• Taking a stand on not taking a stand: media bias in the online reporting of COVID-19

      Johnson, Kyle; Hum, Richard; Taylor, Karen; Timm, Kristin (2021-05)
      This thesis was written to examine the digital communication strategies of three major news organizations when reporting on COVID-19 in the U.S. for bias. The research looked at social media posts, online article counts and themes, main websites of each organization and audio/visual broadcast segments from all three organizations posted online. This research used an advocacy approach, examining the tension between entertainment and journalism ethics by holding news organizations to journalism standards to see how they compare. Results showed that NPR and Fox News produced more online articles than MSNBC and linked to their own articles on twitter more. The audiovisual content from MSNBC and Fox News did not follow the code of ethics created by the Society of Professional Journalists. All three organizations used biased methods for providing information to the public, during a time period where public knowledge is key to managing a pandemic.
    • Temporal and size-based patterns in juvenile sablefish energy allocation and diet

      Callahan, Matthew W.; Beaudreau, Anne H.; Mueter, Franz J.; Heintz, Ronald A. (2020-08)
      A recent marine heatwave in the Gulf of Alaska caused depressed growth, poor body condition, and low survival in many fish species, but juvenile sablefish (Anoplopoma fimbria) thrived. These fast-growing piscivores are the target of a valuable commercial fishery in Alaska as adults and have historically shown high variability in recruitment. The first winter is a period of nutritional stress and high mortality for many fish species and first winter survival may dictate year class strength, but the importance of the first winter for juvenile sablefish is understudied. We examined juvenile sablefish energy storage, growth, and diet during their first two years of life, specifically as newly settled juveniles in their first autumn, in late winter, and during their second summer and autumn. Sablefish grew rapidly in autumn and growth slowed but continued through winter. Mean energy density (kJ g⁻¹) declined over the winter but total energy (kJ individual⁻¹) increased significantly between October and March. Slopes of energy density and total energy versus length regressions were atypical for high latitude marine fish in that they were steepest in March. This indicates that large fish grew during winter with minimal energy depletion while small fish grew but depleted their energy stores. Stable isotope results revealed that larger fish were enriched in [delta]¹³C and [delta]⁻¹⁵N in March relative to smaller fish, suggesting diet differences may contribute to size-specific energy storage patterns during winter. Pacific herring (Clupea pallasii) dominated diets but consumption of herring and other prey varied seasonally and annually. Relative stomach content weights were highest in autumn 2018, which was a period of rapid growth. Results of this study show advantages for sablefish achieving large size prior to winter and broadly support the hypothesis that first winter is a life history bottleneck for juvenile sablefish. The generalist feeding strategy of sablefish and rapid growth early in life may provide the ability to adapt to a wide range of environmental conditions.
    • Threat, opportunity, cooperation, and competition: defining China's integration into the Arctic

      Bowman, Susan Elizabeth; Boylan, Brandon; Skya, Walter; Bertelsen, Rasmus (2020-12)
      Despite widespread attention to China's interest in the Arctic, little research examines how the country approaches the region. This thesis uses an inductive and qualitative approach to examine China's relationships with the eight Arctic states and major international institutions in the Arctic. This thesis asks: How is China integrating into the Arctic? How do Arctic states view China's integration? Through content analysis, narratives tell the story of China's relationship with the Arctic 8 and Arctic institutions. China's integration is explored on a fundamental level through the comparison of bilateral and multilateral relations, followed by more strategic undertones including threat, opportunity, cooperation, and competition. China's integration into the Arctic is multi- faceted and demonstrates a range of characteristics. The primary focus of China's integration is the use of bilateral and multilateral approaches and the use of strategic soft and sharp power. Each Arctic state views China's integration differently depending on its tolerance for China's approach to integration. This study adds to the existing literature of China in the Arctic and provides a baseline for future research on non-Arctic states in Arctic international relations.
    • Timescales of magmatic processes from diffusional profiles recorded in minerals of the 2016-2017 eruption of Bogoslof Volcano, Alaska

