Pacific salmon (Oncorhynchus spp.) rearing in lakes and reservoirs have been known to become heavily infected with an ectoparasitic copepod (Salmincola californiensis). Little is known about the factors that affect the parasite infection prevalence and intensity. However, previous research suggests that the parasite may negatively affect the fitness and survival...
The Columbia River Basin historically supported abundant populations of Pacific salmon (Oncorhynchus spp.) but, largely due to anthropogenic influence, many populations are now listed as threatened or endangered under the U.S. Endangered Species Act. Habitat restoration efforts have been a critical component of salmon recovery plans. However, although the importance...
Anadromous salmonid populations in the Pacific Northwest have declined over the past 150 years. In 1999, wild spring Chinook salmon (Oncorhynchus tshawytscha) were federally listed as threatened within the Willamette Basin, OR. Currently, practices to restore wild populations in the upper Willamette Basin involve trapping wild adults at the base...
The goal of my dissertation was to explore how scale influences stream restoration prioritization strategies for an anadromous species and identify influential uncertainties that exist at different scales. My objectives were to (1) produce a comprehensive review of the Chinook salmon management challenges in California’s Central Valley and identify the...
A critical seasonal event for anadromous Chinook salmon (Oncorhynchus tshawytscha) is the time at which adults migrate from the ocean to breed in freshwater. We investigated whether allelic variation at the circadian rhythm genes, OtsClock1a and OtsClock1b, underlies genetic control of migration timing among 42 populations in North America. We...
This investigation demonstrates the feasibility of a
polyculture system using effluent water from land-based
salmon culture systems to feed juvenile Manila clams, Tapes
japonica (Deshyes), and an evaluation of an artificial diet
for feeding juvenile clams. An economic analysis of the
polyculture system was compared to cultures of a single...
The performance of an organism or organismic subsystem is
the result of the interaction between the performance capacity of
the system and Its environment. Environmental conditions can
stress an organism and thus affect it's performance. In this
study, three whole organism performances were examined: critical
swimming speed, fatigue time and...
Biochemical variation in 12 different chinook populations, sampled from 10 hatcheries along the Columbia River and the Oregon coast, was studied with starch gel electrophoresis. An index was
used to describe the genetic differences between pairs of populations. Differences were observed between spring and fall chinook and between Columbia River...
Temperature was elevated approximately 4° C in a model stream relative to an unheated, but otherwise similar control stream. The streams were located outdoors, received identical amounts of exchange water from a nearby creek, and followed natural diurnal and seasonal temperature cycles Juvenile spring chinook salmon (Oncorhynchus tshawytscha) were introduced...
Chinook salmon, Oncorhynchus tshawytscha, were reared from
fertilization of the eggs to several weeks after complete yolk absorption
at dissolved oxygen concentration of 3.5, 5.0, and 7.3 mg/liter and air-saturation
at temperatures of 10.5, 12.0, 13.5, and 15.0 C. Decrease of either
temperature or dissolved oxygen concentration resulted in increase...
This study was designed to provide life history information about juvenile fall Chinook salmon, Oncorhynchus tshawytscha
(Walbaum), in a small coastal river by 1) documenting the length of residence of the juveniles throughout the river, 2) exploring several factors possibly influencing their length of residence, and 3) assessing the relative...
A study of the effects of stabilized and unstabilized kraft mill effluents on the production of chinook salmon (Oncorhynchus tshawytscha) in six laboratory streams was conducted at the Pacific Cooperative Water Pollution Laboratories, Oregon State University-from May through August, 1969. Similar salmon biomasses were stocked in each stream. Changes in...
Juvenile fall chinook salmon were acclimated to full strength sea water at 66, 73, and 80 days after hatching. Survival in sea water for 14 days was used as the criterion for successful acclimation. The growth of salmon acclimated to sea water was slower over the period of observation (134...
This thesis reports the results of a study on the influence of biologically
stabilized kraft mill effluent (SKME) on the food relations and
production of juvenile chinook salmon, Oncorhynchus tschawytscha
(Walbaum), in laboratory streams. Experiments were conducted at
the Oak Creek Fisheries Research Laboratory, Oregon State University,
during 1967 and...
The effects of sublethal concentrations of kraft mill effluents
(KME) on the growth, food consumption, and swimming ability of
juvenile chinook salmon, Oncorhynchus tschawytscha (Walbaum),
were studied from February 1966 to May, 1967.
The KME used in these studies was obtained from two pulp and
paper mills producing paper from...
A study of the population ecology of Columbia River fall chinook
salmon, Oncorhynchus tshawytscha (Walbaum), was made in an attempt
to determine the cause of a serious decline in this run which occurred
in the early 1950's. Fluctuations in abundance of major salmon runs
the North Pacific were examined to...