Snake River fall Chinook salmon life history investigations: Annual report 2010

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This report summarizes three research activities conducted in 2010-2011. The first was a radiotelemetry study conducted in the lower Clearwater River. The second was a hydroacoustic study conducted in Lower Granite and Little Goose reservoirs. The third was an analysis of covariates affecting juvenile fall Chinook salmon survival and behavior. In 2010, we used radiotelemetry to evaluate the migratory behavior, delay, and relative mortality of subyearling fall Chinook salmon in the Clearwater River and Lower Granite Reservoir. We captured, tagged, and released a total of 100 run-at-large subyearlings in the Transition Zone of the lower Clearwater River in late July and monitored their downstream movement past fixed detection sites and by mobile tracking through the end of August. The Transition Zone is that portion of the river where it transitions from free-flowing to impounded habitat. Median residence time of fish that passed through the Transition Zone, Confluence, and Upper Reservoir reaches was relatively short (8.8-25.6 h). However, for fish that remained in the Transition Zone that were detected by mobile tracking, median residence time was over 30 d (N=6). Median migration rates through the study reaches were variable but slow (range 2.9-17.2 km/d) compared to that of more active migrants indicating that subyearlings from the Clearwater River were not actively migrating during July and August. The fate of radio-tagged subyearlings was determined from mobile tracking records. A total of 37 of the 71 fish detected during tracking were deemed to be dead, 22 were determined to be alive, and the fate of 16 was unknown. We also radio tagged 66 smallmouth bass in the Confluence reach and later detected 59 bass during mobile tracking. Predators were primarily located along shorelines in the Confluence reach, but a few fish did swim downstream into the Upper Reservoir reach. Most radio-tagged subyearlings that we determined to be dead were also located in shoreline areas suggesting that predation could account for some of the mortality we observed.

Study Area

Table of Contents

Chapter 1: Migration delay of juvenile fall Chinook salmon in the vicinity of the confluence of the Snake and Clearwater rivers

Chapter 2: Hydroacoustic assessment of the density of overwintering juvenile fall Chinook salmon in Lower Granite and Little Goose reservoirs, 2010-2011

Chapter 3: Covariate analysis for survival parameters and travel time addendum to 2009 Annual Report

Publication type Report
Publication Subtype Other Government Series
Title Snake River fall Chinook salmon life history investigations: Annual report 2010
Year Published 2012
Language English
Publisher Bonneville Power Administration
Contributing office(s) Western Fisheries Research Center
Description 85 p.
Country United States
State Oregon, Washington
Other Geospatial Lower Clearwater River, Lower Granite reservoir, Little Goose reservoir
Online Only (Y/N) N
Additional Online Files (Y/N) N
Google Analytic Metrics Metrics page
Additional publication details