• 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.
    • Integration of remote sensing technologies into Arctic oil spill response

      Garron, Jessica I.; Meyer, Franz; Trainor, Sarah; La Belle-Hamer, Nettie; Lee, Olivia; Mahoney, Andrew (2020-12)
      Identifying the tools and pathways to successful integration of landscape level science into decision-making processes is vital for quality environmental stewardship. Remote sensing information can provide critical facts to decision makers that historically were only available via manned airplane flights and ground truthing expeditions. Remote locations like the Arctic are well suited for monitoring with remote sensing tools due to the lack of transportation infrastructure and communications bandwidth. Remote sensing tools can be valuable when monitoring specific Arctic targets like ocean going vessels, sea ice, coastal erosion, off-shore resource development infrastructure, and oil spills. This dissertation addresses how to mount a more efficient and informed response to Arctic oil spills by capitalizing on available RS tools. I posed three research questions to frame this work, 1) What remote sensing tools are currently available, as compared to those currently used in the Incident Command Structure of an oil spill response? 2) Are there barriers to additional remote sensing tool use for oil spill response support? 3) What process changes can improve or increase remote sensing data use in oil spill detection and response? I conducted a four-phased, exploratory sequential mixed methodological study to examine current remote sensing capacity and solutions to expand remote sensing use in support of oil spill response. Phase One defined the remote sensing tools available to support oil spill response, identified how those tools are being used in support of oil spill response actions, and was used as the foundational research to inform the following phases of the study. Phase Two used cloud-processing resources to establish an automated oil detection pipeline. Phase Three addressed human-driven barriers to remote sensing tool use identified in phase one through remote sensing tool training, knowledge coproduction, and remote sensing data integration into oil spill response exercises. Synthesizing all components of Phases One, Two and Three, a remote sensing protocol for the use of unmanned aircraft systems in support of oil spill response was developed and integrated into U.S. Coast Guard operational policy in Alaska to complete Phase Four of this research. This research identifies opportunities and solutions that support improved Arctic oil spill response decision-making through the application of remote sensing data and information.
    • Interpretations of climate change on grazing systems: the comparison of Arctic and Subarctic carex

      Harritt, Iris Cato; Wolf, Diana; Ruess, Roger; Takebayashi, Naoki; Flint, Paul (2022-05)
      Stresses imposed by climate change are altering arctic and subarctic ecosystem structure and function. On the Yukon-Kuskokwim River Delta (YKD) in subarctic western Alaska, Pacific Black Brant geese (Branta bernicla nigricans) are losing their available grazing lawns of shortstatured Carex subspathacea due to its conversion into a taller, less nutritious growth form. However, C. subspathacea on Alaska's Arctic Coastal Plain (ACP) grows in extensive lawns that remain short even when ungrazed. Our goal was to compare the growth responses between arctic C. subspathacea and subarctic C. subspathacea when grown in arctic and subarctic conditions. We used reciprocal common gardens to study the variation in height, tiller density, aboveground biomass, and green leaf nitrogen percentage between these reputed taxa. We explored the growth responses that occur in C. subspathacea when grown in the arctic and subarctic using linear mixed effect models. We found that environmental differences between these regions influence the morphology of these taxa. Subarctic C. subspathacea is phenotypically plastic, and was able to grow tall in subarctic conditions, while remaining short in the Arctic. However, arctic C. subspathacea was short in both gardens, suggesting arctic C. subspathacea will not grow tall under warming conditions. Understanding the functional causes of the difference between these two grazing systems is important for predicting the effects of future climate change on both regions. This study provides insight to how changing climate will impact these different growth forms and affect future grazing dynamics along arctic and subarctic coasts.
    • Investigation of variability of internal tides in the Tasman Sea

