Fish, asymptomatically infected with Enteric Redmouth
Bacterium (ERMB), were tested for their ability to transmit
bacteria to non-infected fish. Unstressed carrier fish
were unable to transmit enough bacteria to cause
epizootics or produce carrier fish. However, when the
ERMB carriers were stressed with heat, sufficient bacteria
were shed to infect...
Crosses were made between a stock of summer steelhead (Salmo
gairdneri) known to be resistant to infection by Ceratomyxa
shasta and stocks of summer steelhead known to be susceptible.
Ceratomyxosis, the disease caused by C. shasta was initiated by
exposure to Willamette River water. I found that the crosses
were...
Tuberculosis in salmonoid fishes was first observed in the 1952 run of fall chinook salmon (Oncorhynchus tshawytscha) returning to the Bonneville Hatchery of the Oregon Fish Commission. In the studies reported here, tuberculosis was found not only in adult spring chinook but in silver salmon (0. kisutch), blueback salmon (0....
The Nehalem and North Fork Nehalem rivers are the major tributaries of Nehalem Bay, an estuary on Oregon's north coast (Fig 1). The winter steelhead (Salmo gairdneri) and related fisheries of both streams have been the object of a study which began in 1972. Some data from creel surveys were...
Mean weights, lengths, and condition factors of three isozyme
phenotypes of lactate dehydrogenase (LDH) enzyme differed significantly
for experimentally reared winter steelhead trout (Salmo
gairdneri) fry. Time of emergence from the gravel was unrelated
to LDH phenotype. Relative mortality of the phenotypes between
eyed-egg stage and emergence was unaffected by...
Twenty-two steelhead trout (Salmo gairdneri) containing coded wire tags (CWT's) were captured in gillnets fished by the Oshoro-Maru in the Gulf of Alaska and along 180 during 1982-85. These fish originated from North American streams and hatcheries in British Columbia, Idaho, and Washington. One fish was age 0.1, 16 were...
Growth characteristics of otoliths were used to determine age, and to separate known races and stocks of steelhead trout (Salmo
gairdneri). Otoliths were the first calcified structures observed in X-ray photographs of steelhead embryos, and a continuous record of events through life was interpreted from these structures. A direct
relationship...
The migrations upstream of pre-spawned adult steelhead (Oncorhynchus mykiss) and
downstream of post-spawned steelhead (referred to as "kelts") can geographically and
temporally overlap in the Snake River, leading to management challenges for populations
listed under the Endangered Species Act (ESA). This thesis describes the development and
application of a method...
Hatchery O. mykiss that fail to emigrate to the ocean, referred to as residuals, present an ecological and genetic risk to naturally-produced species through resource competition, predation, and spawning interactions. The Lower Snake River Compensation Plan’s Wallowa stock steelhead program in northeast Oregon has established methods of reducing and quantifying...
In August 2011, the final Upper Willamette River basin salmon and steelhead recovery plan was adopted by NOAA Fisheries and the Oregon Department of Fish and Wildlife. The plan highlights a variety of activities that need to be taken by both public and private entities in order to recover these...
A study was conducted at the Pacific Cooperative Water Pollution
and Fisheries Research Laboratories, Oregon State University,
to determine the effects of pentachlorophenol (PCP) on the early developmental
stages of the steelhead trout (Salmo gairdneri). Experiments
were performed from May, 1965, through May, 1968, on the
survival, growth, and bioenergetics...
Anglers and naturelovers prize steelhead trout for their mystique and power. Oregon has two subspecies of steelhead (so-called because of the metallic appearance of maturing adults) or rainbow trout: a coastal form and an inland form.
Results of the first year of the Deschutes summer steelhead ecology and hatchery assessment. “This report covers the first year of a study of Deschutes summer steelhead ecology and factors limiting efficiency of hatchery production of summer steelhead smolts” (Contents).