• Fate and effects of commercial crude oil bioremediation products in Arctic seawater

      Gofstein, Taylor R.; Leigh, Mary Beth; Simpson, William; Guerard, Jennifer; Collins, R. Eric (2020-08)
      With increased oil exploration, development, and transport in the Arctic in recent years, the potential for disastrous oil spills is imminent. Biodegradation, the consumption of contaminants by indigenous microorganisms capable of using them as an energy source, can be enhanced using bioremediation treatments and may be a viable spill remediation method when traditional physical recovery techniques are not. The EPA National Contingency Plan (NCP) product schedule lists oil spill response treatments that can be used in the event of a spill, many of which can stimulate intrinsic biodegradation. However, there is often little to no experimental data demonstrating the effectiveness of these products in aiding the remediation of a spill. Here we investigate the effects of the currently listed NCP products Corexit 9500 and Oil Spill Eater II (OSEII) on crude oil biodegradation in Arctic seawater and the associated shifts in the microbial community using mesocosm incubations. Despite conflicting reports in the literature, Corexit 9500 showed no inhibitory effects on the biodegradation of crude oil. When oil and Corexit were co-present, chemical and microbial data revealed a sequential degradation beginning with the non-ionic surfactant components of Corexit (Span 80, Tween 80, Tween 85), followed by the degradation of the labile alkane oil components, with the degradation of other Corexit components such as dioctyl sodium sulfosuccinate (DOSS) and dipropylene glycol n-butyl ether (DGBE) less clear. 16S rRNA gene sequencing revealed that oil and Corexit stimulate different microbial communities but some taxa are stimulated by either (Oleispira, Pseudofulvibacter, Roseobacter), suggesting that these organisms may be capable of degrading both. Further analysis with metatranscriptomic sequencing showed increased gene expression in the presence of Corexit, even when co-present with oil, suggesting that Corexit may enhance the metabolic activity of oil degraders. Increased expression of β-oxidation pathway genes (fadE, fadA, fadB) in the presence of Corexit coincided with the chemical loss of Corexit components. Based on these findings and the abundance of ester groups in the chemical structures of Corexit 9500 surfactant components, we propose a biodegradation pathway that involves the transformation of ester groups into fatty acids either through biotic lipase enzymes or abiotic hydrolysis, before funneling into the β-oxidation fatty acid degradation pathway. Taxonomic origins for these transcripts showed a diverse number of genera expressing these genes, which along with its lability may serve to explain the number of taxa observed to respond to Corexit both here and in the literature. Characterization of the contents of OSEII revealed the presence of sugars, surfactants, nutrients, phytochemicals, amylase, protease, and the non-hydrocarbonoclastic non-viable microorganisms Lactobacillus and Saccharomyces. Incubation experiments targeting the efficacy of OSEII showed a slight enhancement of n-alkane loss at 30 days, suggesting that it may have utility in longer term use following a post-spill nutrient depletion. However, the nutrient contents of OSEII were up to 32-fold times higher for ammonia and 100,000-fold times higher for iron than in ambient Arctic seawater, which although are limiting nutrients in seawater, may also cause more harmful ecological effects following a spill by inducing phytoplankton blooms. Based on these findings, the non-ionic surfactants of Corexit 9500 appear to be easily degraded through the proposed β-oxidation fatty acid pathway. Future NCP dispersants should target these labile ester chemical moieties while also being effective at dispersion. It is imperative for NCP products to undergo more rigorous third-party experiments to demonstrate their suitability, effectiveness, toxicity, and unintended side effects that may occur in situ before an oil spill occurs. Doing so will allow decision-makers to have comprehensive information to aid in selection of appropriate oil spill response techniques.
    • Feasibility of multiple camera large-scale particle image velocimetry techniques for rivers in Alaska

      LaMesjerant, Eric N.; Toniolo, Horacio; Barnes, David; Shur, Yuri (2020-12)
      Alaska is characterized by sparse hydrologic data. Non-intrusive gauging is one method of increasing the data available but is limited in its current application. This study seeks to assess the feasibility of using commercially available software and multiple cameras to diversify the conditions for which large-scale particle image velocimetry may be applied. Using available software and the deployment of multiple cameras, stereoscopically determined discharge is compared with discharge determined using an acoustic Doppler current profiler and accepted single camera practices currently in use with large-scale particle image velocimetry. The results indicate that the use of commercial software and multiple cameras is feasible, with additional work, and that there is a statistically significant relationship between the velocity index (alpha) and aspect ratio (B/H, width divided by average depth). The velocity index-aspect ratio data indicate that the velocity index is a result of the environmental and geometric conditions for a given cross section and that an empirical relationship could be established.
    • Genomic signatures of optimal growth temperature in the family Colwelliaceae