      Brazhnikov, Dmitry; Simmons, Harper; Kowalik, Zygmunt; Johnson, Mark; Marchenko, Alexey; Horrillo, Juan J. (2021-05)
      Surface tides, when obstructed by bottom relief, give rise to periodic oscillations within the stratified oceanic interior. Such transformation of the depth independent (barotropic) tide into internally propagating (baroclinic) waves comprises 1/3 of the global energy losses from the surface tide. Internal waves of tidal period known as internal tides tend to have low vertical shear and hence are very stable and long lived. They have been observed to propagate essentially unchanged across ocean basins. Details of the internal tide wave life-cycle are not well known, yet turbulent dissipation powered by the slow decay of these waves is one of the key processes shaping deep ocean water properties. The Tasman Sea stands out as a natural laboratory to investigate the internal tide life cycle. In this dissertation, the generation and propagation of internal tides were examined by means of realistic simulations of ocean circulation under varying conditions, and were compared to observations obtained during the Tasman Tidal Dissipation Experiment (TTIDE). The simulations reveal that the barotropic-to-baroclinic conversion is intensified at the Macquarie Ridge near New Zealand by coupling with secondary, nonlocally produced internal tides. Because of this complexity, regionally varying hydrographic conditions drive remarkable temporal and spatial variability of internal tide generation. The internal tides that are created at the ridge constructively superpose into a spatially confined, beam-like feature (Tasman beam) that radiates across the Tasman Sea over 1000 kilometers from its generation region and reaches the Tasman shelf. The beam is described well at first order by simple plane wave propagation theory, but also exhibits non-plane wave characteristics associated with diffraction. Additional intricacy arises from development of a standing wave, the result of the beam's reflection near Tasmania. Temporal changes include hydrography-induced refraction and strong perturbations from interactions with eddies. It is concluded that in-situ mooring measurements and ship surveys of internal tides exhibit a great deal of apparent spatial and temporal variability that can be difficult to interpret. This variability can largely be eliminated in the analysis of numerical models which allow the underlying wave field energy life cycle to be quantified.
    • Investigations on the impacts of ship traffic in the Bering Sea on aerosol optical depth using automatic identification systems data, and MODIS collection 6.1 data

      Summers, Tyler; Mölders, Nicole; Friberg, Mariel; Fochesatto, Javier (2021-05)
      Increasing Arctic shipping requires study of the increasing aerosol emissions impact on aerosol optical depth (AOD) in the Bering Sea and the Bering Strait. This study used Moderate Resolution Imaging Spectroradiometer (MODIS) 550 nm AOD 3 km products to study the seasonal variability over the length of the Arctic shipping season, from June to October, over 2011 and 2014. Bucket resampling was used to project and downscale the MODIS AOD to a 0:25 by 0:25 grid during overpasses. An overpass is dened as consecutive MODIS granules from both the Terra and Aqua satellites. Ship positional data obtained from automatic identication systems (AIS) was aggregated to hourly data. Collocation of ships and AOD from overpasses were determined for all quarter degree grid cells and times. Area-weighted means for both grid-cells with ship occurrence and without ships were determined for each month. AOD decreases with increasing time in the shipping season due to the increasing frequency of low pressure system and hence aerosol removal via washout and scavenging. Comparison of the AOD of 2011 and 2014 revealed that the position of the Aleutian Low not only strongly aects the sample size, but also AOD over the Bering Sea. The sea-ice area seemed to be without notable impact on the number of ships and AOD. A weak positive correlation was found between AOD and the number of ships present in the same grid cell during a overpass for 7 out of the 10 months. A strong skewing towards October occurred in 2011 due to a strong positive correlation of the number of data points.
    • It's complicated: immigrant parents in Alaska navigating the process of raising bilingual children

      Dosch, Katerina; Sickmann, Sabine; Marlow, Patrick; Martelle, Wendy (2021-05)
      This qualitative study investigates the process of raising bilingual children in Fairbanks, Alaska. The study was guided by an overarching question: Why do some children in bilingual families become bilingual speakers, whereas other children who also have the chance to become bilingual do not? From that, two main research questions have evolved. 1. What are the elements involved in raising bilingual children in Fairbanks, Alaska as reported by the parents? 2. What is the role of a family's place of residence on their children's bilingualism? Data were collected through a socio- demographic questionnaire, semi-structured in-depth interviews, and focus groups. Three rounds of interviews were conducted with each participating family - an initial interview, a follow up interview, and a focus group interview. Seven families participated in the study and only parents were interviewed. These families consisted of either first generation immigrant parents (sharing or not sharing the same native language) or parents in mixed marriages (immigrants married to native- born Americans). Over 19 hours of data were audio recorded, manually transcribed ad verbum, and analyzed. From the method of grounded theory data coding, groups of elements that are involved in the process of raising bilingual children and the development of children's heritage language (HL) emerged, namely: parental and children's HL related actions, factors influencing bilingualism, factors determining bilingualism, and place of residence. The findings suggest that the process of raising bilingual children is positively or negatively influenced and determined by a complex net of interconnected elements. Raising bilingual children, thus, rests on a combination of supportive and detrimental elements, which are in a constant struggle. It seems that the process of raising bilingual children can absorb a certain amount of detrimental elements without collapsing. Considering the elements involved in raising bilingual children, it is not only parents and their actions that play an important role in the process of raising bilingual children. While parents are the instigators of the process, children greatly influence parental actions connected to the transmission of the HL. The findings of this study suggest though, that children and their actions alone do not decide if the process fails or succeeds. Parents seem to be able to mitigate children's detrimental influences (if they exist) through their consistent use of the HL. On the other hand, some parents hinder their own efforts either through their fears, beliefs, or other personal limitations. Finally, based on the data, place of residence does not seem to play a significant role in the process. Some parents are able to raise bilingual children despite living in a place that poses challenges to bilingual families. These parents are able to overcome obstacles through their own efforts and consistency of the HL use.
    • Landscape characteristics influence climate change effects on juvenile chinook and coho salmon rearing habitat in the Kenai River watershed

