Laserfiche WebLink
Studies related to this project began in 1975 and have resulted in <br />the Ames and Prewitt theses mentioned above. Ames (1977) studied aquatic <br />insects at six stations on the Yampa River from Steamboat Springs to Cross <br />Mountain (a distance of 177 km) in 1975 and 1976. Insects were collected <br />by use of a kick net and were identified to genus or species. Mayflies <br />and caddisflies were most abundant at all sites, and total mean abundance <br />was greatest near Hayden. Significant variation was found between numbers <br />of organisms collected at various sites and on various dates from the Yampa <br />River. Diversity indices showed the Yampa to be a generally-clean river. <br />As on the White River, ecology of certain mayfly species was <br />emphasized. Prewitt (1977) analyzed catostomid fish samples collected from <br />July 1975 through October 1976. Pure and hybrid suckers were identified by <br />morphometric, meristic, electrophoretic and discriminant-function methods. <br />Caudal peduncle depth/body length ratios of bluehead suckers decreased in <br />downstream progression on the Yampa River, Bluehead x white and flannel- <br />mouth x white sucker hybrids were common in the Yampa; flannelmouth x <br />bluehead hybrids were rare, supporting theories of reproductive isolation <br />among sympatric species. Abundance of hybrid suckers in the upper Yampa <br />River was believed due to the presence of the introduced white sucker and <br />recent environmental disturbances. <br />Prewitt, Wick and Snyder (1978) reported on fish collection by <br />seine, dipnet, and electrofishing at eight stations between <br />Maybell and Sunbeam, Colorado, in 1977 (Table 4). Yampa River collections <br />were much more diverse but contained a lower percentage of native species <br />than did collections from the White River, <br />QuestionablF data on the fish populations of the Yampa River were <br />contained in the Final Environmental Statement on Colorado Coal (U.S. <br />19 <br />