Laserfiche WebLink
<br />Workina Hvoothesp.s: <br /> <br />) <br /> <br />. <br /> <br />The Tusher Wash Diversion is a barrier to upstream move~ent of <br />adult/sub-adult native fish at low flows. <br /> <br />. The Tusher Wash Diversion Canal entrains native fish. <br /> <br />IV. Study Goals, Objectives, End Product: <br /> <br />Goal: To determine if the Tusher Wash Diversion restricts native fish movement <br />or entrains native fish. <br /> <br />Objectives: <br /> <br />To determine if the Tusher Wash Diversion prevents the upstream movement of <br />sub-adult native fishes. <br /> <br />To determine if the Tusher Wash Diversion Canal entrains native fish. <br /> <br />To determine if the Tusher Wash Diversion needs to be modified to better <br />accommodate native fishes. <br /> <br />End Product: A final report with results of the study and recommendations for <br />Tusher Wash Diversion. <br /> <br />V. Study area (river miles, if appropriate): Green River from Swasey's <br />rapid (RM 131.8), 3.5 miles upstream from the diversion, to 1 mile below <br />the diversion (RM 127.3). <br /> <br />VI. Study Methods/Approach: <br /> <br />Evaluation of sub adult fish Dassaoe <br /> <br />Task la. Tagging <br />After flows have subsided (July), five electrofishing trips will be made over <br />the course of two weeks. These trips will be made from Swasey's Rapid to <br />approximately 1 mile downstream of the Tusher Diversion with the effort <br />concentrated at the diversion. All fish collected within 1-1.5 miles of the <br />diversion (upstream and downstream) will be marked and released below the <br />diversion. All endangered fish will be PIT-tagged and non-endangered sub- <br />adult/adult fish will be floy-tagged. If large numbers of fish are caught <br />(too large to process all fish), preference will be made to floy-tag juvenile <br />native fish (200-400 rom). Following marking, one electrofishing trip will be <br />completed bi-weekly for three months in the study reach upstream from the <br />diversion to look for marked fish that may have moved upstream past the <br />diversion. Additional unmarked fish caught during these trips will be floy- <br />tagged (as described above) when it is feasible to release these fish <br />downstream from the diversion. <br /> <br />Task lb. Radio-telemetry <br />Since 1995, 12 Colorado squawfish (mean TL ~ 466.75; range 304 - 611) have <br />been collected in the two mile stretch of the Green River immediately <br />downstream from Tusher Diversion, while five Colorado squawfish (mean TL = <br />458.8; range 316 - 502) have been collected in a corresponding stretch above. <br />Efforts (in conjunction with floy-tag sampling) will be made to implant radio <br />transmitters in sub-adult Colorado squawfish (300-400 rom TL; up to 10) and <br />sub-adult native fish (bluehead sucker, flannelmouth sucker, roundtail chub). <br />We will attempt to implant radios into at least 20 fish. A remote, data- <br /> <br />Tusher 3 <br />