      Gentilhomme, Anais; Collins, R. Eric; Hennon, Gwenn M.M.; Leigh, Mary-Beth; Drown, Devin (2020-12)
      The temperature range supporting growth defines a complex physiological phenotype that depends on interactions between an organism's genome and its environment. Its implications are widespread since small changes in optimal growth temperature (OGT) can alter an organism's ability to inhabit an ecological niche. Thus, organisms with extreme thermal growth traits (e.g., psychrophilic, with OGT < 15℃, or thermophilic, with OGT 60 -80℃) may be useful for identifying promising targets when searching for life on other planets, as well as predicting population dynamics in a warming Arctic. We performed comparative genomic analyses of bacteria newly isolated from Arctic sea ice that were affiliated with Colwelliaceae, a family of Gammaproteobacteria that contains many psychrophilic strains, to identify genomic factors that might be used to predict OGT. A phylogenomic analysis of 67 public and 39 newly-sequenced strains, was used to construct an updated phylogenetic tree of Colwelliaceae, of which at least two genera were well represented. To augment the previously reported OGTs of 26 strains, we measured growth rates at −1, 4, 11, and 17 ℃ to determine the OGTs of these 39 new strains of Colwelliaceae. We found that growth rates among all isolates were comparable at −1℃, but varied widely above 10 ℃, indicating higher variability in the ability to tolerate warmer temperatures. To analyze the phenotypic differences on a genomic level, we examined indices of amino acid substitutions that have previously been linked with cold adaptation via an increase in protein flexibility. We found that these indices were significantly correlated with OGT at the whole genome level, although the sign of some correlations were opposite of the predicted positive correlation between temperature and the indices. Using these data, we fit a multiple linear regression model for OGT within the Colwelliaceae family that incorporates the three most informative amino acid indices: GRAVY, Aliphatic Index, and Acidic Residue Proportion. Additionally, a putative cold-adaptive gene cassette was identified that was likely introduced by horizontal gene transfer between two closely related clades with different OGTs. These contributions offer key insights into OGT variability and its underlying genomic foundation in the family Colwelliaceae.
    • Geochemical, spatial, and temporal relationships of the intrusives and meta-intrusives of the Pogo deposit, eastern Interior, AK

      Thompson, William D.; Newberry, Rainer; Keskinen, Mary; Mezger, Jochen (2020-12)
      The Pogo deposit is an intrusion-related gold deposit (IRGD) located approximately 90 km southeast of Fairbanks, Alaska. It consists mainly of shallowly NW dipping quartz veins hosted in amphibolite facies paragneiss and predominately granite orthogneiss bodies. To date the deposit has produced over 4 million ounces of gold. U-Pb zircon dating of the orthogneisses shows they have Devonian-Mississippian protolith ages. Dates from the metamorphic zircons, established by microprobe Th data and cathodoluminescence studies, constrain a mid-Cretaceous metamorphic event to ~116 Ma. Recrystallization of kyanite to sillimanite and zircon recrystallization indicates this was a large fluid flux event that predated mineralization by 10 million years. Due to the fine-grained nature of the intrusive rocks at Pogo, identifying rocks in hand sample proved problematic. By combining XRF analysis of the rocks' major and trace elements and age data from this and previous studies, I identified and differentiated several suites of igneous rocks. The oldest is peraluminous granite, emplaced at ~2.5 ± 0.5 kb at ~109-107 Ma, predating mineralization at 104 Ma at a pressure of 2.0 kb. Non-peraluminous granite is less common and of uncertain relationship to the peraluminous granite. Next, temporally, is a body named the Football pluton (and associated dike) of granodioritic to tonalitic composition, emplaced at 2.0 ± 0.5 kb at 103 ± 2 Ma. Not only indistinguishable from age and depth of mineralization, a dike of this body is present downdip underneath the Liese veins (main zone of mineralization), making it the most likely candidate for being the causative pluton for mineralization. The final mid-Cretaceous body is the Liese pluton (and associated dikes), of quartz diorite to tonalite. This forms a large body with E-W dikes cutting the Pogo mineralization and post-dating it at 95.4 ± 0.2 Ma, emplaced at a pressure of 1.0 kb. Thermobarometry and radiometric dating indicate a consistent uplift rate of about 0.6 mm/year during the mid-Cretaceous, 116 to 95 Ma. Initially an extensional event, subduction-related magmatism began at about 105 Ma. At the same time, the thrust faults were re-activated as low angle normal faults that apparently acted as pathways for the Liese mineralization.
    • Gravity and mountain waves and their phenomena in Fairbanks, Alaska: a comparative case study

