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Green River Floodplain Inundation 9 June 2005 Valdez and Nelson (2004) used a model developed by Valdez to evaluate the potential for each priority floodplain wetland to entrain drifting larvae. This model is based on the assumption that the number of drifting larvae present in the main channel declines substantially for each river mile downstream of the spawning area. The model results presented by Valdez and Nelson (2004) suggested that the proximity of a particular floodplain habitat to the spawning bar may be important and that only about 1 % of the drifting larvae were expected to remain in the main channel 58 kIn (36 mi) downstream from the spawning bar. On this basis, Valdez and Nelson (2004) speculated that the priority floodplains that are nearest to the spawning bar ate likely to entrain the greatest number of larvae, and, therefore, may be higher priority areas for recovery than are habitats located further downstream. There is, however, some uncertainty associated with the entrainment model, and the rapid loss of larvae in relationship to distance downstream of the spawning bar may be overestimated. Several pieces of evidence suggest that more larvae are transported further downstream than the model predicts. First, Colorado pikeminnow larvae are produced upstream of the razorback sucker spawning bar, but are known to be transported as far as Ouray in substantial numbers. Second, light-trap capture data for razorback sucker larvae (Muth et al. 1998) suggests that the number of larvae in the Ouray area was at least 50% of that in upstream Escalante (Thunder Ranch) and Jensen areas in some years. Third, Modde (2001) reported captures of wild razorback sucker juveniles in the Old Charley Wash floodplain (Table 2), which is 97 kIn (60 mi) downstream of the razorback sucker spawning bar. The Valdez model predicts that considerably less than 1 % of the larvae produced would be transported that distance.