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<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 /> <br />split channel below the diversion dam and we may not have spent a proportionate amount of <br /> <br /> <br />effort resampling that habitat. More attention will be paid to this in the 2001 sampling. <br /> <br /> <br />Density estimates in fish/km for the Colorado and Yampa Rivers are similar for both <br /> <br /> <br />the 1999 and 2000 reports. However fish per 1000 m' are different in this report from those <br /> <br />reported last year. A mean stream width of 100 meters was used to calculate fish per square <br /> <br />meter in last year's report (Anderson and Stewart 2000). Based on results of Stewart (2000) a <br /> <br /> <br />stream width of 55 meters is used this year, since it represents wetted width at 1400 cfs, a <br /> <br /> <br />flow typical in the base flow period (discussion in habitat section). <br /> <br /> <br />The Colorado River in the 15 Mile Reach averaged 4.5 times more fish /1000 m'than <br /> <br /> <br />the Yampa River at Sevens and Il.l times more fish than Duffy in 2000. For the 1999 data, <br /> <br /> <br />Com Lake station (Colorado River) was 3.0 times higher than Sevens and 9.4 times higher <br /> <br /> <br />than Duffy. It is recognized that predation is a major impact to density on the Yampa River, <br /> <br /> <br />especially at Duffy, and it will be considered in the analysis. However a hypothesis of this <br /> <br /> <br />study that habitat availability is an important factor determining carrying capacity and the fact <br /> <br /> <br />there is an extreme difference in density between the tVlO rivers indicates habitat is a principle <br /> <br /> <br />factor. <br /> <br />The Lily Park station is an interesting contrast to the other Yampa River sites. It has a <br /> <br /> <br />higher total fish and flannel mouth sucker density than found on the Colorado River and <br /> <br /> <br />bluehead is only about half of the Colorado River. It is likely that habitat at Lily Park will be <br /> <br /> <br />more similar to the Colorado River than to the other Yampa sites. <br /> <br />DOLORES RIVER <br />The total fish density estimate per kilometer and per hectare in the Dolores River is <br /> <br />low compared to the Colorado and Yampa Rivers (Table 7). Fish per square meter is based <br /> <br />on a conservative estimated stream width of 18 m, since cross section results are not available <br /> <br />at this time. Therefore fish per square meter will be different when a standardized stream <br /> <br />39 <br />