      Brink, Hannah; Mölders, Nicole; Fochesatto, Javier; Polyakov, Igor; Newman, David (2021-05)
      The area of Fairbanks, Alaska is in a valley surrounded by mountains from the Alaska Range to the South, the Brooks Range to the north, and the eastern mountain range that extends into Canada. The topographical nature of this subarctic area brings unique atmospheric features to the Fairbanks area, such as temperature inversions and mountain wave perturbation. This thesis will examine two case studies of gravity wave phenomena; one a mountain wave from December 2017, the other a non-mountainous gravity wave from December 2016. Data was collected from radiosondes and Global Data Assimilation Model (GDAS) maps, with the former smoothed for comparative purposes. Profiles of the atmosphere were created to see direct changes that mountain waves create on atmospheric parameters and the subarctic valley area. Methods were explored to separate mountain wave buoyancy effects from other atmospheric buoyancy effects, and then used to compare mountain wave buoyancy effects with frontal motion buoyancy effects. In all cases, the polar jet stream was found to have signicant influence on gravity wave effects in the Fairbanks area. Attention to the polar jet stream location can help predict mountain wave effects and associated atmospheric perturbations. Weather phenomena localized by altitude due to gravity waves were also identified. These include localized short-term surface pressure systems on the day of gravity wave cases. Mountain waves were found to be strongly linked to synoptic temperature events in Fairbanks, Alaska, and the mountain wave case was found to have more pronounced atmospheric effects than the gravity wave case.
    • Growth and reproductive rates of calanoid copepods in the northern Bering and southern Chukchi Seas

      Poje, Alexandra; Hopcroft, Russ; Coyle, Kenneth; Danielson, Seth (2020-08)
      Egg production and copepodite growth rates were measured for the calanoid copepods Pseudocalanus spp., Calanus marshallae/glacialis, and Metridia pacifica in the northern Bering and southern Chukchi Seas during June of 2017 and 2018. For all taxa, instantaneous growth rates generally decreased with increasing copepodite stage, though the differences between most stages was not significant. The growth rates for Pseudocalanus spp. averaged 0.03 ± 0.002 day⁻¹, Calanus spp. 0.09 ± 0.004 day⁻¹, and M. pacifica 0.05 ± 0.03 day⁻¹. Egg production rates increased with prosome length for all species, but when standardized to body weight this trend reversed. All Pseudocalanus species had similar weight-specific egg production (SEP): 0.18 ± 0.01 for P. acuspes, 0.15 ± 0.00 for P. newmani, and 0.11 ± 0.02 for P. minutus. The SEP for Calanus was considerably lower, 0.09 ± 0.01, while for M. pacifica it was 0.11 ± 0.01. These rates suggest considerable discrepancies between growth rates and egg production weights that we propose are due to differences in life history strategies. Pseudocalanus reproduce nearly year round, they appear to invest less in somatic growth, preferring to quickly reach their adult stage where they invest heavily into reproduction. Calanus spp. have 1 or possibly 2 generations per year in this region, they invest more into somatic growth in order to ensure their population is ready for a reproductive season timed to the spring phytoplankton bloom. The more omnivorous M. pacifica is also likely limited to 1 or 2 generations, although their ability to thrive on a wider range of food sources than Calanus seems to allow for relatively higher investment in reproduction and perhaps lower investment in somatic growth. Consistent with other studies, global growth models do not match our observations particularly well, likely because they are dominated by egg production estimates at lower latitudes.
    • Habitat use of spectacled eider broods in relation to salinity and food availability on the Yukon-Kuskokwim Delta, Alaska

      Graff, Nathan R.; Lindberg, Mark; Hollmén, Tuula; Knut, Kielland (2021-08)
      Spectacled eiders (Somateria fischeri) nest and raise their broods in coastal areas of the Yukon-Kuskokwim Delta, which may be vulnerable to projected climate change effects of increased temperatures, storms, and sea level rise. These changes in turn will likely affect wetland salinity levels used by ducklings, which are a potential constraint to growth and survival of young ducklings while their salt glands develop. To examine this potential concern, I investigated spatial and temporal pond salinity dynamics, food availability, and habitat use of spectacled eider broods at Kigigak Island, AK during 2011-2012. I found that salinity was highly variable across the island, ranging from 0-23.9 ppt and averaged 4.9-12.9 ppt in ponds at brood observation sites during the first 30 days of brood rearing. Salinity typically increased through the summer across all habitat types, but at the highest rate in high sedge habitat. The most common invertebrate taxonomic groups included Eurytemora, Harpacticoida, Annelida, and Chironomidae, which were found in nearly all ponds sampled with salinity ranging from 0.7- 16.1 ppt. Neither salinity nor invertebrate abundance explained pond foraging use by broods. Additionally, I used robust design occupancy models to estimate brood foraging patterns. Pond occupancy ranged from 0.43-0.59 between years. Overall, brood use of ponds was not dictated by salinity levels or invertebrates present, suggesting that most ponds provide suitable brood rearing habitat. I did not detect any obvious constraint to pond use within brood rearing habitat under the environmental conditions encountered.
    • Health benefits of the hunter/gatherer lifestyle

