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<br />Introduction
<br />
<br />The initial goal of this study was to determine the status, ecological requirements, and assess the role of
<br />stocking augmentation for the razorback sucker and bonytail in the lower Colorado River main stream.
<br />Unfortunately, funding rescissions (-60%) made it necessary to reduce and refocus this study.
<br />The study focused on the Mohave and Chemehuevis Valleys which contained the last remnant populations
<br />of wild bonytail and razorback sucker. Native fish populations in Lake Mohave have been the topic of
<br />extensive study for nearly four decades. Far less effort has been directed toward the lower Mohave Valley
<br />where natives were last reported inhabiting portions of the remaining, but altered river.
<br />More than 30,000 razorback suckers and nearly 18,000 bonytail have been stocked in the Colorado River
<br />between Davis and Parker dams during the past decade. Fish were stocked by Arizona Game and Fish
<br />Department (AGFD), U.S. Fish and Wildlife Service (FWS), Bureau of Reclamation (BaR), and Bureau of
<br />Land Management (BLM); however, little effort has gone into examining their fate. For these reasons, we
<br />focused our remaining resources at examining the fish community found in the 60 km reach of river between
<br />Lake Havasu and Davis Dam.
<br />The following report contains five chapters that represent the main components of the study. They include:
<br />1. Fish Surveys: Davis Dam to Lake Havasu; 2. Telemetry Studies; 3. Stocking Assessment; 4. Bibliography
<br />for the Big River Fishes, Colorado River; and 5. The Role of Stocking in Management and Recovery.
<br />Additional information generated from this project is provided in the following papers and reports:
<br />
<br />Marsh, G.A., and Mueller, G., 1999, Spring-summer movements ofbonytail in a Colorado River reservoir,
<br />Lake Mohave, Arizona, and Nevada: USGS/BRD Open-File Report 99-103, Denver, Colo.
<br />Marsh, P.c., and Kesner, and B.R., 2000, Movement of sub-adult razorback sucker in a regulated reach and
<br />reservoir of the Lower Colorado River: Cooperative agreement 1445-0009-94-1108, task 6, submitted to
<br />USGS, Denver, Colo.
<br />Marsh, P.c., Pacey, c., and Mueller, G., 2001, Bibliography of the Big River Fishes, Colorado River, created
<br />at Arizona State University, Tempe, under contract to USGS, Denver, Colo.
<br />Mueller, G.A., P.C. Marsh, G. Knowles, and T. Wolters. 2000. Distribution, movements, and habitat use of
<br />razorback sucker (Xyruchen texanus) in a lower Colorado River reservoir, Arizona-Nevada. Western North
<br />American Naturalist. vol. 60, p. 180-187.
<br />Mueller, G.A., and Marsh, P.C., 2002, Lost, a desert river and its native fishes: A historical perspective of the
<br />Lower Colorado River, Information and Technology Report USGS/BRD/ITR-2002-00 1 0, U.S. Government
<br />Printing Office, Denver, Colo, 69 p.
<br />Mueller, G.A., Marsh, P.c., Foster, D., Ulibarri, M., and T. Burke. 2003. Factors influencing post-stocking
<br />dispersal of razorback sucker: North American Journal of Fisheries Management. vol. 23, p. 270-275.
<br />Mueller, G.A., and Wydoski, R., In Press, Reintroduction offlannelmouth sucker (Catostomus latipinnis):
<br />North American Journal of Fisheries Management.
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