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Characterization of the humoral immune response to Renibacterium salmonarium in Chinook salmon Oncorhynchus tshawytschaWood, Patricia A. (Patricia Ann), 1969- 09 November 1994 (has links)
Graduation date: 1995
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A model of fall chinook salmon (Onchorhynchus tshawytscha) life historyHirai, Takayuki 13 March 1990 (has links)
The research involved development of two ecological
simulation models to explain the complex dimensionality of
chinook salmon (Oncorhynchus tshawytscha) life history
structure (represented by the age composition of the
spawning stock) and management difficulties entailed in the
complexity.
Since different sizes of chinook salmon are thought to
adapt differently to heterogeneous habitats, age composition
of the spawning stock is determined by characteristics of
the habitats of the substocks. Numerical properties of
substocks result from the incorporation of individual
spawners in different age classes and each substock performs
differently because their age compositions are distinctive.
A stock or population consists of substocks whose age
compositions are concordant with their habitats. The
productive capacity of a population will result from the
incorporation of substocks. If habitat structures of
streams are different, the age and size compositions and
productive capacity of the populations may differ.
Selective harvesting affects spawners in different
ways, so that age compositions must be deformed differently
by fishing pressure. Once the age composition deviates from
the natural age composition, the productivity of the
population will decrease.
Population dynamics are strongly correlated with
substock structure which is determined by habitat structure
in a stream system. Hierarchical population structure make
fisheries management difficult and requires not only
quantitative but also qualitative analysis on the
populations in relation to habitat classification. / Graduation date: 1990
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Investigating patterns of mitochondrial DNA inheritance using New Zealand chinook salmon (Oncorphynchus tshawytscha) as a model organism : a thesis submitted in partial fulfilment of the requirements for the degree Doctor of Philosophy in Biological Sciences in the University of Canterbury /Wolff, Jonci N. January 2008 (has links)
Thesis (Ph. D.)--University of Canterbury, 2008. / Typescript (photocopy). Includes bibliographical references. Also available via the World Wide Web.
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The effects of single and multiple pathogen and parasite infections on juvenile chinook and coho salmon during early marine residency /Sandell, Todd A. January 1900 (has links)
Thesis (Ph. D.)--Oregon State University, 2011. / Printout. Includes bibliographical references (leaves 126-139). Also available on the World Wide Web.
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The length of residence of juvenile Fall Chinook salmon in Sixes River, Oregon.Reimers, Paul E. January 1971 (has links)
Thesis - Oregon State University. / Bibliography: ℓ.95-99. Also available online.
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The effects of elevated temperature and stress on immune function in juvenile chinook salmon (Oncorhynchus tshawytscha)Harrahy, Laura Nicole Martini 28 November 2000 (has links)
Stress, including extreme or rapidly changing temperatures, are known to have deleterious effects on fish health and physiology. This thesis examines the combined effects of elevated acclimation temperature and acute handling stress on the number of antibody producing cells, plasma lysozyme concentrations, and the number of pronephric leukocytes in juvenile chinook salmon (Oncorhynchus tshawytscha). An additional goal of this thesis was to explore the effects of a temperature fluctuation, as a potential instigator of thermal shock, on innate immunity in wild fall chinook salmon of the Columbia River, specifically to determine if there are effects on plasma lysozyme concentrations and on the frequencies of lymphocytes, neutrophils, and thrombocytes in circulation. Finally, based on results found in an experiment involving elevated acclimation temperature, the relationship between the number of antibody producing cells and fish body weight was examined.
Plasma lysozyme concentrations and the number of pronephric leukocytes were both affected by acclimation to 21��C compared to 13��C. While a positive relationship was found between temperature and lysozyme, an inverse relationship was found between temperature and the number of pronephric leukocytes. Plasma lysozyme concentrations, the number of pronephric leukocytes, and the number of antibody producing cells did not respond to the stressor, and the combination of elevated temperature and stress did not have an additive effect on any of the physiological or immunological variables studied.