      Coker, Melynda Sheri; Greenberg, Joshua; Brinkman, Todd; Duffy, Lawrence; Lindberg, Mark (2021-08)
      The Hunter/Gatherer Lifestyle has long been associated with positive health benefits. I measured specific metabolic parameters associated with this lifestyle, highlighting lean tissue preservation. Severe loss of lean tissue mass (LTM) (sarcopenia) is a progressive, multifactorial disease presenting with decreased functional performance, age-related bone loss, increased falls and fractures, obesity, type II diabetes mellitus, depression, hospitalization, and even mortality. Degradation of LTM, often accompanied with obesity, is cost-prohibitive emotionally, physically, and financially. To counteract LTM deterioration, a positive net protein balance (NB) must be created through increased protein synthesis or suppressed protein breakdown. I utilized isotope tracer infusion methodology to compare equivalent serving sizes of wild, freerange red meat (FR) to grain-fed commercial meat (CB) on human NB. I observed that FR elicited significantly higher NB than CB due to greater suppression of protein breakdown. I next asked if an unscripted 8-12-day Alaska expeditionary backcountry hunt (ABEH) for moose, caribou, and sheep hunters would be executed in negative energy balance and positively influence metabolic markers while maintaining LTM. I found that energy expenditure was far greater than intake and contributed to reductions in body weight, adipose tissue, serum lipids, and intrahepatic lipid, while preserving LTM. Finally, I asked if a proprietary drink with a unique amino acid formulation (EMR) similar to FR could elicit fat loss and LTM maintenance in a cohort unlikely to gain access to FR. EMR or Optifast® was provided once per day to obese, elderly individuals. With no additional manipulations and in one month, there was a net gain of thigh muscle cross-sectional area and significant reductions in total and visceral fat mass. Concluding, I sought specific metabolic outcomes derived from distinct aspects of the understudied hunter/gatherer lifestyle (i.e., FR, ABEH, EMR). I found positive influences on health which would contribute to LTM preservation during aging, decreasing individual, family, and societal burdens linked to loss of LTM. These findings provide increased emotional, physical, and financial value to the hunter/gatherer lifestyle.
    • Holy American burnout! - essays

      Enfield, Sean; Farmer, Daryl; Johnson, Sara; Schell, Jennifer (2021-05)
      Neither students nor educators are ever just the body which occupies a classroom. Both bring their personal histories as well as the socio-cultural and political climates in which they live. The essays in this collection explore the author's development as both a student and as an educator, revolving often around themes of race and religion. At the core of this narratively linked collection of essays is the author's first-year teaching experience in which he worked as an 8th grade literature teacher at a private, quasi-religious school. Cultural and music criticism provide the bridge by which these personal essays broaden their scope into their larger socio-political landscape. It evokes sources as disparate as the disgraced Disney film, Song of the South; Igor Stravinsky's ballet, The Rite of Spring; and the Pulitzer-winning hip hop artist, Kendrick Lamar. These sources serve as the prism with which the author navigates his personal experiences with racism and teaching Muslim students during the mounting of the 45th presidents anti-Islamic, anti-immigrant campaign. All in all, these essays seek to illuminate the many ways learn, develop, and relate to each other in America, looking for new ways to navigate this broken system which so often dead ends in burnout.
    • How aspen tree height influences aspen leaf miner (Phyllocnistis populiella) oviposition and performance

      Tundo, Giovanni; Doak, Pat; Wagner, Diane; Breed, Greg (2021-05)
      Under the optimal oviposition theory, insects are expected to lay eggs on hosts that maximize the success of their offspring. Tree height is known to be an important factor influencing the distribution of phytophagous insects because some species perform better at a distinct range of heights. This difference in performance could lead to incorrect estimates of population parameters if surveys are only conducted on one host plant height. Aspen leaf miners (Phyllocnistis populiella) have undergone a major outbreak in interior Alaska over the last two decades. We quantified patterns of aspen leaf miner oviposition and juvenile survival over 2 years and found that aspen leaf miners were approximately 1.5 times more likely to survive on tall trees than short trees. Parasitism and both egg and larval predation were lower on tall trees. Aspen leaf miners on tall trees also had larger pupal masses than those on short trees. Although aspen leaf miners performed better on tall trees, the number of eggs laid per leaf did not significantly differ by tree height. There were no significant differences in leaf foliar nitrogen between tall and short trees. We also found little differences in wind speed between tall and short trees that could explain ovipositional patterns. Ovipositional patterns may partially reflect the difference in phenology between tall and short aspen trees. Aspen leaf miners only lay eggs on new leaves. Tall aspen trees leafed out 7 days earlier on average than short aspen trees, and tall trees, unlike short trees, ceased to produce new leaves after budburst. Consequently, there was little overlap in the availability of tall and short aspen trees for oviposition, so even if aspen leaf miners have a preference for laying more eggs on tall than short trees, they can only act on it during the short time period when tall trees are available for oviposition. The results suggest that population projections based on data collected from only short trees may underestimate future aspen leaf miner population growth due to lower juvenile survival rates and pupal masses on short trees. More broadly, the results highlight the importance of examining multiple tree heights when studying the performance and population dynamics of phytophagous insects. They also suggest that phenological differences between plants may constrain insects from using higher quality hosts.
    • Human paleoecology from the late glacial to early holocene, Tangle Lakes, Alaska

