The town of Mosier, Oregon, is located near the east, dry end of the Columbia River Gorge, and the local area is known for cherry orchards that rely heavily on groundwater for irrigation. The CRBG groundwater system in Mosier has experienced groundwater declines of up to 60 meters due to over-pumping and or commingling. Declining groundwater levels have led to concerns over the sustainability of the resource, as it is the principle water source for irrigation and domestic use. Despite numerous previous studies of groundwater flow in CRBG aquifers here and elsewhere in the Columbia River basin, an aspect that has received relatively little attention is the interaction between groundwater and surface waters at locations where interflow zones are intersected by the surface waters. The objective of my research is to investigate how CRBG interflow zone exposures in Mosier Creek may be controlling groundwater elevations in the area. The methods used include: (1) geochemical analysis of well cuttings and detailed geologic mapping along area streams to identify interflow zones of individual CRBG flows, (2) analysis of stream discharge data and groundwater elevation data to confirm exchange of groundwater and surface waters, and (3) collection and analyses of 31 water samples from area wells, streams, and springs, to determine if waters from individual CRBG aquifers can be hydrochemically identified and to further constrain understanding of surface and groundwater interactions. My study confirms that the general elevation of the Pomona Member and Basalt of Lolo interflow zone creek exposure is coincident with the elevation where a change in slope of the decline trend in 2004 is seen in Mosier area well hydrographs. Furthermore, the results of stream discharge data indicated a close connection between drawdown from groundwater pumping during irrigation season and groundwater- surface water interaction. At the time of drawdown in the upper-most CRBG aquifer (Pomona), the stream transitions from gaining to losing water into the groundwater system. Elemental chemistry data indicates the Frenchman Springs Sentinel Gap aquifer waters are the most evolved waters in this study. Stable isotopic data reinforced this determination as the Sentinel Gap waters are the lightest, or most negative, with regard to δD and δ18O. Sentinel Gap samples were more depleted than other aquifer samples by 4.38 to 6.89 0/100 for δD and 0.39 to 0.59 0/100 for δ18O. The results of the general chemistry and isotope data reveal a more evolved chemical signature in lower watershed groundwater versus a less evolved signature for waters from wells located higher up on the Columbia Hills anticline. This was interpreted to be the result of the major structural features in the area providing for a more regional pathway of recharge in lower watershed groundwaters, versus a more local source of recharge for upper watershed groundwaters. There was also a pronounced commingled signature in the elemental ratios of lower watershed aquifer waters. The suspected mechanism of recharge to lower watershed wells is through younger Cascadian deposits upslope from the local watershed. The findings of this study reveal the importance of a detailed understanding of CRBG stratigraphy and its relation to surface waters, especially for other areas within the Yakima Fold Belt or Oregon and Washington. Studies that do not consider the influence that individual CRBG flows can have on groundwater-surface water interactions, and the groundwater system as a whole, run the risk of improperly assessing the groundwater resource for a region.

As human development occurs in forested areas, forests become fragmented into small islands in a matrix of urban land uses. This study examined the effect of surrounding urban land uses on the native and exotic plant species found on the edges of forest fragments in the Portland, OR metropolitan region.

Opaque oxide minerals (ilmenite, chromite, and magnetite) in sands from the Oregon continental shelf have been studied to establish the provenance, dispersal, and grade of potential shelf placer deposits. The study area extends southward from offshore of the Columbia River in northern Oregon to the Klamath River in northern California.

A thorough understanding of demographic parameters and their contribution to overall population growth is fundamental to effective conservation of small populations, but this information is often lacking. The Pacific Coast population of the Western Snowy Plover (Charadrius nivosus nivosus) is listed as threatened and has been the target of long-term, multi-pronged management in Oregon. The Oregon coastal population has been intensively monitored since 1990, and over 80% of the population is color banded, but a comprehensive analysis of demographic parameters and the effect of management on vital rates and population growth has been unavailable until now. Here, the author used capture-mark-resight techniques to document survival at each life stage and to explore environmental and management factors that best explained variation in survival over a 25-year study period. The author analyzed the effects of habitat restoration, exclosure use, and lethal predator management on survival at appropriate life stages and evaluated the effects of one management option, lethal predator control, on overall population growth. Chick survival to fledging improved dramatically after the chicks' 5th day, was higher in years with lethal predator management, and was highest during the peak of the long brood-rearing season. Cold weather, particularly during the chicks' first 5 days, had a negative effect on survival to fledging. Juvenile survival from fledging to the following spring declined over the study period, but rebounded after implementation of lethal predator management. Adult survival was lower in wetter-than-average winters and higher in years with predator management. The author used the survival analyses and productivity data collected over 25 years in a matrix population model to reveal that population growth is most sensitive to changes in adult survival, and that while predator management is important for continued growth, its use may be scaled back by as much as 50% and still maintain a growing population. My results, encompassing all phases of this species' life cycle, demonstrate that with holistic and thoughtful adaptive management, and with the cooperation of numerous agencies, a balance can be struck between protection and control of native species to bring about recovery of species threatened with (local) extinction.

