Now showing items 1-20 of 10469

    • Needs Assessment Related to COVID-19 with Special Populations: Brief Report

      Garcia, Gabriel; Mapaye, Joy; Van Wyck, Rebecca; Cueva, Katie; Snyder, Elizabeth; Meyer, Jennifer; Miller, Jenny; Hennessy, Thomas (University of Alaska Anchorage, 2020-07-28)
      A total of 754 adult respondents from the Municipality of Anchorage (MOA) participated in a needs assessment survey conducted between May 25, 2020 and June 30, 2020. The survey aimed to reach out to specific populations: immigrants and refugees (N=246), non-immigrant racial/ethnic minority groups (N=163), and people with disabilities (N=93) each had a large enough sample size to include in this report. The survey also aimed to reach out to LGBTQ+ populations, however, we did not collect enough surveys from people who identified as LGBTQ+ to have reliable information. Key findings from the survey included: Understand Information from MOA • Most (94%) reported being knowledgeable/somewhat knowledgeable about the Municipality’s emergency orders and changes related to COVID-19 • Most (93%) reported that the Municipality’s policies related to COVID-19 are clear/very clear. Less Risk Behaviors • Immigrants and refugees, and people with disabilities, were significantly more likely to engage in COVID-19 related protective behaviors (wearing mask, physical distancing, etc.) compared with other survey respondents. More Worried • In terms of mental health, racial/ethnic minorities and immigrants and refugees reported significantly higher levels of worry in terms of household finances, losing employment, having self or members of their household being infected by coronavirus, and having enough to eat compared with other survey respondents. Information Preferences • All three examined groups preferred receiving information about COVID-19 through Internet, television, texting, and email. • A majority of respondents for each examined demographic group reported that their primary source of information about COVID-19 were general media sources (i.e., KTUU, KTVA, ADN) and official sources of information in Alaska (health departments, Dr. Zink, governor, mayor). A majority of immigrants and refugees in the sample (81%) also got their information from social sources (family, friends, social media).
    • COVID-19 Survey in the Municipality of Anchorage, July 16-18: Highlights

      Garcia, Gabriel; Mapaye, Joy; Van Wyck, Rebecca; Cueva, Katie; Snyder, Elizabeth; Meyer, Jennifer; Miller, Jenny; Hennessy, Thomas (University of Alaska Anchorage, 2020-08-06)
      A population-based cell phone survey on COVID-19 was conducted among Anchorage residents (N = 600) from July 16 to July 18, 2020. This was the second population-based cell phone survey conducted in the Municipality on COVID-19; the first one (N = 996) was conducted May 6-10, 2020. Between the first and second population-based cell phone surveys, four online surveys were conducted every two weeks with a panel of respondents from the first cell-phone survey. In total, six surveys have been done in Anchorage so far. Key findings from the most recent survey are as follows:  Most of the respondents reported practicing physical distancing and good hygiene. o Most (74%) did not have any visitors in their home the day before the survey. o Most (74%) did not have physical contact of any kind with someone who didn’t live with them. o While most (66%) reported not going to or attending events indoors (i.e., church, bar, restaurant, house party) last weekend, this distancing behavior was abided by less than the previous ones listed above. o Most (79%) reported wearing their mask all or most of the time when they were outside their home. o Most (68%) reported wearing a mask all or most of the time when they were within six feet of someone not from their household. o Most (76%) reported washing or sanitizing their hands every time or most of the time after touching things that people outside their household may have touched.  Most reported not being worried or only slightly worried about: transportation (88%), having enough to eat (84%), losing employment (78%), household finances (71%), and not being able to connect with friends and family (62%).  Most reported being worried or very worried about: sending children back to school (64%), other friends and family members being infected by coronavirus (56%), and themselves or members of their household being infected by coronavirus (52%).  Most (75%) felt that the Municipality’s response to the outbreak has been good or very good  Most (84%) felt that the Municipality’s policies related to coronavirus have been clear or very clear  Most (92%) strongly support or mildly support the Municipality’s mask mandate.  Most (53%) reported that they are often or sometimes confused by information on COVID-19. COVID-19 RELATED RISK BEHAVIORS increased among those who: o Had lower perceived threat of COVID-19  Those who had significantly lower perceived threat of COVID-19 included men and those with lower perceived susceptibility to COVID-19.  Those with lower perceived susceptibility included men and whites. o Reported lower perceived benefits of wearing a mask
    • COVID-19 Survey in the Municipality of Anchorage, June 16-18: Highlights

