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<br />) <br /> <br />because it was within the boundary of a wilderness study area. T e1emetry logging stations were <br />located in cooperation with the U.S. Bureau of Land Management. <br /> <br />Both stationary logging stations consisted of two, four filament Yagii antennas, one pointing <br />upstream and one downstream. Antennas were connected to LOTEK model SRX 400 logging <br />receivers which continually scanned II Colorado pikeminnow frequencies (four fish implanted <br />in 1996, five fish implanted in 1997 and two fish occupying Yampa Canyon in 1996). The Cross <br />Mountain became operational on 2 June 1997 and the Maybell Diversion station on 23 June <br />1997. However, difficulty with compatibility of receiver to transmitters prevented efficient <br />operation of the Cross Mountain and Maybell Diversion stations until 30 June and 4 July 1997, <br />respectively. The logging receivers were powered by a photovoltaic panel equipped with a <br />battery that stored electricity. Thus, movements offish past logging stations were monitored <br />continuously from late June - early July until the stations were dismantled in September 1997. <br />Data from logging stations were retrieved on a weekly basis for the first 3 weeks following <br />installation to monitor performance and potential vandalism, thereafter stations were monitored <br />biweekly. <br /> <br />Results: Between I July and 12 August 1997 only 4 of II (includes two fish in Yampa Canyon) <br />transmitter implanted fish in the Yampa River were recorded passing the stationary telemetry <br />logging stations. All four migrant fish were implanted above Yampa Canyon in May 1997. The <br />first fish to move downstream passed the Maybell Diversion before the logging station was <br />operating, but passed the Cross Mountain station on I July 1997. The remaining three fish <br />passed downstream of the Cross Mountain station by 17 July 1997 (Table 4-4). Flows ranged <br />between 1,072 and 3,590 cfs on the Yampa River at the Maybell gage, during downstream <br />movement. Time of return to the Maybell Diversion ranged between 36 and 17 days following <br />initial passage, averaging 27.8 days. Downstream movement of three pikeminnow between the <br />logging stations ranged from 0.8 and 5.0 days, representing a rate of38.3 to 6.1 miles per day <br />(mean = 18.4 mild). Postspawning movement (upstream) off our fish between logging stations <br />ranged between 1.7 and 7.2 days or a rate of 18.3 to 4.2 miles per day (mean = 11.6 mild). Using <br />estimates of distance covered through time between the two telemetry logging stations, the <br />slowest moving fish (4.2 miles per day) would take 17.4 days to move from the primary <br />spawning area (RMI - 18) to the Maybell Diversion (RM198.4). Using the same estimates of <br />travel (computed separately for upstream and downstream movement), the time spent at the <br />spawning site varied between 12 and 20 (mean '" 15.5) days at the spawning area (RMI - 18). <br /> <br />Most fish readily moved past logging stations; however, fish 40.502 remained at the Maybell <br />diversion site for 16.3 hours before moving downstream on its spawning migration. Although <br />most migratory fish passed the antenna reception range of both sites within 60 minutes, fish 502 <br />remained at the Maybell site for 980 minutes. Upstream movement during postspawning <br />migration was slower, averaging between 1.9 hours and 4.1 hours to move beyond the range of <br />reception from the Cross Mountain and Maybell Diversion sites, respectively. <br /> <br />CAP-9c-3 <br />