Graduation date: 1982

The specific activity of ⁶⁵Zn (nanocuries ⁶⁵Zn/g total Zn) was determined in various organs of the common coastal mussel, Mytilus californianus Conrad, collected from six locations along the Pacific Coast. These organs included the gills, mantle, foot, reproductive organs, adductor muscle, and viscera. After ashing and dissolving with nitric acid (8 M), each tissue was analyzed for ⁶⁵Zn by gamma-ray spectrometry. The determination of total zinc concentrations of the various organs was accomplished by atomic absorption spectrophotometry as well as by neutron activation analysis. Variable amounts of both stable zinc and radioactive ⁶⁵Zn were observed within the specific tissues from a given location. The ⁶⁵Zn specific activities of the tissues of organisms from a particular station however, tended to be uniform, at least within the uncertainty of the measurements. Both radiozinc and ⁶⁵Zn specific activity decreased with distance from the Columbia River mouth, whereas the stable zinc tended to remain uniform for a specific tissue. Tissues high in radiozinc were also high in stable zinc and conversely. An estimate of the input specific activity from the mussel' environment (food and/or water) was calculated from a simple model resulting in a value similar to zooplankton values sampled from within the Columbia River plume. Comparison of the concentrations of zinc determined by neutron activation with those determined by atomic absorption spectrophotometry indicated a linear relationship between the two methods. Results of atomic absorption measurements were approximately 27% larger than the results of neutron activation analysis, indicating the presence of a systematic error. The higher values attained by atomic absorption are attributed to evaporation during storage of the ash solution which would lead to an increase in zinc concentration. In considering the two methods of analysis, economy of both time and expenses favors the atomic absorption method over that of neutron activation. / Graduation date: 1971

A structure map was constructed of the continental shelf between Cape Blanco and Coos Bay, Oregon, exclusively from an interpretation of approximately 700 km of continuous seismic profiles. At least ten discernible seismic units were mapped on the bases of acoustic appearance, lateral continuity, angular unconformities, and faults. The offshore units tentatively were correlated with onshore geology and are believed to range in age from the latest Jurassic to late Pleistocene. The sparker profiles reveal that the continental shelf off southern Oregon has experienced significant late Tertiary and Quaternary accretion due to deposition and tectonic uplift. The oldest rock exposures, believed to be the latest Jurassic in age, crop out on the inner continental shelf on the topographic highs off Cape Blanco and Coquille Point. Erosional remnants of probable Late Cretaceous turbidites and the middle Eocene sandstone beds also are exposed on the bathymetric high on the inner shelf southwest of Cape Arago. The initial emplacement of these three uplifted structural blocks is probably a result of late Eocene wrench faulting of the Port Orford shear zone and of the postulated shear zone at Coquille Point. No other early Tertiary sediments apparently are exposed on this portion of the Oregon continental shelf, but they probably extend seaward at depth on the continental margin. Middle Tertiary strata are believed to be exposed on the outer shelf topographic high southwest of Cape Arago. Sediments of Miocene to Pliocene age were deposited throughout much of the continental shelf that was surveyed. The greatest amount of deposition occurred in a north-south trending basin between Cape Blanco and Coquille Bank. Late to post-Pliocene tectonism uplifted and exposed the older underlying rocks on the inner shelf, which are probably of uppermost Jurassic to middle Tertiary age. These same stresses also deformed the Mio-Pliocene sediments into gently undulating structures on the inner shelf. The greatest deformation occurred on the outer shelf and formed Coquille Bank, a north-south trending, doubly plunging, asymmetrical anticline. The terraces or benches on the upper continental slope to the north and south of the Bank are structural features resulting from the doubly plunging anticline. Eustatic sea level lowerings during the Pleistocene truncated the shelf structures as deep as 130 m below present sea level. The detritus was deposited as a wedge of sediments, which forms an unconformable contact with the underlying strata on the outer shelf and upper slope between Coos Bay and Coquille Bank. In areas of deposition there is no distinct break between the shelf and the upper slope; the former merely merges into the latter in a continuous convex curve. In areas of nondeposition, the edge of the shelf is an erosional and structural feature. A possible buried channel was detected northwest of the mouth of the Coquille River. This sediment filled channel is believed to be an erosional remnant of a former course of the Coquille River during a lower stand of sea level. / Graduation date: 1969