      Meyer, Benjamin; Rinella, Daniel; Wipfli, Mark; Schoen, Erik; Falke, Jeffrey (2020-08)
      Changes in temperature and precipitation as a result of ongoing climate warming in south-central Alaska are affecting juvenile salmon rearing habitat differently across watersheds. Work presented here simulates summer growth rates of juvenile Chinook and coho salmon in streams under future climate and feeding scenarios in the Kenai River (Alaska) watershed across a spectrum of landscape settings from lowland to glacially-influenced. I used field-derived data on water temperature, diet, and body size as inputs to bioenergetics models to simulate growth for the 2030-2039 and 2060-2069 time periods, comparing back to 2010-2019. My results suggest decreasing growth rates under most future scenarios; predicted changes were of lower magnitude in the cooler glacial watershed and main stem and more in montane and lowland watersheds. The results demonstrate how stream and landscape types differentially filter a climate signal to juvenile rearing salmon habitat and contribute to a broader portfolio of habitats in early life stages. Additionally, I examined two years of summer water temperature data from sites throughout our study tributaries to assess the degree to which lower-reach sites are representative of upstream thermal regimes. I found that the lower reaches in the lowland and glacial study watersheds were reasonably representative of daily and seasonal main stem thermal conditions upstream, while in the montane study watershed (elevation and gradient mid-way between the lowland watershed) upstream conditions were less consistent and thus less suitable for thermal characterization by a lower-reach site alone. Together, this work highlights examples of the importance of accounting for habitat diversity when assessing climate change impacts to salmon-bearing streams.
    • Liberal deradicalization in the adaptation of novels to film: defining antiheroes, from Heathcliff to Walter White

      Kraft, Benjamin; Carr, Richard; Hirsch, Alexander; Harney, Eileen (2021-08)
      Using research from the history of the Victorian novel and recent media, I demonstrate the value in re-examining the critical importance of the antihero. Using a methodology of combining neo-Marxian analysis, adaptation studies, and a re-thinking of what constitutes novels and television serials, I explore how antiheroes are defined and why those definitions are often not inclusive to controversial, but seemingly definitional antihero examples. As informed by a critique of how antiheroes are defined, I use my research to discuss the underlying characteristics of the antihero across genres. From a perspective of critiquing liberalism adopted from Emily Brontë's Wuthering Heights and Vince Gilligan's Breaking Bad, I structure textual evidence in support of antiheroes being identified according to three traits: sympathy, violence, and radical speech. The literary and real-world impact of each trait is argued according to evidence qualified by a neo-Marxian methodology, using an original synthesis of Louis Althusser's aleatory politics and the Marxist cultural critiques of Raymond Williams. Finally, these three traits are strongly evinced in the real-world systemic critiques of liberalism represented in both Heathcliff and Walter White.
    • Life cycles of the kelps Saccharina latissima and Alaria marginata: implications for mariculture and ecology in Alaska

