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RECOMMENDATIONS <br />x ~~w: <br />`~ Although differences existed between habitat measurements at backwaters used by and <br />~~ <br />"fir <br />~r. <br />devoid of both chubs and Colorado squawfish, these differences varied considerably by sampling <br />~~. <br />"; <br />period. In many instances, differences were exactly opposite between sampling periods. It was, <br />also, not unusual to have individual backwaters used by both chubs and Colorado squawfish, by <br />one or-the other species, and by neither. This complicates drawing definitive conclusions on <br />habitat needs. In addition, the lack of correlation between flow parameters and habitat formation <br />and CPUE confounds predictions of flow effects and habitat suitability. Lastly, because this was <br />only a three year study, there is not a good representation of different flow scenarios. No mid- <br />level flows were sampled at all. <br />The following are brief, and preliminary, discussions and recommendations based on the <br />results presented. They are offered in order to provide USFWS biologists with some indications <br />of habitat use and needs by these species in Desolation and Gray canyons in order to assist them <br />in development of the Biological Opinion on the operation of Flaming Gorge Dam. It must be <br />realized, however, that the analyses presented are not complete (no true analysis has been <br />conducted on non-native fish data) and the recommendations may be adjusted in future reports. <br />Chubs do not appear to select for a certain type of backwater. Backwaters used by chubs <br />varied by month. The only patterns of use consistent across sampling periods were: chubs used <br />backwaters with greater volume and greater turbidity ratings. Colorado squawfish showed more <br />consistent habitat use criteria than chubs. Variability was still quite evident, though. Colorado <br />squawfish used backwaters with greater surface area and volume than those that were unused. <br />~..~a/ ~~ <br />They also used backwaters with less over D~pite the fact that this species used scour <br />(secondary channel) backwaters more than expected, shoreline eddies were over represented in <br />...~--- <br />29 <br />