scholarly journals Survival of Subyearling Fall Chinook Salmon in the Free-flowing Snake River and Lower Snake River Reservoirs in 2003 and from McNary Dam Tailrace to John Day Dam Tailrace in the Columbia River from 1999 to 2002, 1999-2003 Technical Report.

2004 ◽  
Author(s):  
William D. Muir ◽  
Gordon A. Axel ◽  
Steven G. Smith
Keyword(s):  
Chinook Salmon ◽  
Columbia River ◽  
Snake River ◽  
Technical Report ◽  
John Day ◽  
River Reservoirs

Retrospective patterns of differential mortality and common year-effects experienced by spring and summer chinook salmon (Oncorhynchus tshawytscha) of the Columbia River

2001 ◽  
Vol 58 (12) ◽  
pp. 2419-2430 ◽  
Author(s):  
Richard B Deriso ◽  
David R Marmorek ◽  
Ian J Parnell
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Columbia River ◽  
Differential Mortality ◽  
Snake River ◽  
Climate Indices ◽  
Negative Effects ◽  
Positive Effects ◽  
Empirical Estimates ◽  
John Day

We used spawner–recruit data to estimate the instantaneous differential mortality (µ) experienced by seven Snake River spring and summer chinook (Oncorhynchus tshawytscha) stocks relative to six lower Columbia River stocks. We applied 37 Ricker stock–recruit models to these data, incorporating different assumptions about measurement error, transport survival, intrinsic productivity, methods of estimating µ, and common year-effects that affect the survival of all stocks. Estimates of mean µ for the 12 best models ranged from 0.55 to 1.90 (mean of 1.09), implying that passage from Lower Granite Dam to John Day Dam reduced recruitment of 1970–1990 Snake River broods by an average of 42–85% (mean of 66%). Differential mortality was cyclical and moderately high in the 1970s brood years, low for 1980–1983, near average in 1984–1989, and high in 1990. Our empirical estimates of µ showed low bias and were between those produced by two mechanistic passage models. The best empirical models included common year-effects, which shifted from generally positive effects on 1952–1968 brood years to generally negative effects on 1970–1990 broods. Year-effects were not significantly correlated with two climate indices or with water travel time (the time that water takes to travel down the Columbia River).

Assessing covariability among populations in the presence of intraseries correlation: Columbia River spring-summer chinook salmon (Oncorhynchus tshawytscha) stocks

2000 ◽  
Vol 57 (3) ◽  
pp. 616-627 ◽  
Author(s):  
Louis W Botsford ◽  
Charles M Paulsen
Keyword(s):  
Chinook Salmon ◽  
Degrees Of Freedom ◽  
Oncorhynchus Tshawytscha ◽  
Columbia River ◽  
Data Types ◽  
Natural Logarithm ◽  
Different Types ◽  
John Day River ◽  
One Year ◽  
John Day

We assessed covariability among a number of spawning populations of spring-summer run chinook salmon (Oncorhynchus tshawytscha) in the Columbia River basin by computing correlations among several different types of spawner and recruit data. We accounted for intraseries correlation explicitly in judging the significance of correlations. To reduce the errors involved in computing effective degrees of freedom, we computed a generic effective degrees of freedom for each data type. In spite of the fact that several of these stocks have declined, covariability among locations using several different combinations of spawner and recruitment data indicated no basinwide covariability. There was, however, significant covariability among index populations within the three main subbasins: the Snake River, the mid-Columbia River, and the John Day River. This covariability was much stronger and more consistent in data types reflecting survival (e.g., the natural logarithm of recruits per spawner) than in data reflecting abundance (e.g., spawning escapement). We also tested a measure of survival that did not require knowing the age structure of spawners, the ratio of spawners in one year to spawners 4 years earlier. It displayed a similar spatial pattern.

Disease Susceptibility of Hatchery Snake River Spring–Summer Chinook Salmon with Different Juvenile Migration Histories in the Columbia River

2006 ◽  
Vol 18 (4) ◽  
pp. 223-231 ◽  
Author(s):  
Mary R. Arkoosh ◽  
Anna N. Kagley ◽  
Bernadita F. Anulacion ◽  
Deborah A. Boylen ◽  
Benjamin P. Sandford ◽  
...  
Keyword(s):  
Chinook Salmon ◽  
Disease Susceptibility ◽  
Columbia River ◽  
Snake River

A multiple-reach model describing the migratory behavior of Snake River yearling chinook salmon (Oncorhynchus tshawytscha)

1998 ◽  
Vol 55 (3) ◽  
pp. 658-667 ◽  
Author(s):  
Richard W Zabel ◽  
James J Anderson ◽  
Pamela A Shaw
Keyword(s):  
Chinook Salmon ◽  
Migration Rate ◽  
River Flow ◽  
Oncorhynchus Tshawytscha ◽  
Nonlinear Models ◽  
Columbia River ◽  
River System ◽  
Snake River ◽  
Migration Route ◽  
Time Step

A multiple-reach model was developed to describe the downstream migration of juvenile salmonids in the Columbia River system. Migration rate for cohorts of fish was allowed to vary by reach and time step. A nested sequence of linear and nonlinear models related the variation in migration rates to river flow, date in season, and experience in the river. By comparing predicted with observed travel times at multiple observation sites along the migration route, the relative performance of the migration rate models was assessed. The analysis was applied to cohorts of yearling chinook salmon (Oncorhynchus tshawytscha) captured at the Snake River Trap near Lewiston, Idaho, and fitted with passive integrated transponder (PIT) tags over the 8-year period 1989-1996. The fish were observed at Lower Granite and Little Goose dams on the Snake River and McNary Dam on the Columbia River covering a migration distance of 277 km. The data supported a model containing two behavioral components: a flow term related to season where fish spend more time in regions of higher river velocity later in the season and a flow-independent experience effect where the fish migrate faster the longer they have been in the river.

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