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Location: Basin wide Project Summary
Overview Approximately, 350 summer-run sockeye and 150 spring-run chinook will be captured in the lower Fraser River using tangle nets, tagged and tracked during the upstream migration using fixed-station receivers and mobile survey techniques. Fixed-station receivers will be located at site similar to those used in previous studies, including key locations such as: Mission, Qualark, Hells Gate, and major tributary junctions (Thompson, Chilcotin, Quesnel and Nechako). The fixed-station data will provide reliable information on migration rates and fishery residence times for in-season comparison of the Mission and Qualark hydroacoustic data and post-season assessments of harvest rates and fishery impacts for Chinook and sockeye. DNA samples and tracking results for each radio-tagged fish will be combined to produce the stock specific estimates needed for in-river fisheries management and run reconstruction models. Mobile and fixed-station tracking data will be used to assess in-river survival rates for each stock. These data will be important for explanations of any differences observed between the sockeye spawning ground estimates and the hydroacoustic estimates of the number of sockeye that passed the Qualark monitoring site. Data from past studies indicate that species composition can vary substantially between near-shore and off-shore (mid-channel) waters in the lower Fraser River. The Whonnock gillnet test fishery likely provides a good sample of the species composition for off-shore waters but is not suitable for assessing near-shore waters. The opposite is true for the Crescent Island fishwheels. In addition, the 2008 data indicate that the DIDSON hydroacoustic gear, drift gillnet test fishing and radio-telemetry arrays were effective methods for assessing sockeye passage at the Qualark site. We believe that the combination of the data from these three programs (Qualark, Whonnock and Crescent Is.) with the Mission hydroacoustic site can be used to derive reliable specific estimates of salmon escapement past Mission. Objectives Methods The project includes five major components: 1) the deployment and operation of two fishwheels at the Crescent Island site from late June through early September; 2) the capture and radio-tagging of 150 spring-run Chinook along the Fraser River between Hope and Yale; 3) the application of 350 radio-tags equipped with archival thermal loggers (iButtons) to sockeye captured using tangle nets and day-time catches from fishwheels near Crescent Island site; 4) the tracking of radio-tagged sockeye and Chinook salmon throughout the Fraser watershed from their release site to spawning areas; and 5) the tracking of radio-tagged sockeye as they approach and pass the Qualark hydroacoustic site using aerial and underwater antenna arrays. Th fishwheels will be deployed and operated along the south bank of the Fraser River at the Crescent Island site 9 km downstream from the Mission Railway Bridge. The deployment will be similar to the configuration used from 28 July through 5 Sep.2008 including: a floating shoreline abutment and fish weir, one 20 ft. diameter fishwheel, one 40 ft. diameter fishwheel and a 7.5 cm mesh lead net. The only major difference from the 2008 deployment will be the use of a spur-log and float design to eliminate the need for maintaining or driving steel pilings at the site. This new attachment design coupled with the availability of all the other components from the 2008 study substantially reduces the deployment and operation cost for 2009 (roughly $150,000 assuming the fishwheels are operated for 67-77 consecutive days). Radio-transmitters will be applied to a sample of 100 spring-run chinook and 350 sockeye captured using tangle nets. Spring-run Chinook will be capture from mid-April to late-May at sites between Hope and Yale. Sockeye sampling will be 3-4 days per week from late July and late-August (i.e. targeting summer-run stocks) at a location just upstream from Crescent Island. As in other years, only healthy fish that are longer than 50 cm will be radio-tagged. DNA samples will be obtained from every radio-tag sockeye and Chinook for stock identification. Physiological samples (i.e., blood, gill tissue and fat probe readings) may be obtained from a portion of the fish tagged in 2009. Archival thermal loggers (iButton tags) will be attached to each radio tag. This would make it possible to reconstruct the complete thermal migration history for those fish where tags are recovered during spawning ground surveys.
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