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<br />were also applied to the int reted video. General habitat es defined for the <br />~P tYP <br />biological surveys were classified into nine types. Six types were encountered during <br />this study; Scour Channel, Migrating Sandwaves, Horseshoe Vortex, Flooded Tributary <br />mouths, Shoreline Eddy, and Shoreline. <br />Not all general types were needed for the study bar, and two categories were further '~ <br />divided and defined. Scour Channel was divided into either upstream or downstream <br />facing habitats, and Migratory Sandwave into four types which all share the <br />characteristics of being shallow and transient. Isolated pools were included as a <br />separate category. Flooded Tributary and Shoreline Eddy and Shoreline were lumped <br />into "other" or not used. Specific types are described in Table 5, Chapterl. <br />3) Describe the relationship between geomorphological processes of sediment transport and <br />nursery habitat formation and maintenance in the Green River. <br />- Flood magnitudes are divided into three categories: less than bar top, less than bankfull, <br />and greater than baukfull. Antecedent bar top elevation can be high or low. The <br />combined effects on nursery habitat availability of the antecedent condition of bar top <br />elevation and flood magnitude are described in a 2 by 3 matrix (Table 11 in Chapter 1). <br />The relatively infrequent high peaks increase bar elevation. The thalweg scours on the <br />ascending limb of the hydrograph and quickly rebuilds to near previous levels as flows <br />peak and recede. The maximum height of the bar tops build to just under the surface <br />level of the water at peak flow. <br />- The more frequent low peaks and subsequent flows erode and sculpt sand bars. Small <br />migrating dunes and bars can be superimposed on stable bar edges, increasing <br />complexity. <br />- Secondary channels behind large compound bars provide the majority of total and <br />quality habitat. They are generally stable in location from year to year. These channels <br />scour during high peaks, and fill during lower peaks. The area of available habitat in <br />each such channel is a function of bar top elevation (to block throughflow), minimum <br />elevation at the downstream channel mouth, and flow stage, all of which are dependent <br />on antecedent conditions. <br />4) Describe the relationship between nursery habitat types available to and selected by <br />Colorado pikeminnow. <br />- Colorado pikeminnow selected for secondary (scour) channel habitats over all other <br />types of habitat in numbers and area. These were the only type of habitat in which the <br />observed use by pikeminnow was consistently greater than the expected use, although <br />all types of habitats were used to some extent. <br />xv <br /> <br />