Differences between controls and temperature-treated fish were not detected among individual time points throughout a temperature fluctuation experiment, despite overall responses in plasma lysozyme concentrations and the frequencies of circulating lymphocytes. The frequencies of circulating neutrophils and thrombocytes did not respond to the thermal stressor. Finally, a significant positive relationship was detected between the number of antibody producing cells (assessed by a hemolytic plaque assay) and body weight among non-stressed fish acclimated to 21��C and 13��C. Regardless of acclimation temperature, these results emphasize the importance of the standardization of fish size for immunological experiments. Results from this thesis suggest that some components of innate immunity are
affected by elevated acclimation temperatures and that the adaptive immune system is affected by acclimation temperature differently in small and large fish. / Graduation date: 2001
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Variation in mitochondrial DNA and allozymes discriminates early and late forms of chinook salmon (Oncorhynchus tshawytscha) in the Kenai and Kasilof Rivers, AlaskaAdams, Noah Swayambhu 04 February 1994 (has links)
Genetic differences between early and late forms of
Alaskan chinook salmon (Oncorhynchus tshawytscha) were
identified using two genetic approaches: mitochondrial
DNA (mtDNA) analysis and protein electrophoresis. The
study populations consisted of early- and late-run chinook
salmon in each of the Kenai and Kasilof rivers in Alaska,
and a single population from the Minam River, Oregon, that
provided a relative scale for the differences among the
Alaskan populations. Two segments of mtDNA were amplified
separately using the polymerase chain reaction (PCR) and
then digested with 14 to 16 restriction enzymes. Results
showed that the two early runs were genetically similar to
each other but different from either of the late runs.
The late runs were different from each other based on the
frequency of the common haplotypes. The Minam River stock
shared two haplotypes with the Alaskan stocks and
displayed one unique haplotype. The frequency difference
in the shared haplotypes together with the presence of a
unique haplotype allowed us to separate the Oregon
population from those in Alaska. In the protein analysis,
each of the five populations was examined at 30 allozyme
loci to determine variation within and between the runs.
Based on 14 polymorphic loci, Minam River chinook salmon
were genetically distinct from the Alaskan populations.
Within the Alaskan populations, the two early runs were
most similar to each other but different from the two late
runs; the two late runs were also genetically most similar
to each other. Based on all loci, protein electrophoresis
proved to be a useful technique to separate stocks of
chinook salmon. On a locus by locus basis, however, mtDNA
was more powerful. Both mtDNA and allozyme analysis
suggest that chinook salmon may segregate into genetically
different early and late forms within a drainage. / Graduation date: 1995
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Changes in size and age at maturity of Columbia River upriver bright fall chinook salmon (Oncorhynchus tshawytscha) : implications for stock fitness, commercial value, and managementBeaty, Roy E. 18 February 1992 (has links)
The average size and age of chinook salmon (Oncorhynchus
tshawytscha) caught in commercial fisheries along the Pacific Coast
of North America have decreased substantially in this century. These
declines might be caused in part by changes in size and age at
maturity within the stocks contributing to those fisheries. Upriver
Brights (Brights), a stock of fall chinook salmon in the Columbia
River, are one of those stocks. The purposes of this study were to
(1) determine if average size and age at maturity of Brights have
declined, (2) gain a better understanding of the factors that may
contribute to such declines, and (3) describe potential consequences
of these changes.
Data from in-river fisheries suggest that the average weight of
mature Brights returning to the Columbia River has decreased
approximately 2.7 kg since the 1910s, an average rate of about 0.1
lb·yr⁻¹ (45 g·yr⁻¹ ). Most of the potential biases in these data tend
to make this estimate conservative. Insufficient data were available
to describe changes in average age at maturity.
There are many potential causes for the decline in average size
of mature Brights, including factors that affect very early life
stages. Other researchers have determined that size at maturity
appears to be highly influenced by inheritance, gender, and growth
rate. I describe how maternal size can influence -- through time of
spawning, choice of spawning site, and egg size -- the viability of
the young, which carry the dam's genes for size. The size-related
ability to produce viable offspring may have been changed by
modifications in the environment. Very little is known about how
changes in the natural environment for spawning, incubation, and
rearing may have contributed to a decline in average size at
maturity. Artificial propagation and rearing, such as at Priest
Rapids Hatchery, seems to produce adult Brights that are smaller,
younger, and more likely to be male than their natural counterparts.
