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following spawning. Construction of these two projects would <br />require adult squawfish to negotiate or be passed by these two <br />barriers, and move through two reservoirs on their downstream as <br />well as upstream return trip. <br />SUMMARY <br />The biological merits of providing fish passage at one proposed and five <br />existing instream barrier structures in the Green and Colorado River subbasins <br />were discussed. Instream barriers that may be impediments to up- and <br />downstream movement of sub-adult and adult Colorado squawfish in river reaches <br />designated as priority areas for recovery and critical for maintaining <br />squawfish populations were also addressed. Four major items associated with <br />passing fish by instream obstructions were given consideration for each of the <br />three barrier types. <br />Recommendations for passing squawfish by instream barriers include <br />securing water rights at low-head structures as well as using nonconventional <br />methods, such as trapping and trucking at medium- and high-head structures. <br />Four of the five existing instream barriers identified are on the fringe of <br />habitat currently occupied by Colorado squawfish. Only one, Tusher Wash <br />Diversion in the lower Green River, is fish passage recommended to maintain <br />undisrupted, usptream fish movement. The most cost effective method to <br />accomplish this would be to secure adequate flows that would enable fish to <br />pass over the diversion, particularly during low-flow periods. The biological <br />problems associated with providing fish passage at the other existing <br />structures in the UCRB outweighed the biological benefits. <br />The following are provided as additional recommendations; <br />1. At this time, providing fish passage cannot be justified as a <br />biologically or practically sound management tool for maintaining <br />or enhancing populations of Colorado squawfish in the UCRB. <br />16