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abundance of bluehead sucker in seine samples declined dramatically in Browns Park and all Lodore Canyon reaches and constituted < 5% of the fish community in 2002 to 2004. Bluehead sucker relative abundance was similar in the two periods in Island-Rainbow Park. Density of bluehead sucker in seine samples increased sharply in WH1 in 2002 to 2004, compared to upstream and downstream reaches. Bluehead suckers in the 301 to 400-mm TL size class in electrofishing samples dominated in all study reaches. Frequency distributions appeared relatively stable in both study periods in Lodore Canyon except that smaller fish (250 mm TL or less) were less common (Fig. 22). Small bluehead suckers were relatively common in upper Whirlpool Canyon reach WH1, particularly in Echo and Mitten parks. Mottled sculpin was found throughout the study area and generally represented a small proportion of fishes captured with both seine and electrofishing gears. Mottled sculpin was the only native fish to increase in abundance in Lodore Canyon electrofishing samples between the 1994 to 1996 and 2002 to 2004 periods, particularly in LD3 and LD4 (Fig. 23); the difference in CPUE was significant. Mottled sculpin relative abundance in seine samples was generally higher in the 1994 to 1996 period, particularly in reaches LD2 to LD4 compared to the 2002 to 2004 period. Sculpin abundance in seine samples in 2002 to 2004 was relatively low in all reaches except LD3. Thus, abundance of all native fish declined in electrofishing samples collected from Lodore Canyon between the periods 1994 to 1996 and 2002 to 2004, with the exception of mottled sculpin. Declines of all taxa were statistically significant except for Colorado pikeminnow, which showed a moderately substantial decline that was statistically not significant. Declines were severe for speckled dace, roundtail chub, and mountain whitefish. Abundance declines of even common taxa were substantial; CPUE for bluehead sucker and flannelmouth sucker declined 39 and 37%, respectively, over the period. In seine samples, relative abundance of all but one native fish declined between the 1994 to 1996 and 2002 to 2004 periods. Declines were severe for flannelmouth sucker, bluehead sucker, and speckled dace; relative abundance of those taxa in Lodore Canyon seine samples 30