      Moshrefzadeh, Jamshid Akhbar; Izbekov, Pavel; Loewen, Matthew; Larsen, Jessica; Regan, Sean (2020-08)
      Every volcanic eruption is unique, and creates opportunities for scientists to gain insights on magma processes. Studying active volcanoes not only adds to our understanding of fundamental processes that shape our planet, but it is also importantly aids the scientic community to assess and mitigate the many hazards that volcanoes pose. The products of the 2016-2017 eruption of Bogoslof Volcano provide a unique opportunity for the application of diusion chronometry, due to the abundance of distinct, stepwise boundaries within three mineral phases: clinopyroxene, plagioclase, and amphibole. Given that diusion is driven by the presence of a chemical gradient, the compositionally stepwise boundaries between distinct zones can be used to investigate the diusion of elements within the crystals in order to constrain timing of the magmatic processes that created them, as well as crystal residence times. Here we present our analyses of these stepwise boundaries, and discuss the potential correlation of acquired diusional timescales from clinopyroxene with the other two mineral phases, in order to determine what magma processes lead to the formation of these boundaries, and when these processes occurred. Our results suggest that the stepwise boundaries in crystalline phases of the magmas erupted by Bogoslof in August 2017 formed due to mac recharge that resumed in March 2017 and occurred repeatedly until the cessation of the eruption in August 2017. Activity at Bogoslof during March 2017 is additionally characterized by increased seismicity and SO₂ rates, suggesting that our petrologic results are consistent with multiple interdisciplinary observations.
    • Tracing carbon sources of southern Beaufort Sea and Chukchi Sea polar bears using stable isotope analyses

      Smith, Malia E.K.; Horstmann, Lara; Wooller, Matthew; Rode, Karyn (2020-12)
      The Southern Beaufort Sea (SBS) polar bear (Ursus maritimus) subpopulation has declined in response to sea ice loss, while the Chukchi Sea (CS) subpopulation appears stable. The substantial population decline in the SBS subpopulation in recent years is concurrent with increases in the proportion of polar bears coming on shore, and the duration they spend there. Both of these changes have been associated with the loss of access to their primary sea ice habitat, which is mainly used as a platform to hunt seals. The first objective of this study was to determine if the SBS and CS polar bear subpopulations could be distinguished based on stable isotope signatures (delta¹³C and delta¹⁵N values) of bone collagen. The second objective was to examine patterns in SBS polar bear trophic level and terrestrial carbon sources over a 65-year time period, as polar bears have increasingly used coastal environments. We analyzed 112 SBS and CS polar bear bones (predominantly mandibles) from 1954-2019 that had been archived at the University of Alaska Museum of the North, as well as bones from subsistence-harvested polar bears. In addition to delta¹³C and delta¹⁵N, samples from the SBS bears were analyzed for compound-specific stable carbon isotopes of amino acids (delta¹³CAA values). Another 50 bone collagen samples from terrestrial mammals and pinnipeds from northern Alaska were analyzed for delta¹³CAA values to provide a regional comparative dataset. Our study showed a significant difference in bulk delta¹³C (p<0.001) values, but not delta¹⁵N (p=0.654) values between the CS (-13.0‰±0.3‰ and 22.0‰±0.9‰, respectively) and the SBS bears (-14.7‰±1.3‰ and 22.2‰±1.0‰, respectively). We performed a logistic regression analysis (LR) using bulk delta¹³C and delta¹⁵N values of the polar bears to predict their placement into these two subpopulations. Using Icy Cape, AK as the geographical boundary, LR correctly placed polar bears in their respective subpopulations 82% of the time. Overall accuracy of placement changed to 84% when using the current geographical boundary at Utqiaġvik, AK. Bone collagen has a slow turnover rate, providing long-term, potentially life-long stable isotope signatures. Our findings could be used to determine the association of harvested polar bears to Alaska subpopulations, thus aiding in harvest quota management. The LR predicted samples collected from the Wainwright, AK region to be 58% CS and 42% SBS polar bears. This indicates that the area between Wainwright and Icy Cape is a polar bear mixing zone that includes bears from both subpopulations. Over the 65-year study period, two distinct groups of SBS polar bears were identified based on their delta¹³C values of the amino acid proline: a high delta¹³CPro group (1.8‰±2.3‰, n=45) and a low delta¹³CPro group (-15.7‰±1.9‰, n=26). The high proline polar bear group had delta¹³CPro values similar to those of Arctic brown bears (Ursus arctos; 0.4‰±1.6‰), while the low group had delta¹³CPro values similar to ice seals (-15.3‰±1.2‰). Among the available samples, there were more high proline/pelagic bears (n=17) after the 2007 sea ice minimum than high proline/coastal bears (n=12), which is opposite of what we expected. This study provides evidence that two distinct ecotypes in Southern Beaufort Sea polar bears, pelagic and coastal, have existed since at least the 1950's. Overall, our results represent a detailed isotopic view of the Alaskan polar bear subpopulations, demonstrating the possibility of distinguishing and categorizing individuals as either SBS or CS, while also highlighting the existence of two ecotypes in the SBS subpopulation.
    • Transport of CH₄ through open-talik lakes in discontinuous permafrost aquifers

