9552

• UCREFRP Catalog Number: 9552
• Author: U.S. Fish and Wildlife Service.
• Title: Management Plan for the Big-River Fishes of the Lower Colorado River Basin
• USFW Year: 2004.
• USFW - Doc Type: amendment and supplement to the Bonytail, Humpback chub, Colorado pikeminnow, and Razorback sucker Recovery Plans.
• Copyright Material: NO

Currently, small populations of bonytail occur in Lake Mojave and Lake Havasu.
' Both reservoirs are designated critical habitat (USFWS 1994a). Stocking efforts
in Lake Havasu and Lake Mohave are ongoing under projects directed by
biological opinions (BO). Bonytail have successfully recruited in the High Levee
Pond a small isolated site on Cibola National Wildlife Refuge (CNWR) (Mueller
' et al. 2002).
' Colorado pikeminnow
Wild populations of Colorado pikeminnow are extirpated from the tower basin
' (Minckley 1991). There are ongoing activities to reintroduce this species into the
Gila subbasin as an experimental nonessential population (Jahrke and Clark
1999).
1 Humpback chub
' The humpback chub occurs in the Colorado River in Grand Canyon. Although it
occurs sporadically throughout the entire subunit the largest concentration of fish
is associated with the lower 14.2 km of the Little Colorado River and its
' confluence.
Razorback sucker
t Small populations of razorback sucker persist in the Grand Canyon and Lake
Mead subunits (Minckley and Carothers 1975; Abate et al. 2002). The largest
' population of razorback sucker occurs in Lake Mohave where fewer than 3,000
individuals remain from the relic adult population (P. Marsh pers. comm.). The
number of wild razorback sucker in the Lake Havasu and Parker-Imperial
' subunits is Unknown.
Current research on humpback chub in Grand Canyon is based on the Grand
Canyon Protection Act of 1992, directed by the Adaptive Management Work
Group (AMWG), and implemented by the Grand Canyon Monitoring and
Research Center (GCMRC). The Southern Nevada Water Authority (SNWA),
' USBR and NDOW are funding investigations on the razorback sucker population
in Lake Mead. The Lake Mohave Native Fish Group (LMNFG) and the Service
are fulfilling a BO to stock Lake Mohave with subadult razorback sucker and
' bonytail. The Bureau of Land Management (BLM) is completing a BO to stock
subadult razorback suckers and bonytail into Lake Havasu. The AGFD and
a

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