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. DRAFT . 6.0 RESULTS AND DISaJSSlOO 6.1 I'DVEMENl' BY RADIOTAGGED FISH . Movement of the radiotagged fish was classified into three basic patterns: (1) local movement, (2) long-range movement, and (3) no movement. The no movement pattern denotes little or no change in fish position during the observation period. These fish were sometimes intentionally disturbed by the investigator and forced to move to insure that the fish were alive and fit. . Local movement describes activity of the fish within a localized area, with no significant change in position. This pattern often involved movement between two to five closely-spaced 'favorite spots' where the fish spent most of its time. The third movement pattern, long-range movement describes a significant change in position by a fish. This movement pattern was considered transitory between river regions that were sometimes several miles apart. Although long- range movement was generally documented as occurring between tracking trips, it was also observed during the 2-hour and 24-hour monitoring periods. . 6.1.1 Local Movement . Local movement was recorded to deter.mine if certain conditions caused the fish to frequently change their position in the river, indicating additional energy expendi ture or stress. During observation periods of up to 24 hours, the movement of each fish was recorded, relative to a starting position where the fish was first contacted (each fish was observed for a brief period following contact to insure that initial movement was not in response to disturbance by the investigators). In addition to movement in meters/hour, a movement ratio of gross to net movement is presented. Gross movement is the total distance covered by a fish during an observation period; net movement is the linear distance between the start and end points. Thus, a ratio of 2.95 means that for every linear meter that a fish was displaced from the starting point, it moved a total of 2.95 m. . 6.1.1.1 Colorado Squawfish . A significant difference (alpha = 0.05) in total movement by Colorado squawfish was observed between winter 1986-87 (19.01 m/hr) and 1987-88 (45.54 mjhr) (Table 3). This is attributed to the formation and dynamics of river ice cover which was present for nearly 3 months in 1987-88, and for only a brief period in 1986-87 (See Description Of winter Riverine Conditions). . For only periods in which ice cover was present in 1987-88 (Table 4), movement was signficant1y greater for fish under ice cover (47.53 mjhr) than for fish with no overhead ice cover (8.98 m(hr). This relatively greater movement by squawfish under ice is attributed primarily to two factors; (a) behavioral use of ice as cover, and (b) movement by fish to avoid floating ice masses. Movement by fish in the lower region of the study area, where ice cover was more stable, is attributed primarily to factor 'a', or use of ice as a cover element. Movement by radiotagged squawfish in Rainbow Park is attributed primarily to factor 'b', since this partially-frozen region of river was . 22 .