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Statistical Analysis Wl' lllnducted nine trials to compare mortality of exercised and control razorbacks. We compared the number of fish eaten of a total possible ten fish for each treatment (20 prey per trial). Mean mortality of exercised razorback sucker (3.33 :!: 0.62 SE) was significantly lower than control fish (5.11 :!: 0.74 SE) (fig. 10; one-tailed Wilcoxon Matched-Pairs Ranks test; n = 9, z = 1.69, p = 0.046). 70 60 c: S 50 ~ Q) Q) 40 C'l ~ 30 c: Q) ~ 20 Q) 0.. 10 o Control Treated Control Treated 2006 2007 Figure 10. Percent mortality of razorback suckers (mean :t 95 percent Confidence limits) per treatment in 2006 and 2007. Treatment fish in 2006 were exercised only; treatment fish in 2007 were exercised and exposed to a predator event. In both years, treatment fish had significantly lower mortality than control fish (p<0.051. Predation Trials-2007 Razorback Suckers The first year we focused on testing whether flow conditioning increased a razorback sucker's escape performance. The second year our primary objective was to determine if an exposure to a predation event improved survival compared to predator-naiVe fish. Twenty-three trials were conducted from April 10 to June 26, 2007. Initially, we mimicked the previous year's approach of using study groups of ten fish and allowing the predators whatever time necessary to reduce that number by half. However. the first two trials took nearly six nights to complete. During that period, we observed the I <\/mhad ~lIders schlloling and realized that after the first evening, all these fish had some degree of ptL'dalor experience. Avoidance behavior between the treated and control suckers would be most prevalent during the first encounter and decreased each consec'utive night as fish were subjected to repeated predator aggression. We modified our study design to shorten the duration of the predation trial to one or two days by using smaller groups. As a result we increased our intended number of trials from IOlon. 15