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<br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />t <br />I <br />I <br />I <br /> <br />OO~332 <br /> <br />of wat~r passed through the turbine. <br />were taken when both generators were <br />either day or night samples. <br /> <br />All 1995 <br />operating <br /> <br />and 1996 samples <br />and categorized as <br /> <br />Samples were removed from the net and fish were measured, <br />identified, and condition noted. In some cases, it was necessary <br />to reassemble parts to estimate length. Fish found alive were <br />returned to the tailwater, while dead fish were preserved and <br />given to CD OW for further tests. <br /> <br />Reservoir Surveys <br /> <br />A single-beam, model EY-200P Simrad scientific echosounder was <br />used to collect fish distribution and density information. The <br />system is equipped with a 70 transducer that operates at 200 kHz. <br />The transducer generates a sound wave that spreads through the <br />water in a cone-shaped beam. Objects in the sound beam reflect <br />sound waves back to the sending unit (transducer), where they are <br />detected and evaluated for strength (return voltage), travel <br />time, and pattern of return. System gain is varied <br />electronically with time to correct for absorption of the sound <br />beam. Data were collected and recorded using the 40-Log-R time- <br />varied gain (TVG) function for later analyses. <br /> <br />Hydroacoustic surveys were conducted by boat along predetermined <br />transect courses. Transects were plotted and run in an <br />uninterrupted zigzag pattern from Highway 149 to Blue Mesa Dam. <br />Surveys were also conducted up four of the reservoirs major arms. <br />The navigational features of a Magellan Global Positioning System <br />(GPS) , Model 5000 allowed us to revisit transects and helped us <br />to navigate after dark. Attempts were made to survey the entire <br />transect course twice during each field trip producing two <br />individual data sets. <br /> <br />Digitized files were analyzed using the HydroAcoustic Data <br />Analyses System (HADAS) developed by Dr. Torfin Lindem. This <br />system consists of an interface box connected to the DAT <br />recorder, an interface computer card, and software loaded into a <br />desk-top computer that performs final analysis of hydroacoustical <br />data. <br /> <br />B <br />