      Garcia, Gabriel; Mapaye, Joy; Van Wyck, Rebecca; Cueva, Katie; Snyder, Elizabeth; Meyer, Jennifer; Miller, Jenny; Hennessy, Thomas (University of Alaska Anchorage, 2020-07-09)
      An online survey of a panel of 295 Anchorage residents 18 years old and older was conducted June 16-18, 2020. This was the fourth survey since May 2020 conducted by the Municipality of Anchorage (MOA) regarding COVID-19 related knowledge, attitudes, and behaviors. The first survey in the series was a population-based cell phone survey of Anchorage residents conducted May 6-10. The second (May 20-22) third (June 2-4) and fourth (June 16-18) surveys were conducted online with a panel of participants from the first survey. Key findings from the fourth survey included:  Most respondents (72%) wore a mask most or all of the time outside their home.  Most (90%) spent time outside their home the day before the survey.  Most (64%) supported mandating wearing masks either “now” or “later.”  Almost half (47%) had physical contact with someone not in their household.  Most (76%) came within six feet of someone not from their household.  Most (91%) felt somewhat knowledgeable or very knowledgeable about MOA COVID-19 emergency orders.  COVID-19 related risk behaviors increased among those who: o Had less than a college degree o Were younger (<45 years) o Had lower perceived threat of COVID-19 o Were less likely to bring a mask when they went out o Were less likely to wash or sanitize hands when touching things touched by others. Compared with previous surveys, more respondents are leaving their homes and coming into physical contact with others. However, most survey respondents also reported wearing masks outside their home, supported a mandate to wear masks, and did not have physical contact with others. KEY MESSAGES As a whole, panel respondents reported positive COVID-19 mitigation behaviors. Messaging could continue to employ the need for personal responsibility to reduce risk, while emphasizing community/societal responsibility and benefit. Integrated communications with key education partners (ASD, UAA, APU, etc.) could also help reach groups associated with COVID-19 related risk behaviors. To encourage increased receptiveness to mitigation behaviors, messaging could try to incorporate affinity group imagery and rhetorical framing.
    • Second COVID-19 Panel Survey in the Municipality of Anchorage: Highlights

      Garcia, Gabriel; Mapaye, Joy; Van Wyck, Rebecca; Cueva, Katie; Snyder, Elizabeth; Meyer, Jennifer; Miller, Jenny; Hennessy, Thomas (University of Alaska Anchorage, 2020-06-19)
      A panel survey of 309 Municipality of Anchorage residents was conducted via phone June 2-4, 2020. This survey was a follow-up to both a representative survey conducted May 6-10 and a panel survey conducted May 20-22. Although most Anchorage businesses have opened, the second panel survey showed that: • Most respondents (64%) did NOT have physical contact with people not in their household. • Most (70%) wore a mask most or all of the time outside their home. • Most reported being not worried or only slightly worried in many aspects of their life, having good or very good morale in their household (70%), and having low or moderate stress in their household (62%). • Perceived threat of COVID-19 significantly increased from the second to third survey. COVID-related risk behaviors remained high for certain groups including men, younger people (<45 years), those who identified as Republican, and those with children. These groups had lower perceived threat of COVID-19, lower knowledge of the COVID mandates and MOA Emergency Orders, and lower level of clarity regarding Municipality policies related to COVID compared to their counterparts. However, caution should be taken when interpreting findings related to political affiliation given that it is a complex concept that may be an indicator for other factors, including individuals’ ideology, which was not asked about in the survey. These findings mirror national research showing that ideological and political differences may play a role in perceptions and behaviors related to COVID-199 . In order to help increase perceived threat of the virus and decrease COVID-related risk behaviors, messaging from those in the same ideological and political group could help with receptiveness of the message. KEY RECOMMENDATION: Messaging as a whole should continue to focus on the continued threat of COVID-19, personal responsibility to reduce risk, and Alaskans’ ability to succeed in defeating the virus.
    • Addendum to the COVID-19 Panel Survey Report Highlights: Identifying Factors Associated with Risk Behaviors Related to COVID-19

