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Accession Number PB2012-114437
Title Migration of Anadromous Juvenile Bull Trout in the Skagit River, 1990-2009.
Publication Date Dec 2010
Media Count 59p
Personal Author C. Kinsel M. Zimmerman
Abstract Local extinctions and population declines of bull trout (Salvelinus confluentus) led the United States Fish and Wildlife Service to list this species as threatened under the Endangered Species Act. Coterminous listing of all five Distinct Population Segments (DPS) in the continental United States was announced in 1999. Due to their diverse life histories and iteroparous spawning, the health of bull trout populations is particularly difficult to assess. Bull trout in the Coastal-Puget Sound DPS use four different life history strategies resident, fluvial, adfluvial, and anadromous. The anadromous form is unique to this recovery region and perhaps the least understood of all the life history strategies. The goal of this report is to characterize anadromous juvenile bull trout migrations and associated environmental variables in the Skagit River. The Skagit River watershed contains 26 of the 57 local bull trout populations in the Puget Sound Management Unit and all four life history strategies. A juvenile fish trap, operated near Mount Vernon, has collected biological information on juvenile salmonid migrants since 1990. This report (1) summarizes bull trout life history from Skagit juvenile trap collections, (2) evaluates whether juvenile trap catches are a valid index of abundance, (3) determines whether catch expansions to a total abundance estimate are warranted, and (4) identifies the contributions of spawner abundance, rearing temperatures, and food availability to anadromous juvenile bull trout.
Keywords Bull trout (Salvelinus confluentus)
Dolly Varden (Salvelinus malma)
Fish collection
Fish traps
Juvenile bull trout

Source Agency United States Fish and Wildlife Service
NTIS Subject Category 98F - Fisheries & Aquaculture
47D - Biological Oceanography
48B - Natural Resource Management
57Z - Zoology
Corporate Author Washington Dept. of Fish and Wildlife, Vancouver. Fish Program.
Document Type Technical report
Title Note N/A
NTIS Issue Number 1226
Contract Number N/A

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