      Eckhardt, Bridget A.; Barnes, David L.; Daanen, Ronald P.; Liljedahl, Anna K.; Romanovsky, Vladimir E.; Anthony, Katey Walter (2020-08)
      As northern regions of the world experience warming climate, scientists look to permafrost, a crucial component of Arctic and subarctic ecosystems, as a source and sink of atmospheric carbon. It is well-known that the thawing of permafrost from above as a result of warming climate is a considerable source of greenhouse gases. However, few studies have considered the production of methane, a potent greenhouse gas, beneath the permafrost. A rugged permafrost bottom is proposed to favor the storage of gas in "pockets" that have been formed through permafrost thaw and degradation from below. Sub (below)-permafrost methane can migrate to reach the atmosphere when connections between the sub-permafrost and supra- permafrost open pathways from the pocket to the bottom of an open talik lake. We hypothesized that the migration of methane occurs through advection and diffusion as a dissolved gas and by movement as an immiscible fluid. Through measurement of environmental tracers in two thermokarst lakes in Goldstream Creek Basin, Fairbanks, Alaska, we found that advection was variable and was seasonally and climatically dependent demonstrating both upward and downward groundwater flow within our study lakes. Measurements of dissolved methane concentrations in the lakes demonstrated that diffusion of methane was not a significant transport mechanism in the groundwater-to-lake pathway due to the extreme temporal and spatial variability of methane concentrations. Immiscible flow of free-phase methane is likely the dominant transport mechanism but is dependent on the lake sediment composition and the formation of secondary pathways within the talik. Data obtained from this study allowed for a better understanding of methane transport and thermokarst lake dynamics.
    • Trend analysis of temperature, precipitation, and stream flow in the National Petroleum Reserve Alaska

      Marshall, Sara; Toniolo, Horacio; Rasley, Brian; Schnabel, William (2021-05)
      Seven hydro-meteorological stations in the National Petroleum Reserve Alaska were analyzed to look at precipitation, discharge, and temperature trends. These hydro-meteorological stations included: Fish Creek, Judy Creek, Ikpikpuk, Ublutuoch, Seabee, Prince, and Otuk. A linear regression was performed on a year-by-year basis to fill in data gaps in the temperature time series, for all six stations with temperature data. The Seasonal Mann-Kendall test and a Modified Seasonal Mann-Kendall test were performed to determine if a trend appeared present in the time series and, if so, how significant the trend was. The Sen's slope analysis was then utilized to determine the magnitude of the trend, if a trend was observed in both analyses. The temperature trends showed an increasing trend in the temperature data for four stations: Judy Creek, Ublutuoch, Fish Creek, and Ikpikpuk. No trend was shown in the remaining station, Otuk station. One station, Prince, was removed from analysis due to a high percentage of missing data. The Modified Seasonal Mann-Kendall tests showed a trend in four of the five stations, and a slight positive trend in one of the five stations. The precipitation data showed 'no trend' in the Seasonal Mann-Kendall analysis. The Modified Seasonal Mann-Kendall test showed a slight trend (Fish Creek), a moderate trend (Otuk), and no trend (Ikpikpuk) for the precipitation data. Using the seasonal Mann-Kendall analysis the discharge data showed no trend in five out of seven stations and two trends (Fish Creek and Seabee). The Modified Seasonal-Mann-Kendall analysis showed and a significant trend twice (Fish Creek and Seabee), a moderate trend three times (Ikpikpuk, Prince, Otuk), a slight trend once (Ublutuoch), and no trend one time (Judy Creek) in the discharge data.
    • Trophic structure of rocky intertidal communities in contrasting high-latitude environments

      Siegert, Danielle; Iken, Katrin; Konar, Brenda; Lindeberg, Mandy (2020-08)
      Coastal ecosystems in high latitudes are increasingly impacted by glacial melt and river discharge due to climate change. One way to understand ecosystem responses to these stressors is assessing trophic relationships. The goal of this study was to better understand how hydrographic conditions influence trophic structure in high-latitude rocky intertidal systems. I compared the trophic structure of rocky intertidal assemblages in two regions in the northern Gulf of Alaska that comprise the same regional species pool but are hydrographically distinct, one glacially influenced and one primarily marine influenced. Common macroalgal and invertebrate taxa, as well as particulate organic matter (POM) were sampled at three rocky intertidal communities in each region in 2017 and 2018. Food web structure was compared using trophic metrics based on the distribution of shared taxa in isotopically-derived (delta¹³C and delta¹⁵N) trophic niche space. I found that trophic niche space in the glacially-influenced rocky intertidal system was larger, driven by larger ranges in both carbon and nitrogen stable isotope values. In particular, the lower delta¹³C values in Kamishak Bay suggest that an additional food source, most likely terrestrial organic material from glacial discharge, was incorporated into the food web. This supported the hypothesis that patterns in food web structure differed based on hydrographic influences to maintain overall stability. Isotopic evenness, i.e., the distribution of the shared taxa within trophic space, did not differ between the two regions. Macroalgae were overall a more important food source than POM in both regions, and even more so in the glacially-influenced region, where macroalgae may be an energetically beneficial food source compared to silt-laden glacial inputs. This study showed that common intertidal taxa have high tropic flexibility enabling them to respond to variable food sources under a variety of environmental conditions. As hypothesized, taxa in food webs occupying a larger trophic niche space engaged in more heterogeneous trophic pathways and used diverse resources depending on local environmental conditions, making these systems more stable to perturbations affecting a single resource. The common taxa of high-latitude rocky intertidal systems studied here are responding to current levels of glacial input with more diverse resource use, but it remains to be seen how well those systems are suited to maintain trophic stability with an expected increase in glacial stress from climate warming.
    • UAF's light-duty vehicle fleet lifecyle, maintenance costs and composition: ordinary least square regression and panel data analysis

      Hix, Edward R.; Wright, Christopher; Baek, Jungho; Little, Joe; Goering, Greg; Platt, Nathan (2020-08)
      The University of Alaska Fairbanks maintains a vehicle fleet for use by its staff, faculty, and students. Given the multifaceted needs of the campus and the impact that the harsh subarctic climate can have on vehicles, management of the fleet to meet the needs of its users is a complex task. One method UAF uses to manage the cost of the fleet is to extract the depreciation expense from each fleet vehicle into a non-interest bearing recharge account to eventually purchase its replacement. While several reviews have been conducted regarding the management of this fleet, a gap in research involves analysis of cost of this fleet over its lifecycle. This study examined the effects of fleet vehicle lifecycle extension beyond the predetermined 10-year useful life at UAF. Three novel datasets were created from UAF Facilities Services' archival maintenance work order data: a vehicle dataset, work order dataset, and a panel dataset. Ordinary least squares regression methods were used to examine the impact of model year on a vehicle's nominal purchase price and the impact of vehicle specification on real purchase price. Fixed and random effects panel methods were used to examine the impact of vehicle specification and vehicle age on maintenance costs. The effects of extending the fleet lifecycle from ten to twenty-years on maintenance and operational cost were estimated. Population dynamics models estimated the impact of the ten year lifecycle extension on the replacement fund. The results of this study suggested increasing vehicle lifecycles by ten years increased operating, maintenance, and replacement costs and effectively reduced the replacement fund purchasing power. The extension of vehicle lifecycles resulted in continually increasing rental rates and ultimately to the insolvency of the replacement fund.
    • Uncertainty quantification in unconventional reservoirs using conventional bootstrap and modified bootstrap methodology

      Okoli, Chukwuemeka; Awoleke, Obadare; Goddard, Scott; Ahmadi, Mohabbat (2020-12)
      Various uncertainty quantication methodologies are presented using a combination of several deterministic decline curve analysis models and two bootstrapping algorithms. The bootstrapping algorithms are the conventional bootstrapping method (CBM) and the modied bootstrapping method (MBM). The combined deterministic-stochastic combination models are applied to 126 sample wells from the Permian basin. Results are presented for 12 to 72 months of production hindcast given an average well production history of 120 months. Previous researchers used the Arps model and both conventional and modied bootstrapping with block re-sampling techniques to reliably quantify uncertainty in production forecasts. In this work, we applied both stochastic techniques to other decline curve analysis models∎namely, the Duong and the Stretched Exponential Production Decline (SEPD) models. The algorithms were applied to sample wells spread across the three main sub-basins of the Permian. A description of how both the deterministic and stochastic methods can be combined is provided. Also, pseudo-codes that describes the methodologies applied in this work is provided to permit readers to replicate results if necessary. Based on the average forecast error plot in the Permian Basin for 126 active wells, we can also conclude that the MBM-Arps, CBM-Arps, and MBM-SEPD combinations produce P50 forecasts that match cumulative production best regardless of the sub-basin and amount of production hindcast used. Regardless of concerns about the coverage rate, the CBM-Arps, MBM-Arps, CBM-SEPD, and MBMSEPD algorithm combinations produce cumulative P50 predictions within 20% of the true cumulative production value using only a 24-month hindcast. With a 12 month-hindcast, the MBM-Arps combined model produced cumulative P50 predictions with a forecast error of approximately 20%. Also, the CBM-SEPD and MBM-SEPD models were within 30% of the true cumulative production using a 12- month hindcast. Another important result is that all the deterministic-stochastic method combinations studied under-predicted the true cumulative production to varying degrees. However, the CBM-Duong combination was found to severely under-predict cumulative production, especially for the 12-month hindcast. It is not a suitable model combination based on forecast error, especially when hindcast fractions on the low end of the spectrum are used. Accordingly, the CBM- Duong combination is not recommended, especially if production history of no more than 24 months is available for hindcasting. As expected, the coverage rate increased, and the forecast error decreased for all the algorithm combinations with increasing hindcast duration. The novelty of this work lies in its extension of the bootstrapping technique to other decline curve analysis models. The software developed can also be used to analyze many wells quickly on a standard engineering computer. This research is also important because realistic estimates of reserves can be estimated in plays like the Permian basin when uncertainty is correctly quantied.
    • Utility of trace element studies for improving our understanding of geochemical processes within the arctic ocean environment

