Hatcheries are often perceived as a source of pathogen amplification, potentially increasing disease risk to free-ranging populations; at the same time, free-ranging fishes may introduce pathogens into hatcheries through untreated water sources. Many pathogens exist naturally within the environment (with the exception of introduced pathogens) and the presence of a...
Spring Chinook salmon, Oncorhynchus tshawytscha, are transported above dams in the Willamette River to provide access to blocked spawning habitat. However, 30-95% of these transplants may die before spawning in some years. To varying degrees, salmon in other tributaries--both blocked and unblocked--have similar prespawn mortality (PSM). Our study determined if...
Experiments were conducted to determine the effects of feeding
sulfamethazine to chinook salmon (Oncorhyncus tshawytscha, Walbaum)
as it is used in the Oregon Moist Pellet diet (OMP) for control of
bacterial infections and to compare this drug with sulfisoxazole and
sulfadimethoxine. These drugs were compared in the following manner:
toxicity,...
This project was initiated to determine the incidence, distribution
and species of fish affected by Ceratomyxa shasta in Oregon
waters. Returning adult Pacific salmon and steelhead trout were
chosen for the survey because they were known to be susceptible to
infection. The parasite was also believed to be an important...
This thesis describes the viral susceptibility of two cell
cultures established from embryonic tissue of salmonid
fish, chinook salmon line CHSE-114 and steelhead trout line STE-137. The viruses used were Oregon sockeye salmon virus (OSV),
Sacramento River chinook disease virus (SRCD), Western equine
encephalitis virus (WEE) and Newcastle disease virus...
The purpose of this project was to study the possibility of controlling
furunculosis in salmonid fish using immunological procedures.
Antiserum with an agglutinating antibody titer of 1:20,480
against Aeromonas salmonicida was produced in a horse. This
hyperimmune serum was used to passively immunize coho salmon,
Oncorhynchus kitsutch, (jacks). However, this...
The detection and antigenic nature of the causative Corynebacterium
of bacterial kidney disease and chemotherapy of this disease
in juvenile coho salmon (Oncorhynchus kisutch) were examined.
Each of 207 yearling coho salmon collected from a population
undergoing a severe epizootic of bacterial kidney disease were examined
for the presence of...
An oral vaccine was developed for control of vibriosis
in Pacific salmon. The vaccine consists of a lyophilized
sonicate of cells of Vibrio anguillarum, the causative
agent of this disease. The preparation was incorporated
into a ration and fed to salmon in fresh water before the
fish were transported and...