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<br />fish composition compares between it and the shorter surveyed Site since deep runs of this <br /> <br /> <br />size are not typical. The deeper habitat in the surveyed Site is even more attractive to large <br /> <br /> <br />fish in low flow years like 2000 when more of the river is too shanow to be unusable habitat. <br /> <br /> <br />Therefore fish concentrate in the deepest habitats and the density estimates in the Survey Site <br /> <br />increased in the low flow years, even though a reduced density was estimated for the river in <br /> <br />general. <br /> <br />The deep run habitat in the Duffy Site also appears to be more attractive to bass and <br /> <br /> <br />white suckers during all three years. The surveyed Site estimate for small mouth bass was <br /> <br /> <br />three times higher and the white sucker estimate was more than doubled compared to the <br /> <br /> <br />entire Reach in 2000. In contrast flannel mouth sucker were less common in the Site in 1998 <br /> <br /> <br />and 1999 (high flow years) compared to 2000. Also large predators like northern pike and <br /> <br /> <br />Colorado Pike minnow were more apt to be collected in this deep run. <br /> <br /> <br />Fish density estimates were similar in 1998 and 1999 at the Sevens on the Yampa <br /> <br /> <br />River, but estimates were significantly (alpha = .05) lower in 2000 than in 1998 and 1999 <br /> <br /> <br />(Table A5). Flannelmouth sucker density was also significantly less in 2000 and in 1998. <br /> <br /> <br />The fact that total density was less in 2000 at both Yampa sites add credibility to suggesting <br /> <br /> <br />that low base flows could be impacting fish abundance in the Yampa River. <br /> <br /> <br />Density estimates were very different for the three sites sampled in 2000. As the case <br /> <br />in prior years, Duffy Reach density for total fish over 15 em is very low at only 316 fish/km <br /> <br /> <br />and is higher at Sevens with 778/km (Table 6). Density estimates are very poor for all native <br /> <br /> <br />fish at Duffy: bluehead sucker (16/km), flannel mouth sucker (111km), and roundtail chub <br /> <br /> <br />(5/km). At Sevens density of native suckers were much better for bluehead, flannel mouth and <br /> <br /> <br />roundtail chub at 309, 296 and 54 per kilometer, respectively. The estimate for total fish at <br /> <br /> <br />Lily Park is exceptionally high at 6279 fish/km. Flannelmouth sucker were estimated at an <br /> <br />34 <br /> <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />