The mechanisms of mortality during critical life stages of fish are not well-understood and, for many species, it is not clear if the mechanisms are similar for naturally and artificially propagated individuals. For Chinook salmon (Oncorhynchus tshawytscha), natural fish potentially face negative interactions, such as competition, and survival disadvantages, such as smaller size, that may limit survival when in association with hatchery fish. To better understand the mechanisms of mortality for hatchery and natural Chinook salmon during the critical early marine residence stage, I: (1) developed a model to discriminate between hatchery and natural juveniles using otolith structure; (2) directly compared migratory patterns of hatchery and natural juveniles; and (3) determined if there was evidence for selective mortality during early marine residence. I followed two cohorts through space and time by collecting juveniles from May-September in the Columbia River estuary and off the coast in September of 2010 and 2011. I compared attributes of those juveniles when they firstentered marine waters with those of survivors after their first summer at sea. I used a combination of genetic stock identification, otolith chemistry and structure, and physical tags to determine stock of origin, size at and timing of freshwater emigration, marine growth, and production type (hatchery or natural). I focused on the subyearling life history of a federally managed genetic stock group (upper Columbia River summer and fall Chinook salmon, UCR Su/F) because: 1) it is an abundant stock group; 2) subyearlings may be more vulnerable to size-selective mortality than yearlings; and 3) it is currently impossible to assess impacts of hatchery production due to low rates of marking the hatchery fish within this stock group. The classification model included two metrics, the presence or absence of a previously unreported transfer check associated with hatchery rearing and variability in otolith increment width, and predicted production type with a 92% jack-knifed accuracy. Overall, timing of marine entry was similar for hatchery and natural UCR Su/F juveniles, which entered marine waters from May-September with a peak in July and August in both years. Estuarine residence times were brief: 80% of the individuals captured in the estuary had resided in saline waters for < 3 days and mean estuarine residence was significantly greater (7 ± 1.3 d) in 2010 than 2011 (1 ± 0.3 d). The only clear difference was that natural individuals captured in the estuary in 2011 migrated to saline waters earlier (July 13th ± 4 d) than hatchery conspecifics (August 10th ± 6 d). However, the timing of marine entry was similar (July 27th ± 1 d) between hatchery and natural fish collected later in the ocean. This observation could be due to differential survival related to the timing of marine entry. Alternatively, estuarine collections may not have adequately represented the emigrating population due to rapid emigration. I documented clear spatial overlap between production types during early marine residence but no difference in median size at marine entry (100 ± 3.5 mm), size at capture (152 ± 4.0 mm), or marine growth (0.94 ± 0.1 %b l d-1). There were also no significant differences in size at marine entry between estuary and ocean collections, which indicates that size-selective mortality had not occurred. Based on both external tags and the otolith classification model, the mean percentage of natural fish in ocean collections was 17% (± 4.8) greater than in the Columbia River estuary; this finding may indicate that estuarine collections are biased to hatchery fish or, more likely, that natural fish survived at higher rates than hatchery fish. Increased survival of natural fish may be related to greater selection pressure during freshwater rearing and prior experience with predators. This study provides the first direct stock-specific comparison of juvenile migratory behavior in natural and hatchery juvenile Columbia River Chinook salmon during early marine residence. Further research is needed to determine if natural fish consistently survive better than hatchery conspecifics and, if so, determine the specific traits and behaviors that afford a survival advantage. / Graduation date: 2013

Altered flows that are low-MgO chemical types of the Grande Ronde Basalt crop out in the steep walls of the Grande Ronde River canyon near Troy, Wallowa County, Oregon. The alteration effects in these flows are being investigated as a natural analog system to a high level nuclear waste repository in basalt. The flows within the study are referred to as the analog flow, in which the alteration effects are the strongest, and the superjacent flow. The analog flow crops out at Grande Ronde River level and a roadcut-outcrop is developed in the flow-top breccia of this flow. The two flows have been divided into flow zones based on intraflow structures observed in the field and primary igneous textures observed in thin section. These zones include, from the base upward, the flow interior, transition, and flow-top breccia zones of the analog flow, the interflow contact zone, and the flow interior and flow-top breccia zone of the superjacent flow. The intraflow structures and textures of the transition and interflow contact zones are atypical of Grande Ronde Basalt flows. The transition zone is transitional in textures between the flow interior zone and flow-top breccia zone, and includes holocrystalline spines mantled with fused in situ breccias. The interflow contact zone reflects the dynamic interaction during the emplacement of the superjacent flow manifested as invasive basalt tongues, clasts shed from tongues, pipe vesicles and tree molds, and pockets of breccia caught up in the base of the superjacent flow.

I sought to determine the effect of managed flooding on Phalaris arundinacea L. and other plant species distributions in a large wetland complex, Smith and Bybee Wetlands (SBW), in northwestern Oregon. Altered hydrology has reduced historically high spring flow and prematurely initiated the historic summer drying period at SBW. This alteration has increased the coverage of invasive plants (e.g., P. arundinacea) causing a decrease in native plant cover and thus degrading ecological functions. SBW managers installed a water control structure (WCS) between SBW and the Columbia Slough/River system to impound winter rainfall and thus approximate the ecological benefits that natural flooding provided as well as reduce the abundance of P. arundinacea. Prior researchers conducted intensive vegetation and hydrological monitoring in 2003 (during the season immediately before WCS installation) and 2004. I conducted similar analysis in the fifth and sixth years, 2008 and 2009, following establishment of the WCS. Both study years, I determined percent cover of all vegetation on transects established in 2003. The results, including 2004, as well as 2008 and 2009 showed a reduced cover of P. arundinacea in areas experiencing at least 0.6 meters of inundation and an increased cover of native plant communities when compared to the 2003 baseline data. Native Carex aperta Boott. cover increased 7-fold from 0.3% to 2.3%; Polygonum species cover increased from 20.0% to 52.6%; and Salix lucida Muhl. ssp. lasiandra (Benth.) E. Murray cover increased from 10.9% to 15.5% cover. P. arundinacea declined by over one-third from 44.4% to 28.1% cover following water management. Since hydrology management began, the native Polygonum species community replaced P. arundinacea as the dominant species in the emergent zone. The results of this study refined the suggested depth of inundation needed to reduce P. arundinacea cover in such lake-wetland complexes as SBW from 0.85 meters (based on 2004 study results) to 0.6 meters. Shannon Diversity decreased following water management. The findings of this study demonstrated that water management can enhance native bottomland communities, especially those comprised of obligate wetland species, and reduce P. arundinacea cover in areas experiencing at least 0.6 meters of inundation.

No description available.

No description available.

