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The overwhelming majority (96.8%) of chubs were collected in backwaters for an overall <br />July/August catch rate of 0.489. However, they were not equally distributed in these habitats on a <br />temporal or spatial scale. A Chi square analysis of the habitat area with vs without YOY chub <br />indicated there was a significant amount of heterogeneity (Table 7). Backwaters were used <br />slightly less than the contingency table expectation, while YOY chubs were found in secondary <br />channels more than expected. Taking into account the disproportionate distn~bution of sampling <br />effort it is probably safest to say that chubs were ubiquitous with the greatest densities occurring <br />in the backwaters in this stretch. Adult humpback chub are not common in this reach. <br />Backwater availability in July and August was positively correlated with both flow at the time of <br />sampling .(R2 = .87) and annual peak flow at the State Line gage (R2 = . 86). This relationship held <br />true for sample flows nearing 9000 c£s, but did break down soon after that. (In related studies <br />backwater area was found to be is inversely related to flow in the Green and Colorado River <br />nursery habitat areas.) Backwater habitats were virtually non existent when this stretch was <br />sampled 07 July 93 and the river was flowing 13,800 cfs. At extremely high flows (22 June 95; <br />approx 40,000 cfs) the only true low veloaty habitat was flooded Westwater Wash. <br />DRAFT <br />18 <br />