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<br />d <br />I <br />I <br />] <br /> <br />1 mile upstream of the structure and working downstream to the structure. Care was taken not to <br />electrofish radio tagged fish utilizing the sampling reach. <br /> <br />Nettin~. Netting was conducted during Trips 1, 4 and 5. Netting was only conducted in the <br />plunge pool complex immediately below the diversion structure. Typically two nets were set during <br />each netting run, one on each side of the main chute so that the nets fished eddy lines between the <br />thalweg and large, slow eddies below the structure. Netting was usually conducted during the <br />afternoon and evening. Up to four net sets were made during each of Trips 1, 4 and 5. High <br />densities of drifting filamentous algae, particularly during Trips 4 and 5, clogged nets quickly and <br />probably reduced their effectiveness. <br /> <br />Handlin~ Fish. Ail fISh handled through Trip 4 were measured for total length and weighed. <br />Ail fish captured were identified to species by an experienced biologist. Sex of each individual was <br />recorded when possible and expression of sexual maturity was noted when present. Ail native fISh <br />captured that exceeded approximately 150 mm were implanted with a PIT tag. Ail non-natives <br />captured that exceeded approximately 200 mm were tagged with a either a blue or yellow model FD- <br />68BC Flay tag engraved with a unique serial number. <br /> <br />No fish were tagged during Trip 5. A subsample of non-native species and game fISh were <br />weighed and measured and the remainder tallied as adults, juveniles and young-of-year. Total length <br />and weight were recorded for all native species and recaptures during Trip 5. <br /> <br />Radiotelemetry <br /> <br />Radiotelemetry was used to track the movements of radio tagged fIannelmouth suckers, roundtail <br />chub and northern pike that were implanted within 1 mile of the diversion structure. A total of 17 <br />transmitters were implanted during the course of the study, nine in northern pike, seven in <br />fIannelmouth suckers and one in a roundtail chub. <br /> <br />Radiotransmitters and receivers. All transmitters were manufactured by Smith-Root Inc. Eight <br />Model 10001, 6 volt transmitters, weighing 37 gm and having a 180-day life expectancy were used in <br />northern pike. Eight Model 150M, 6 volt transmitters, weighing 13 gm and having a life expectancy <br />of 70 days were used in round tail chub and fIannelmouth sucker. Minimum weights of implantable <br />fish was 1850 gm for northern pike and 650 gm for roundtail chub and fIannelmouth sucker. All <br />transmitters operated within a 40.600 - 40.700 mhz band. Individual transmitters were identified by <br />unique frequency and pulse rate combinations. Frequencies of individual transmitters were separated <br />by 10 hz. Transmitters with the same frequency were separated by the use of two pulse rates, 40 and <br />60 pulses per minute. <br /> <br />Receivers used to radio track fish for this study included the Smith-Root search (SR-40) and <br />standard tunable tracking (RF-40) receivers and the Advanced Telemetry Systems (ATS) Model 2000 <br />programmable scanning receiver. Larsen Kulrod NMO-40 omnidirectional whip antennas and Smith- <br />root directional loop antennas were used with these receivers. <br /> <br />Sur~ical imolant of radiotransmitters. Radiotransmitters were implanted surgically according to <br />techniques described by Tyus (1982,1988). Fish were anesthetized with tricaine methanosuIfate (MS- <br />222) in a 4O-gallon plastic bucket until they could no longer maintain equilibrium. Surgery was <br />performed in a specially designed cradle placed on top of a portable table. Water with anesthetic was <br /> <br />5 <br />