Spawning Distribution of Outplanted Adult Summer Chinook Salmon in the South Fork Salmon River, 1992-1994
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SPAWNING DISTRIBUTION OF OUTPLANTED ADULT SUMMER CHINOOK SALMON IN THE SOUTH FORK SALMON RIVER, 1992-1994 Project Progress Report Paul Sankovich Fishery Technician Peter F. Hassemer Principal Fishery Research Biologist Report #99-04 March 1999 Spawning Distribution of Outplanted Adult Summer Chinook Salmon in the South Fork Salmon River, 1992-1994 Project Progress Report By Paul Sankovich Peter F. Hassemer Idaho Department of Fish and Game Fisheries Research—LSRCP Hatchery Evaluation Studies 1414 East Locust Lane Nampa, ID 83686 To U.S. Fish and Wildlife Service Lower Snake River Compensation Plan Office 4696 Overland Road, Room 560 Boise, ID 83702 Cooperative Agreement 14-48-0001-96503 IDFG Report Number 99-04 March 1999 TABLE OF CONTENTS ABSTRACT...................................................................................................................................1 INTRODUCTION ..........................................................................................................................2 METHODS ....................................................................................................................................4 Outplanting...................................................................................................................... 4 Spawning Distribution ..................................................................................................... 5 Data Analysis ..................................................................................................................7 RESULTS .....................................................................................................................................7 DISCUSSION..............................................................................................................................12 RECOMMENDATIONS...............................................................................................................14 ACKNOWLEDGEMENTS ...........................................................................................................15 LITERATURE CITED..................................................................................................................16 APPENDICES...............................................................................................................................1 LIST OF TABLES Table 1. Number of adult chinook salmon outplanted in the Stolle Meadows reach of the South Fork Salmon River, 1992-1994. All females were tagged; the number of tagged males is given in parentheses. Release site locations are shown in Figure 2.4 Table 2. Spawning success and general distribution of various groups of female chinook salmon outplanted in the Stolle Meadows reach of the South Fork Salmon River, 1992-1994.8 Table 3. Percentages of tagged, outplanted chinook salmon males that migrated downstream of Stolle Meadows in 1992 and 1993. Release site locations are shown in figure 2.12 i K:\Nampa Research\Reports\Complete\99-04 Sankovich 92-4OUTP.doc LIST OF FIGURES Figure 1. Locations of the McCall Fish Hatchery, the McCall Fish Hatchery spawning facility and weir, and landmarks and unit sections in the South Fork Salmon River study area.3 Figure 2. Locations of release sites used to outplant adult chinook salmon into the Stolle Meadows reach of the South Fork Salmon River, 1992-1994.6 Figure 3. Fates of female chinook salmon outplanted into the Stolle Meadows reach of the South Fork Salmon River in 1992 (a), 1993 (b), and 1994 (c). Females that were not accounted for were never observed on a redd or recovered.9 Figure 4. Distribution of redds made by female chinook salmon released at the South Fork Salmon River weir and outplanted in the Stolle Meadows reach of the South Fork Salmon River, 1992-1994. Redds in Curtis Creek, a tributary entering the South Fork Salmon River in mid-unit 2, are not included. Unit locations are shown in Figure 1.10 Figure 5. Relative dispersal of redds made by female chinook salmon outplanted at various sites in the Stolle Meadows reach of the South Fork Salmon River in 1992, 1993, and 1994. Positive and negative numbers along the X-axis correspond to distances up and downstream, respectively, of each release site. Females that lost their tags and made redds (release site unknown) are not included.11 LIST OF APPENDICES Appendix A. Distribution of redds made by females outplanted in the Stolle Meadows reach of the South Fork Salmon River and by females released upstream of the South Fork Salmon River weir, 1992-1994.18 Appendix B. An analysis of the outplanting-related mortality of salmon in 1992, 1993, and 199419 ii K:\Nampa Research\Reports\Complete\99-04 Sankovich 