Adult Chinook Salmon Abundance Monitoring In Lake Creek Idaho 2001

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ISBN 13 :
Total Pages : 155 pages
Book Rating : 4.:/5 (684 download)

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Download or read book Adult Chinook Salmon Abundance Monitoring in the Secesh River and Lake Creek, Idaho, 2000 Annual Report written by and published by . This book was released on 2001 with total page 155 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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 population under the Idaho Salmon Supplementation study. This project has demonstrated the successful application of underwater video adult salmon abundance monitoring technology in Lake Creek in 1998 and 1999. Emphasis of the project in 2000 was to determine if the temporary fish counting station could be installed early enough to successfully estimate adult spring and summer chinook salmon abundance in the Secesh River (a larger stream). Snow pack in the drainage was 93% of the average during the winter of 1999/2000, providing an opportunity to test the temporary count station structure. The temporary fish counting station was not the appropriate technology to determine adult salmon spawner abundance in the Secesh River. Due to its temporary nature it could not be installed early enough, due to high stream discharge, to capture the first upstream migrating salmon. A more permanent structure used with underwater video, or other technology needs to be utilized for accurate salmon escapement monitoring in the Secesh River. A minimum of 813 adult chinook salmon spawners migrated upstream past the Secesh River fish counting station to spawning areas in the Secesh River drainage. Of these fish, more than 324 migrated upstream into Lake Creek. The first upstream migrating adult chinook salmon passed the Secesh River and Lake Creek sites prior to operation of the fish counting stations on June 22. This was 17 and 19 days earlier than the first fish arrival at Lake Creek in 1998 and 1999 respectively. Peak net upstream adult movement at the Secesh River site occurred June 28 and at the Lake Creek site on June 27. Peak of total movement was August 16 at Secesh River and August 7 at Lake Creek. The last fish passed through the Lake Creek fish counting station on August 31 and on September 8 at the Secesh River site. Migrating salmon in the Secesh River and Lake Creek exhibited two behaviorally distinct segments of fish movement. The first segment of movement was characterized, mainly, by upstream movement only. The second segment consisted of upstream and downstream movement with very little 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. Fish movement was greatest between the period of 5:00 p.m. and 4:00 a.m. 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 allowed by this fish counting station design may be an important factor affecting reproductive success as male salmon seek other females to spawn with. Traditional weirs operated for broodstock collection do not allow for downstream movement of adults. This methodology has the potential to provide more consistent and accurate salmon spawner abundance information than single-pass and multiple-pass spawning ground surveys. Accurate adult abundance would allow managers to determine if recovery actions were benefiting these salmon spawning aggregates and if recovery goals were being met.