      Bolt, Channing; Aguilar-Islas, Ana; Rember, Robert; Reynolds, Jennifer; Rivera-Duarte, Ignacio; Simmons, Harper (2021-05)
      The Arctic Ocean is a dynamic region undergoing rapid change. Sea ice and meteoric water are intrinsic components of the Arctic environment that play key roles in its ecosystem, including the distributions and cycling of trace elements throughout the pan-Arctic Ocean. Meteoric water (e.g., rivers and snow deposition) contributes to the input of trace elements to surface waters, while sea ice dynamics contribute to the transport of these constituents across Arctic basins. Trace element distributions can provide insights into Arctic processes. The focus of Chapter One is on particulate (>0.2 μm) trace elements in Arctic pack ice, associated snow, and underlying surface waters collected from September-October 2015 during the US GEOTRACES Western Arctic cruise (GN01). This late-season pack ice provides a snapshot of sea ice characteristics in regions near the North Pole, within the Makarov and Canada Basins, and can estimate the impact melting sea ice may have on particulate trace element inputs to Arctic waters. Chapter Two presents on the utility of dissolved barium (dBa), a bio-intermediate element of lithogenic origin, as a tracer of meteoric water throughout the Siberian Arctic Ocean. Samples for Chapter Two were collected during the 2018 Nansen and Amundsen Basin Observatory System. The distribution of dBa in this region may provide useful insights into important shelf processes, such as tracing shelf waters along continental slopes. In Chapter 3, additional spatiotemporal geochemical parameters (δ¹⁸O and salinity) are considered alongside dBa to model how Arctic water mass fractions (meteoric, sea ice melt, and Atlantic waters) changed between 2013, 2015, and 2018 within the Siberian Arctic Ocean. This dissertation contributes to the understanding of Arctic Ocean processes through the application of trace element studies and highlights the usefulness of combining tracers to better understand this dynamic environment.
    • Vertebrate ichnology and paleoenvironmental associations of Alaska's largest dinosaur track site in the cretaceous Cantwell Formation (Maastrichtian) of Denali National Park and Preserve

      Stewart, Dustin G.; Druckenmiller, Patrick; Fowell, Sarah; McCarthy, Paul (2020-10)
      The Upper Cretaceous Cantwell Formation in Denali National Park and Preserve (DENA) has recently been recognized as a major high latitude dinosaur track-bearing unit in Alaska. The abundant trace fossil record of the Cantwell Formation, which represents a diverse community of avian and non-avian dinosaurs, compliments the body fossil record of the state's other major dinosaur-producing unit, the Prince Creek Formation of northern Alaska. However, research in the Cantwell Formation is still in its infancy due to its wide aerial extent and remoteness, and many questions remain concerning the temporal, ichnological, and paleoenvironmental relationships of the formation. Here I describe and analyze the largest known single track site currently known in DENA and all of Alaska -- a football field-sized outcrop named the Coliseum. This site is composed of 65+ meters of vertical section, with laterally extensive fine- to medium-grained sandstone, indurated mudstone, fissile shale, and bentonite. Trace fossils at the Coliseum include true tracks, undertracks, natural casts, and trackways that vary in their preservation from eroded, trampled surfaces to individual prints with skin impressions. The tracks were documented via handheld and UAV-assisted photogrammetry, enabling a large-scale 3-dimensional mapping of the Coliseum. Facies analysis of the site reveal the tracks were formed on crevasse splay and overbank deposits within a fluvial floodplain. U-Pb dating of zircons collected from a bentonite horizon return an age of 69.3±0.9 Ma (early Maastrichtian), improving the temporal constraints of the formation and revealing one of the youngest ages of deposition for the formation. Several new dinosaurian ichnotaxa previously unrecognized from the formation are described, revealing the presence of large-bodied ornithopods, ceratopsids, and non-avian and avian theropod trackmakers. The Coliseum provides a snapshot of an ancient forested environment inhabited by a diverse dinosaurian community deposited in the Late Cretaceous paleo-Arctic.
    • Western Gwich'in classificatory verbs

