Laserfiche WebLink
relatively low and warm and only in downstream reaches. After normal dam operations <br />commenced in 1967, sampling noted near absence of reproduction by native fishes in the <br />regulated reach and their replacement by salmonids. Following penstock modifications that <br />warmed reservoir releases in June 1978, sampling detected a total of nine native and 13 <br />introduced taxa and two sucker hybrids. With the exception of rare native or incidental non-native <br />taxa, most fishes reproduced in the regulated reach. Colorado pikeminnow (n = 2) and razorback <br />sucker were captured (n = 2) but reproduction was not noted or suspected. Natives mountain <br />whitefish, mountain sucker, and mottled sculpin re-appeared in collections, and first documented <br />collections of introduced red shiner, sand shiner, and white sucker were made (Holden and Crist <br />1981). <br />Sampling during 1994 to 1996 detected a total of eight native fishes, 14 introduced ones, <br />and five sucker hybrids. Notable was presence of a moderately-abundant population of Colorado <br />pikeminnow (N = 17 individuals captured). Roundtail chub was rare, and mountain sucker was <br />absent. Similar to previous studies, bonytail and humpback chub were not detected in the study <br />area, and razorback sucker was rare (N = 1). Reproduction by Colorado pikeminnow and <br />razorback sucker was not detected. Reproduction by six other native taxa, including roundtail <br />chub, was detected. Sampling also detected the presence of three additional hybrid sucker <br />combinations and three additional piscivores: northern pike, green sunfish, and smallmouth bass. <br />Non-native Utah chub Gila atraria, and creek chub Semotilus atromaculatus, which were rare in <br />1978-1980, were not detected during sampling in 1994-1996. <br />Sampling during 2002-2004 captured a total of 24 species, eight native and 16 non-native, <br />and seven hybrids. A single bonytail was the additional native species collected in the 2002 to <br />2004 period (autumn 2002) and was captured in Browns Park just after stocking. All other native <br />fishes collected from 1994 to 1996 were also collected during 2002 to 2004, with the exception of <br />razorback sucker. Abundance of Colorado pikeminnow was slightly reduced compared to 1994 <br />to 1996 based on electrofishing sampling, but angling conducted in a separate study showed high <br />abundance of Colorado pikeminnow in Lodore Canyon (Kitcheyan and Montagne 2006). <br />Potential reproduction by Colorado pikeminnow and razorback sucker in Lodore Canyon has <br />61