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490 The Southwestern Naturalist voL 53, no, 4 out the reach (4.6-m long, 1.8-m deep, 4,7-mm mesh size) in spring, summer, and autumn, Deeper main- channel habitat "vas sampled with e1ectrofishing gear and with b"ammel nets in summer and autumn during 3-4 trips/year. Inflatable rafts were equipped with Smith-Root e1ectrofishing units and a 5-kW generator, which produced 3-6 amperes. Each side of the liver from river km 585.4 at the head of Lodore Canvon downstream to river km 538 at the lower end of \\ihirlpool Canyon was sampled in summer and autumn 2002-2005, with follo\\:up sampling in 2006 and 2007. We set trammel nets (22.9-m long, 1.8-m deep, 25-mm-mesh inside panel, 225-mm,mesh out~ide panels) throughout the same area but concentrated most effort in Upper 'v\11irlpool Canyon from river km 551.6 to river km 543.9. Trammel-net sampling effort was variable each year but totaled 634 net h (one net set for 1 h is a net h) from 2002 to 2005 in V\lnirlpool Canyon. Nets were set in recirculating eddies adjacent to riffles or in low-velocity pools near canyon walls. Day (nets set 0800-1700 h) and night (nets set after 1700 h or before 0800 h the following day) sets were used; nets were cleared of fish at intervals of :52 h, All fish captured were identified, and most were weighed and measured, Bony tails were PIT-tagged ,md measured (total length, plus weights on a few fish) at the hatchery prior to stocking. All endangered fishes were scanned for the presence of a PIT tag and were tagged if none was found. We conducted analvsis of covariance (ANCOVA) and compared least-squar'es means to determine if differ- encesexisted between length:weight relationships (i.e., condition) between bony tails captured :511 days after release in September 2004 and for fish stocked in June 2005 and captured 4 months later in September. We could not compare differences in the length:weight relationship for June-stocked bony tails in 2005 com- pared to recaptures made in September 2005 because individual bonyt:ai.ls weights for June-stocked fish were not available. Log transformations oflengths or weights were not used because they did not improve fit-of- regression relationships, Changes in length ofbonytails recaptured in 2005 that were at large :54 months were assessed, , RESULTS AND DISCUSSION-A total of 24,422 bony tails were released in the study area during 2002-2005 (Table 1), which represents about (me-half of those fish released in the Upper Colorado River Basin in the same period. Survival of bony tails in our study area apparently Vias low in all years because the maximum interval between release and recapture for individual fish was :54 months. One bonytail was captured in 2002 in Browns Park 4 days after release and 0.4 river kIn downstream of the release area. It had fresh wounds, presumably from a wading-bird attack, and was moribund upon capture. A.lthough sampling in Lodore Canyon and downstream in 2002 and 2003 occurred prior to stocking in each year, no other fish from releases in 2002 or 2003 were recap- tured in subsequent years in Lodore Canyon in 2003-2007. An additional 10,000 smaller bony- tails were released in the lower Yampa River in 1999 (mean total length = 114 mm) and 20,000 in 2000 (mean total length = 82 mm; P. V. Badame and]. M. Hudson, in litt.). All of those smaller bony tails were coded-wire tagged, but none were detected during our sampling in reaches. of the Green River just downstream of there. In September 2004, we sampled the Green River within 11 days after two b'TOUPS ofbonytails were stocked at Echo Park boat ramp (river km 554.6, just downstream of the Yampa River). Most bonytails captured with raft electrofishing were concentrated v.rithin 300 m downstream of the boat ramp, where we captured 16 individuals, and observed but did not net ca. 60 more. We quit sampling until we were ca. 800 m down- stream to reduce stress on concentrated bony- tails; electrofished individuals displayed flared gills and were rigid. Bony tails were captured from ca. 100 m upstream of the boat ramp downstream 9.7 river kIn to just below Jones Hole Creek, a rate of dovmstream dispersal of ca. 1 km/ day, which was considerable, and poten- tially, biologically significant. We also sampled with trammel nets in Vvl1irlpool Canyon during that time and captured 9 bonytails, 15 roundtail chubs Gila robusta, and 1 humpback chub Gila CYPha. That was likely the first time those three native species have been captured from a single habitat area since Kaeding et al. (1986) captured the last verified bOny1ail in the Upper Colorado River Basin in 1984. Bony tails captured in autumn 2004 appeared healthy over the short post-stocking period. In 2005, 2,580 bony tails were stocked at Echo Park in June. We captured 10 of those bonytails byelectrofishing (all in August, none in Septem- ber) and 35 by trammel netting (conducted only in September). The June-stocked bOn}1ails were found 517 river km downstream 8 weeks later in August 2005, but most fish were captured near the release site. No bony tail captured in August was in reproductive condition. No bony1aiI stocked in 2002-2005 has been detected in subsequent similar sampling in 2006 and 2007 in the study area. T. E. Chart and ].S. Cranney (in litt.) also noted low survival of adult bOn}1ails that were radio tagged and released into the Green River in