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• <br />Paria River Fish Monitoring Annual Report <br />suckers occurred throughout 1996, when there were no floods until late in the summer (Brouder <br />and Hoffnagle 1997a). Brouder and Hoffnagle (1997a) and Thieme et al. (1997) hypothesized <br />that a lack of flooding and the presence of a ponded mouth permitted YOY flannelmouth <br />suckers to rear in the Paria River throughout the summer of 1996 and Thieme (1997) later <br />attributed this primarily to the presence of a ponded mouth. Results from 1998 sampling suggest <br />that the lack of flooding may have been the primary factor. The Colorado River discharge has <br />been higher than normal throughout 1998, significantly ponding the mouth of the Paria River. <br />• Flooding occurred in the Paria River this year and catches of YOY flannelmouth suckers were <br />greatly reduced or absent after these events, even in the ponded mouth. At a minimum, it <br />appears that this year's pool was an insufficient buffer to prevent young fish from being flushed <br />into the Colorado River by late spring floods. <br />Speckled Dace <br />Speckled dace were captured in the Paria River on all 1998 sampling trips, except in June <br />(Figure S; Table 6) and at all sampling sites {Figure 3). Mean CPUE for this species ranged from <br />0.1- 3.7 fish / 100 mZ seined, in December and September, respectively. Speckled dace ranged <br />in length from 20 -123 mm and in weight from 0.1 - 21.1 g (Table 7). Both YOY and adult <br />speckled dace were captured (Table 8). <br />Speckled dace are the most abundant fish in the Paria River and they use the river, at <br />least throughout the period in which it is warmer than the Colorado River. Only one speckled <br />dace was captured during December and that was caught in the mouth. Surprisingly, no <br />• <br />speckled dace were captured in June. This was likely due to one, or both, of two reasons. First, <br />larger speckled dace were probably able to evade the net in the clear, shallow water, and several <br />lazger fish were observed darting ahead of the net. Secondly, it was probably too early in the <br />season for larval speckled dace to be present. )n 1996 and 1997, YOY speckled dace appeared <br />in the catches by late May (Brouder and Hoffnagle 1997a; b}. However, it is likely that speckled <br />dace also spawned later than usual in 1998, due to a late and prolonged spring flood, which is a <br />spawning cue for this species (John 1963). Most of the speckled dace captured during July were <br />YOY, indicating a successful spawn after or just prior to the June sampling period. John (1963) <br />also noted spawning cued by monsoon floods in the Chiricahua Mountains, Arizona, which has <br />• <br />18 Arizona Game .~ Fish Department Ho8'nagle 1999, Paris River 1998 Annual Report <br />