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Steelhead (Oncorhynchus mykiss) Kelt Abundance, Condition, Passage, and Survival in the Lower Snake and Columbia Rivers, 2003 Item Info

Title:
Steelhead (Oncorhynchus mykiss) Kelt Abundance, Condition, Passage, and Survival in the Lower Snake and Columbia Rivers, 2003
Report Type:
Technical Report
Date:
2004
Authors:
Normandeau Associates, Inc
Affiliations:
Idaho Cooperative Fish and Wildlife Research Unit; Normandeau Associates, Inc
Report Number:
2004-9
Publisher:
University of Idaho
Funder:
U.S. Army Corps of Engineers, Walla Walla District
Abstract:
Steelhead (Oncorhynchus mykiss) may exhibit an iteroparous life history, returning to the ocean between spawning episodes. In the Snake River, post-spawn steelhead (kelts) must pass up to eight dams during out-migration and each year thousands are observed falling back over dams via juvenile bypass systems. Between 12 April and 15 June 2003, we sampled 1,774 steelhead from the Lower Granite Dam separator and used ultrasound imagery to distinguish post-spawn kelts from spring migrating pre-spawn steelhead. Of steelhead sampled, 96.8% were determined to be kelts. Kelts were predominantly female (82.7%) and of wild origin (~50%). The majority (72.6%) of kelts were in good or fair physical condition and were best distinguished from pre-spawn steelhead by a thin, imploded abdomen (72.4%). We estimate that at least 4,026 kelts were bypassed from the Lower Granite Dam separator during this study period.
Species:
Steelhead, Oncorhynchus mykiss
Location:
Lower Granite Dam
Source:
University of Idaho, Fish Ecology Research Lab
Original Filename:
2004-09 Kelt 03 Report FINAL DRAFT to Normandeau.pdf
Format:
application/pdf

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Preferred Citation:
"Steelhead (Oncorhynchus mykiss) Kelt Abundance, Condition, Passage, and Survival in the Lower Snake and Columbia Rivers, 2003", Adult Salmon and Steelhead Migration Studies: 1996-2014, University of Idaho Library Digital Collections, https://www.lib.uidaho.edu/digital/ferl/items/ferl-tr-2004-9.html
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