      Garcia, Gabriel; Mapaye, Joy; Van Wyck, Rebecca; Cueva, Katie; Hennessy, Thomas (University of Alaska Anchorage, 2020-06-10)
      Additional analysis with the panel survey data was conducted to identify which modifiable and demographic factors were independently associated with risk behaviors related to COVID-19 (i.e., demographic groups less likely to practice physical distancing and good hygiene). We found that as the respondents’ level of perceived threat of COVID-19 and age decreased, the COVID-related risk behavior increased. Groups who had lower levels of perceived threat of COVID-19 included people with low socioeconomic status (SES), those who had children in their household, and those who lacked clarity regarding the Municipality’s policies related to COVID-19. These findings suggest that efforts to decrease overall risk of COVID-19 in Anchorage should consider developing education and communication strategies that heighten awareness of the seriousness and threat of COVID-19 to public health. These strategies could be designed to reach out specifically to people from low SES groups, as well as those with children in their households. Additionally, communication strategies could improve the community’s understanding of policies related to COVID-19.
    • COVID-19 Panel Survey in the Municipality of Anchorage: Highlights

      Hennessy, Thomas; Garcia, Gabriel; Mapaye, Joy; Van Wyck, Rebecca; Snyder, Elizabeth; Meyer, Jennifer; Miller, Jenny; Cueva, Katie (University of Alaska Anchorage, 2020-06-04)
      A panel survey of 316 individuals was conducted from May 20 to May 22, which was a follow-up to the phone survey conducted two weeks prior. Based on the results of the panel survey, the overall risk of infection by COVID-19 significantly increased in Anchorage. Additionally, surveyed individuals were more likely to have physical contact with those outside their household, practiced less physical distancing, touched things outside their home more often, and had decreased perceived threat to COVID-19. However, the majority of respondents were still engaging in behavior that limited transmission, such as refraining from physical contact with those outside their household, wearing masks some or all of the time they were out, and avoiding visiting or receiving friends. About half of respondents reported that Anchorage was opening up at about the right pace, while about a third felt Anchorage was opening up too quickly. Despite Anchorage opening up, most respondents also reported feeling uncomfortable engaging in activities that had been previously restricted, such as going to a bar, going to the movies, or exercising at an athletic club. While the findings from these surveys are informative, this survey does not fully capture the needs and perspectives of Anchorage’s marginalized communities. Consequently, the UAA team is currently conducting a needs assessment of Anchorage’s marginalized communities, with results anticipated in early July. As Alaska and Anchorage continue to open, particularly with increasing protests around systemic racial inequity, the community could be reminded to give each other SPACE9 to continue to prevent further transmission of COVID-19. This document is a brief summary of panel survey highlights. Two more panel surveys of Anchorage residents are planned to track changes in behaviors, perceptions of COVID-19, and mental health as the situation continues to change.
    • COVID-19 Survey in the Municipality of Anchorage: Highlights

      Hennessy, Thomas; Garcia, Gabriel; Mapaye, Joy; Van Wyck, Rebecca; Snyder, Elizabeth; Meyer, Jennifer; Miller, Jenny; Cueva, Katie (University of Alaska Anchorage, 2020-05-21)
      As of May 20, 2020, 206 of the 402 identified cases of COVID-19 statewide have occurred among Anchorage residents (51%). Between May 6-10, 2020, approximately 56 days since the first case of COVID-19 in Anchorage was announced, a representative sample of 996 adults in the Municipality of Anchorage completed a cell phone survey designed to assess knowledge, attitudes, perceptions and behaviors related to the epidemic locally. This is a brief summary of highlights, and a detailed report will follow.
    • At the edge of somewhere: journeying on the Dalton Highway

      Wheeler, Charlotte A.; Farmer, Daryl; Holt, Joseph; Ehrlander, Mary (2022-05)
      Some journeys need to be made. In At the Edge of Somewhere, the writer embarks on a cycle ride from Fairbanks to Prudhoe Bay on Alaska's remote and dangerous Dalton Highway. Drawn obsessively to the Arctic sea ice some years earlier and, now, onto "the road," her journey attempts to bring closure to the long-standing need to be on the move, at once not able or even wanting to settle but also seeking a place within herself, and therefore a physical location, she might call home. She travels with a found notebook, acquired unexpectedly at the start of her ride, which reveals the heart-wrenching story of Samuel Morgan. As she journeys through boreal forest, high alpine and tundra, we learn not only of Samuel's abandonment to boarding school as a young boy but of the writer's traumatic childhood. Painful memories, reminiscences of working on "the road" and new encounters blend with Samuel's search for peace amid an encounter with the artistic works of an 18th century German Romantic painter. Touching on themes of trauma, art, and their relationships with the landscape, both the writer and Samuel reach Prudhoe Bay and the Arctic Ocean ready to let go of their pasts.
    • Coastal wetland carbon and mineral responses to storm and climate change through time, at Cape Espenberg Alaska

