Laserfiche WebLink
<br />OOZ452 <br /> <br />downstream to nursery backwaters that are restructured by high spring flows and maintained by <br />relatively stable base flows, Threats to the Colorado pikeminnow include streamflow regulation, <br />habitat modification, competition with and predation by nonnative fishes, and pesticides and other <br />pollutants, However, its longevity (40+ years) and adaptability maintain the long-term viability and <br />stabilityofits populations, under environmental variation, through pulsed recruitment from periodic, <br />strong year classes (USFWS 2002c). <br /> <br />Pursuant to Section 4(b)(2) of the ESA, on March 21,1994 (59 FR 13374) the Service designated <br />critical habitat for the Colorado pikeminnow within its historic range, including the Yampa River <br />and its I DO-year floodplain from the Colorado State Highway 394 bridge at Craig, Colorado, in T. <br />6 N"R. 91 W., section 1 (6th Principal Meridian) to the confluence with the Green River in T. 7 N., <br />R, I03 W., section 28 (6th Principal Meridian), The Colorado pikeminnow is a highly mobile, wide- <br />ranging species. Individuals of this population can be found throughout critical habitat in both the <br />Middle Green and Yampa rivers, and occasionally may occur as far upstream as Hayden, Colorado. <br />ill spring, Colorado pikeminnow congregate on spawning bars in Yampa Canyon, dispersing on the <br />descending limb of the hydrograph after spawning. <br /> <br />Recovery goals for the Colorado pikeminnow prescribe 11 management actions needed for recovery, <br />of which the following eight actions are applicable to the YampalGreen River complex: <br /> <br />1. Provide and legally protect habitat (including flow regimes necessary to restore and maintain <br />required environmental conditions) necessary to provide adequate habitat and sufficient <br />range for all life stages to support recovered populations. <br />2.. Minimize entrainment of subadults and adults in diversion canals. <br />3. Ensure adequate protection from overutilization. <br />4. Ensure adequate protection from diseases and parasites. <br />5. Regulate nonnative fish releases/escapement into the main river, floodplain, and tributaries. <br />6. Control problematic nonnative fishes as needed. <br />7. Minimize the risk of hazardous-materials spills in critical habitat. <br />8. Provide for the long-term management and protection of populations and their habitats <br />beyond delisting (i,e., conservation plans), <br /> <br />Razorback sucker (Xyrauchen texanus) <br /> <br />This Colorado River endemic species from the sucker family (catostomidae) is the only member of <br />a monotypic genus (Xyrauchen). Adults may attain a maximum size of about 40 inches total length <br />and weigh II-I3 pounds. Remaining wild populations are in seriously depleted (Table 3, Figure 5). <br />Razorback sucker currently are found in small numbers in the Green River, Upper Colorado River, <br />and San Juan River subbasins; Lower Colorado River between Lake Havasu and Davis Dam; Lake <br />Mead and Lake Mohave; in small tributaries ofthe Gila River subbasin (Verde River, Salt River, <br />and Fossil Creek); and in local areas under intensive management, such as Cibola High Levee Pond. <br />Achii Hanyo Na1ive Fish Facility, and Parker Strip, Most populations are comprised of aged and <br />senile adults with little or no recruitment, except for the middle Green River and Lake Mead, where <br />the presence of small numbers of juveniles and young adults indicate low recruitment levels <br />(USFWS 2002d). The largest razorback sucker population in the Upper Colorado River Basin is <br />found in low-gradient, flat-water reaches of the middle Green River between the Duchesne and <br />Yampa rivers (Table 3), <br /> <br />Management Plan for Endangered Fishes in the Yampa River Basin <br /> <br />16 <br />