      Darcy, Audra J.; Reuther, Joshua D.; Bigelow, Nancy H.; Clark, Jamie L. (2021-08)
      This study examines paleoenvironmental change from the Late Glacial to the Early Holocene in the Tangle Lakes region of interior Alaska to explore changes in resource distribution and impacts on prehistoric hunter-gatherer subsistence patterns in upland settings (>500 masl). In interior Alaska, prehistoric hunter-gatherer subsistence economies were organized around the procurement of large herbivores (bison, caribou, elk, and moose), which were primarily regulated by habitat availability. Changes in habitat availability altered the distribution of key faunal resources, necessitating shifts in land-use strategies. The palaeoecological record from Glacier Gap helps contextualize resource distribution within dynamic landscapes by identifying changes in habitat availability for grazing, mixed-feeding (bison, caribou, elk), and browsing (moose) herbivores. This study applies pollen analysis, as well as carbon and nitrogen isotope analysis, of lake and peat deposits to reconstruct paleoenvironmental change from ~14,000 to ~6,000 Cal yr. BP. Results indicate grazing habitats persisted until approximately ~13,500 Cal yr. BP, which allowed for initial expansions of bison and elk, but habitats became mixed following the appearance of birch shrubs. Existing archaeological data indicate that initial use of upland regions coincided with expansion of bison and elk habitat, which would have represented large-bodied, predictable sources of food. As shrubs continued to expand, grazing and browsing habitats became increasingly fragmented in a mixed-feeding period between ~13,000 to ~10,000 Cal yr. BP. Fragmentation of bison and elk habitats made these species less predictable on the landscape, which likely led to the abandonment of the Tangle Lakes. A shift from mixed-feeding to browsing habitats occurred following the Holocene Thermal Maximum at ~10,000 Cal yr. BP with increasing shrub growth and the expansion of peat, supporting caribou and moose populations. Settlement patterns indicate re-occupation of the Tangle Lakes, and intensified use of uplands, when browsing specialists became more predictable, and subsistence focus shifted to the procurement of caribou ~6,000 Cal yr. BP. Taken together, grazing and browsing habitats represent homogeneous environments where resources were more abundant and predictable for hunter-gatherers, while mixed-feeding habitats represent heterogeneous environments where herbivores were fragmented and less abundant or predictable on the landscape.
    • I hear what you're saying: evaluating the couple validation training (CVT), a brief behavioral intervention

      McKay, Jessica; Worrall, Michael J.; Gifford, Valerie; Lopez, Ellen; Eldridge, Gloria; Fitterling, James (2020-12)
      Couple distress has strong implications for individual, couple, and family functioning. Research has found couple relationship education to be an effective tool in alleviating couple distress, thus improving the quality of couple communication and problem-solving skills. Couple relationship education has been shown to be more cost-effective and less likely to provoke the typical fears couples face when considering couple therapy, increasing the likelihood of receiving needed help. This study used a brief, highly structured behavioral intervention to teach partners to identify and code effective and ineffective ways of communicating. The primary research question sought to determine whether learning a structured coding process would lead to observable behavior changes through increased use of validating communication behaviors and decreased use of invalidating communication behaviors during a conflict-based discussion with a partner. Secondary questions pertaining to effective communication, relationship satisfaction, and training satisfaction were also explored. Participants were 16 couples who identified as being in a committed (nonmarried), heterosexual relationship, ages 18-40 (M = 26.00, SD = 6.61), and who were interested in improving their communication skills. The study used a quasi-experimental, three-level multilevel model to assess for dependence and change in the dependent variable (communication behaviors) over time. Hypothesis testing using the multilevel model found a significant difference between intervention and control groups pre to post workshop. However, inconsistent with the hypothesis the control condition increased validations significantly while the intervention condition showed no significant change over time. No other significant difference between groups were found. Other areas of interest emerged from the data. Couples self-reported a benefit from engaging in the study; over 85% of couples reported feeling satisfied with their experiences in the workshop and gave positive feedback about their experience. Future studies may explore the mechanisms of change and the possibility of additional clinically relevant changes which are not measured in this study. Keywords: relationship education, couples, validation, invalidation.
    • Identifying spatial patterns of storm driven flooding and erosion at Nelson Lagoon, Alaska

