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While numerous individuals were seen swimming at the surface as <br />we shocked through runs or riffles, these reaches were typically <br />fast flowing and capture of even larger fish was difficult. <br />Brown trout, the sixth most abundant form occurring in 18 <br />collections, was represented by 23 specimens. This species' <br />distribution in May and August was limited to the upper half of <br />the study area but in October it was collected throughout. <br />Target species captured by electrofishing included two <br />Colorado squawfish and one roundtail chub. As indicated earlier, <br />the two squawfish specimens were taken with the use of the USBR <br />shocking boat on the May field trip. The first was captured on 7 <br />May 1987, approximately at River Mile 151.5. The second <br />squawfish was stunned at River Mile 140.1 on 8 May 1987 but it <br />was not collected at that time. It was seen again and collected <br />approximately 1 river mile downstream that same day. <br />A roundtail chub (163 mm TL)., initially identified as a <br />Colorado squawfish, was collected on 11 October 1987 at River <br />Mile 139.5. At this station, the habitat was characterized as a <br />deep shoreline run with a rubble-boulder substrate. Protruding <br />from the shore was a large undercut boulder, which provided <br />refuge from the fast current. <br />Electrofishing data from the three San Juan River trips <br />revealed a consistent pattern of species distribution and <br />relative abundance. Common carp, flannelmouth sucker, bluehead <br />sucker, and speckled dace were taken throughout the study area on <br />all three trips. Upstream movement of channel catfish appears to <br />be blocked by the Power Plant diversion. No specimens were taken <br />26