The net result is that the average hatchery fish may have only about
0.80 of the reproductive potential of the average natural fish.
Changes in growth conditions in the ocean probably did not contribute
to the change in size, although the ocean fisheries of Southeast
Alaska and British Columbia appear to select, in the genetic sense,
against large size and old age in Brights.
Since 1978, in-river commercial fisheries have caught larger
Brights and a higher proportion of females than are found in the
escapement of the Priest Rapids Hatchery component of the stock, but
the fisheries impact the two sexes differently by taking the larger
males and the smaller females. The effect on the natural component
may differ because of their apparently larger average size. I found
no evidence that larger fish or more females were caught when 8-in.
minimum restrictions were in effect on gillnet mesh size relative to
periods when mesh size was not restricted. Impounding the mainstem
during the last 50+ yr may have removed obstacles to migration (e.g.,
Celilo Falls) that selected for large size in Brights, but that
hypothesis could not be tested.
The perserverance of larger and older phenotypes in the Bright
stock suggests that countervailing selection -- perhaps during
spawning, incubation, and/or early rearing -- may have resisted the
effects of a century of size- and age-selective fisheries. That
resistance, however, may reduce the productivity of the stock.
Declines in average size and age at maturity can have
undesireable consequences. Lower average size means less biomass
landed and lower commercial value. Lower average fecundity and a
diminished ability to reproduce in some environments are also
expected. Loss of size and age classes may reduce the ability of the
stock to adapt to environmental variations.
These results are relevant to several management practices. A
holistic approach to fishery management issues is necessary to avoid
erroneous conclusions based on narrow perspectives. Measuring
reproductive potential of the catch and escapement would be superior
to the conventional practice of simply counting numbers of fish.
Many aspects of artificial propagation can be improved, including
broodstock aquisition, mating regimes, and rearing practices. Stock
abundance is a major factor in determining the effect of many
management practices on the stock. In general, fisheries managers
must be mindful that they manage very complex natural systems. / Graduation date: 1992
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Effects of estuarine circulation patterns and stress on the migratory behavior of juvenile salmonids (Oncorhynchus sp.) /Truelove, Nathan Kobun. January 1900 (has links)
Thesis (M.S.)--Oregon State University, 2006. / Printout. Includes bibliographical references (leaves 63-68). Also available on the World Wide Web.
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Thermal Preference of Spring and Fall Chinook Salmon (Oncorhynchus tshawytscha) during SmoltificationSauter, Sally T. 06 August 1996 (has links)
Innate species-specific temperature preferences of fish are subjected to fluctuations under a variety of environmental, physiological, and developmental conditions. The temperature preference patterns of two ecologically distinct races of chinook salmon (Oncorhynchus tshawytscha) were investigated as laboratory held animals underwent smoltification. Smoltification is a distinct developmental stage in the life history of anadromous salmonids when juvenile fish undergo profound behavioral, morphological, and physiological differentiation prepatory to seawater entry. A group of spring and fall chinook salmon were held under identical conditions of increasing water temperature over the course of smoltification. Another group of spring and fall chinook salmon were held at a constant water temperature of 8° C over the same period of time. Changes in the preferred temperature of juvenile chinook salmon were associated more closely with the size (fork length) of fish than with time (days). Both spring and fall chinook salmon held at 8° C showed an increase in thermal preference of about 1° C as fork length increased in these respective groups. This increase in thermal preference is thought to be thermoregulatory, accelerating smolt development in fish held in inhibitory low water temperatures. Spring chinook salmon held at increasing water temperatures showed no change in thermal preference associated with smoltification. Fall chinook salmon held at increasing water temperatures displayed a large drop in thermal preference towards the end of smolt development. Differences in the thermal preference patterns of spring and fall chinook salmon during smoltification may result from local habitat adaptations, as well as seasonal differences in smolt migration.
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