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<br />movement. When available, the invertebrate-rich floodplain habitat created by high <br />flows provide important postspawning habitat for immature and adult razorback sucker. <br />High flows and the duration of flows which maintain connectivity of the river and <br />floodplain are, thus, important attributes in defining quality and quantity of spring habitat <br />for all life stages of the razorback sucker. <br /> <br />Inundated floodplain habitat produces higher standing stocks of invertebrates <br />than main-channel habitat. The high invertebrate production, elevated temperature, <br />and cover provided by abundant aquatic vegetation growth in floodplain wetlands <br />should provide excellent environments for growth and survival of immature life stages of <br />both native and nonnative fishes. Although large numbers of nonnative fish are <br />produced and exist in wetlands, management to enhance floodplain habitat may <br />increase the growth and survival of early life stages of razorback sucker. <br /> <br />RECOMMENDATIONS <br /> <br />1. Flow patterns characteristic of the natural hydrograph of the middle Green River <br />appear to serve as a cue to the concentration of razorback sucker at the primary <br />spawning (Escalante) site and should be maintained to concentrate spawning adults, <br />both spatially and temporally. <br /> <br />2. Because several individual razorback sucker were located on both the Escalante <br />and Yampa River spawning sites during the spawning period, it is recommended that <br />the fish in the Green River subbasin above Desolation Canyon be considered a single <br />population (Le. middle Green River population), as suggested by the RIP genetics <br />guidelines. <br /> <br />3. Evidence supports the concept that floodplain habitat is beneficial as nursery habitat <br />for early life stages and postspawning adult razorback sucker. At the same time, the <br />large number of nonnative fishes using and produced in depression wetlands causes <br />concern about the long-term management of this habitat. Information needs to be <br />gained regarding the impact of nonnative fish production in depression and terrace <br />floodplains on the survival and recovery of listed and other ~ative fishes. <br /> <br />8 <br />