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<br />3, Determine factors that affect growth, survival, and dispersal of early <br />life stages of Colorado squawfish. <br /> <br />B. Objectives: <br />1. To validate techniques for aging otoliths in larval and juvenile Colorado <br />squawfish. This tool can then be used to determine factors that affect <br />growth, survival, and recruitment of young Colorado squawfish in the <br />wild. <br /> <br />2. To comparatively describe the earty morphological ontogeny'of <br />selected important fishes, including morphology and development of <br />sense organs and locomotor structures. <br /> <br />3. To evaluate responses of selected important fishes to manipulated <br />conditions and assess the role of sensory and locomotor systems in- <br />various earty behaviors such as feeding, predator avoidance, and <br />swimming performance. <br /> <br />4. To evaluate effects of environmental factors (e.g., streamflow, water <br />temperature, food supply, and diet) on growth, survival, and behavior <br />of earty life stages of Colorado squawfish, and other fishes in <br />laboratory and field studies. <br /> <br />5. To evaluate marking techniques for early life stages of razorback <br />sucker. <br /> <br />C. End products: Final reports for these and other objectives are planned for FY <br />94. <br /> <br />VII. How is this study contributing to recovery? Are the study goals and <br />objectives being met? <br /> <br />Efforts to recover endangered fishes in the Colorado River Basin must incorporate all <br />life-history aspects if sound management practices are to be devised and <br />implemented. This project strives to enhance our knowledge of factors that may <br />affect survival and growth of earty life stages of Colorado squawfish and other fish <br />species, especially as it relates to operation of Flaming Gorge Dam on the Green <br />River. Development of the otolith-aging technique will provide a unique tool to <br />assess factors that affect growth, survival, and recruitment of Colorado squawfish in <br />the Green River under different flow conditions. Results from other earty biology <br />studies will be used to determine how earty life stages of Green River fishes interact <br />with their physical and biological environments. This knowledge will aid in evaluating <br />effects of management decisions (e.g., flow enhancement, nonnative fish control) on <br />the biology of early life stages of Colorado River Basin fishes. These data will also <br />be used as part of an annual assessment of reproduction and recruitment of native <br />and nonnative fishes in the Green River. Goals and objectives of this project are <br />being met. <br /> <br />3 <br />