2011-05-12_PERMIT FILE - M2011028 (2)

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CHAPTER3 AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES Table 3.7-3 Special Status Fish Species Potentially Occurring Within the Project Area Common Name Scientific Name Federally Listed Species Colorado Pikeminnow Ptychocheilus lucius Razorback Sucker Xyrauchen texanus Source: U.S. Fish and Wildlife Service (June 23, 1999 memorandum) Colorado Pikeminnow Since 1991, a number of Colorado pikeminnow have been collected in the San Juan River as part of the San Juan River seven-year research plan and SJRBRIP. Nineteen (17 adult and 2 juvenile) wild Colorado pikeminnows were collected between 1991 and 1995 by electrofishing. Preliminary information from radio telemetry studies of adult Colorado pikeminnow (Ryden 2000a) indicate that adult Colorado pikeminnow are most abundant between Cudei and Four Corners. Fish captured and radio-tagged within the reach tend to stay in that section of river. Local movements of fish, however, have occurred and there is evidence that the range of the species extends up to the Hogback Diversion at RM 158.6. Miller and Ptacek (1999) reported that one radio-tagged fish moved above Cudei Diversion in July 1994, and two probable sightings also occurred between Shiprock (RM 148) and Hogback Diversion (RM 158.6) during research sampling (Ryden and Pfeifer 1995). Fifty adult Colorado pikeminnows were stocked in the San Juan River in October 1997. These fish were released in the San Juan River near the confluence with the Animas River. Fifteen of these fish were implanted with radio transmitters prior to release and monitored for habitat use until late summer 1998. Sampling of young fish, conducted as part of the SJRBRIP, include drift collection of larvae at Mexican Hat (RM 52), near Four Corners (RM 119), and the "Mixer" (RM 129), and seining collections between Hogback (RM 159) and the San Juan Arm of Lake Powell (<RM 0). Since 1991, wild young-of-the-year Colorado pikeminnow have only been collected from the lowermost river reaches in or near the high water zone of Lake Powell. Larval Colorado pikeminnow have only been collected from the Mexican Hat drift site. Experimental stocking of young Colorado pikeminnow was initiated in 1996. These fish were monitored for retention in the system and habitat use after stocking. A larger percentage of the fish stocked remained in the upper portion of the river than in the lower river. The fish were found in low-velocity habitats until they reached a size large enough to move to alternate habitats in the main channel of the river. These larger fish (approximately 125mm - 300mm) are beginning the show up in the ongoing river-wide monitoring and population estimate investigations. The San Juan River flow recommendations developed by the SJRBRIP Biology Committee were designed to benefit the endangered fish and the native fish community on which they depend. The flow recommendations include flow magnitude, duration and frequency. The recommendations used historic hydrology and the research results as the basis for the flow levels. The flow recommendations mimic the shape of a natural hydrograph with a peak in late May or early June followed by a descending limb to base flow in late July or early August. The flow regime was designed to provide the channel forming and channel maintenance requirements of the San Juan River. These components are necessary to maintain ANU»raS?cAut°.Z ?¢p•?trGZ u.Jimtr isCf) ,a h ,' '/ Qct?c(b?Tt? • P??v° l? - ? 3-115 3.7 SPECIAL STATUS SPECIES Box AA - Towaoc, CO 8_ _