      Bogardus, Reyce C.; Maio, Chris; Mann, Daniel; Overbeck, Jacquelyn (2021-05)
      This project quantifies localized potential for shoreline change and flooding at Nelson Lagoon, a small fishing community located on the Bering Sea coast of the Alaska Peninsula. The overall goal of this project is to generate societally relevant and locally applicable map and data products through synergistic relationships with federal, state, private, tribal, and public partners. This project intends to substantiate anecdotal observations by local residents, with the ultimate goal of informing erosion and flooding mitigation efforts moving forward. Long-term trends of shoreline change were measured using multi-temporal orthorectified aerial imagery between 1983 and 2019, while annual changes in shoreline morphology were measured via cross-shore elevation profiles using a survey grade Real-time-Kinematic Global Navigational Satellite System (RTK-GNSS). Shoreline positions were extrapolated using linear regression techniques. A digital surface model (DSM) of the community was derived using Structure-from-Motion (SfM) with >2,400 aerial images collected with an Unmanned Aerial Vehicle (UAV) and used to assess flooding vulnerability after being geodetically referenced and related to a local tidal datum computed by this project. New and existing topographic and bathymetric datasets were compiled and refined into a 6,000 km² topobathymetric "seamless elevation" model of the Nelson Lagoon area, over which storm-tide induced currents were simulated using Delft3D FM Suite HMWQ. Remote sensing records indicate that the Nelson Lagoon spit elongated by more than 800 m and narrowed with an average Net Shoreline Movement (NSM) of -16.9 m between 1983 and 2019 (distal end not included). Though, NSM values show high variability ([sigma] = 21.9 m) and the lagoon and seaward sides of the spit are exhibiting very different erosional regimes. On both sides of the spit, episodes of rapid erosion mainly occurred during high storm-tide events that coincided with significant wave action. For this reason, the long-term erosion rates ultimately reflect the combined erosional impact of just a few storm events. Sand dunes in the supratidal zone on both sides of the spit are eroding at the vegetation line while the dune face retreats landward. By assessing erosion and flooding vulnerabilities for the Nelson Lagoon community, this study adds to an ever-growing database of such assessments statewide; which, ultimately, advance our understanding of regional coastal change in a shifting environment.
    • If women were dragons: a study of the conquest of women and dragons in Ragnar's saga, the Volsunga sagas, and the Nibelungenlied

      Baalke, Claire-Elise A.; Harney, Eileen; Stanley, Sarah; Riley, Terry (2020-08)
      This thesis is a study displaying the connections between female characters and dragons in Old Norse and Middle High Germanic literature. The main associations that I examine are the ways that female characters and dragons share the characteristics of greed or hoarding, prophetic sight or supernatural power, and "monstrosity" or "Otherness." The fundamental argument is that the women and dragons have common characteristics which define them as dangerous and thereby cause the men or heroes of the tale to feel the need to silence or depower them through conquest. Typically, the dragon is the barrier between the woman and the hero in these kinds of stories and thus the dragon is violated or slain in a manner that represents quashing of feminine power. I argue that the dragon is defeated as proxy to the defamation or depowering of deviant female characters, non-conforming women who do not follow socially accepted gender roles. The texts used to present these arguments are The Poetic Edda, The Volsunga Sagas and its prequel Ragnar's Saga, and The Nibelungenlied. In the majority of dragon stories there is a direct relationship between a dragon and a female character, commonly a princess who is being protected or arguably kept captive by the dragon. I argue, however, that these characteristics of the dragon, which are imitated by female characters, can manifest metaphorically as well. In the texts considered in which there are no "real" or physical dragons, a woman stands in as the metaphorical dragon that must be defeated.
    • Iliamna Lake ethnogeography: Yup'ik place names and sense of place

      Kugo, Yoko; Charles, Walkie; Ehrlander, Mary; Holton, Gary; Koskey, Michael; McCartney, Leslie (2021-05)
      This dissertation explores Iliamna Lake ethnogeography, the physical and mental understanding of the landscape, by researching Yup'ik place names and stories about these places from Iliamna Lake Yup'ik perspectives (Yupiit iingitgun). Many Yup'ik place names were forgotten after Euro-Americans arrived and introduced modern education in the early twentieth century. Some Iliamna Lake Yup'ik Elders remember Indigenous place names even though the subsistence resources in the places have declined or they no longer travel there due to environmental and cultural changes. Prompted by the declining population of Iliamna Lake Yup'ik speakers, along with their knowledge, the Iliamna Lake communities requested this study of Iliamna Lake Yup'ik place names and narratives about the places. Using two methods, oral history and a community-based participatory approach, the community participants and the author recorded 219 Yup'ik and over 100 contemporary place names during eight ethnographic field trips conducted from 2016 to 2019. This dissertation used two analytical methods--grounded theory and mindful inquiry--to categorize place names in themes that are relevant to Iliamna Lake community perspectives. This research revealed that place names and stories about these places illustrate community histories, lifeways, and cultural ethics and practices that are grounded in the people's intimate relationships with their homeland. Telling and retelling these stories enables the people to visualize their landscape, while affirming and reinforcing the knowledge and practices that have enabled the Yup'ik people to survive and thrive in the region for many generations. Ethnogeography addresses how these cultural landscapes intertwine with local histories and changes in land use from insider perspectives. Yup'ik names and stories related to these places act as mnemonic pegs or mental landmarks that assist the people in commemorating and continuing to navigate within their homelands. Maintaining their place names with accounts about these places supports Iliamna Lake residents in continuing to share their geographic knowledge, cultural practices, Yugcetun (Central Yup'ik language), and community histories, thereby enhancing community cohesiveness, which in turn promotes community and ecological well-being.
    • Impacts of climate change on juvenile broad whitefish Coregonus nasus in Arctic Alaska: bioenergetics model development and application