      Bushey, Scott T.; Tuttle, Siri; Peter, Hishinlai'; Vajda, Edward (2021-05)
      One of the many challenges faced by learners and teachers of Gwich'in, an endangered Athabascan or Dene language of Alaska and Canada, is a lack of instructional material for classificatory verbs. These verbs classify states and actions, such as lie, carry, and fall, by perceived qualities, such as cloth-like and stick-like, that indicate how and with which nominal entities the state or action takes place. For students of Gwich'in and other Dene languages, such as Navajo and Koyukon, classificatory verbs are an important grammar objective when included in the curriculum. Recognition and production of classificatory verbs is a main objective for students in the second year of the UAF Gwich'in class. Classificatory verb words are also present in vocabulary learned from the first year, such as gishreiin'ąįį "it's sunny" and OBJ naltsuu "I'm wearing OBJ [upper-body garment]". In this thesis I present a documentary, descriptive study of classificatory verbs and their qualities in modern spoken Gwich'in. The first goal of the study is to document examples of Gwich'in classificatory verbs in conversational and narrative discourse, and the second is to describe their morphosemantic properties and behavior. The third goal is to accomplish these documentary and descriptive aims in a way that can be adapted readily to the needs of not only linguists, but also Gwich'in language learners and teachers. Informed by previous documentary and descriptive work on classificatory verbs in other Dene languages, I attempt to provide a similarly useful text for Gwich'in, reconciling several competing nomenclatures and illustrating the relationship between classificatory verb theme sets, such as "carry", and semantic classes of verb stems, such as "animate", in a broad range of modal and aspectual contexts. Although this thesis is intended primarily as a reference work for learners and teachers, it also provides a resource for linguists comparing Gwich'in classificatory verbs with those in related Dene languages. The classificatory verb data in this thesis is drawn from a body of Gwich'in class notes and assignments, well as transcribed Gwich'in oral literature and consultation with a native speaker of the language. Classroom instruction took place between 2018 and 2020 at the University of Alaska Fairbanks and emphasized spoken language production with communicative aims. In addition to work from the Gwich'in language classroom, limited native speaker consultation regarding classificatory verbs was also conducted in February 2020. The third data source for this study is the rich body of narrative discourse available in the form of transcribed oral literature. These works record Gwich'in traditional narrative knowledge, lore, and history across a broad range of topics, in which classificatory verbs may be readily encountered and examined. Having drawn from these three pools of data, this thesis describes the morphosemantic qualities of Gwich'in classificatory verbs while considering the available data on other Dene languages and considers actual and potential application of this data in the language classroom.
    • Widespread capacity for denitrification in soils, streams, and thermokarst lakes of boreal Alaska

      Burnett, Melanie S.; Harms, Tamara K.; Ruess, Roger W.; Walter Anthony, Katey M. (2021-05)
      Rapid warming in Alaska is causing permafrost to thaw, especially in the region of discontinuous permafrost, where soil temperatures may only be a few degrees below 0 °C. An intensifying fire regime may also be exacerbating permafrost thaw with more frequent and severe fires removing insulating organic layers above permafrost. Permafrost thaw releases carbon and nitrogen (N) into the actively cycling pools, and whereas carbon emissions following permafrost thaw are well documented, the fates of N remain unclear. Denitrification and release of nitrous oxide (N₂O) or nitrogen gas (N₂) could result in N loss from ecosystems, but the contributions of these processes to the high-latitude N cycle remain uncertain. I quantified microbial capacity for denitrification and nitrous oxide production in boreal soils, lakes, and streams, and assessed correlates of denitrifying enzyme activity in interior Alaska to determine if denitrification could contribute significantly to N loss from the boreal forest. Across all landscape positions, median potential denitrification rate under anoxic conditions with nitrate and organic carbon amendment was 4.15 [mu]g N₂O-N /kg dry soil*h (range -6.39 to 479.94). Denitrification potential was highest within and along streams in both sediments and adjacent riparian soils, upland soils were intermediate, and lakes supported lower rates, whereas deep permafrost soils supported little denitrification. Time since last burn had no effect on denitrification potential in upland soils. Across all landscape positions, denitrification potential was negatively correlated with ammonium pools. In lakes, potential rate of denitrification declined with sediment depth, and was positively driven by organic matter content. In this era of anthropogenic climate change, pervasive N loss to denitrification in the boreal forest could constrain the capacity for N-limited primary producers to preserve carbon stocks in soils following permafrost thaw.
    • The Yup'ik relationships of qiluliuryaraq (processing intestine)

