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<br />COLORADO RIVER RECOVERY PROGRAM <br />FY 97 ANNUAL PROJECT REPORT <br /> <br />RECOVERY PROGRAM <br />PROJECT NUMBER:CAp.4b <br /> <br />I. Project Title: Evaluation of the Effectiveness of the Fish Passage <br />Structure at the Redlands Diversion Dam and Flow Requirements in the <br />2.3-mile Reach of the Lower Gunnison River <br /> <br />II. Principal Investigator(s): Frank K. Pfeifer. Project Leader <br />organization: Colorado River Fishery Project <br />address: 764 Horizon Drive, South Annex A <br />Grand Junction, CO B1506-3946 <br />phone: (970) 245-9319, FAX (970) 245-6933 <br />E-mail: R6FFA GRJ@MAIL.FWS.GOV <br /> <br />III. Project Summary: <br /> <br />This is the second year that the fish passageway at the Redlands <br />Diversion Dam has been operated since it was completed in June 1996. <br />In 1996, it was operational from 24 June to 25 October. In 1997. the <br />fish passageway was operational 27 March to 27 October. It was <br />winterized in late-October 1997 and will be operational again in the <br />spring of 1998. <br /> <br />The overall goal is to evaluate whether sub-adult and adult Colorado <br />squawfish and razorback sucker will use a passageway. This <br />passageway was constructed as an experimental facility to determine <br />the utility of using fish passage as a recovery tool for these <br />species at other instream barriers in the Upper Colorado River Basin. <br />Specific objectives were to determine 1) the use of the fish <br />passageway seasonally by all native and nonnative fishes and 2) the <br />extent of movement of sub-adult and adult Colorado squawfish in the <br />fish passageway, in the plunge pool, and in the 2.3-mile reach <br />downstream of the diversion dam using radiotelemetry. <br /> <br />In 1997, eighteen sub-adult and adult Colorado squawfish ascended the <br />fish passageway compared to only one adult Colorado squawfish that <br />was collected in the fish trap in 1996. In 1997, four squawfish used <br />the fish passageway in July and 14 in August. Three of these fish <br />had been captured previously from the Colorado River downstream of <br />Moab, Utah. In 1996, the one adult squawfish that used the fish <br />passageway also ascended the ladder during August. All squawfish <br />were released upstream of the dam. <br /> <br />In 1997, a total of 12,235 fish comprising six native and eight <br />nonnative species plus three hybrid sucker fishes were collected in <br />the fish trap. Ninety-four percent of the fish collected were <br />natives. Flannelmouth sucker comprised 43% of the catch, bluehead <br />sucker, 41%. White sucker comprised the largest number of nonnative <br />fish (2%). <br /> <br />Of the 12 adult Colorado squawfish that were implanted with 360-day <br />LOTEK@ radiotags during April, May, and June 1997, none used the fish <br />passageway. None of the squawfish implanted with radiotags in 1996 <br />used the passageway in 1996 or 1997. One land-based tracking station <br />located at the dam and two located downstream in the 2.3.mile reach <br /> <br />1 <br />