      Raymond, Annie E.T.; Stekoll, Michael S.; Eckert, Ginny L.; Bergstrom, Carolyn A. (2020-08)
      Kelp farming has the potential to economically diversify coastal communities of Alaska while offering other ecosystem services, including carbon sequestration and mitigation of eutrophication. Two bottlenecks to the expansion of the industry are understanding the natural kelp life cycle and manipulating the life cycle to produce seed. We address these questions with specific research aimed to increase knowledge of the expected natural variability of the kelp life cycle and test methods to effectively manipulate storage of kelp seed string to add flexibility to the kelp farming industry. First, in Chapter 1, we documented the patterns of sporophyte fertility for two commercially important kelp species, Saccharina latissima and Alaria marginata, in the wild. We found S. latissima exhibited both annual and perennial life history varying by location and year, with an increasing proportion of fertile sporophytes present in the fall and winter season. In contrast, A. marginata displayed a predictable annual life history, recruiting in spring with the proportion of fertile sporophytes increasing into the fall. Results from Chapter 1 suggest A. marginata has a more reliable brood stock availability and, therefore, has the potential to be a suitable commercial crop. Ecologically, Chapter 1 results suggest A. marginata may contribute consistently to habitat across Alaska in spring and summer months. In Chapter 2, we tested how different culture conditions, including light, temperature, and culture media, affected gametophyte growth with the goal of developing storage methods for kelp seed string. We found that low temperature is effective in slowing gametophyte growth and reducing gametogenesis and is the best condition for seed storage. Further experiments tested how storage in cold temperatures affects seed quality, leading to the development of a method called "cold banking," which enables extended seed storage or staggering of seed string for at least an additional thirty-six days in a storage setting without adverse effects to sporophyte density and length at the time of outplanting and up to three weeks after outplanting. Ecologically, Chapter 2 results demonstrate the diversification of microscopic stages used as an overwintering strategy by S. latissima. As the kelp mariculture industry is expected to grow in Alaska and around the world, we hope this information will be a jumping-off point for research promoting productive and sustainable commercial kelp production.
    • The linguistic dreamstate: Freud, Lacan, and intertextuality in Samuel Beckett's The Unnamable

      Kay, Michael R.; Coffman, Chris; Holt, Joseph; Carr, Richard; Brightwell, Gerri (2022-05)
      This thesis focuses on the process of symbolization and signification in Samuel Beckett's novel, The Unnamable. The introduction presents readers with important and relevant critical interpretations of the novel, primarily those that are focused on the self, the use of language, and psychoanalytic theory. Then, the thesis introduces readers to key concepts in semiotic and psychoanalytic criticism, such as that of the signifier, sign, big-O Other, and the Lacanian Imaginary, Symbolic, and Real, by applying these concepts to a reading of The Unnamable. The next section, "The Linguistic Dreamstate," argues that the novel's narrator occupies a state tangential to consciousness, subconsciousness, and unconsciousness. In occupying this state, one that is outside of physical reality, the narrator is confronted with a language he does not understand and, while speaking, seeks to understand what he has previously said, mirroring the process of psychoanalysis as it concerns the meaning of dreams. Finally, it is shown that the narrator attempts to use language to as a means to stop using language. In so doing, the narrator illustrates the inability of language (and the Symbolic) to reconstruct the Real, and the innate desire for the Real (or objet a) even in those who do not have a reality within which they see the lack of the Real.
    • Lipid accumulation in three species of Neocalanus copepod in the northern Gulf of Alaska

      Coleman, Delaney M.; Hopcroft, Russell; Danielson, Seth; Hennon, Gwenn (2022-05)
      The Northern Gulf of Alaska experiences pronounced seasonality and inter-annual variability characterized by a significant bloom of phytoplankton in the spring. Neocalanus copepods in the NGA have evolved to match their lifecycle to the seasonality of the Gulf of Alaska and feed upon the spring phytoplankton bloom. All three of these Neocalanus species utilize diapause as an over-wintering strategy; acquiring large stores of lipid to sustain them through winter hibernation and subsequent reproduction. Zooplankton were sampled with 150 and 505 µm mesh nets from 0 to 1200 m along the Seward Line and within Prince William Sound in the Northern Gulf of Alaska during 2018-2020 to track the physiological process of Neocalanus copepods preparing for diapause. We measured lipid sac area, lipid volume and percent lipid to quantify lipid content. Neocalanus showed significant interannual variability in final lipid accumulation both at depth and in the surface during the study period. For all three species, lipid content increased with increasing stage and prosome length. Lipid content increased from spring to summer for N. flemingeri, remaining steady into fall as animals molted into adults and descended to depth for diapause. Neocalanus plumcrhus stored lipid from spring to summer before descending slightly after N. flemingeri. Neocalanus cristatus exhibited dissimilar behavior to the other two species, storing consistently low amounts of lipid, alluding to a different lifecycle. Each Neocalanus species displayed similar lipid accumulation behavior with offset timing from one another. Neocalanus exhibits an earlier developmental timing as compared to other lipid accumulating copepods giving them a competitive advantage to reach maturity in time to feed on the early phase of the spring phytoplankton bloom faster than other species. Our data provided some evidence for both the lipid accumulation hypothesis and the developmental program hypothesis being utilized in Neocalanus populations in the Northern Gulf of Alaska. This work serves as the first detailed study of body condition and lipid sac condition in Neocalanus populations throughout the water column within the Northern Gulf of Alaska.
    • Long-term shifts in community structure, growth, and relative abundance of nearshore Arctic fishes: a response to changing environmental conditions

