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<br />numbers of adult sized chubs and electrofishing is a better technique to collect juveniles. <br />Electrofishing was conducted in attempt to maximize our captures. One pass of <br />electrofishing was conducted throughout the study area (between sites where feasible) <br />with more intensive sampling at each of the twelve sites. Six to eight trammel nets were <br />set at each sampling location, depending on availability of habitat at each site. Trammel <br />nets were fished at each site from late afternoon until midnight and again the next day <br />during the pre-dawn and morning hours. Each net was checked at one and a half to two <br />hour intervals and all chubs were removed and placed in a holding pen to avoid <br />recapturing the same fish twice within a sample site. One night was spent at each of the <br />twelve sites. In addition to electrofishing and trammel netting, hoop nets and minnow <br />traps were set at each site as conditions allowed. One or two hoop nets and one to four <br />minnow traps were set per site. Hoop nets and minnow traps were baited with cat food <br />and set parallel to flow if any existed. Both the nets and traps were set in the afternoon <br />after arrival at each site and checked in the morning prior to leaving. <br /> <br />A total of259 humpback chub were collected in 1,598 trammel net sets during the two <br />trips through Desolation/Gray canyons, yielding an overall catch rate of 0.127 fish/net <br />hour (Table 1). Electrofishing effort in 2002 was twice that in 2001. Forty-two <br />humpback chub were collected during electro fishing yielding a catch rate of 2.4 <br />fish/shock hour. Electrofishing captured thirteen percent of all humpbacks collected. <br />Captures of humpbacks between sites were low (2% of total humpbacks caught from all <br />methods). Hoop nets and minnow traps set at each of the sampling sites collected nine <br />humpbacks, six of which were juveniles. <br /> <br />Overall average total length of all humpbacks collected by all methods was 240.5 mm <br />(Figure I). Fifteen percent of the total humpback catch were subadults (< 200 mm TL). <br />Ofthis fifteen percent, 7.8% were taggable (> 150 mm TL), and 7.2% were < 150 mm <br />TL. Average total length of humpback chub caught in trammel nets was 252 mm with ,\ <br />range of 109-409 mm. Average total length of all humpbacks collected during <br />electrofishing (n = 42) was 190 mm (range 82-359 mm). Humpbacks captured in hoop <br />nets averaged a total length of 151 mm (n=9, range 71-246 mm). <br /> <br />Two humpbacks were recaptured within the same trip, five days apart. One of these fish <br />moved 10 miles upstream while the other moved 13 miles downstream. Six chub were <br />recaptured during the second trip that had been tagged during the first trip. Of these six <br />fish, one moved downstream eight miles while the remaining five stayed within a mile of <br />their original capture location. Eighteen total long term recaptures (fish PIT tagged in <br />previous years) were captured in 2002. <br /> <br />The results presented in this report are a preliminary summary of the raw data. Following <br />further verification and analysis of this data a population estimate will be generated. <br /> <br />FY 2002 Annual Report 22k Page - 3 <br />