Twenty-three bottom-trawl fish assemblages were identified from the relative biomass of 33 dominant species that occurred in the National Marine Fisheries Services' triennial trawl surveys over the continental shelf and upper slope off California, Oregon, and Washington from 1977 to 1992. The assemblages accounted for about 70% of the total variation in species composition among 2,565 hauls. Although the assemblages persisted over the 15-yr study period and occurred within broad geographic boundaries, some had substantially different spatial distributions among surveys. The ability to differentiate assemblages across five environmental variables (latitude, depth, surface and bottom water temperatures, and surficial substrate) was low. The preponderance of hake-dominated assemblages throughout the study area suggests that Pacific hake (Merluccius productus) may play a large role in the dynamics of demersal fish communities off the west coast of the United States. The same data were used to establish general features regarding the abundance and distribution of the 33 dominant fish, and investigate intersurvey regional variation in species composition. Flatfish were generally widespread and at low density within areas of their occurrence. In contrast, rockfish were comparatively less widespread, and were at higher density within areas of their occurrence. Pacific hake, spiny dogfish, and sablefish were both widespread and occurred in high density. The greatest amount of variation in species composition occurred in the shallow shelf region off California, and the shallow and deep regions between Cape Mendocino and Cape Blanco. These regions corresponded to areas with the greatest amount of annual variation in upwelling. Contrary to upwelling, intersurvey variation in surface temperature did not appear to correspond to variation in species composition, but there was an unanticipated negative correlation between variation in bottom temperature and variation in species composition. Species composition was influenced in most regions by Pacific hake, spiny dogfish, and sablefish. A conceptual model was developed to explore the relationship between regional changes in a species' biomass, incidence, and density, and their potential affect on species composition. Empirical examination of the model was difficult. Five of six flatfish species (Pacific sanddab, rex sole, Pacific halibut, Dover sole, and English sole) exhibited a significant positive linear relationship between incidence and log-transformed biomass which is consistent with density-dependent habitat selection. There was evidence (albeit weak) from patterns in the occupancy of substrate types by these flatfish, that marginal habitats are associated with areas of mud for Pacific sanddab and areas of sand for rex sole, Pacific halibut, and Dover sole. / Graduation date: 1997

This study examines the spatial evolution of the Eastern Pacific halibut fishery over the period 1888-1972 in terms of resource exploitation and vessel-port interaction and attempts to delineate the factors which brought about the observed patterns. Four distinct stages of development are identified: (1) a stage of spatial confinement and resource depletion characterized by corporate involvement and restricted vessel range, (2) a stage of spatial extension, company fleet decline, and independent fleet expansion, (3) a stage of spatial adjustment, quota control, and extreme competition, (4) a stage of further spatial extension, fleet decline, and maximum sustained yields. The spatial structure of the industry at each stage of development is shown to be a function of resource availability, fishing costs, and changes in halibut fleet behavior. The time-cost-distance factor between producing grounds and the landing/processing sector of the industry proved to be a critical factor in a fishery that was characterized by increased competition for annual quotas. Conceptual models of the industry's spatial structure have been developed to portray the major changes which occurred from one stage to the next. These in turn are further developed to conceptualize the evolution of the halibut fishery over the 1888-1972 period. / Arts, Faculty of / Geography, Department of / Graduate

A total of 627 echinoderm species (12 crinoids, 185 asteroids, 185 ophiuroids, 95 echinoids and 150 holothuroids) are known from the shallow and deep waters between southern California and southern Peru, and an up-to-date classification scheme is given for them. Distribution tables provide detailed presence-absence data for latitudinal increments, geographic range endpoints, depth ranges, and substrate associations of each species. Annotated lists of all species include relevant synonyms and mistaken records as well as literature citations used for both lists and distribution tables. A species-level biogeographic analysis shows that echinoderm provinces conform to those generally observed for other marine taxa, including mollusks, crustaceans and fishes. Based on cluster analysis and more traditional approaches (using species richness, faunal turnover and faunal composition), overall faunal similarity of the shelf echinoderms is very high between 23°N and 4°S, in the tropical Panamic province. There is a northern warm-temperate fauna (California province) between Pt. Conception, California and Pt. Eugenio, Baja California that also extends into lower Baja and the Gulf of California. Warm-temperate elements in the subtropical Gulf of California distinguish it from the tropics, and it is recognized as a faunal province in spite of its low endemism. Echinoderm endemism is unusually high in the Galapagos province and is attributed to the wide habitat diversity and isolation of the archipelago. There is no evidence for a Mexican province, but there is evidence for a distinction between the tropics to the north and south of Costa Rica/Panama. Transition zones (especially in Panama and southern California) often have high species richness, increased habitat diversity, and a number of endemic species. The warm-water eastern Pacific genera are most closely related to those of the west Atlantic tropics, but very few species are shared between the regions. Trans-Pacific species in the CEP are widespread throughout the region. A confinement of Indo-Pacific species to offshore CEP islands is only seen at Clipperton Island, the lone coral atoll of the eastern Pacific.