92-4OUTP.doc ABSTRACT We studied the spawning distributions of adult chinook salmon Oncorhynchus tshawytscha outplanted in the Stolle Meadows reach of the South Fork Salmon River in 1992, 1993, and 1994. Adult salmon were held at the South Fork Salmon River trap for a period of time after capture, and were than trucked to the Stolle Meadows reach and released. Of the females outplanted and known to have spawned each year, 83% to 91% remained in the Stolle Meadows reach. Only 3% to 8% migrated downstream to spawn in the area near Knox bridge, where they likely originated (natural spawning) or were released as juveniles from the hatchery. Females typically spawned upstream and within 1.6 km of their release site. At least 10% and 15% of the tagged males outplanted in 1992 and 1993, respectively, migrated downstream of Stolle Meadows. Only 5% (1992) and 8% (1993) migrated as far downstream as the Knox bridge area. We conclude that outplanting of adult chinook salmon can be a viable tool to restore natural spawning to previously important production areas. Authors: Paul Sankovich Fishery Technician Peter F. Hassemer Principal Fishery Research Biologist 1 K:\Nampa Research\Reports\Complete\99-04 Sankovich 92-4OUTP.doc INTRODUCTION Hatchery-reared chinook salmon Oncorhynchus tshawytscha juveniles have been released annually in the upper reaches of Idaho's South Fork Salmon River since 1977. These releases were made because the number of wild summer chinook salmon spawning in the Stolle Meadows reach had been declining for many years. Adults for hatchery production were collected at two lower Snake River dams, Little Goose (1975-1978) and Lower Granite (1979 and 1980), and from the upper South Fork Salmon River (1980 to the present) (Idaho Department of Fish and Game et al. 1990). Adults collected at the dams were assumed to be summer-run, based on the timing of passage of summer chinook salmon. Progeny of the adults collected at the dams were used to bolster the indigenous upper South Fork Salmon River population while McCall Fish Hatchery was being built. The hatchery was completed in 1981 and has operated under the Lower Snake River Compensation Plan, authorized to compensate for fish and wildlife losses caused by four lower Snake River dams (Herrig 1990). The hatchery is located in McCall, Idaho (Figure 1). A satellite facility, including a temporary weir, trap, adult raceways, and spawning shed, is located on the upper South Fork Salmon River. After the completion of hatchery and satellite facility construction in 1980, at least one-third of the adult chinook salmon trapped each year were released upstream of the weir to spawn; about two-thirds (up to the rearing capacity of the hatchery) were retained for hatchery production. Hatchery smolts have been released in the South Fork Salmon River at Knox bridge, approximately 1.6 km upstream from the satellite facility weir. Only a portion of the smolts were marked before their release; therefore, adult returns have been a mixture of marked hatchery-, unmarked hatchery- , and unmarked naturally-produced fish. All marked adults, along with some unmarked adults, have been retained for hatchery production. Only unmarked fish were released upstream of the weir. Sankovich and Bjornn (1992) concluded that hatchery operations had altered the historic distribution of chinook salmon spawners in the upper South Fork Salmon River in 1991 and 1992. Before McCall Fish Hatchery began operations, most chinook salmon redds upstream from the present weir site were observed in the Stolle Meadows Reach, and few were made near Knox bridge (see Figure 1 for landmark locations). Because most hatchery- and naturally-produced adults (each identified using scale pattern analysis) spawned near Knox bridge in 1990 and 1991, Sankovich and Bjornn made three conclusions: 1) hatchery adults had a high fidelity to their juvenile release site before as well as during the study; 2) most naturally produced fish spawning near Knox bridge had some hatchery ancestry; and 3) the indigenous population had been well integrated into the hatchery operation. In 1992 and 1993, a record high 2,848 and 2,703 chinook salmon, respectively, were trapped at the McCall Fish Hatchery satellite facility. In 1994, 527 adult salmon were trapped. To seed the Stolle Meadows reach area and reduce spawner density near Knox bridge, some adults that would otherwise have been released at the weir were trucked to and outplanted in the Stolle Meadows reach. We conducted a study to determine the spawning distribution of the outplanted adults in 1992, 1993, and 1994. 2 K:\Nampa Research\Reports\Complete\99-04 Sankovich 92-4OUTP.doc South Fork Salmon River study area weir Salmon River 1 Juvenile release site 1 South Fork Knox bridge McCall Salmon R. 2 2 3 Curtis Creek 3 1 McCall Fish Hatchery 2 McCall Fish Hatchery