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<br />Catch of SPD was the highest that has ever been recorded since monitoring began in <br />1987 (Figure 10). The reason this increase is unknown but could be attributed to lower numbers <br />of large predators in the LCR including humpback chub and lower numbers of rainbow trout in <br />the mainstem near the confluence. Catch of SPD is highly variable among years with no <br />significant trends in CPUE of SPD from 1987 to 2004 (Figure 10). <br />Nonnative species <br />There is some indication that the number of fathead minnows in the system has increased <br />since 1994 although differences are not statistically significant (Figure 11). Catch rate of red <br />shiner also appears to have increased since 2002 (Figure 11). Black bullhead has shown higher <br />variability in catch since 1995 (Figure 11). Channel catfish show no significant increase in <br />CPUE since monitoring began in 1987 (Figure 11). Seven channel catfish <105 mm TL were <br />caught in 2004 suggesting that some spawning of channel catfish is occurring within the Little <br />Colorado River. No trends are evident in catch rate of common carp (Figure 11). Adult carp are <br />unsusceptible to capture in hoopnets within the Little Colorado River so hoopnet catch trends are <br />likely not be a good indicator of the carp population within the Little Colorado River. The <br />percentage of nonnative fish in the catch, although low, appears to be increasing since <br />monitoring began in 1987 (Figure 6). <br />Remote detection of PIT tags using a continuous underwater PIT tag scanner <br />Recent technological advances and 134.2 kHz PIT tags allow new possibilities for remote <br />detection of fish which may help to address questions of fish movement and population closure <br />within the Little Colorado River. During the 2004 lower 1200 meter monitoring we <br />experimented with a solar powered PIT tag antenna to remotely detect tags in fish without <br />handling them. An 11- inch diameter remote antenna (Biomark) was fastened to the cod end of a <br />baited Fyke net and fished in 3 separate locations in the Little Colorado River for 28 nights. A <br />total of 62 unique fish passed through the antenna and a date and time stamp was recorded for <br />each PIT tag detected. This type of non-intrusive sampling with a remote antenna could be used <br />in conjunction with a tem~orary weir to answer questions about spawning and movement <br />patterns of humpback chub in the Little Colorado River. <br />Long-term catch trends <br />Catch-per-unit-effort trends presented in this report may appear slightly different than <br />trends reported in previous years. Differences in collection methodology among years created <br /> <br />11 <br />