Graduation date: 1979

Oregon English sole catch data from 0 to 80 fathoms between Coos Bay and Cape Lookout were examined for the years 1973, 1975, and 1976. English sole is a major target species of this inshore trawl fishery. Comparison of depths of maximal values of catch per unit effort, effort, and total English sole landings for each month was used to determine when effort in this mixed-species fishery was directed on English sole. Petrale sole, normally a deeper water species, move inshore during late spring and summer months and may be a primary target during this season. Dover sole appeared to be a target species during certain spring months but rarely overshadowed either English or petrale sole catches. External factors such as weather conditions and market variability affected total monthly effort levels and were included in an interpretation of seasonal abundance and migration trends of English sole. Longshore movements were largely obscured by the month-to-month fluctuations of effort from Newport and Coos Bay, the two major fishing ports within the defined landing area. The Newport fleet is somewhat larger, but variable weather conditions may result in greater effort on the part of the Coos Bay fleet during certain months. Seasonal inshore-off shore movements of English sole, however, were consistently evident for the three years. Average depths of capture and catch per effort increased during fall and early winter months suggesting movement into deep water. Examination of ovary condition of English sole caught in the vicinity of Heceta and Stonewall Banks off the central Oregon coast linked this concentration and offshore movement to spawning. Inshore movement and decreased landings in the spring suggested a post-spawning dispersal. / Graduation date: 1980

The 36 samples collected with a 22-foot semi-balloon shrimp trawl at depths from 40 to 1,829 meters off the central coast of Oregon between July 1961 and June 1962 provided preliminary data on the distribution, species composition, and associations of benthic fishes with respect to depth and sediment type. Sixty-seven species of bottom fishes representing 21 families were collected; 86 percent of the total number of fishes was composed of specimens from the families Pleuronectidae, Scorpaenidae, and Bothidae. Four communities of benthic fishes were found off the central Oregon coast within the depth interval from 40 to 1 ,829 meters. They were characterized by two or three dominant species, depth, and average sediment type. Ninety-seven percent of the species occurring in the communities showed high abundance in only one community. Some species also demonstrated size segregation by communities. The total number of species collected in progressively deeper communities was 26 (42 to 73 meters), 31 (119 to 199 meters), 20 (594 to 1,143 meters), and 9 (1,383 to 1,829 meters). Therefore the highest number of speciesoccurred in the community on the outer continental shelf and upper slope, while the lowest number of species occurred at the extreme depths on the continental slope. The number of species found on the continental shelf and slope were similar. Species inhabiting the continental slope, however, usually occurred over greater depth ranges. A comparison of the catches of the 22-foot shrimp trawl and a 94-foot fish trawl indicated that the small trawl used in this study retained comparatively few large fishes or semi-pelagic species. Fishes of the genus Sebastodes were grossly undersampled and probably comprised a major portion of the fish population, especially between the depths of 183 to 547 meters. / Graduation date: 1968

The life cycle of Callianassa californiensis Dana, 1854, was studied in the tidal estuary, Yaquina Bay, Oregon. At this latitude it is largely restricted to intertidal sandy mudflats under predominately marine influence. Salinity and temperature appear to determine its distribution to a greater extent than does sediment type. Vertical movement within the sediment is related to the tides on a day to day basis and to temperature on a seasonal basis. Large-scale breeding generally begins in the spring, and ovigerous females may be plentiful in the cooler layers of mud until August. It is not clear what triggers larval release, but temperature and tidal conditions seem to be important. All five zoeal stages are found in the plankton from the mouth of the bay to three miles offshore during late spring and summer. Nearshore waters appear to act as a larval reservoir along this part of the coast, and successful larval settlement may depend upon high-tide transport into a bay. / Graduation date: 1972

From February to September of 2001, a significant body of qualitive data was collected to investigate barriers for Hispanic participation in Oregon's managed care Medicaid program. As a means to investigate this topic, comments were solicited from physicians, hospital administrators, social service agencies, and low-income Hispanics through semi-structured focus groups and individual interviews. This methodology presents the reader with a rich enthnohistoric and cultural context to the local issues surrounding Hispanic under-participation in Oregon's managed care Medicaid program. Finally, through an analytical framework of critical medical anthropology, connections are drawn from local barriers to state and corporate policies. / Graduation date: 2002

Fishery dependent data--length distributions, sex ratios, maturity schedules, and species composition of landed catches--are necessary for stock assessments. These data are currently collected by state port biologists using a sampling design that randomly selects samples from a small percentage of a very large target population. Sampling programs may need to increase the sample size and possibly expand data collection times into evenings and weekends. This must also be accomplished in an economically reasonable manner, which is a significant challenge. Working cooperatively with the seafood processing plants is one way to meet these challenges. This study explored the feasibility of implementing a cooperative sampling program for Pacific West Coast groundfish, with the goal of improving the precision and accuracy of estimates derived from the fishery dependent samples. The study was a cooperative project utilizing seafood processing plant workers to collect fish length frequency data. There is evidence that the seafood plant workers can measure fish with reasonable accuracy. This cooperative effort has the potential to dramatically increase the sample size and the coverage of sampled catch landings. / Graduation date: 2001