      Priest, Justin T.; Sutton, Trent M.; Mueter, Franz J.; Raborn, Scott W. (2020-08)
      Environmental conditions influence the presence, species composition, abundance, and growth of fish species in the nearshore Arctic ecosystem. With ongoing shifts in Arctic conditions due to climate change, how fish communities and individual species respond to such changes to environmental variability more broadly is unknown. This study analyzed catch and length data from a long-term fish monitoring project near Prudhoe Bay, Alaska, 2001-2018, to quantify the effects of environmental variables on the overall fish community and on the juveniles of two important whitefishes, Arctic Cisco Coregonus autumnalis and Broad Whitefish Coregonus nasus. Abundance data (n = 1.78 million fish) from daily sampling (July-August) at four stationary sampling locations showed distinct shifts in fish community metrics. Since 2001, annual species richness has significantly increased by one species per decade while water temperature warmed by over 1.4°C. The species composition based on biweekly catch data has significantly changed across years, with distinct variations among sample locations and throughout the season. Species composition was significantly affected by both salinity and water temperature. The effects of environmental conditions on growth showed that water temperature was positively and linearly associated with increases in growth for juvenile whitefish, while salinity negatively affected growth of age-0 Arctic Cisco. Changes in the abundance of juvenile whitefishes were related to both water temperature and salinity. Results from all analyses suggest that species positively associated with observed warming in the aquatic environment are generalist species such as Broad Whitefish. This study concluded that continued climate change, and especially Arctic warming, will likely increase growth, change the species composition, and alter abundance in the Arctic nearshore ecosystem. These changes will have impacts on subsistence harvests and on upper trophic level species that prey on nearshore fishes.
    • Marine debris in the Bering Sea: combining historical records, toxicology, and local knowledge to assess impacts and identify solutions

      Padula, Veronica M.; Beaudreau, Anne; Causey, Douglas; McDonnell, Andrew; Konar, Brenda; Hollmen, Tuula (2022-05)
      Marine debris, particularly plastic marine debris, has numerous impacts on the environment, wildlife, and human communities. This research examines dimensions of marine debris in the Bering Sea and Aleutian Islands, Alaska, including impacts of marine debris pollution on wildlife and the environment; the history of marine debris research, monitoring, and cleanup activities; and community perspectives on local to global solutions. The first chapter of this dissertation is an integrative literature review to better understand the current status of marine debris knowledge in the Bering Sea region and identify critical knowledge gaps. We synthesized the depth and breadth of research, monitoring, and cleanup activities to better understand the sources, prevalence, and impacts of marine debris on wildlife and coastal communities. Our review revealed several knowledge gaps, including two that were a focus of the final chapters of the dissertation: measuring the extent of plastic-associated contaminants in the Bering Sea and capturing community perspectives and concerns about marine debris in the Bering Sea. The second chapter examined variation in phthalates, a class of plastic-associated chemicals, in Aleutian Islands seabirds, to refine hypotheses regarding ecological and environmental factors that affect phthalate exposure in marine wildlife. We quantified phthalates in seabirds collected across >1700 km of the Aleutian Islands, Alaska, and measured six phthalate congeners in seabirds representing ten species and four feeding guilds. Phthalates were detected in 100% of specimens (n = 115) but varied among individuals (range 3.64 - 539.64 ng/g). Total phthalates did not vary geographically, but differed among feeding guilds, with significantly higher concentrations in diving plankton-feeders compared to others. Our findings suggest feeding behavior could influence exposure risk for seabirds and lend further evidence to the ubiquity of plastic pollutants in marine ecosystems. The final chapter of the dissertation explored perspectives and concerns of St. Paul Island community members regarding marine debris and plastic pollution. This component of the research aimed to catalyze the inclusion of local knowledge in marine debris solutions for St. Paul Island, Alaska, by documenting community members' perceptions of marine debris, including its origin, impacts, and proposed solutions. We interviewed thirty-six St. Paul Island community members from 2017 to 2020 about the types, amount, distribution, and impacts of marine debris they have observed on the island and its surrounding waters over recent decades. Research participants reported increases in plastic debris since the 1980s, particularly plastic bottles. Nearly 80% expressed concern about impacts to subsistence resources, including entanglement and ingestion of plastic particles by marine mammals and fishes. St. Paul Island community members' experiences highlight that solving the problem of marine debris cannot rely on local efforts alone but requires broader policies and mitigation strategies to address the sources of debris and advance environmental justice for coastal communities. Overall, this dissertation contributes an improved understanding of the social and ecological impacts of plastic pollution in the Bering Sea region and the potential science and policy solutions that can stem the tide of marine debris.
    • Melt on Antarctic ice shelves: observing surface melt duration from microwave remote sensing and modeling the dynamical impacts of subshelf melting

