calculation since the negative sign only indicated flow direction. Comparisons of velocities used between years showed that both means and ranges utilized in rum habitat were higher in winter 1, a higher-flow year (Table 13). Velocities reported for the ED PO category were mostly from eddy habitat in Winter 1 and pool habitat in Winter 2, explaining differences in this category. As mentioned in the discussion of depth, velocity differences between years were not very large considering the magnitude of flow differences. There were slight velocity differences between habitat groups. lowest average velocity was observed in BA EM habitats. This is expected since these habitats tend to be off-channel habitats with no velocity inside and only marginal velocity along their interfaces with the main channel. F&ayments have larger interfaces with the main channel than backwaters and have more of an eddy effect at their lower ends where velocities are usually slightly above zero. The next highest average velocity was from ED PO habitat. Eddy velocity was mostly negative, but some positive or zero velocity was present along the eddy and run interface. RU SH had higher velocities than other habitat groups. Most of these observations were from run habitat. Squawfish shifted from run to shoreline habitat in Winter 1 during higher discharges :(Appendix E). As discharge increased in Winter 1, the range and means of velocities used increased. In Winter 2, velocities used were much more consistent in RU sH habitats, reflecting the camparatively stable flaws in Winter 2. RU SH, in addition to having the highest average velocity, also had the greatest rand of velocities on each trip. In general, squawfish showed preference for law-velocity habitat and appeared to prefer a velocity range between 0.2 to 1.0 ft/s in run habitat. 43