Black rockfish (Sebastes melanops) is an important marine recreational species throughout the Pacific Northwest. Recent catch data indicate a trend of age-truncation in the black rockfish population off the Oregon coast, with older females rapidly disappearing from the population. In populations with broad age distributions, older fish may contribute disproportionately to larval production through a variety of mechanisms. Thus, the removal of older age classes through fishing may impact the population far beyond the simple loss of biomass. We tested the hypothesis that older females produce higher quality offspring, or offspring otherwise more capable of survival, than those from younger females. Mature female black rockfish of various ages were captured live and held until parturition. Larvae were then reared under identical conditions to compare performance in terms of growth, starvation, and mortality. Results indicate that older females produce offspring that grow faster in both length and weight, survive longer in the absence of an exogenous food supply, and exhibit lower mortality rates than offspring from younger mothers. This difference in larval performance may be explained by the relatively greater amount of endogenous energy reserves present in the oil globules of offspring from older mothers. Larval oil globule volume at parturition was significantly related to all larval performance factors and was strongly correlated with maternal age. Given the difference in larval quality, it is critical for the management of black rockfish, and possibly other species as well, that these older individuals not be addressed solely in terms of biomass, but their relative reproductive contribution and the repercussions of their removal from the population be considered. / Graduation date: 2004

This ethnography describes RV [recreational vehicle] seasonal migration as an adaptive, transhumant strategy. The study population is retired, transhumant migrants, who are members of a nation-wide, membership camping organization. Fieldwork was conducted over a period of seven months at two sites located on the West Coast. These sites reflect northern and southern locations corresponding to seasonal migration patterns. Standard scholarly orientations to the study of retired RV seasonal migrants manifest ethnocentrism and a tendency to stereotype RVers as amenity-migrants. An original and primary objective of the present study was to reach beyond these conceptualizations and popularized images through first-hand, descriptive accounts collected within the context of the culture. This research expands on two existing studies focusing on social and cultural aspects of RV seasonal migration. In contrast to these accounts, the present study provides cultural description of the daily life of retired RVers focusing on the distinctive ways that members of this subculture express mainstream American cultural values underlying their adaptive strategies. This study proposes an alternative conceptualization of RV seasonal migration, derived from the culture itself. The conclusion is that these adaptive strategies reflect patterns of social organization, patterns of resource management, and patterns of social, familial, and interpersonal relationships, that are congruent with mainstream American cultural values of self-reliant individualism, equality, and material comfort; values that have historical, philosophical roots in the Protestant Work Ethic. The RVers' identity derives from maintaining membership in a temporary, fluid, mobile community. They have cohesive social networks with well-defined boundaries, which they defend against threats to group identity. This study contributes to an understanding of what RV seasonal migration means to the participants themselves, and by extension, to their families, to communities, and to our aging society. / Graduation date: 1996