      Johnson, Andrew Carl; Hock, Regine; Fahnestock, Mark; Aschwanden, Andy; Bueler, Ed (2021-12)
      Melt on the surface and underside of Antarctic ice shelves are important to the mass balance and stability of the ice sheet, and therefore pose significance to global sea levels. Satellite-based passive microwave observations provide daily or near-daily coarse resolution surface observations from 1978 on, and we use this record to identify days in which melt water is present on the ice sheet and ice shelf surfaces, called melt days. There are significant differences in the results of melt detection methods however, and we evaluate four different passive microwave melt detection algorithms. There is a lack of sufficient ground truth observations, so we use Google Earth Engine to build time series of Sentinel-1 Synthetic Aperture Radar images from which we can also detect melt to serve as a comparison dataset. A melt detection method using a Kmeans clustering algorithm developed here is shown to be the most effective on ice shelves, so we further apply this method to quantify melt days across all Antarctica ice shelves for every year from 1979/80 to 2019/20. The highest sums of melt days occur on the Antarctic Peninsula at 89 melt days per year, and we find few linear trends in the annual melt days on ice shelves around the continent. The primary mode of spatial variability in the melt day dataset is closely related to the Southern Annular Mode, a climate index for the southward migration of Southern Westerly Winds, which has been increasing in recent decades. Positive Southern Annular Mode index values are associated with decreased melt days in some regions of Antarctica. We also present a novel application of passive microwave analysis to detect changes in firn structure due to unusually large melt events in some regions and we show how this method detects ice lens formation and grain growth on specific ice shelves. To study the impacts of subshelf melt we focus on the Filchner-Ronne region of Antarctica, which contains the second largest ice shelf on the continent. We performed an ensemble of ice sheet model runs for a set of ocean warming scenarios. Each ensemble used a realistic range of physical parameters to control ice dynamics and sliding, generated by a Bayesian analysis of a surrogate model and observed velocities. Increased ocean temperatures were associated with increased mass loss, and by the year 2100 this region contributed 14 mm to sea level per degree of ocean warming at depth between +0°C and +4°C of ocean potential temperature. Beyond +4°C, the rate mass loss increased substantially. This mass loss corresponded to grounding line retreat across the region.
    • Mental health problems in the mountains: needs, assets, and recommendations for managing mental health problems in mountain-focused wilderness-based education and related fields

