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Table 4. Species composition for fish Over and Under 15 em caught in the YampaRiver in August/September 2001. LILY SEVENS DUFFY LILY SEVENS DUFFY PARK PARK 2001 2001 2001 2001 2001 2001 Species > 15cm > 15cm > 15cm <15cm <15cm <15cm Flannelmouth Sucker 67.7% 53.1% 2.0% Bluehead Sucker 7.1% 13.2% 4.4% .08% Roundtail Chub 0.03% 3.4% 3.1% Colo. Pikeminnow 0.03% 0% 0.6% White sucker 0.07% 10.2% 17.9% White X Flannelmouth 0.13% 5.0% 26.9% White X Bluehead 0% 0.4% 4.7% White S. + Crosses 0.2% 15.6% 49.5% 1.2% 6.0% 0.8% Channel Catfish 17.7% 5.2% 4.4% Carp 2.1% 4.1% 2.2% 0.3% Smallmouth Bass 5.1% 5.0% 32.4% 79.9% 58.3% 98% Northern Pike 0.2% 0.3% 1.0% White Crappie 0% 0.0% 0% Mottled Scuplin 3.7% 0.7% Speckled Dace 2.0% 0.2% Sand Shiner 15.2% 33.8% 0.2% Fathead Minnow Creek Chub 0.03% Stickleback 0.03% Sample size 2,990 676 859 164 151 3,854 The very high degree of consistency in species composition of fish over 15 cm for the first three years 1998, 1999, and 2000 was somewhat maintained at Sevens, but poorly maintained at Duffy in 200 1 (Table AI). Flannelmouth suckers at Sevens varied between 46% and 53% during the four-year period (Table AI). At Duffy, flannel mouth composition was 5% between 1998 and 2000 and dropped to only 2% in 2001 (Table AI). Bluehead sucker composition at Sevens was between 18 and 22% during the first three years but dropped to 13% in 2001. Bluehead sucker composition at Duffy varied between 4 to 6% over the four years. Roundtail chub were fairly consistent between sites comprising between 3 to 6% of the catch at Sevens and 3 to 4% at Duffy over the study period (Table AI). No Colorado pikeminnow were caught in Sevens in 2001, slightly down from 0.2% in earlier years. At Duffy, pikeminnow composition was 1.5%, .06% and 0.8% in 1998, 1999, and 2000 respectively and was 0.6% in 2001. For the over IS-em size group, native fish were common at Sevens and were 72% in 1998,68 % in 1999, 76% in 2000 and 70% in 2001 (Table AI). At Duffy, native fish comprised about 14% of the fish population in the first three years, but dropped to 10% in 2001 (Table AI). The white sucker with crosses group comprised between 69 and 73% of the catch at Duffy between 1998 and 2000, but dropped to 50% in the 2001 sample (Table AI). In contrast, there was a large increase in species composition for small mouth bass in 2001. Small mouth bass comprised 8%, 6% and 10% of the catch over 15 cm between 1998 and2000, but strongly 18 I I I I I I I I I I I I I I I I I I I