The sheeted complex of the ~92 Ma Tenpeak pluton, in the Northern Washington Cascades crystalline core, forms a <1.5-km wide zone with a moderate, NE-dip at the SW margin of the pluton. Sheeted magmatic complexes, such as the one in the Tenpeak pluton, are common in plutons and represent examples of incremental growth of plutons. Though it is widely accepted that plutons are constructed incrementally over prolonged timescales of several million years, it is not clear if and to what degree individual batches of magma interact, the timing and size of each magma pulse, and the role, timing, and location of magmatic differentiation. This project uses a combination of field evidence, bulk rock chemistry, and mineral geochemistry to address the (1) role of magma mixing and fractionation, (2) constraints on the relative timing of magma differentiation, (3) diversity of mixing styles preserved, and (4) physical properties that dictate how individual batches of magma interact within this sheeted complex. Rock samples were collected throughout the complex from mafic, felsic, dioritic, thinly-banded, and gradational sheets. Field evidence shows a range of sheet contacts that vary from sharp to diffuse, strong prevalence of mafic enclaves, and localized cases of mechanical mixing in which plagioclase feldspars from a felsic sheet are incorporated into a mafic sheet. In general, sheet thickness increases farther from the contact with the White River shear zone. The bulk rock and mineral chemistry suggests that the felsic magmas in sheets formed independently from the more mafic and hybridized sheets. The composition of the felsic sheets cannot be modeling by binary mixing processes involving mafic and felsic magmas or result from fractionating the most mafic magmas. However, mass-balance calculations using a linear least-squares mass balance calculation and Rayleigh fractionation models indicate that it is possible to explain the range of felsic compositions by internal, crystal fractionation driven mostly by plagioclase crystallization (~40-58%). Negative Eu anomalies in amphiboles from the felsic sheets imply that plagioclase fractionation commenced prior to the onset of amphibole crystallization. With the exception of the most primitive mafic sheet sampled, the mafic and hybridized sheets represent variable proportions of the mafic parental magma and the range of felsic differentiated magmas. Efficient mixing that resulted in these mafic to hybridized magmas must also have occurred prior to mineral growth as the mineral chemistry reflects intermediate, mixed compositions. The bulk rock and mineral chemistry of the most primitive, mafic sheet suggest that it did not mix with any felsic magmas. However there is evidence that the mafic sheet underwent plagioclase fractionation prior to emplacement. This is evident by lower bulk rock Sr/Ba relative to calculated Sr/Bamelt of plagioclase that cannot be reconciled without removing ~40-58% plagioclase. In contrast to the felsic sheets, the amphiboles from this mafic sheet lack Eu anomalies implying that amphibole crystallization occurred prior to major plagioclase fractionation. Chemical evidence reveals that magma mixing played an important role in controlling the chemical composition of individual sheets and field observations suggesting that there was a range of mixing styles. Throughout the sheeted complex, there are localized sites of mechanical mixing where plagioclase phenocrysts from adjacent felsic sheets are mechanically mixed into mafic sheets. Evidence for mechanical mixing is present across both sharp and gradational contacts. This implies varying rheological and viscosity contrasts between different sheets, though in both cases crystallinity and viscosity appears sufficiently low to allow crystals to migrate across sheet contacts. Variability in sheet thickness and contact type suggests that the physical parameters (i.e. temperature, viscosity, rheology, and magma flux) of the system continue to evolve throughout the formation of the sheeted complex. Near the White River, sheets are thin and more heterogeneous but become progressively thicker (>302 m) and more felsic in composition up-section. The composition of plagioclase and amphibole is remarkably uniform in all of the felsic sheets suggesting that each sheet formed from an array of felsic parental magmas. Thicker, felsic sheets most likely reflect hotter conditions where larger magma fluxes could be accommodated or viscosity-temperature contrasts that were low enough to allow for efficient mixing between two adjacent sheets and therefore erase sheet contacts. / Graduation Date: 2013

Thesis (M.E.S.)--The Evergreen State College, 2007. / Title from title screen viewed (1/17/2008). Includes bibliographical references (leaves 67-68).

Thesis (M.E.S.)--The Evergreen State College, 2007. / Title from title screen (viewed 1/23/2008). "A thesis: essay of distinction submitted in partial fulfillment of the Master of Environmental Studies, The Evergreen State College, June 2007." Includes bibliographical references (leaves 66-70).

