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impeded by turbid water, if there is a choice to be made. We speculate that high turbid-water - catch rates may be due to greater susceptibility overall and higher abundance of fish in shallow riffles. Clear and shallow riffles sometimes support few fish, perhaps because fish lack the cover needed to occupy such places or because they detect the approaching raft and retreat to other habitats. Speas et al. (2004) found that capture rates of rainbow trout increased in turbid compared to clear water and attributed the increase to inability of fish to see the approaching boat, and possibly, reduced ability to escape due to low water temperatures. Channel catfish capture rates were slightly lower in turbid than clear water. This is reasonable because many channel catfish never undergo taxis to the raft anode where they are visible and available for capture. Instead, channel catfish are often stunned directly over the substrate and roll along the bottom in the current, such that their capture would be less likely in turbid than in clear water. Although fish capture rates were affected by a number of factors including turbidity and sampling season, we could not attribute any differences to factors that existed solely in one or the other periods, 1994 to 1996 or 2002 to 2004. In the absence of artifacts caused by environmental conditions or differences in sampling efficiency, we consider reductions in capture rates in the recent period as unbiased and reflect real reductions in native fish abundance. Effects of reach, season, and year, on fish density, 2002 to 2004 seine samples.-Seine samples showed significant differences in abundance of all taxa captured among years, seasons, and reaches and all first order interactions among those effects were also significant. Across all years from 2002 to 2004, average abundance of each fish taxa in seine samples was lowest in Browns Park (mean = 1.15 fish/lOm2, 95% CL = 0.805 to 1.50) and the Lodore Canyon reaches LD1 and LD2 (LD1 mean = 0.95 fish/1Om2, 95% CL = 0.61 to 1.30; LD2 mean = 0.71 fish/ IOM2, 95% CL = 0.42 to 1.30), slightly higher in LD3 and LD4 (LD3 mean = 1.49 fish/I Om', 95% CL = 1.02 to 1.97; LD4 mean = 1.36 fish/lOm2, 95% CL = 0.88 to 1.84), increased substantially in Whirlpool Canyon (W1I 1 mean = 4.14 fish/1Om2, 95% CL = 3.04 to 5.23; WH2 mean = 3.13 fish/ IOm', 95% CL = 2.17 to 4.10), and then declined in Island-Rainbow Park (IRP mean = 1.44 fish/1 Om2, 95% CL = 1.09 to 1.78. The GLM analysis of abundance as a function of reaches was significant (x2 = 91.69, 7 df, p < 0.0001). 40