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with a seine. Seining under the ice was very laborious, and effort was limited to one to three seine hauls per day. The most efficient technique for under-ice sampling was the use of an underwater camera and video cassette recorder. The equipment could be set up at various locations in the backwater to observe diurnal, nocturnal, and crepuscular fish activity. Fish could be observed swimming in the water column or staging along the substrate. The total number of fish could be counted over a 6- to 8-h time frame. The information recorded, such as fish activity and temperature, was a representation of actual events occurring in the field. Ideally, most species and age-classes (i.e., juvenile or adult) could be identified in the video. Suckers and small cyprinids were easily identified. One or two suspected young-of-year Colorado pikeminnow were observed. Movement Rates under Simulated Winter Condition Component Results of the investigation showed that the temperature-dependent response of fish movement in the absence of disturbance was best approximated by an exponential model with the form y--0.0895e 0.1521 where y is body lengths/s (bl/s) and t is temperature (°C). The influence of temperature on fish movement was not consistent when environmental disturbance was present. Disturbance increased fish movement at temperatures s 10°C and decreased movement at 15 °C. Disturbance treatments were not intended to be ecologically relevant, but they may have elicited a natural response to a perceived threat. Casual observations revealed that fish frequently responded to the stimulus with rapid swimming followed by cessation of movement near the substrate. This pattern of swimming was not completely spontaneous, because a stimulus was required to elicit it, but the purpose of the disturbance treatments was to cause fish to move at relatively high rates so that maximum spontaneous movement rates could be approximated. This objective was achieved for temperatures s 10°C. Maximum movement rates ranged from 0.82 bVs at 1°C to 1.1 bl/s at 50C. Other observations support the conclusion that these estimates approximate xlv