      Johnson, Samuel H.; Dulin, Patrick L.; Lopez, Ellen D. S.; Gifford, Valerie M.; Rivkin, Inna D. (2020-08)
      Background: Through controlled exposure to stress, wilderness-based education programs can buildcapacity for adaptive coping and produce long lasting improvements to participants' quality of life.However, stress can also overwhelm them, resulting in the emergence and exacerbation of mental health vulnerabilities in the field. However, empirically grounded best practices for training, pre-trip screening, and protocol/policy for mental health specific to the wilderness context are not well developed. Aim: The aim of this study was to assess needs and assets, and develop recommendations for training, pre-trip screening, and organizational protocol/policy to assist with successful management of mental health problems in mountain-focused, wilderness-based education and related fields such as outdoor leadership, guiding, environmental education, snow safety, search and rescue, and wilderness therapy. Methods:A pragmatic, two phase, sequential mixed methods approach was utilized to explore this topic within the context of an overarching collaborative community based participatory research (CBPR) framework with organizational partners: National Outdoor Leadership School, Outward Bound USA and Canada, the Wilderness Risk Management Conference, and the Alaska Mountaineering School. A preliminary quantitative study utilized a cloud-based survey to determine baseline characteristics for 64 wilderness-based educators, guides, outdoor leaders, snow safety professionals, and search and rescue personnel. Qualitative interviews with 16 experienced and prepared key informants addressed the study aim in more depth, consistent with partnering organization priorities, in the tradition of CBPR. Findings: Mental health topics and skills are underemphasized in current training, and training was found to be of less value than personal and professional experiences with mental health. In the future, mental health should be increased and emphasized, possibly through the utilization of existing resources such as the stress continuum or curriculum such as Psychological First Aid as well as practical training opportunities that emphasize experiential learning around mental health. Current screening can present both risks and benefits for clients, instructors, and organizations. Nondisclosure and the impacts of stigma and prejudice on the interpretation and utilization of mental health screening information were major concerns. However, screening can guide preventive and proactive efforts, and build working relationships with potential participants. Future screening should be used to inform participants about course stress, encourage disclosure, and direct curriculum development. Multi-step screening, utilizing multiple interactions with participants before the course, was identified as a utilitarian way to facilitate improvements for future screening. In protocol/policy, field management of mental health problems is underemphasized relative to evacuation, resulting in overutilization of disruptive evacuation processes. While many organizations do well at responding to instructor mental health needs after incidents such as a fatality in the line of work, inconsistencies in implementation can create unintended barriers to instructor self-care. Future protocol/policy should prioritize instructor mental health by addressing inconsistencies in implementation, removing barriers to self-care and guiding the deployment of resources such as responsive staffing or free counseling benefits. Implications: This study contributes uniquely to the literature by providing an empirically-based perspective into a little researched topic, and multiple avenues for implementation of findings such as increasing mental health content and experience-based training, utilization of multi-step screening processes, and consistent implementation of organizational protocol/policy in support of client and instructor mental health. Recommendations for implementation address weaknesses and build upon strengths already present in training, screening, and protocol/policy. Overall, practice and research in this area are in need of further investigation and development. Future dissemination, research, and practice development could help develop measures or resources to support the improvement of training, screening, and protocol/policy across wilderness-based education and related fields.
    • Metabolite influence on the hibernating Arctic ground squirrel

      Rice, Sarah A.; Drew, Kelly; Kuhn, Thomas; Coker, Robert; Ritter, Robert (2020-12)
      Hibernation is a state of extreme metabolic plasticity and fasting. How hibernators maintain nitrogen homeostasis and regulate amino acid metabolism and how those metabolites influence hibernation physiology remains unknown. We first utilized three approaches to understand nitrogen homeostasis and amino acid metabolism in hibernation: longitudinal metabolic profiling within individual animals over undisturbed torpor, in vivo amino acid isotope tracing in deep torpor, and ¹⁵N isotope tracing in vivo during arousal from hibernation in Arctic Ground Squirrels (AGS). We observed that in vivo whole body production (WBP) of metabolites in deep torpor are profoundly and selectively suppressed in deep torpor. Metabolic profiling over undisturbed torpor bouts shows amino acids with nitrogenous side chains accumulate over torpor while urea cycle intermediates remain unchanged. During arousal from hibernation, ¹⁵N isotope tracing demonstrates recycling of free nitrogen into non-essential amino acids, essential amino acids and the gamma-glutamyl system. We next utilized two approaches to understand potential metabolite influences on thermogenesis and behavior in hibernation: we infused ammonium acetate in deep torpor and fed diets high in omega 3 fatty acids and monitored body temperature and torpor bout length. We found high doses of a nitrogen donor, ammonium acetate, as well as diets high in omega 3 fatty acids both influence thermogenesis in hibernation. In conclusion, production of metabolites in deep torpor indicate highly regulated metabolism with accumulation of nitrogen carrying amino acids. We additionally show metabolites and nitrogen can exert thermogenic influence on hibernating AGS.