      Green, Duncan G.; Sutton, Trent M.; Norcross, Brenda L.; Cunningham, Curry J. (2020-08)
      Anthropogenic climate change is contributing to rising temperatures worldwide, yet the increase is particularly rapid in the Arctic. Despite their position on the front of global temperature warming, the responses of Arctic ecosystems and the individual species within them are poorly understood. Broad whitefish Coregonus nasus in the Alaska nearshore Beaufort Sea not only inhabit a rapidly changing ecosystem, but are also a key component of subsistence harvest in the region and a relatively understudied fish. I parameterized and corroborated a bioenergetics model through species-specific physiological investigation and laboratory rearing trials, and used the resulting model to simulate potential responses in growth and consumption under climate change scenarios projected with global climate models. Simulations at current estimated prey energy densities projected increases in future consumption rates of up to 4% required to maintain historically observed summer growth, while simulations in which prey energy density was reduced by 50% resulted in projected consumption increases of up to 107% necessary to maintain historic growth. Simulations in which prey energy density was increased by 50% indicated the ability for juvenile broad whitefish to reduce consumption rates by up to 32% and maintain current growth rates. These results suggest that, although the physiological effects of rising water temperatures have the potential to increase growth rates of juvenile broad whitefish, climate-induced shifts in prey availability or prey quality are likely to be regulating factors that determine the magnitude and direction of changes in growth rates.
    • Impacts of climate change on mass movements in Denali National Park and Preserve, Alaska

      Robert, Zena V.; Mann, Daniel; Farquharson, Louise; Romanovsky, Vladimir; Meyer, Franz; Maio, Chris (2021-08)
      The northeastern portion of Denali National Park and Preserve (DENA) is a high-altitude (800 m - 1400 m asl), subarctic (63°N) environment where climate is now changing rapidly. This landscape is underlain by discontinuous permafrost (perennially frozen ground), and the recent surge of mass movements occurring there could be the result of permafrost thaw. Some of these mass movements have the potential to damage the Denali Park Road, alter the flow of groundwater and stream systems, destroy vegetation cover, and endanger the half a million visitors that DENA receives every year. The purpose of this study to understand how mass movements in DENA are being affected by different aspects of climate change, to assess the role of permafrost thaw in their dynamics, to determine when DENA's landscape experienced periods of geomorphic instability in the past, and to better understand the potential trajectory of the landscape changes now occurring. Results show that many ongoing mass movements in DENA are reactivations of landslides that were active earlier in the Holocene (the last 11,700 years). A representative example is the Mile 35 landslide, a complex mass movement initiated along the Park Road during the summer of 2016 after a quiescent period of around 4000 years. I use a combination of remote sensing and field surveys to establish a four-year timeline of this landslide's movements and then compared these observations to records of weather and climate. Results suggest that freeze/thaw processes and extreme rainfall events strongly affect the initiation and subsequent movements of the Mile 35 landslide. Looking farther back in time, lichenometric dating of rockfalls in DENA suggests their frequency peaked 100 to 200 years ago during the initial stages of climate warming at the end of the Little Ice Age. These findings suggest that warming climate triggers a predictable sequence of mass movement responses in DENA, with the initial warming triggering a bout of more frequent rockfalls, and then, as warming penetrates deeper into the ground, causes deep-seated mass movements like the Mile 35 landslide. These results suggest that cycles of hillslope stability and instability in response to climate change are characteristic, long-term features of DENA's ecosystems and dynamic ecosystems and landscapes.
    • Impacts of cover cropping and tillage on weed populations and soil nutrients in a sub-Arctic environment