This thesis explore the technological role of bone and antler artifacts from two contact period southern Northwest coast archaeological sites, the Cathlapotle site (45CL1) and the Meier site (35CO5). Technological measures of sedentism are based on lithics, and predict residential sedentism promotes technological expediency in hunter-gatherers (Parry and Kelley 1987). Cathlapotle and Meier lithic assemblages consist of expedient and opportunistic assemblages and raw material stockpiles, with the exception of highly curated projectile points and endscrapers (Hamilton 1994). The expectation that residential sedentism promotes technological expediency in hunter-gatherers was tested on the Cathlapotle and Meier bone and antler artifact assemblages in two ways. First, curation and expediency were recorded for each artifact by measuring level of energy investment in manufacture or degree of working. Second, a spatial analysis was used to explore methods of artifact storage and disposal. Results revealed both Cathlapotle and Meier osseous assemblages are highly curated, except for expedient awls and flakers. Specifically, artifact classes related to subsistence procurement, modification including woodworking, and ornamentation were highly curated. Both sites contain stockpiles of unmodified bone and antler. The spatial analysis showed level of curation did not affect artifact disposal method. Despite this, some patterns were evident. At Cathlapotle, curated procurement and modification artifacts, expedient awls as well as worked fragments were concentrated outside the houses, specifically in Sheet Midden. Broken modification artifacts, ornaments, and detritus were randomly distributed. At the Meier site, curated procurement and modification artifacts, as well as expedient awls were randomly distributed. Broken modification artifacts, detritus and worked fragments were concentrated outside the houses. Ornaments were concentrated in the northern segment (elite area) of the house. There were also significantly more curated complete tools recovered from the cellar facility, while significantly fewer curated complete tools were recovered from the midden facility at Meier. In this thesis, the effects of contact on osseous assemblages were examined. It is an assumption of North American archaeologists that European-introduced metals replace and/or change the character of traditional technologies such as lithic and osseous technologies. Few quantitative studies comparing pre and postcontact artifact assemblages exist (Bamforth 1993, Cobb 2003). In some parts of northeast North America, European contact is followed by a proliferation of osseous tool working, and over time osseous artifacts drop out of the archaeological record (Snow 1995, 1996). Cathlapotle and Meier were occupied from AD 1400 to AD 1830, spanning European contact. People at Cathlapotle were in direct contact with Europeans and Euro-Americans since 1792 (Boyd 2011). Previously, it was assumed Cathlapotle was more involved in the fur trade than Meier, because Cathlapotle was mentioned several times in ethnohistoric accounts, while Meier was never mentioned. Also Cathlapotle contains far more historic trade items than Meier (Ames 2011). The assumption that European-introduced metals replace and/or change the character of traditional technologies was tested on the Cathlapotle and Meier assemblages by comparing artifact frequency, density, and assemblage diversity of pre and postcontact assemblages. Results show contact is reflected in the osseous assemblages at both Cathlapotle and Meier. Contact is evident, but is reflected in different ways. At Cathlapotle, artifact frequencies, densities, and assemblage diversity decrease postcontact. In contrast at Meier, artifact frequencies and densities increase postcontact, with some artifact classes tripling or quadrupling in frequency. The introduction of metal could have enabled people to work osseous materials faster and easier, decreasing manufacture time, cost, and overall energy investment. The gain in efficiency promoted the proliferation of bone working and an abundance of osseous tools at the Meier site. These results encourage a reevaluation of Meier's role in the fur trade. At Cathlapotle, metal objects may have replaced osseous tools resulting in the decline of bone and antler working and/or activity patterns shifted away from activities requiring osseous tools. The results of this thesis deviate from typical Northwest Coast bone and antler assemblages, challenge technological models of sedentism that are based on lithics, and contradict assumptions of Lower Columbians involvement in the fur trade.

The Columbia River Gorge National Scenic Area (NSA) was created in 1986 in response to a growing interest in preserving the scenic beauty of the gorge. The creation of the NSA and other areas around the country with a scenic resource emphasis indicates a growing interest in protecting landscapes with diverse scenic qualities that are not showcase areas such as the Grand Canyon and Yosemite. NSA mandates included the protection and enhancement of scenic, natural, cultural, and recreational resources (SNCRs) as the primary concern in the consideration of new land uses. The NSA management plan contains a complex mix of management tools for the protection of SNCRs in the gorge. This research was an investigation into how scenic resources policy was developed, with a focus on the scenic resources of the NSA. One issue was the definition of scenic resources, which are undefined in the management plan. Because of the difficulty of identifying scenic resources, other resources may be managed as a surrogate for them. An analysis was made of the scenic resources management schemes of several federal reserve lands with a stated scenic management objective to determine if this was the case, and to compare their management strategies for the NSA. A second issue was the public's understanding of what constitutes a scenic resource and the role that public input had in the development of the management plan. Empirical work suggests that complexity of issues may hinder successful public input processes. A final issue was how identifiable stakeholders in the Columbia River Gorge differed in their views on scenic resources, which may depend on their proximity to and relationship with such resources. Results of data analysis and the interview process reveal that public understanding about scenic resource concepts is low, and that gorge planners were primarily responsible for development of scenic resources policy in the NSA management plan. As expected there were some identifiable differences in the views on scenic resources among various stakeholders. Scenic resources management elsewhere is done primarily through traditional zoning requirements, and the basis of management of scenic resources appears to be for other culturally-defined purposes such as recreation.