      Smith, Lindsey Michelle; Maio, Chris; Bigelow, Nancy; Eagle, Meagan (2022-05)
      The Arctic is experiencing warming and ecological shifts due to climate change and the compounded effects of polar amplification. There is a deficit of information surrounding the carbon cycle response in Arctic Alaskan coastal marsh environments to these forces. The Cape Espenberg barrier beach system has been mostly preserved through time as a shoreline-parallel, linear geometry prograding geomorphic feature. This study determines the Arctic carbon and mineral accumulation trends in marsh environments at Cape Espenberg for both paleo (pre 1850 AD) and modern (post 1850 AD) timeframes. This project makes connections between the responses of carbon and mineral materials to paleo and modern climate changes, and how this relationship may have evolved through time. Analytical analyses through radioisotope ¹³⁷Cs and ²¹⁰Pb, ¹⁴C, stable isotope spectrometry (δ¹³C), elemental (%C, %N, C:N), and dry bulk density and carbon density measurements yield a comprehensive physical and chemical dataset. Radioisotope dating techniques in the Arctic have proved challenging due to the dynamism of the environment. However, the combination of Constant Rate of Supply and Constant Initial Concentration age depth models has helped constrain ages to sediment cores even under variable conditions. Results indicate carbon and mineral accumulations have increased from paleo to modern times which indicates better growing and/or preservation conditions for organic matter (OM) under a modern climate. This agrees well with paleoclimate trends in the Medieval Climate Anomaly (MCA), and warm periods interspersed within the Little Ice Age (LIA), which correlate to greater productivity of terrestrial organic matter and isotopically lighter δ¹³C values (a terrestrial signature). Cold climate periods within the Little Ice Age correlate with increased aquatic organic matter sourcing and heavier δ¹³C values. Modern warming will likely continue to drive carbon sourcing towards terrestrial signatures as future temperatures are predicted to rise with global climate change. If the swale environments at Cape Espenberg can maintain ideal growing conditions (i.e. wet/anoxic soils and lower salinity to limit organic material decay, higher temperatures to promote growth) then Cape Espenberg will likely remain a viable carbon reservoir in the future. However, the question of whether the barrier system as a whole will continue to prograde under a regime of rising sea levels and increased storm impacts is unclear. The results of this study contribute towards understanding the dynamism of Arctic coastline mineral and carbon cycling and their ecological response to the current warming climate.
    • Acoustic detection and characterization of sea ice and surface waves in the northeast Chukchi Sea

      Sandy, Savannah J.; Danielson, Seth; Iken, Katrin; Mahoney, Andy; Simmons, Harper (2022-05)
      Monitoring the status of Arctic marine ecosystems is aided by oceanographic moorings that autonomously collect data year-round. Near Hanna Shoal in the northeast Chukchi Sea, the Chukchi Ecosystem Observatory moorings include an ASL Environmental Sciences Acoustic Zooplankton Fish Profiler (AZFP) datalogger, a multi-frequency upward-looking sonar that is programmed to collect data from across the upper 30 m of the water column every 10-20 seconds. Using six years of nearly continuous data, here we describe a statistical analysis of the datalogger's 455 kHz acoustic backscatter return signal. When used in conjunction with a selforganizing map machine learning algorithm, these data allow us to accurately differentiate between the presence of sea ice and open water and characterize surface waves. The approach detects short-duration (e.g., 15 minutes or longer) sea ice leads that pass over the mooring in winter, and sparse ice floes that pass over in summer. The ability to algorithmically identify small-scale features within the information-dense acoustic dataset enables rich characterizations of sea ice conditions and the ocean surface wave environment. Example applications include quantifying the recurrence of leads during ice-covered seasons, sparse ice in otherwise open water, statistics of ice keels and level ice, and wave height statistics. By automating the acoustic data processing and alleviating labor- and time-intensive analyses, we can maximize the use of these year-round acoustic data. Beyond applications to newly produced datasets, the approach opens possibilities for the efficient extraction of new information from existing upward-looking sonar records from recent decades.
    • Theory, design, and development of an open-source 3D printed peristaltic pump for microfluidics applications

