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<br />f. i- <br />\.. "".. <br /> <br />mile 0.0, the confluence with Lake Powell. Sampling crews will consist of approximately 10-13 <br />people. In support of objective #4 below, all fish collected in the Fannington to Hogback <br />Diversion (New Mexico) reach will continue to be FLOY -tagged and monitored during 1997 <br />sampling to evaluate the impact of instream diversion structures in this reach of river on native <br />fish movement. In support of objective #5 below, the stomachs from alllentic predators sampled <br />during 1997 electrofishing studies will be analyzed to determine their predatory impact on native <br />fish. Our sampling efforts in the lower 38 miles of the river will be closely coordinated with the <br />National Park Service. <br /> <br />At present, all radio tags that were implanted in Colorado squawfish have expired. All new adult <br />Colorado squawfish captured during 1997 adult monitoring trips will be implanted with radio tags <br />and monitored as in years past. The purpose of this work will be to document movement and <br />habitat utilization by adult Colorado squawfish and razorback sucker under low flow conditions <br />and afterwards, as well as to evaluate the impact of instream diversion structures on these species. <br />Adult monitoring will also sample for experimentally stocked razorback suckers and allow radio <br />tracking of the same. Aerial searches for radio-tagged fish were scheduled to continue on a <br />regular basis in FY-96. Due to the difficulty oflocating radio-tagged fish from an airplane, an <br />aerial monitoring trip was conducted in December 1995 using a helicopter. The premise behind <br />this flight was that a helicopter would allow researchers to track at slower speeds than in an <br />airplane, yet still cover a large portion of the river in a single day. However, no radio-tagged fish <br />were contacted on this flight and the further flights were canceled due to the apparent low <br />efficiency of this tracking method in obtaining data on weak-signaled razorback sucker radio tags. <br />Aerial monitoring may be re-iilitiated later in 1996, either in conjunction with channel catfish radio <br />telemetry efforts, or ifnumerous Colorado squawfish are radio-tagged in 1996. Ground searches <br />will be conducted during adult monitoring trips, razorback sucker moilitoring trips, and other <br />sampling efforts. Collection of tissue samples from rare fish for contaminants studies will <br />continue. <br /> <br />Objectives: <br /> <br />1.) Detennine shifts in fish community structure, abundance and distribution, and <br />length/weight frequencies under the research flow regime. <br /> <br />2.) Monitor Colorado squawfish population trends (spawning and staging areas, habitat <br />needs) . <br /> <br />3.) Moilitor experimentally stocked razorback sucker (growth rates, dispersal patterns and <br />habitat use). <br /> <br />4.) Continue evaluation of movement data and rare fish distribution to determine the <br />extent to which current structures (dams, weirs, etc.) are impeding endangered fish <br />movement. <br /> <br />2 <br />