      Carr, Erin L.; Zhang, Mingchu; Seefeldt, Steven; Sparrow, Stephen (2021-08)
      One of the biggest challenges for organic crop and vegetable producers is weed control. Traditional practices, such as cover cropping and tilling, aid in controlling weeds on fallow land. However, both methods can impact soil nutrient availability. For producers in sub-Arctic regions with a limited growing season, such as interior Alaska, these practices would remove valuable farm land from production for at least a year and potentially impact soil nutrients. The objective of this study was to determine cover cropping and tilling intervals that would reduce weed seedbank size without negatively influencing soil nutrient availability and taking land out of production for multiple growing seasons. A two year (2008 and 2009) study at two interior Alaska farms (UAF-AFES and Rosie Creek) measured weed density, weed seedbank size, and extractable macro and micro soil nutrients at two soil depths (0-15 cm, 15-30 cm) among seven treatments: continuous tillage (TILL), continuous cover crop (CC), tillage + middle season cover crop (TC), and cover crop + middle season tillage (CT). Two species, Hordeum vulgare L. (Albright barley) and Pisum sativum subsp. Arvense (Austrian winter field peas) were planted as cover crops. Field weed estimates were measured prior to treatment applications (tillage or planting) followed by soil core samples post treatment for weed seedbank analysis. Soil cores were collected for soil nutrient analysis at the beginning, middle and end of the growing season. In 2008 at UAF-AFES, weed density among treatments were different mid-season (p<0.05) and the subsequent growing season (p<0.05), TILL and TC treatments reduced weed populations. Weed seedbank size was different among treatments the subsequent growing season (p<0.05). In 2008 at Rosie Creek, only the subsequent growing season were there differences among treatments (p<0.05). In 2009 both study sites had no differences among treatments at any sample period. Extractable soil nutrients varied among location, year and soil depth. The highest concentrations of nitrate (NO₃-N) were measured in the tillage treatments and the lowest concentrations of NO₃-N were measured in the cover crop barley treatments (p<0.05). The research suggested that continuous tillage and tilling through the first half of the growing season has a greater impact on reducing the weed population, but can impact soil nitrate concentrations. Producers may be able to till and cover crop within one growing season, but this is highly dependent on weed density and there may be a loss of soil available nutrients for subsequent crops.
    • In pursuit of harm reduction in the Alaskan context: patient cultural explanatory models of addiction and treatment outcomes for a medically-assisted program utilizing a buprenorphine/naloxone formulation

      Vasquez, Ángel R.; Campbell, Kendra; Lopez, Ellen; Gifford, Valerie; Gonzalez, Vivian (2020-08)
      This study explored the process of completing a private-for-profit medically-assisted treatment (MAT) program which treats opioid use disorder in a semi-rural community in Alaska. The goal of the study was to answer two broad research questions: (a) did patients get better during the medically-assisted treatment program, and (b) what characterized patient experiences participating in the MAT program? Limited research has been conducted to understand patient experiences of completing medically-assisted treatment in small communities and how various factors may impact treatment outcomes and recovery trajectories. To achieve this goal, a mixed methods case study approach was conducted to evaluate changes in symptom distress and characterize the experience of patients who participated in the program. Three Phases were implemented. Phase I involved archival data analysis of a 22 patient dataset was conducted to assess pre-post treatment outcomes. In Phase II three participants were interviewed who initiated in the program to explore patient treatment themes. Phase III involved co-interpretation of preliminary findings MAT program providers to synthesize findings and gain insights into systemic factors that may have impacted participant experiences. The three-phase research study revealed three major findings. First, MAT patient program completers in our sample who utilized buprenorphine/naloxone in conjunction with counseling experienced a statistically significant reduction in psychological distress with a large observed effect size (Phase I). Second, themes that emerged from semi-structured interviews suggest motivation and treatment process factors play an important role in treatment success (Phase II). Finally, community stakeholders on the provider treatment team were consulted to more deeply understand why it is important to assess patient needs and co-interpret key study findings (Phase III).
    • Influence of environmental attributes on intertidal community structure in glacial estuaries

      McCabe, Mary K.; Konar, Brenda; Iken, Katrin; Kelley, Amanda (2021-05)
      High-latitude coastal environments are experiencing dramatic changes due to climate warming. Increased glacier discharge rates modulate downstream environmental conditions in coastal watersheds. These fast-changing environments are predicted to influence the structure of nearshore marine communities. Here, rocky intertidal community structure, recruitment of key organisms, and environmental correlates were examined at nine watersheds in two regions (Kachemak Bay and Lynn Canal) that bookend the Gulf of Alaska, which were separated by approximately 1000km. Each watershed was part of a gradient in each of the regions that spanned 0-60% glacial coverage. Percent cover, biomass surveys, and recruitment of intertidal organisms, along with environmental monitoring of salinity, temperature, dissolved oxygen, river discharge, turbidity, and nutrient loading were completed from April - September 2019 in each watershed. Biological community structure and variance were analyzed by taxa and by ecological group (i.e., primary producer, filter feeder, omnivore, grazer, predator) and then in relation to the local environmental spatiotemporal profiles. In general, larger watersheds with more glacial coverage and river discharge resulted in higher cover of primary producers and less cover of filter feeders. This pattern was more apparent in the region with more oceanic influence as compared to the other region located within an inlet. In relation to specific environmental drivers, salinity was negatively correlated with primary producer cover (r = -0.52), but positively associated with barnacle cover (r = 0.40). Additionally, turbidity was positively correlated with primary producer biomass (r = 0.50), but negatively correlated with mussel cover (r = -0.30). In contrast, there was a positive relationship among mussel recruitment and discharge and turbidity. There was variability in within-ecological group response between regions that could be a response to local circulation and oceanic influences. Barnacles were the main filter feeder species driving patterns in the more saline region located close to the open ocean, while mussels drove patterns in the other less oceanic region. As glaciers recede, environmental conditions, such as salinity, will increase and turbidity will decrease, which may alter future intertidal community assemblages dominated by filter feeders.