      MacEachern, Joshua M.; Chen, Cheng-fu; Peterson, Rorik; Huang, Daisy; Laughlin, Bernard (2022-05)
      Microfluidics research is a constantly evolving and developing field of research in the biological, chemical, and medical sciences. To perform microfluidic analyses, various types of pump designs have been developed or optimized. These pumps are generally capable of pumping flow in the range of 0.1-100s of microliters (µL) per minute, with the goal of pumping fluid with an extremely consistent flow rate. These pumps include, but are not limited to, peristaltic, syringe, membrane, and lobe pumps. Both commercial and open-source designs have been developed to meet the needs of continued research. Commercial designs are very expensive, but offer limited flexibility to tailor the usage for custom assays. Open-source designs that have been presented may lack support, or may be designed to use fabrication technologies that are less commonly available than conventional desktop 3D printing. Due to this, many laboratories may be limited in their microfluidic research work due to either availability of commercial pumps, or usability of open-source pump designs. This work presents two iterations of a novel design for a 3D-printable microfluidic peristaltic pump. The pumps developed herein have been tested to demonstrate consistent performance operating over long-term periods of up to ten days continuously. These pumps have been tested to demonstrate capability of delivering aqueous flow as slow as flow ranges of 10s of µL/min. These pumps are capable of maintaining an outlet pressure of up to 220 kilopascals (kPa). In a tube of 1 mm inner diameter, this pressure would drive a flow rate of 10 µL/min through tubing up to 6.6 meters long. Finally, this design has been optimized to improve the user experience and make these peristaltic pumps both easy to maintain and easy to operate by a non-technical user.
    • Assessing the demographic and genetic contributions of precocial males in a naturally spawning population of coho salmon

      King, Erika M.; McPhee, Megan; Tallmon, David; Vulstek, Scott; Cunningham, Curry (2022-05)
      Despite the importance of alternative life history strategies to population productivity, little is known about the mating structure of precocial ('jack') males in Pacific salmon. The number of successful matings obtained by jacks in the wild is not well characterized and the impact of including or excluding jacks in the management of Pacific salmon populations is unknown. This study aims to fill knowledge gaps in the understanding of jack life history by 1) determining the typical contribution of jacks to the next generation in a natural mating population; and 2) estimating the impact of jacks on genetic diversity. The study capitalizes upon 11 years of demographic and genetic data from a naturally spawning population of Coho Salmon from Auke Creek, in Juneau, Alaska. Individuals returning over this time period (~8,000 individuals) were genotyped at ~250 single-nucleotide polymorphism (SNP) loci. Using these genotypes, we quantified the adult-to-adult reproductive success of different male types using parentage analysis for each of seven return years and compared genetic and demographic estimates of effective population size. We demonstrated that although jacks were less successful than full-size males on a per individual basis, they contributed substantially to the population and influenced population and evolutionary dynamics.
    • Technical and economic evaluation of the first ever polymer flood field pilot to enhance the recovery of heavy oils on Alaska's North Slope via machine assisted reservoir simulation

