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~W~i'~ i I I ! , , The Southwestern Naturalist vol. 38, no. 4 366 16 14 Q \ t\l \ E 12 \ \ 0 \ 0 10 \ ..... - \ .r. \ en 8 \ u: \ .5 \ w 6 \ \ :J \ a. 4 \ U 0", 2 .... .... . . River 1989 . . Reservoir 1989 o---~ River 1990 0- - - -0 Reservoir 1990 o May June July July Aug Sap Oct Nav 30 Month FIG. 2-Catch-per-unit-of-effort for Colorado squaw fish in the White River and Kenney Reservoir, 1989 and 1990. ued to move downstream after exiting the res- ervoir, as indicated by the collection of squaw fish farther downstream on each successive sampling occasion in 1989 (except September) and in 1990 (Table 3). The majority of Colorado squaw fish that emigrated appeared to have done so during a short time between May and June each year. Section 2, immediately downstream from the dam, showed percentages that decreased, sug- gesting an initial "pulse" of dispersal. Relatively more squaw fish were collected in section 2 in June and July, section 3 in September, and sec- tion 4 in November. No squawfish were collected in section 5, probably due to a lack of suitable backwater habitat. This mass of squawfish mov- ing downstream was also discern able in 1990, although smaller sample sizes make it less evident (Table 3). Colorado squaw fish were not found upstream from the reservoir in 1988 or 1989. In 1990 fish were found at sites 7.2 km upstream from the reservoir in June and again at one site, a large, deep (>1.8 m) backwater, 1.6 km upstream from the reservoir in July. None were collected after July, mirroring the decline in catch-per-unit-ef- fort in the reservoir and in areas downstream from the reservoir. Total collections of fingerling squawfish were a small percentage (1.0%) of the 96,597 stocked, despite intensive sampling. Of all fish collected L ._~~?~~0,"~~p~~~:. TABLE 3-Percentages of the total number of squaw- fish captured in the White River each month, per sec- tion of the study area (Fig. 1). Year Month section May June July Aug. Sept. Oct. Nov. Total 1989 2 0 100 78 44 0 0 40 3 0 0 18 .44 100 0 0 4 0 0 4 12- 0 0 60 Total 0 109 55 32 5 0 5 206 1990 2 100 80 0 0 0 0 0 3 0 20 0 0 0 0 0 4 0 0 0 100 100 0 0 Total 7 44 0 1 1 0 0 53 during this study, squawfish accounted for 0.4% in 1988, 1.4% in 1989, and 1.0% in 1990. Based on seining data, catch rates of stocked squawfish (number per 100 m2) declined precipitously in the months following stocking in both the res- ervoir and the river (Fig. 2). Telemetered Colorado squaw fish exhibited wide-ranging movements throughout the reser- voir. Based on these erratic movements, the fish did not appear to establish home ranges. Of the four hatchery fish tagged, two died within 29 days without leaving the reservoir. One fish moved upstream and then back to the reservoir within 36 days of being tagged. The fourth fish was last contacted in the reservoir on 12 June, and sub- sequently recontacted 12 km downstream from the dam 58 days later where it remained into October. Of the three wild fish tagged, one died in eight days. A second remained in the reservoir until early July and then moved upstream 3.2 km. It was last located in August, 1.6 km above .the reservoir. The remaining fish exited downstream on 12 June, and remained downstream from the dam into October. DISCUSSION-Early hopes that Kenney Res- ervoir might imitate a large instream pool or backwater, inducing the Colorado squaw fish to remain in the reservoir, were not realized. In- stead, large numbers of Colorado squaw fish ex- ited the reservoir and continued downstream, and catch rates declined in all areas. The rapid dis- appearance of the species from the study area has