Adult Chinook Salmon Abundance Monitoring in Lake Creek, Idaho, Annual Report 2001.

Faurot, Dave

United States. Bonneville Power Administration.

关键词: Abundance;    Adults;    Drainage;    Males;    Snow;   

DOI  :  10.2172/821797
RP-ID  :  DOE/BP-00004600-2
RP-ID  :  00003091
RP-ID  :  821797

美国|英语

来源: UNT Digital Library

【 摘 要 】

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 and 2001. The adult salmon spawner escapement estimate into Lake Creek in 2001 was 697 fish, the largest escapement since the project began. Jack salmon comprised 10% of the spring migration. Snow pack in the drainage was 38% of the average during the winter of 2000/2001. The first fish passage on Lake Creek was recorded on June 9, 19 days after installation of the fish counting station and two weeks earlier than previously reported. Peak net upstream movement of 52 adults occurred on June 22. Peak of total movement activity was July 3. The last fish passed through the Lake Creek fish counting station on September 6. Redd count expansion methods were compared to underwater video determined salmon spawner abundance in Lake Creek in 2001. Expanded index area redd count point estimates and intensive area redd counts in 2001, estimated from 1.3 percent fewer to 56 percent greater number of spawners than underwater video determined spawner abundance. Redd count expansion values had unknown variation associated with the point estimates. Fish per redd numbers in Lake Creek have varied widely. In 2001 there were 2.07 fish per redd. In 1999, there were 3.58 fish per redd, 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 2001. Mainly upstream only movement characterized the first segment. The second segment consisted of upstream and downstream movement with less net upstream movement. 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. There appeared to be a segment of ''nomadic'' males that moved into and out of the spawning area, apparently seeking other mates to spawn with. 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 single-pass and multiple-pass spawning ground surveys. Accurate adult escapement information would allow managers to determine if recovery actions benefited listed chinook salmon in tributary streams. A major project recommendation is to locate an adult salmon abundance monitoring site on the Secesh River that would assess the total Lake Creek and the Secesh River spawning area. This would provide a measure of the recovery actions being implemented on listed chinook salmon in the Snake River basin.