Graduation date: 1969

Quartz is an ubiquitous component of marine sediments. Textural characteristics of this component reflect the dynamics of its transport and at the same time are indicative of its source. Quartz may be extracted from marine sediments by means of a sodium pyrosulfate fusion and hydrofluosilicic acid dissolution without significantly modifying its size distribution. The size distribution of the chemically purified quartz is determined by means of a Cahn sedimentation balance which provides a continuous analog record. These records are digitized and computer processed to obtain size frequency distributions that subsequently are resolved for their modal components by means of an analog computer. Three rather different sets of samples were studied to evaluate the application of this methodology to questions of the origin and dispersion of quartz in deep-sea sediments. Textural analysis of chemically purified quartz reveals the following general features: 1. All the samples are polymodal in the 2 to 64 micron size range. 2. The modal character of quartz in river sediment persists in the marine environment and can serve as a provenance indicator. 3. Dispersal processes that act on a fine-grained sediment may change the relative proportions of the constituent quartz modes, but do not significantly alter the position of these modes. The way in which the relative proportion of the assorted modes vary within a depositional area may serve as a tool for mapping energy fields at the sea floor. / Graduation date: 1972

Phytoplankton dynamics in Auke Bay, Alaska, were studied during summer, 1969. Nitrate, chlorophyll a, particulate organic carbon, phytoplankton and zooplankton species composition and hydrographic and meteorological data were collected and analyzed. Nitrate input into Auke Bay through freshwater runoff was negligible. A bloom of Thalassiosira aestivalis formed the spring bloom in Auke Bay in 1969. No phytoplankton bloom occurred during a June period when winds were light and variable. Two major blooms of Skeletonema costatum occurred after periods when Auke Bay surface layers were mixed by wind-induced turbulence. The water column became nearly isothermal after periods of high wind mixing although a pronounced density and halal structure persisted, a consequence of input of freshwater to the bay from Auke Creek. Examination of fecal pellets collected from the bay and results of laboratory grazing experiments suggested that Skeletonema costatum was not grazed by zooplankton living in Auke Bay. Nonlinear ordinary differential equations were written to describe phytoplankton and nitrate dynamics in Auke Bay. The phytoplankton dynamics equation included formulations for time-varying insolation and for time-varying wind mixing coefficients. Formulations for effects of nitrate concentration on the photosynthetic assimilation number and for effects of phytoplankton standing crop on the extinction coefficient of light in the water column were included. The nitrate dynamics equation included a formulation for effects of wind-mixing of nitrate-rich water into the euphotic zone from deeper layers of the water column, as well as a formulation for utilization of nitrate in phytoplankton growth. Computer simulation response of the equations reproduced the bloom pattern observed in the field data with some discrepancies caused by assumptions used in model development. The phytoplankton and nitrate model response was strongly coupled to the pattern of the wind-mixing coefficient, as required by the field data. Variations in model parameters had little effect on phase relations between model response and field data but strongly affected model response magnitude. / Graduation date: 1972

Graduation date: 1976

Clinocardium nuttallii from Yaquina Bay, Oregon, were found to harbor an algal symbiont in the siphon, mantle and occasionally the foot tissues. Approximately 35 percent of the population in the study area was infected to some degree with the alga; however, no cockles under two years of age were infected. The degree and frequency of infection increases in the older age groups. Symbiont cells were removed from the host and grown on artificial media and the temperature tolerances on these media were determined. Mantle fluid from variously infected and noninfected cockles from several age groups was used to fortify the artificial media and no difference between the fluids was noticed; however, a two month lag period in unfortified media was shortened to ten days by the addition of as little as ten percent mantle fluid filtrate. Chromatographic pigment analysis shows the alga to be a chlorophyte. Chloroplast structure, cell size and growth characteristics are very similar to algae of the genus Chlorella; this alga will be tentatively placed in this genus. Cockles under one year of age are not susceptible to infection by the symbiont, whereas mature cockles become infected by feeding on either fresh or cultured symbiont. Blood amoebocytes in vitro will readily engulf either fresh or cultured symbiont cells. Microscopic examination of infected tissues showed amoebocytic cells in the algal colonies, sometimes carrying several algal cells. The algal colonies in situ are dense masses which grossly displace the host tissue; however, there is no overt reaction by the host to the presence of these colonies. / Graduation date: 1973

Thesis (M.S.)--Oregon State University, 1970. / Typescript (photocopy). Includes bibliographical references (leaves 35-36). Also available on the World Wide Web.

Thesis (M.S.)--Oregon State University, 1970. / Typescript (photocopy). Includes bibliographical references (leaves 54-59). Also available on the World Wide Web.

Thesis (M.S.)--Oregon State University, 2007. / Printout. Includes bibliographical references (leaves 70-73). Also available on the World Wide Web.

Thesis (Ph. D.)--Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1984. / Includes bibliographical references (p. 451-473).

Thesis (M.S.)--Oregon State University, 1977. / Typescript (photocopy). Includes bibliographical references. Also available via the World Wide Web.