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<br />n"' '-70 <br />U~lJ ' <br /> <br />Chapter 3 - Affected Environment and Environmental Consequences <br /> <br />razorback sucker, and bonytail, the Recovery Program is developing and implementing plans to <br />acquire and restore floodplain habitat and reduce competition and predation by nonnative fish. <br /> <br />Other native fish species found in the Colorado River include flannelmouth sucker, bluehead <br />sucker, mountain sucker, and roundtail chub. Fish surveys upstream and downstream of the darn <br />show a higher composition of native than nonnative species upstream of the darn, and many of <br />the nonnative species found downstream of the dam are absent upstream (Wydoski, 1994). <br />Nonnative fish species that are absent upstream include channel catfish, northern pike, red <br />shiners, large mouth bass, bluegill, and black crappie. Black bullhead, small mouth bass, and <br />green sunfish are rare (U.S. Fish and Wildlife Service, 1998). <br /> <br />Predation by and competition with nonnative fishes are believed to be significant factors in the <br />decline of the Colorado River fishes. Channel catfish and green sunfish, along with other sport <br />fish such as smallmouth and largemouth bass and northern pike, are predators of endangered fish. <br />Off channel ponds have been identified as a source of many of the nonnative sport fishes that <br />occur in the river and endangered fish nursery areas. Small nonnative fish (minnows and shiners) <br />are assumed to be significant predators of fish larvae as well as important competitors (Wydoski, <br />1998). Fathead minnows and sand shiners are more common downstream from the dam, and red <br />shiners have been found downstream from the dam, but not upstream (U.S. Fish and Wildlife <br />Service, 1998). The distribution of native and nonnative fish upstream and downstream of the <br />dam indicate the dam also serves as a barrier to nonnative fish, and may help control the spread <br />of nonnative fish upstream. <br /> <br />Impacts <br /> <br />No Action: If no passage is provided, a self-sustaining population of endangered fish <br />would be less likely to develop via natural upstream recolonization. Even if stocked fish mature, <br />and succeed in reproducing upstream, young fish that drift or move downstream of the dam could <br />not return as adults. If native fish cannot access upstream habitat, related Recovery Program <br />efforts to acquire and restore floodplain habitat, stock Colorado pikeminnow and razorback <br />sucker, and remove nonnative fishes would be less effective. <br /> <br />The 1989 FERC EA for the Jacobson No.1 Hydro Project discusses Interior's request that the <br />licensee allow the Service to construct a fish passage facility at the project - if determined <br />necessary for the recovery of the endangered fish. Article 411 of the 1990 FERC license honors <br />this request. For purposes of this analysis, we assume the Service would not prescribe <br />construction of a fish passage facility in association with the hydropower project. From a <br />cumulative standpoint, additional impacts to endangered fish would occur as a result of <br />development and operation of the hydropower facility (but not from the fish ladder). <br /> <br />FERC completed a biological assessment for the project and consulted with the Service. At that <br />time, the razorback sucker had not been listed and critical habitat had not been designated. The <br />biological opinion from the Service, dated April 13, 1990, determined the project was not likely <br />to adversely affect the Colorado pikeminnow. The opinion also recommended measures to <br />reduce impacts, and these were included in the 1990 FERC license, To assure maintenance of <br /> <br />38 <br />