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Title: Chinook Salmon Adult Abundance Monitoring in Lake Creek, Idaho, 2002 Annual Report.

Underwater time- lapse video technology has been used to monitor adult spring and summer chinook salmon (Oncorhynchus tshawytscha) escapement into the Secesh River and Lake Creek, Idaho, since 1998. Underwater time-lapse videography is a passive methodology that does not trap or handle this Endangered Species Act listed species. Secesh River chinook salmon represent a wild spawning aggregate that has not been directly supplemented with hatchery fish. The Secesh River is also a control stream under the Idaho Salmon Supplementation study. This project has successfully demonstrated the application of underwater video monitoring to accurately quantify chinook salmon abundance in Lake Creek in 1998, 1999, 2001 and 2002. The adult salmon spawner escapement into Lake Creek in 2002 was 410 fish. Jack salmon comprised 7.1 percent of the run. Estimated hatchery composition was 6.1 percent of the spawning run. The first fish passage on Lake Creek was recorded on June 26, 15 days after installation of the fish counting station. Peak net upstream movement of 41 adults occurred on July 8. Peak of total movement activity was August 18. The last fish passed through the Lake Creek fish counting station on September 2. Snow pack in the drainage was 91% of themore » average during the winter of 2001/2002. Video determined salmon spawner abundance was compared to redd count expansion method point estimates in Lake Creek in 2002. Expanded index area redd count and extensive area redd count point estimates in 2002, estimated from one percent fewer to 56 percent greater number of spawners than underwater video determined spawner abundance. Redd count expansion methods varied from two percent fewer to 55 percent greater in 2001, 11 to 46 percent fewer in 1999 and 104 to 214 percent greater in 1998. Redd count expansion values had unknown variation associated with the point estimates. Fish per redd numbers determined by video abundance and multiple pass redd counts of the larger extensive survey areas in Lake Creek have varied widely. In 2002 there were 2.05 fish per redd. There were 2.07 fish per redd in 2001, 3.58 in 1999 and in 1998, with no jacks returning to spawn, there were 1.02 fish per redd. Migrating salmon in Lake Creek exhibited two behaviorally distinct segments of fish movement in 2002. Mainly upstream only movement of both sexes characterized the first segment. The second segment consisted of upstream and downstream movement with less net upstream movement and appeared to correspond with the time of active spawning. The fish counting stations did not impede salmon movements, nor was spawning displaced downstream. Fish moved freely upstream and downstream through the fish counting structures. The downstream movement of salmon afforded by this fish counting station design may be an important factor in the reproductive success of listed salmon. This methodology provides more accurate salmon spawner abundance information than expansion of single-pass and multiple-pass redd counts. Accurate adult escapement information would allow managers to determine if recovery actions benefited listed chinook salmon in tributary streams.« less
Publication Date:
OSTI Identifier:
Report Number(s):
TRN: US200917%%107
DOE Contract Number:
Resource Type:
Technical Report
Research Org:
Bonneville Power Administration (BPA), Portland, OR (United States)
Sponsoring Org:
Country of Publication:
United States