Laserfiche WebLink
<br />002H9 <br /> <br />HUJllp~a.c~ chub (Gila cypha) <br /> <br />This species is restricted to deep, swift, canyon-bound reaches of the Colorado, Green, Yampa and <br />Little Colorado rivers. Six extant wild populations are known: (1) Black Rocks, Colorado River, <br />Colorado; (2) Westwater Canyon, Colorado River, Utah; (3) Yampa Canyon, Yampa River, <br />Colorado; (4) Desolation/Gray Canyons, Green River, Utah; (5) Cataract Canyon, Colorado River, <br />Utah; and (6) the mainstem Colorado River in Marble and Grand Canyons and the Little Colorado <br />River, Arizona (USFWS 2002a). The first five populations are in the Upper Colorado River Basin, <br />while the sixth population is in the Lower Colorado River Basin (Table I, Figure 5), <br /> <br />Large members of the minnow family (cyprinidae), adult humpback chub may reach up to 19 inches <br />in total length and weigh up to 2.5 pounds. They require eddies and sheltered shoreline habitats <br />maintained by high spring flows. High spring flows maintain channel and habitat diversity, flush <br />sediments from spawning areas, rejuvenate food production, and deposit gravel and cobble used for <br />spawning, Humpback chub spawn on the descending limb of the spring hydrographat water <br />temperatures typically from 16 to 220C. Young require low-velocity shoreline habitats, including <br />eddies and backwaters, that are more prevalent under base-flow conditions. Threats to the species <br />include streamflow regulation, habitat modification, predation by nonnative fish species, parasitism, <br />hybridization with other native Gila, and pesticides and other pollutants (USFWS 2002a). <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 humpback chub within its historic range, including the Yampa River from the <br />boundary of Dinosaur National Monument (DNM) in T.6 N., R.99W., section 27 (6th Principal. <br />Meridian) to the Green River confluence in T.7N., R.l03W., section 28 (6th Principal Meridian), <br />The Yampa River humpback chub population is less mobile than those ofthe Colorado pikeminnow <br />orrazorback sucker; the humpback spends its entire life cycle within a relatively narrow home range <br />in DNM from Yampa Canyon downstream to Whirlpool Canyon on the Green River. <br /> <br />The recovery goals for the humpback chub prescribe 10 management actions needed for recovery. <br />Of these, the following eight are applicable to the YampalGreen River complex: <br /> <br />I. Provide and legally protect habitat (including flow regimes necessary to restore and maintain <br />required envirornnental conditions) necessary to provide adequate habitat and sufficient <br />range for all life stages to support recovered populations. <br />2. Ensure adequate protection from overutilization. <br />3, Ensure adequate protection from diseases and parasites. <br />4, Regulate nonnative fish releases/escapement into the main river, floodplain, and tributaries. <br />5. Control problematic nonnative fishes as needed, <br />6. Minimize the risk of increased hybridization among Gila spp. <br />7, Minimize the risk of hazardous-materials spills in critical habitat. <br />8. Provide for the long-tenn management and protection of populations and their habitats <br />beyond deli sting (i.e., conservation plans). <br /> <br />Management Plan for Endangered Fishes in the Yampa River Basin <br /> <br />12 <br />