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40 <br />• U.S. Fish and Wildlife Service (1987b) reported summer flow and <br />Colorado squawfish recruitment to be related. <br />o Unnaturally high late summer flows are detrimental to survival of Colorado <br />squawfish larvae. Such flows are often the result of dam re-regulation <br />practices where peak spring flows are redistributed to late summer and fall. <br />Jones and Tyus (1985a, b) reported elevated flows during the primary <br />Colorado squawfish nursery period (August-September) to be <br />detrimental to their survival. Regression analysis of larval catch per effort <br />on mean daily discharge in August and September resulted in an r value <br />of -0.89 (p=0.05). Mean daily discharge explained 80 percent of the <br />variation in catch per unit effort. They speculated an inverse relationship <br />• exists between discharge and availability of backwaters suitable for <br />Colorado squawfish larvae. Their observation that less area of low or <br />zero velocity water within backwaters exists at high flows than low flows <br />supports the idea. <br />Archer et al. (1986) reported that all backwaters observed in the Green <br />River at 800 cfs were transformed to moving waters at 4000 cfs. They <br />reported a correlation between high late summer-fall discharges and <br />decreased recruitment of Colorado squawfish. <br />o A balance between unnaturally high late summer flows and very low flows may <br />be necessary to transport Colorado squawfish larvae to downstream reaches <br />with large amounts of rearing habitat. <br />0