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APPENDIX P
<br />McClane Canyon Mine Expansion and Fruita Loadout f=acility Biological Assessment
<br />dewatering, and channelization); competition with and predation by introduced, rion-native fish
<br />species; and hybridization with other species of the genus Gila (FWS, 1990b). Reduced water
<br />flows have also affected, humpback chubs (Woodling, 1985; FWS, 1990b; FWS, 1994).
<br />Life History, Habitat, Distribution. The humpback chub prefers waters that are deep,' fast-
<br />moving, and turbid (Woodling, 1985) and they are often associated with large boulders and
<br />steep cliffs (CDOW, 2007c); however, they have been found in relatively quiet waters as well
<br />and they may use diverse habitats (FWS, 1990b). Evidence, suggests that humpback chubs
<br />may spawn from April to June with water temperatures between 61°F to 68°F (FWS, 1990b).
<br />Optimal temperature for egg hatch is in warmer (68°F) water. Similar to other species of Gila,
<br />humpback chubs feed on benthic invertebrates but will also feed on insects floating on the
<br />surface (FWS, 1990b).
<br />in the Black Rocks and Westwater Canyon reaches, young humpback chubs appear to utilize
<br />shallow waters with depths averaging 2.1 feet but not exceeding 5.1 feet (Valdez et al., 1990).
<br />Alternatively, adults in the same areas were found in water averaging 50 feet (maximum depth
<br />of 92 feet) and associated with in -stream large boulders where there were steep cliffs along the
<br />riverbanks (Valdez- et al., 1982; Wicket al., 1981).
<br />Species Recovery. The second revised Humpback Chub Recovery Plan was released in 1990.
<br />The goal of the plan is the protection or restoration of five viable, self-sustaining populations in
<br />the Colorado River basin, as well as the protection of their habitat (FWS, 1990b).
<br />Management actions include (FWS, 1990b):
<br />• Resolve taxonomic problems.
<br />• Identify and define populations.
<br />• Implement monitoring -programs to determine the status and trends of populations.
<br />• Investigate the life historyand ecological requirements.
<br />• Protect populations and their habitats.
<br />• Assess_ potential, reintroduction or augmentation sites, and implement stocking.
<br />• Promote and encourage information.
<br />• Determine biological criteria for downlisting or delisting.
<br />Critical habitat. The FWS designated critical habitat for the humpback chub in river channels
<br />and flooded, ponded, or inundated riverine habitats that would be suitable for adults and young
<br />(FWS, 1994). Critical habitat within Colorado has been designated within the'same portion -of
<br />the Colorado River as for bonytall (FWS, 1994). The PCEs are the same as critical habitat for
<br />Colorado pikeminnow described, above.
<br />.4.3.4.2 Environmental Baseline
<br />Current Status in the Action Area. The known historic distribution of humpback chubs includes
<br />portions of the mainstem Colorado River and four of its tributaries: the Green, Yampa, White,
<br />and Little Colorado (FWS, 2002d). The distribution of humpback chub in 1990 included the
<br />Colorado River mainstem reaches in the vicinity of Westwater Canyon, Utah and Black Rocks,
<br />Colorado, approximately 8 miles downstream from the confluence of Salt Creek and the
<br />Colorado River (FWS, .1990). The estimated population in the Black Rocks reach was 900 to
<br />1,500 humpback chubs (FWS, 20024), although estimates .are uncertain (Tyus and Saunders,
<br />2001). However, there are no records of their occurrence within the Action Area.
<br />Critical Habitat. There is no critical, habitat for humpback chub in the Action Area in Reed Wash.
<br />Critical habitat has been designated on the Colorado River from Ruby Canyon (Black Rocks
<br />River'Mile 137), downstream to Fish Ford River on the Utah -Colorado border (FWS, 1994). The
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<br />PR -02 10/12
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