      Carrlee, Ellen; Schweitzer, Peter; Koester, David; Lee, Molly; Hill, Erica; Plattet, Patrick (2020-12)
      This project explores multiple Native cultural contexts that intersect in the use and understanding of intestine. Gut (tissues of internal organs including stomach, intestine, bladder and esophagus) as a raw material was historically used by many circumpolar cultures to make items like drums, raincoats, hats, windows, sails, containers, and hunting floats. These items are abundant in museum collections, but rarely seen today in cultural practice or the art market. Intestine is a natural material that was replaced by synthetic materials, but its dual physical properties of protection and permeability are the only features replicated by plastics. Examination of intestine as an obsolete material reveals both changes and resilience in different kinds of relationships. Emphasizing the meaning and materiality of gut over analysis of artifacts made from it emphasizes interactions among human, animal, and spiritual beings over formalistic approaches privileging object interpretations. Preferential investigation of a raw material over finished artifacts focuses the study on actions and values in Native places. Fieldwork components for this study include documentation of indigenous gut processing, sewing and repair workshops in museum contexts, processing fresh intestine in the Yup'ik village of Scammon Bay, and discussion of gut with Yup'ik cultural experts. The theoretical approach uses Actor-Network Theory (ANT) as a foundation, animated with practice theory and relational ontology. Since ANT creates space for human, animal, and object agency, reciprocal relationships among these actors will be explored through frameworks of materiality, object biography, gender studies, animal personhood, and the gift. This endeavor may promote a new model for the use of material culture to illuminate Native values. In the case of intestine, its decline in use connects to changes in technology and spirituality while resilience and revitalization of gut technology promotes identity and demonstrates traditional values.
    • Zooplankton community composition in relation to environment and juvenile salmon diets in Icy Strait, Southeast Alaska

      Fergusson, Emily A.; Eckert, Ginny; McPhee, Megan; Heintz, Ron (2020-12)
      Zooplankton in the nearshore marine habitat function as an important prey resource for many pelagic fishes, are a major component of the lower tropic level, and serve as a vital ecosystem indicator. Understanding how the zooplankton community changes in response to fluctuations in biophysical factors is critical in a changing climate and is important to understanding the dynamics of commercially important upper-trophic level species that depend nutritionally on zooplankton. The Alaska Fisheries Science Center's Southeast Coastal Monitoring project has surveyed the pelagic ecosystem in eastern Icy Strait monthly from May to August since 1997 to understand how environmental variation affects the pelagic food web and the sustainability of salmon resources. I used this long-term dataset (1997-2017) to address the goals of this study: 1) to investigate the influence of temperature on the Icy Strait zooplankton community; and 2) to understand how juvenile salmon utilize zooplankton prey in relation to temperature driven fluctuations in the zooplankton community. In Chapter 1, I noted that the composition of the zooplankton community varied in years with anomalously high or low temperatures. I observed shifts in the timing of development in many key taxa during these anomalous years. For example, in anomalously cool years, several taxa were found in higher densities later in the summer than in anomalously warm years. In Chapter 2, I examined how oceanographic factors influenced the diet composition and quality of four species of juvenile Pacific salmon (Oncorhynchus spp.) in Icy Strait (Southeast Alaska) from 2013 to 2017. In 2015 I observed a change in diets, including zooplanktivorous (pink salmon O. gorbuscha, chum salmon O. keta, and sockeye salmon O. nerka) and piscivorous (coho salmon O. kisutch) species, from typically diverse diets to diets dominated by euphausiids. This year was notable for warm waters, deep pycnoclines, and below average zooplankton nutritional quality. Juvenile salmon appeared to supplement their lipid intake and meet nutritional requirements by switching to larger euphausiid prey. The results from these studies increase our understanding of zooplankton community dynamics, salmon trophic relationships, and the resilience and flexibility of the food web during climate-driven reorganizations of the pelagic marine ecosystem.