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<br />::> <br />:) <br />:.;J <br />\) <br />tti.) <br />Xl <br /> <br />movement and habitat use, Additional information will be collected following <br />augmentation, including growth and survival of stocked fish, and interactions between <br />hatchery-reared fish and other species, This information will be critical to future decisions <br />concerning the efficacy and need for larger scale stocking efforts in the recovery of the <br />Colorado sQuawfish in the San Juan River. <br /> <br />The investigations that comprise this proposal will focus on low-velocity habitat use of <br />Age-O and juvenile Colorado sQuawfish to test two hypotheses concerning the low <br />numbers of young Colorado squaw fish found in the San Juan River: the spatial and <br />temporal dynamics and quality of nursery habitat is limiting recruitment of Age-O fish, or <br />low adult Colorado squawfish densities, not poor or limited nursery habitat, result in <br />limited recruitment. The objectives of the proposed action are listed below: <br /> <br />1. To empirically monitor the annual recruitment of young-of-year Colorado <br />sQuawfish in relation to flow patterns in the San Juan River. <br /> <br />2. To determine the Quality .and Quantity of low-velocity habitats in the San <br />Juan River for use by Colorado sQuawfish by experimentally stocking young- <br />of-year fish. <br /> <br />3. To determine the effects of diversion canals on young-of-year Colorado <br />squawfish drift/movement (e.g., stranding, etc.). <br /> <br />4. To characterize the early-life stage ichthyofaunal community in low-velocity <br />(nursery) habitats. <br /> <br />5, To characterize nursery habitats and their use in the San Juan River system. <br /> <br />6. To determine overwinter survival of experimentally stocked Age-1 sized <br />(approximately 70-90 mm) Colorado squawfish. <br /> <br />7. To determine what habitats juvenile Colorado sQuawfish utilize. <br /> <br />8. To determine spray marking mortality and spray marking retention. <br /> <br />Eight geomorphically distinct reaches have been identified by Bliesner and Lamarra (1995) <br />in the San Juan between the two major features that essentially define the river for the <br />purposes of conservation of the Colorado sQuawfish: Lake Powell at the downstream <br />terminus of flowing water,-and Navajo Dam at the upstream control of flows in the river. <br />. The eight distinct reaches were screened through several data sets within the categories <br />of: river valley width, channel contact geology (material in cut-banks & bedrock contact!, <br />riparian vegetation, channel gradient, channel pattern (braiding and sinuosity!, tributary <br />influence, anthropogenic influences (diversion dams, irrigation, levees, etc.) and aquatic <br />habitat (six categories at three flow rates). Utilizing these categories, the following <br />reaches of the San Juan have been identified (by River Mile [RM]): <br /> <br />1. Lake Powell influence (RM 0 to RM 14) <br />2. Canyon (RM 15 to RM 67) <br />3. Chinle to Aneth (RM 68 to 105J <br />4. Aneth to Mixer (RM 106 to RM 1301 <br /> <br />3 <br />