      Keith, Cody D.; Zhang, Yin; Ahmadi, Mohabbat; Dandekar, Abhijit (2022-05)
      Polymer flooding has become globally established as a potential enhanced oil recovery method for heavy oils. To determine whether this technology may be useful in developing the substantial heavy oil resources on the Alaska North Slope, a polymer flood field pilot commenced at the Milne Point Unit in August 2018. This study seeks to evaluate the results of the field pilot on a technical and economic basis. A reservoir simulation model is constructed and calibrated to predict the oil recovery performance of the pilot through machine-assisted reservoir simulation techniques. To replicate the early water breakthrough observed during waterflooding, transmissibility contrasts are introduced into the simulation model, forcing viscous fingering effects. In the ensuing polymer flood, these transmissibility contrasts are reduced to replicate the restoration of injection conformance during polymer flooding. Transmissibility contrasts are later reinstated to replicate fracture overextension interpreted in one of the producing wells. The calibrated simulation models produced at each stage of the history matching process are used to forecast oil recovery. These forecasts are used as input for economic analysis, incremental to waterflooding expectations. The simulation forecasts indicate that polymer flooding significantly increases the heavy oil production for this field pilot compared to waterflooding alone, yielding attractive project economics. However, meaningful variations between simulation scenarios demonstrate that a simulation model is only valid for prediction if flow behavior in the reservoir remains consistent with that observed during the history matched period. Critically, this means that a simulation model calibrated for waterflooding may not fully capture the technical and economic benefits of an enhanced oil recovery process such as polymer flooding. Subsequently, the simulation model and economic model are used in conjunction to conduct a sensitivity analysis for polymer flood design parameters, from which recommendations are provided for both the continued operation of the current field pilot and future polymer flood designs. The results demonstrate that a higher polymer concentration can be injected due to the development of fractures in the reservoir. The throughput rate should remain high without exceeding operating constraints. A calculated point-forward polymer utilization parameter demonstrates the decreasing efficiency of the polymer flood at later times in the pattern life. Future projects will benefit from starting polymer injection earlier in the pattern life. A pattern with tighter horizontal well spacing will observe a greater incremental benefit from polymer flooding.
    • 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.
    • Application of probabilistic decline curve analysis to unconventional reservoirs

      Egbe, Uchenna C.; Awoleke, Obadare; Goddard, Scott; Ahmadi, Mohabbat (2022-05)
      This work presents the various probabilistic methodology for forecasting petroleum production in shale reservoirs. Two statistical methods are investigated, Bayesian and frequentist, combined with various decline curve deterministic models. A robust analysis of well-completion properties and how they affect the production forecast is carried out. Lastly, a look into the uncertainties introduced by the statistical methods and the decline curve models are investigated to discover any correlation and plays that otherwise would not be apparent. We investigated two Bayesian methods - Absolute Bayesian Computation (ABC) and GIBBS sampler - and two frequentist methods - Conventional Bootstrap (BS) and Modified Bootstrap (MBS). We combined these statistical methods with five empirical models - Arps, Duong, Power Law Model (PLE), Logistic Growth Model (LGA), and Stretched Exponential Decline Model (SEPD) - and an analytical Jacobi 2 theta model. This allowed us to make a robust comparison of all these approaches on various unconventional plays across the United States, including Permian, Marcellus, Eagle Ford, Haynesville, Barnett, and Bakken shale, to get detailed insight on how to forecast production with minimal prediction errors effectively. Analysis was carried out on a total of 1800 wells with varying production history data lengths ranging from 12 to 60 months on a 12-month increment and a total production length of 96 months. We developed a novel approach for developing and integrating informative model parameter priors into the Bayesian statistical methods. Previous work assumed a uniform distribution for model parameter priors, which was inaccurate and negatively impacted forecasting performance. Our results show the significant superior performance of the Bayesian methods, most notably at early hindcast size (12 to 24 months production history). Furthermore, we discovered that production history length was the most critical factor in production forecasting that leveled the performance of all probabilistic methods regardless of the decline curve model or statistical methodology implemented. The novelty of this work relies on the development of informative priors for the Bayesian methodologies and the robust combination of statistical methods and model combination studied on a wide variety of shale plays. In addition, the whole methodology was automated in a programming language and can be easily reproduced and used to make production forecasts accurately.
    • Spatial and temporal variability of fish and mussel distributions revealed through eDNA metabarcoding

      Dokai, William; McPhee, Megan; Larson, Wesley; Tallmon, David; Zanatta, David (2022-05)
      Unionid mussels (order Unionida) are freshwater bivalves distributed worldwide and are among the world's most endangered taxonomic groups. Unionid mussels utilize various fish species as obligate hosts for their parasitic larval stage, and as a result, native fish species are vital to unionid persistence. One of the primary conservation needs for both unionids and fishes is more complete distributional data. However, these data are labor and resource intensive to collect using traditional survey methods. Here, we utilized an eDNA metabarcoding approach to detect unionid mussels and fishes within a large portion of the lower peninsula of Michigan, USA, with the goal of validating this method for the paired detection of these two groups of taxa. We investigated whether communities of fishes and mussels varied between the tributaries of Lake Michigan and the Grand River watershed, between early- and late-summer sampling events, and between areas of high and low mussel diversity. We detected 21 unique mussel taxa and 46 unique fish taxa within the Grand River watershed and 20 Lake Michigan tributaries. We detected differences in fish and mussel communities across different sampling regions and between sampling events. We also found fish taxa associated with areas of high and low mussel diversity. Notably, we detected more mussel taxa within the Grand River watershed compared to Lake Michigan tributaries, more fish in the August sampling event compared to June, three fish taxa more frequently at areas of high mussel diversity, and four fish taxa more frequently at areas of low mussel diversity. This study demonstrates the utility of combining unionid and fish metabarcoding primers to efficiently describe the co-distribution of these interdependent taxa within the Great Lakes region.
    • 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.
    • The effect of sea otter predation and habitat structure on nearshore crab assemblages in Southeast Alaska