Recent climate change forecasts have aroused growing interest in the influence of water scarcity and climate on agricultural production and irrigation practice. However, it is common in the economic literature to aggregate disparate crops when modeling irrigation choices. That approach confounds the crop-specific effects of climate and water scarcity that govern such choices. Given the sensitivity of agricultural production to water scarcity and climate, understanding their influence on irrigation choices is a key contribution to policy evaluation. This paper addresses the impact of water scarcity and climate on irrigation choices through estimated models of cropland proportion irrigated (PI), and crop-specific irrigation technology choice (TC) and water application rates (AR). This approach is applied to agricultural production data for major crops (orchard/vineyard, vegetable, wheat, alfalfa, hay, and pasture) on the West Coast (California, Oregon, and Washington). Crop-specific modeling provides information about the distributional impacts of agricultural policy and climate change. This advantage is particularly important for the diverse agricultural landscape of the West Coast, where the distributional impacts of policy can be complex. The most important policy implications that are found involve asset heterogeneity and the distributional impacts of agricultural policy. Several findings provide valuable information about how irrigators would respond and adapt to climate change. The current findings also lead to commonly advocated revisions to federal water subsidy policies. Some key differences between the irrigation choices of higher- and lower-value crops are also identified. Identifying these differences sheds further light on the distributional consequences of agricultural policy. Many findings from this research are crop-specific and will have a high degree of policy relevance to irrigation districts or other agricultural jurisdictions that cultivate some of the West Coast's major crops. Furthermore, the data used in this research has a large degree of variation in water scarcity and climate, making the findings applicable to other Mediterranean climates in the world. It is found that specific crops have a proclivity for certain irrigation technologies that can mitigate particular climatic stressors (i.e., frost damage and heat stress). For example, the results indicate that water pricing policies will tend not to encourage water conservation by technology adoption for many orchards, vineyards, and vegetable farms, thereby imposing pure costs to these producers. In essence, climate heterogeneity limits options available to farmers and reduces the set of production technologies that a farm can use. This finding exemplifies that with climate heterogeneity, the distribution of water policy impacts depends on prior land allocation decisions such as crop choices. Heterogeneity in land quality is also found to have important influences on TC. The effects of temperature on irrigation choices are found to be more profound than the effects of precipitation. Because of the large study region used, the effects of temperature and precipitation on irrigation choices are often found to be quadratic-like. These quadratic-like relationships reveal thresholds where irrigators begin to respond very differently to climate. However, this was not the case for all crops. Thus, it is demonstrated that the effects of climate on irrigation choices are crop-dependent. The results indicate that for several crops, the discontinuance of irrigation water (i.e., water supply or price uncertainty) creates an option value that delays and discourages adoption of water-saving technologies. The discontinuance of irrigation water is also shown to reduce water demand at the farm-level extensive proportion (i.e., PI) and crop-level intensive margin (i.e., AR). Water price is found to impact all three irrigation choices as well. Well depth is found to facilitate adoption of water-saving technologies for several crops. This paper demonstrates that irrigation choices are highly dependent on water scarcity and climate. Institutional arrangements, geographic qualities of the farm, and demographic characteristics of the farmer also exhibit important influences on irrigation choices. By using crop-specific equations, quadratic climate variables, and a study region with large variation in climate conditions, this research resolves many inconsistent findings regarding the determinants of irrigation choices. Furthermore, this study establishes a research agenda for crop-specific analysis of irrigation choices. Some of the estimated results warrant verification with further studies. Future crop-specific irrigation choice studies would benefit from panel micro data with improved land quality variables, and seasonal or monthly climate variables that are better able to identify the effects of climate stress (e.g., heat stress and frost damage) on irrigation choices. / Graduation date: 2013

With congressional passage of the BEACH Act in October of 2000, Coastal and Great Lakes states were mandated to assess coastal recreation waters for the application of ambient water quality standards. This research encompasses two components involved in applying the BEACH Act statues to Oregon. The first component was to select beach sites in Oregon. The second component involves applying bacterial recreational water standards to select Oregon beaches. Using the guidelines provided by the United States Environmental Protection Agency (EPA), this study develops a method to appraise Oregon marine recreational waters taking into account the following factors: use, available information, pollution threats, sanitary surveys, monitoring data, exposure considerations, economics, and development. In an effort to protect the public from swimming-associated illness attributable to microbial pollution, 24 beaches were identified in Oregon. Of these, 19 beaches were classified as tier 1, or high priority, and five sites were classified as medium priority, or tier 2. Future studies should be directed at ascertaining the beach lengths utilized by Oregon marine recreators since this is an important parameter in targeting bacterial monitoring. Ongoing monitoring of these 24 sites is warranted and new information could be used to update beach tier levels in Oregon. In the second phase of this study, bacterial monitoring data was used for comparison to recreational water quality standards. In October of 2002, the Oregon Department of Environmental Quality (ODEQ) sampled 26 beaches for enterococci and Escherichia coli (E. coli) densities. Of the water sampled from all 26 beach sites, nine exceeded s single sample maximum density of 104 enterococci colony forming units (cfu) per 100 milliLiters (mL). The Oregon beach with the highest exceedance occurred at Otter Rock's South Cove where the enterococci concentration was 4352 most probable number (MPN)/100 mL. A comparison of the 26 sampled beaches to ODEQ's estuarine E. coli standard of 406 organisms/100 mL resulted in two beaches with exceedances. Otter Rock at South Cove had the highest E. coli concentration at 1850 MPN/100 mL. Based on the limited data used in this study, should Oregon adopt the enterococci standard in lieu of the current ODEQ estuarine E. coli standard, more beaches will have exceedances of the recreational water standard. Additional bacterial monitoring is warranted to further characterize the nature and extent of the problem in Oregon. To protect the health of the marine recreating public, future Oregon marine water quality studies should delineate the "no swim" zone around creeks and model the impacts of rainfall on beach sites. / Graduation date: 2004