Incidence of Renibacterium salmoninarum infections in juvenile hatchery spring chinook salmon in the Columbia and Snake Rivers

Journal of Aquatic Animal Health
By: , and 

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Abstract

From 1988 through 1992, we assessed the prevalence (frequency of occurrence) and severity (degree of infection) of Renibacterium salmoninarum (RS) among fish in marked groups of Columbia River basin and Snake River basin hatchery spring chinook salmon Oncorhynchus tshawytscha before release and during their seaward migration. During the study, prevalence of RS infection decreased (from >90% to <65%) in six of the eight hatchery groups. We attributed this decrease to changes in hatchery practices that reduced vertical and horizontal transmission. Fish from Snake River hatcheries had a higher prevalence of infection when sampled at dams (mean >90%) than in the hatchery (mean <70%), but there were no differences in similar comparisons of Columbia River fish. Although prevalence and severity of RS infection were not correlated in the groups studied, it appears that fish from the Snake River were more severely infected than those from the Columbia River. Some groups of Snake River fish had higher severity of infection at dams than in the hatchery, but infection in fish from Columbia River hatcheries did not change. These differences between Snake River and Columbia River fish might have resulted from differences in river conditions and the distances from hatcheries to dams.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Incidence of Renibacterium salmoninarum infections in juvenile hatchery spring chinook salmon in the Columbia and Snake Rivers
Series title Journal of Aquatic Animal Health
DOI 10.1577/1548-8667(1996)008<0037:IORSII>2.3.CO;2
Volume 8
Issue 1
Year Published 1996
Language English
Publisher American Fisheries Society
Contributing office(s) Western Fisheries Research Center
Description 10 p.
First page 37
Last page 46
Country United States
State Oregon, Washington
Other Geospatial Columbia River, Snake River