      Cates, Rebecca Jeanette; Eckert, Ginny L.; Cunningham, Curry; Siddon, Christopher (2022-05)
      Sea otter Enhydra lutris predation has resulted in conflict with humans for shared marine resources, as sea otters reduce the abundance and size of nearshore crabs. Several species of crab in Southeast Alaska are prey for sea otters including Cancer magister, a highly valued commercial and subsistence species, as well as Cancer gracilis, Cancer productus, and Telmessus cheiragonus, species that are abundant in the nearshore and of ecological and subsistence importance. Understanding the influence of sea otters and habitat structure on valuable crab species is of particular importance in Southeast Alaska as the abundance and range of sea otters expands across important crab nursery habitat. We 1) conducted breakpoint analyses to identify sea otter density thresholds that affect the abundance and biomass of nearshore crab species, 2) used a two-factor type III Analysis of Variance (ANOVA) to test the impact of sea otter presence and year on crab size, and 3) used general linearized models (GLM) to test the impacts of sea otter density and habitat structure on crab species abundance and size distribution. We found evidence of sea otters decreasing crab species' abundance, biomass, and size. C. magister, C. gracilis, and C. productus experienced a significant decline in size in the presence of sea otters, while T. cheiragonus size did not differ as a function of sea otter presence. We found a significant decrease in biomass in C. magister and in biomass and abundance in C. productus, associated with increasing sea otter density. Different responses across crab species are likely attributed to size distributions and sea otter foraging behavior. Habitat characteristics, such as eelgrass biomass and shoot density, had a small influence on crab abundance and size that depended on the species of crab. These results suggest that populations of large crabs do not persist in the presence of sea otters, small crabs may co-occur with sea otters, and eelgrass biomass and density marginally influence crab abundance and size.
    • An analysis of turbulent effects on hydrokinetic power generation

      Browning, Emily A.; Kasper, Jeremy; Hung, Daisy; Peterson, Rorik (2022-05)
      The effects of turbulence on power generation from a Current Energy Converter (CEC) are not fully understood. This thesis investigates the correlation between a vertical axis CEC's power output and the water velocity in the frequency and time domains. Chapter 2 shows the correlation between velocity and electrical power in frequency space. This correlation gives insight into the size of eddies that influence the CEC's power output. The results of this correlation analysis show that eddies of diameter around 0.8m have a noticeable impact on the power generation. Calculating the observed average integral length scale, the range of eddy diameters around the CEC are 0.52m-5.8m. Since 0.8m is in this observed range it suggests that the turbulence may influence the CEC's power output. Chapter 3 analyzes the relationship between the turbulence velocity cubed and electrical power through the correlation of the two data sets. The correlation was carried out by first separating out the four velocity components derived from cubing the sum of the turbulence and average velocities. The commonly used ratio of the turbulence kinetic energy to total kinetic energy does not include these cross terms nor are these cross terms typically included in the calculation of power derived from the turbulence velocity. The turbulence velocity cubed has a correlation of -0.007 with the CEC power output indicating that the turbulence has a small, negative impact on the CEC power output.
    • Juneau's Changing Climate and Community Response

      Powell, James E.; Tankersley, Molly; Ainsworth, Tom; Amundson, Jason M.; Armstrong, Bob; Botelho, Bruce; Carstensen, Richard; D'Amore, David V.; Foy, Robert James; Hood, Eran; et al. (Alaska Coastal Rainforest Center, 2022-07)
      This report is designed as a living document to inform the community, decision makers, and academics and to serve as a learning and teaching tool. The nine key messages summarized on pages 6 and 7 are intended for use as a quick reference. Unique for this type of report, these key messages highlight actions by Juneau's civil society, including local nonprofit organizations.