Laserfiche WebLink
<br />, .. <br /> <br />26 <br /> <br />staging fish. High spring flows mobilize and deliver nutrients and sediments <br />downstream and aid in the fonmatian .of nursery areas. Additional studies are <br />required to refine this relationship. <br /> <br />Humoback Chub <br /> <br />Humpback chub predominantly use high-gradient, rocky, canyan habitats, and <br />availability of such habitat may be adversely affected by the present <br />alteration of spring runoff in the Green River. Spawning of humpback chub <br />occurs shortly after highest spring discharge at river temperatures of about <br />20.C in the Yampa River, and presumably in the Green River as well. Reduced <br />spring runaff promotes growth of the introduced salt cedar, Tamarix spp., <br />resulting in bank stabilizatian and increased availability of spawning habitat <br />for introduced fish. Relationships between magnitude and duration of spring <br />runaff should be further evaluated with a consideration of availability of <br />shoreline eddy habitat" bank stabilization due to exotic vegetation, <br />overgrowth, and abundance of nonnative and other potential competitor and <br />predator fish. <br /> <br />Razorback Sucker <br /> <br />Spawning of razorback suckers occurs with increasing flows associated with <br />highest spring runoff. Curtailment of spring runoff in the mainstream Green <br />River may be associated with loss of recruitment to the juvenile stage. <br />Overbank flooding during spring runoff is considered beneficial to adults and <br />may be important for dispersal and rearing of yaung. Flaming Gorge releases <br />should pramote spring flooding of historic flooded lowlands. Influence of <br />spring flows on razorback sucker spawn in the Green River should be more fully <br />evaluated. <br /> <br />Bonvtall Chub <br /> <br />Because so few bony tail chub were collected in the wild, their spring behavior <br />and requirements are unknown. It is hypothesized that if the habitat and life <br />history requirements of squawfish, humpback chub, and razorback suckers are <br />met, then the remaining bony tail chub will benefit. <br /> <br />SUl1lller <br /> <br />Colorado Sauawfish <br /> <br />Gradually decreasing fl~s and sediment transport regimens and warming river <br />temperatures in early and midsul1lller are necessary for successful spawning, <br />hatching, and downstream transport of drifting larvae. The gradual decline of <br />SUl1lller flows following spring scouring maintains natural sediment transport <br />equilibria, prevents siltation of spawning substrate, aids downstream drift of <br />larvae, and creates productive nUrsery areas. <br /> <br />Humoback Chub <br /> <br />Rapidly declining summer flows adversely affects spawning and nursery habitats <br />by concentrating fish in suboptimal habitats and increasing the potential for <br />